CEBP CTRC-AACR San Antonio Breast Cancer Symposium Cancer Health Disparities Conference 2009
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
Cancer Research Clinical Cancer Research
Cancer Epidemiology Biomarkers & Prevention Molecular Cancer Therapeutics
Molecular Cancer Research Cancer Prevention Research
Cancer Prevention Journals Portal Cancer Reviews Online
Annual Meeting Education Book Meeting Abstracts Online
This Article
Right arrow Abstract Freely available
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow reprints & permissions
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Samowitz, W. S.
Right arrow Articles by Slattery, M. L.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Samowitz, W. S.
Right arrow Articles by Slattery, M. L.
Cancer Epidemiology Biomarkers & Prevention Vol. 10, 917-923, September 2001
© 2001 American Association for Cancer Research

Microsatellite Instability in Sporadic Colon Cancer Is Associated with an Improved Prognosis at the Population Level1

Wade S. Samowitz2, Karen Curtin, Khe-Ni Ma, Donna Schaffer, Landon W. Coleman, Mark Leppert and Martha L. Slattery

Departments of Pathology [W. S. S., L. W. C.] and Human Genetics [M. L.], University of Utah Health Sciences Center, Salt Lake City, Utah 84132; Health Research Center, Department of Family and Preventive Medicine, Salt Lake City, Utah 84108 [K. C., K-N. M., M. L. S.]; and Division of Research, Kaiser Permanente Medical Care Program, Oakland, California 94611 [D. S.]


   Abstract
Top
 Abstract
Introduction
 Materials and Methods
 Results
 Discussion
 References
 
Some previous studies have reported an improved prognosis in sporadic colon cancers with microsatellite instability, whereas others have not. In addition, relatively few of those reporting an improved prognosis controlled for tumor stage or were population-based. Therefore, we evaluated the relationship between microsatellite instability and prognosis, tumor stage, and other clinical variables in a population-based study of 1026 individuals. Microsatellite instability was determined by the noncoding mononucleotide repeat BAT-26 and the coding mononucleotide repeat in transforming growth factor-ß receptor type II. Significant relationships were seen between microsatellite instability and proximal tumor location, female gender, young and old age at diagnosis, poor histological differentiation, and low tumor stage (P < 0.01). There was a significant relationship between microsatellite instability and improved prognosis, even after adjusting for stage, with a reduction in the risk of death attributable to colon cancer of ~60%. Most of this risk reduction occurred in individuals with American Joint Committee on Cancer stage III tumors, although transforming growth factor-ß receptor type II mutations were associated with a significant reduction in colon cancer death in tumors with distant metastases. We conclude that microsatellite instability in sporadic colon cancer is associated with an improved prognosis at the population level.


   Introduction
Top
 Abstract
 Introduction
Materials and Methods
 Results
 Discussion
 References
 
Microsatellite instability is seen in nearly all colon cancers from individuals with HNPCC3 (1 , 2) . The genetic basis for instability in these tumors is inherited germ-line mutations of mismatch repair genes, mostly involving hMSH2 and hMLH1 (3) . Microsatellite instability is also seen in 10–15% of sporadic colon cancers; in these tumors the basis for instability is usually acquired hypermethylation of the hMLH1 promoter with subsequent transcriptional silencing (4, 5, 6, 7, 8) .

Previous studies (1 , 9) have indicated an improved prognosis for HNPCC-associated colon cancer relative to nonfamilial colon cancer. Some studies have also reported a statistically significant improved prognosis for sporadic colon cancer with microsatellite instability (10, 11, 12, 13, 14, 15, 16, 17, 18, 19) , although others have not (20, 21, 22, 23) . In addition, studies reporting an improved prognosis have not always shown that this relationship was independent of tumor stage, and only one of those studies was population-based. The lone population-based study was, moreover, restricted to individuals <=50 years of age (17) . Because such relatively young individuals account for <10% of those with colon cancer (24) , it is questionable whether the results of that study can be extrapolated to the population at large. Also, whereas that study of 607 individuals was relatively large, it had insufficient power to demonstrate a statistically significant improved survival at a given tumor stage (25) , again limiting the clinical applicability of its findings (26) . Therefore, we evaluated the relationship between microsatellite instability and prognosis, tumor stage, and other clinical variables in a population-based study of 1026 individuals with colon cancer, the largest sample evaluated in this manner to date. The age range of subjects (30–79 years) includes the most frequent ages of colon cancer diagnosis, additionally ensuring the applicability of results to the general population.


   Materials and Methods
Top
 Abstract
 Introduction
 Materials and Methods
Results
 Discussion
 References
 
Study Population.
Study participants were black, white, or Hispanic and were from either the Kaiser Permanente Medical Care Program of Northern California or an eight-county area in Utah (Davis, Salt Lake, Utah, Weber, Wasatch, Tooele, Morgan, and Summit counties). Microsatellite instability results from 154 individuals in the Utah sample were reported in a previous study of microsatellite instability and family history (27) . In the Utah and Kaiser Permanente Medical Care Program we were able to extract normal and tumor DNA for 95.6 and 81.1%, respectively, of all of the cases diagnosed in the area, making this a truly population-based study from these geographic locations. Eligibility criteria for cases included diagnosis with first-primary incident colon cancer (International Classification of Diseases for Oncology 2nd edition codes 18.0, and 18.2–18.9) between October 1, 1991 and September 30, 1994; ages 30–79 years at time of diagnosis; and mentally competent to participate in the study. Cases with cancers of the rectosigmoid junction or rectum (defined as the first 15 cm from the anal opening) or with known familial adenomatous polyposis, ulcerative colitis, or Crohn’s disease were not eligible. The study sample was part of a larger epidemiological-based study which excluded rectal cancers; however, microsatellite instability is mostly seen in proximal tumors (10) . All of the cases were adenocarcinomas or carcinomas.

Information on age at time of diagnosis, sex, tumor site, and tumor stage were available from the Northern California Tumor Registry, the Sacramento Tumor Registry, and the Utah Cancer Registry. These registries are members of the SEER program. Proximal tumors were defined as cecum through transverse colon; tumors in the splenic flexure, descending, and sigmoid colon were defined as distal. Staging data were summarized as local, regional, or distant depending on extent of disease and node and other organ involvement as indicated by the SEER summary stage codes provided by the respective tumor registries (28) . We also staged the tumors according to AJCC criteria and determined histological grade by reviewing pathology reports (29) . Because we did not have access to complete medical records, AJCC stage IV tumors were identified using SEER summary stage codes to determine whether or not distant metastases were present. Vital status, date of death, primary cause of death, and two contributing causes of death were obtained from local tumor registries using death certificate information. Active follow-up of people diagnosed with cancer is done through the cancer registries on a continuous basis. Vital status as of December 30, 1999 was obtained for all of the study participants. For individuals of which the vital status or cause of death could not be determined through local tumor registries, National Death Index tapes were used. Months of survival were calculated by subtracting the date of last contact or death from the date of diagnosis. Deaths from any cause as well as deaths attributed to colon cancer were assessed. All of the aspects of this study were approved by the University of Utah Institutional Review Board.

Microsatellite Instability.
Colon cancer tissue was microdissected and DNA extracted from formalin-fixed paraffin-embedded tissue blocks as described previously (30) . The respective normal DNA from each individual was extracted from peripheral blood or from paraffin blocks of normal colonic mucosa. Each tumor was evaluated for microsatellite instability with the noncoding mononucleotide repeat BAT-26 and the coding mononucleotide repeat in codons 125 to 128 of TGFßRII (31) . The primer sequences and PCR conditions were as described previously (32 , 33) . As before, primers were labeled with fluorescent dye, and the sizes of PCR products were evaluated on an ABI machine. Also, a 5' tail (GTTTCT) was added to the reverse primer to complete the addition of an extra adenosine to PCR products (34) .

Both tumoral DNA and normal DNA were PCR amplified with the above primer sets. Microsatellite instability for a given primer set was defined as the appearance of one or more new PCR products either smaller or larger than those produced from normal DNA. For BAT-26 a deletion of at least 4 bp was required for a designation of instability (35) . Instability in TGFßRII was indicated by deletions of one or two bases or an insertion of one base (33) .

Most of the microsatellite evaluation in this study was performed before the publication of the Bethesda consensus panel (36) . However, instability in BAT-26, a component of the consensus panel, has been shown to be highly correlated with generalized dinucleotide repeat instability (35) and with the Bethesda panel itself in the Utah subset of the current study (37) .

Statistical Analyses.
Differences in microsatellite instability were determined for age, tumor site, tumor grade, gender, and disease stage using {chi}2 statistics. Crude survival was evaluated using Kaplan-Meier survival curves for both overall mortality and mortality from colon cancer alone. Associations between survival and microsatellite instability were determined using Cox proportional hazards models, adjusting for age at time of diagnosis, disease stage, tumor grade, and site. Using these multivariate models, we estimated the likelihood of dying from any cause as well as from colon cancer alone. Median follow-up was 62 months. Five-year survival (Table 2)Citation was determined for individuals who had complete 5-year follow-up data. Of the total sample, 89 people were censored alive before 5 years of follow-up and were excluded from the analyses shown in Table 2Citation .


View this table:
[in this window]
[in a new window]
  		Table 2 Univariate relationships with survival

 

   Results
Top
 Abstract
 Introduction
 Materials and Methods
 Results
Discussion
 References
 
Microsatellite instability was identified in 12.8% (128/1000) of colon cancers with BAT-26 and 11.6% (114/986) with TGFßRII. Representative electropherograms demonstrating alterations in these repeats in four unstable tumors are shown in Figs. 1Citation and 2Citation . Instability in the coding mononucleotide repeat of TGFßRII consisted of one or two bp deletions (-1 and -2) or one bp insertion (+1).



View larger version (25K):
[in this window]
[in a new window]
  		Fig. 1. Paired normal (N) and tumor (T) results for four tumors with BAT-26 microsatellite instability (TGFßRII results for the same tumors are shown in Fig. 2Citation ). In each tumor one or more BAT-26 alleles smaller than those seen in normal DNA are present (size in bp, scale above each repeat result; signal amplitude, scales at right).

 


View larger version (21K):
[in this window]
[in a new window]
  		Fig. 2. Paired normal (N) and tumor (T) results for four tumors with TGFßRII instability (BAT-26 results for the same tumors are shown in Fig. 1Citation ). Deletions of one (-1) or two (-2) bp and/or insertions of one bp (+1) relative to wild type (W) are seen in each tumor (size in bp, scale above each repeat result; signal amplitude, scales at right).

 
The relationship of microsatellite instability to age, sex, tumor location, tumor grade (differentiation), and stage is delineated in Table 1Citation . Instability was significantly related to age at diagnosis, because it was more common in the relatively young (<55) and older (71–79) ages. Microsatellite instability also was significantly more common in tumors from women, proximal tumors, in tumors of relatively low stage, and in poorly differentiated tumors. All of these statistically significant relationships were seen with both measures (BAT-26 and TGFßRII) of instability.


View this table:
[in this window]
[in a new window]
  		Table 1 Description of population by microsatellite instability status

 
Univariate relationships between microsatellite instability, clinical variables, and survival are indicated in Table 2Citation . Microsatellite instability, low tumor stage, and distal tumor location were all significantly related to improved 5-year survival, whereas poor differentiation was associated with a decreased 5-year survival; there was a borderline significant relationship between age and survival. The statistically significant (P < 0.01) relationship between microsatellite instability and prognosis was seen with both measures of instability.

The relationship between microsatellite instability and prognosis is additionally delineated in the results of a multivariate analysis shown in Table 3Citation . Individuals with microsatellite unstable tumors were significantly less likely to die of any cause or of colon cancer in the first 8 years after diagnosis; this relationship was independent of age, stage, tumor site, tumor grade, and the method used for assessing instability. The age, stage, grade, and site-adjusted reduction in risk of colon cancer death associated with microsatellite instability was ~60%.


View this table:
[in this window]
[in a new window]
  		Table 3 Hazard rate ratios (HRR) and 95% confidence intervals (CI) for likelihood of dying during follow-up comparing unstable to stable tumors (as classified by BAT-26 or TGFßRII)

 
The relationship between microsatellite instability and prognosis for each stage of colon cancer is shown in Table 4Citation . Most of the decreased risk of colon cancer death is seen in AJCC stage III tumors and SEER regional stage, with risk reductions in stage III tumors of approximately 60–66% depending on the microsatellite measurement. Interestingly, a statistically significant nearly 60% reduction in risk of colon cancer death is seen in tumors with distant metastases that harbor TGFßRII mutations.


View this table:
[in this window]
[in a new window]
  		Table 4 Stage-specific age-adjusted hazard rate ratios (HRR) and 95% confidence intervals for risk of dying of colon cancer comparing microsatellite unstable to stable tumors (as classified by BAT-26 or TGFßRII)

 
The relationship between TGFßRII mutations and prognosis is also demonstrated in Kaplan-Meier survival curves stratified by AJCC stage (Figs. 3Citation and 4Citation ). In Fig. 3Citation , all of the causes of mortality are taken into account, whereas in Fig. 4Citation only mortality from colon cancer is considered. Microsatellite instability in TGFßRII does not appear to be related to colon cancer survival in stage I or II tumors. TGFßRII mutations are associated with a significantly improved prognosis in stage III and IV tumors (P < 0.01; Mantel Cox statistic); interestingly, the survival curve for stage III unstable tumors is very similar to that for stage II stable tumors for colon cancer mortality (Fig. 4)Citation and to stage I and II tumors for overall mortality (Fig. 3)Citation .



View larger version (30K):
[in this window]
[in a new window]
  		Fig. 3. Kaplan-Meier survival curves stratified by colon cancer stage and microsatellite instability (as determined by TGFßRII). Microsatellite instability was associated with a significantly improved survival in both stage III and stage IV tumors. (Fig. 3Citation takes into account all causes of mortality; Figure 4Citation considers mortality from color cancer alone. S, stable; U, unstable.

 


View larger version (29K):
[in this window]
[in a new window]
  		Fig. 4. Kaplan-Meier survival curves stratified by colon cancer stage and microsatellite instability (as determined by TGFßRII). Microsatellite instability was associated with a significantly improved survival in both stage III and stage IV tumors. (Fig. 3Citation takes into account all causes of mortality; Figure 4Citation considers mortality from color cancer alone. S, stable; U, unstable.

 

   Discussion
Top
 Abstract
 Introduction
 Materials and Methods
 Results
 Discussion
References
 
This population-based study of >1000 individuals with sporadic colon cancer identified significant relationships between microsatellite instability and proximal tumor location, female gender, young and old age at diagnosis, poor histological differentiation, and low tumor stage. The relationships to proximal tumor site (10 , 38 , 39) and poor histological differentiation (15 , 17 , 38 , 39) have been seen by numerous previous studies. The relationship to female gender was seen in two previous studies (8 , 18) , and one of those studies (8) as well as an additional study (17) reported a relationship with low tumor stage. The relationship to age was seen in a previous smaller study (27) , which included some of the individuals in the current analysis, and a relationship to young age at diagnosis was seen in two other studies (19 , 23) . Several other studies (10 , 12 , 13 , 20 , 21 , 39) have failed to identify significant relationships between microsatellite instability and age, gender, and tumor stage, but most of these studies were of relatively small numbers of tumors and may have lacked sufficient power to detect statistically significant relationships. Notably, most of the studies in addition to ours which did show relationships to gender and stage evaluated >500 individuals with colon cancer.

In the current study, microsatellite instability, low tumor stage, low tumor grade, and distal tumor location were all significantly related to improved prognosis in univariate analyses (Table 2)Citation . A multivariate analysis (Table 3)Citation revealed that the relationship between instability and improved prognosis was independent of stage, site, tumor grade, and age and was associated with a 60% decrease in death attributable to colon cancer. Several previous studies (10, 11, 12, 13, 14, 15, 16, 17, 18, 19) have reported a relationship between instability and prognosis, although others (20, 21, 22, 23) have not. Studies that failed to show this association were usually of relatively small numbers of individuals and, therefore, evaluated very few unstable tumors and probably lacked the power to show a statistically significant relationship. Of the studies that did show a relationship between instability and improved prognosis, in only five was this association shown to be independent of tumor stage (12 , 15, 16, 17, 18) , an important consideration given the relationship we and others have observed between instability and low tumor stage. Of these five studies, only one was population-based, and that study was restricted to individuals <=50 years of age (17) , and, therefore, would be predicted to account for <10% of all colon cancer (24) . Thus, our current study, the largest to date, is the first population-based study of sporadic colon cancer that includes the most frequent ages at diagnosis and demonstrates a stage-independent improved prognosis associated with microsatellite instability. These features indicate that our findings, in contrast to those of most previous studies, are directly applicable and clinically relevant to the population at large.

Most of the reduction of risk of colon cancer death associated with microsatellite instability occurred in AJCC stage III tumors (Table 4)Citation . This is similar to a previous report, which identified an improved prognosis in Dukes’ C tumors with microsatellite instability but not in Dukes’ B tumors (15) . The only previous population-based study (17) demonstrated a survival benefit of microsatellite instability, which was independent of tumor stage in a multivariate analysis but had insufficient power to show a statistically significant survival advantage at a particular stage (25) .

The improved prognosis in stage III tumors, cancers with lymph node metastases, was quite dramatic in our study, because microsatellite instability essentially "downstaged" such tumors to the colon cancer mortality of stage II tumors, cancers without nodal metastases (Fig. 4)Citation . An improved prognosis was also seen in stage IV tumors with TGFßRII mutations (Table 4Citation ; Figs. 3Citation and 4Citation ), although the significance of this latter finding is somewhat uncertain because of the small numbers of individuals in this category. Still, it is of interest that 33% (3 of 9) of individuals with stage IV, TGFßRII unstable tumors survived colon cancer, compared with only 6.3% (15 of 239) of individuals with stage IV, TGFßRII stable tumors. Additional studies with larger numbers of individuals with unstable stage IV tumors will be necessary to determine the generalizability of this finding.

Besides its utility as an indicator of prognosis, microsatellite instability could also be clinically important if it could be used to predict the response to therapy. One retrospective, nonrandomized study suggested that the survival benefit associated with microsatellite instability was only seen in individuals who received chemotherapy (18) , whereas another such study found no relationship between instability and chemotherapeutic response (15) . A third study (40) reported that chemotherapy was efficacious in individuals with unstable tumors, but nearly half of those patients had HNPCC, and, therefore, those results are of questionable relevance for the majority of individuals of which the unstable tumors are not attributable to an inherited predisposition (4, 5, 6, 7, 8) . Information regarding chemotherapy or radiation therapy was not readily accessible on the individuals in our study, although from the time period of colon cancer diagnosis (October 1, 1991 to September 30, 1994), one would expect that most individuals with stage III disease received adjuvant chemotherapy. There is also some experimental evidence that tumors with microsatellite instability show different degrees of responsiveness to different classes of chemotherapeutic agents (41) . It is possible that future prospective, randomized studies that stratify patients according to tumor instability may identify a treatment regimen specifically suited to unstable tumors and/or to what extent the improved prognosis in unstable tumors is related to a better response to chemotherapy.

The microsatellite instability analysis in this study was performed before the National Cancer Institute workshop, which developed the Bethesda Consensus Panel (36) . Our results with BAT-26, one of the consensus panel repeats, should be a fairly good indicator of what would have been seen with the entire panel, because we have shown that instability in BAT-26 correlates extremely well with the complete consensus panel in the Utah subset of these colon cancers (37) . It should be noted that the National Cancer Institute workshop on instability did not mandate the use of a particular panel and acknowledged that in different situations panels other than the Bethesda Consensus Panel might be more appropriate (36) . There are some advantages to the approach used in this study. Determination of BAT-26 and/or TGFßRII instability is an extremely rapid and inexpensive way to screen large numbers of samples. In addition, the strongest relationships in this study were seen with TGFßRII, a coding mononucleotide repeat that is not one of the five repeats in the main Bethesda consensus panel. It is possible that the most prognostically significant microsatellite instability panel is yet to be determined.


   Acknowledgments
 
We thank Dr. Bette Caan, Judy Morse, Sandra Edwards, and Leslie Palmer for the data collection and tissue processing efforts, and the genomics core facility, Melanie Nichols and Kristen Gruenthal for assistance with genetic analyses.


   Footnotes
 
The costs of publication of this article were defrayed in part by the payment of page charges. This article must therefore be hereby marked advertisement in accordance with 18 U.S.C. Section 1734 solely to indicate this fact.

1 This work was supported by CA48998 and CA61757 (to M. L. S.); by the Utah Cancer Registry, which is funded by National Cancer Institute Contract N01-PC-67000; by the State of Utah Department of Health and the University of Utah; the Northern California Cancer Registry; and the Sacramento Tumor Registry. Back

2 To whom requests for reprints should addressed, at Department of Pathology, University of Utah Health Sciences Center, Salt Lake City, UT 84132. Phone: (801) 585-2556; Fax: (801) 585-3831; E-mail: wsamowitz{at}msscc.med.utah.edu Back

3 The abbreviations used are: ; HNPCC, hereditary nonpolyposis colon cancer; AJCC, American Joint Committee on Cancer; SEER, Surveillance, Epidemiology, and End Results; TGFßRII, transforming growth factor-beta receptor type II. Back

Received 12/ 1/00; revised 4/20/01; accepted 6/ 8/01.


   References
Top
 Abstract
 Introduction
 Materials and Methods
 Results
 Discussion
 References
 

  1. Aaltonen L. A., Peltomaki P., Leach F. S., Sistonen P., Pylkkanen L., Mecklin J. P., Jarvinen H., Powell S. M., Jen J., Hamilton S. R., Petersen G. M., Kinzler K. W., Vogelstein B., Chapelle A. Clues to the pathogenesis of familial colorectal cancer. Science (Wash. DC), 260: 812-819, 1993.[Abstract/Free Full Text]
  2. Aaltonen L. A., Peltomaki P., Mecklin J. P., Jarvinen H., Jass J. R., Green J. S., Lynch H. T., Watson P., Tallqvist G., Juhola M., Sistonen P., Hamilton S. R., Kinzler K. W., Vogelstein B., de la Chapelle A. Replication errors in benign and malignant tumors from hereditary nonpolyposis colorectal cancer patients. Cancer Res., 54: 1645-1648, 1994.[Abstract/Free Full Text]
  3. Kinzler K. W., Vogelstein B. Lessons from hereditary colorectal cancer. Cell, 87: 159-170, 1996.[Medline]
  4. Kane M. F., Loda M., Gaida G. M., Lipman J., Mishra R., Goldman H., Jessup J. M., Kolodner R. Methylation of hMLH1 promoter correlates with lack of expression of hMLH1 in sporadic colon tumors and mismatch repair-defective human tumor cell lines. Cancer Res., 57: 808-811, 1997.[Abstract/Free Full Text]
  5. Cunningham J. M., Christensen E. R., Tester D. J., Kim C. Y., Roche P. C., Burgart L. J., Thibodeau S. N. Hypermethylation of the hMLH1 promoter in colon cancer with microsatellite instability. Cancer Res., 58: 3455-3460, 1998.[Abstract/Free Full Text]
  6. Herman J. G., Umar A., Polyak K., Graff J. R., Ahuja N., Issa J. P. J., Markowitz S., Willson J. K. V., Hamilton S. R., Kinzler K. W., Kane M. F., Kolodner R. D., Vogelstein B., Kunkel T. A., Baylin S. B. Incidence and functional consequences of hMLH1 promoter hypermethylation in colorectal carcinoma. Proc. Natl. Acad. Sci. USA, 95: 6870-6875, 1998.[Abstract/Free Full Text]
  7. Veigl M. L., Kasturi L., Olechnowicz J., Ma A., Lutterbaugh J. D., Periyasamy S., Li G. M., Drummond J., Modrich P. L., Sedwick W. D., Markowitz S. D. Biallelic inactivation of hMLH1 by epigenetic gene silencing, a novel mechanism causing human MSI cancers. Proc. Natl. Acad. Sci. USA, 95: 8698-8702, 1998.[Abstract/Free Full Text]
  8. Thibodeau S. N., French A. J., Cunningham J. M., Tester D., Burgart L. J., Roche P. C., McDonnell S. K., Schaid D. J., Vockley C. W., Michels V. V., Farr G. H., O’Connell M. J. Microsatellite instability in colorectal cancer: different mutator phenotypes and the principal involvement of hMLH1. Cancer Res., 58: 1713-1718, 1998.[Abstract/Free Full Text]
  9. Sankila R., Aaltonen L. A., Jarvinen H. J., Mecklin L. P. Better survival in patients with MLH1-associated hereditary colorectal cancer. Gastroenterology, 110: 682-687, 1996.[Medline]
  10. Thibodeau S. N., Bren G., Schaid D. Microsatellite instability in cancer of the proximal colon. Science (Wash. DC), 260: 816-819, 1993.[Abstract/Free Full Text]
  11. Cawkwell L., Li D., Lewis F. A., Martin I., Dixon M. F., Quirke P. Microsatellite instability in colorectal cancer: improved assessment using florescent polymerase chain reaction. Gastroenterology, 109: 465-471, 1995.[Medline]
  12. Bubb V. J., Curtis L. J., Cunningham C., Dunlop M. G., Carothers A. D., Morris R. G., White S., Bird C. C., Wyllie A. H. Microsatellite instability and the role of hMSH2 in sporadic colorectal cancer. Oncogene, 12: 2641-2649, 1996.[Medline]
  13. Lukish J. R., Muro K., DeNobile J., Katz R., Williams J., Cruess D. F., Drucker W., Kirsch I., Hamilton S. R. Prognostic significance of DNA replication errors in young patients With colorectal cancer. Ann. Surg., 227: 51-56, 1998.[Medline]
  14. Cawkwell L., Gray S., Murgatroyd H., Sutherland F., Haine L., Longfellows M., O’Loughlin S., Cross D., Kronborg O., Fenger C., Mapstone N., Dixon M., Quirke P. Choice of management strategy for colorectal cancer based on a diagnostic immunohistochemical test for defective mismatch repair. Gut, 45: 409-415, 1999.[Abstract/Free Full Text]
  15. Halling K. C., French A. J., McDonnell S. K., Burgart L. J., Schaid D. J., Petersen B. J., Moon-Tasson L., Mahoney M. R., Sargent D. J., O’Connell M. J., Witzig T. E., Farr G. H., Jr., Goldberg R. M., Thibodeau S. N. Microsatellite instability and 8p allelic imbalance in stage B2 and C colorectal cancers. J. Natl. Cancer Inst., 91: 1295-1303, 1999.[Abstract/Free Full Text]
  16. Massa M. J., Iniesta P., Gonzalez-Quevedo R., de Juan C., Caldes T., Sanchez-Pernaute A., Cerdan J., Torres A. J., Balibrea J. L., Benito M. Differential prognosis of replication error phenotype and loss of heterozygosity in sporadic colorectal cancer. Eur. J. Cancer, 35: 1676-1682, 1999.
  17. Gryfe R., Kim H., Hsieh E. T. K., Aronson M. D., Holowaty E. J., Bull S. B., Redston M., Gallinger S. Tumor microsatellite instability and clinical outcome in young patients with colorectal cancer. N. Engl. J. Med., 342: 69-77, 2000.[Abstract/Free Full Text]
  18. Elsaleh H., Joseph D., Grieu F., Zeps N., Spry N., Iacopetta B. Association of tumour site and sex with survival benefit from adjuvant chemotherapy in colorectal cancer. Lancet, 355: 1745-1750, 2000.[Medline]
  19. Johannsdottir J. T., Bergthorsson J. T., Gretarsdottir S., Kristjansson A. K., Ragnarsson G., Jonasson J. G., Egilsson V., Ingvarsson S. Replication error in colorectal carcinoma: association with loss of heterozygosity at mismatch repair loci and clinicopathological variables. Anticancer Res., 19: 1821-1826, 1999.[Medline]
  20. Salahshor S., Kressner U., Fischer H., Lindmark G., Glimelius B., Pahlman L., Lindblom A. Microsatellite instability in sporadic colorectal cancer is not an independent prognostic factor. Br. J. Cancer, 81: 190-193, 1999.[Medline]
  21. Curran B., Lenehan K., Mulcahy H., Tighe O., Bennett M. A., Kay E. W., O’Donoghue D. P., Leader M., Croke D. T. Replication error phenotype, clinicopathological variables, and patient outcome in Dukes’ B Stage II (T3, N0, M0) colorectal cancer. Gut, 46: 200-204, 2000.[Abstract/Free Full Text]
  22. Feeley K. M., Fullard J. F., Heneghan M. A., Smith T., Maher M., Murphy R. P., O’Gorman T. A. Microsatellite instability in sporadic colorectal carcinoma is not an indicator of prognosis. J. Pathol., 188: 14-17, 1999.[Medline]
  23. Ko J. M., Cheung M. H., Kwan M. W., Wong C. M., Lau K. W., Tang C. M., Lung M. L. Genomic instability and alterations in Apc, Mcc, and Dcc in Hong Kong patients with colorectal carcinoma. Int. J. Cancer, 84: 404-409, 1999.[Medline]
  24. Slattery M. L., Friedman G. D., Potter J. D., Edwards S., Caan B. J., Samowitz W. S. A description of age, sex, and site distributions of colon carcinoma in three geographic areas. Cancer, 78: 1666-1670, 1996.[Medline]
  25. Gryfe R., Redston M., Gallinger S. Microsatellite instability in colorectal cancer. N. Engl. J. Med., 342: 1608 2000.[Free Full Text]
  26. Ponz de Leon M., Roncucci M. Microsatellite instability in colorectal cancer. N. Engl. J. Med., 342: 1607 2000.[Free Full Text]
  27. Samowitz W. S., Slattery M. L., Kerber R. A. Microsatellite instability in human colonic cancer is not a useful clinical indicator of familial colorectal cancer. Gastroenterology, 109: 1765-1771, 1995.[Medline]
  28. Shambaugh E. M. Weiss M. A. Axtell L. M. eds. . Summary Staging Guide for Cancer Surveillance, Epidemiology and End Results Reporting. NIH Publication No. 81–2313, : 63-76, U. S. Department of Health and Human Services, Public Health Service, NIH Bethesda, MD 1981.
  29. American Joint Committee on Cancer. 5th ed. . AJCC Cancer Staging Manual, : 83-88, Lippincott-Raven Philadelphia 1997.
  30. Spirio L. N., Samowitz W. S., Robertson J., Robertson M., Burt R. W., Leppert M. F., White R. Alleles of APC modulate the frequency and classes of mutations that lead to colon polyps. Nat. Genet., 20: 385-388, 1998.[Medline]
  31. Parsons R., Myeroff L., Liu B., Wilson J. K. V., Markowitz S. D., Kinzler K. W., Vogelstein B. Microsatellite instability and mutations of the transforming growth factor ß type II receptor gene in colorectal cancer. Cancer Res., 55: 5548-5550, 1995.[Abstract/Free Full Text]
  32. Samowitz W. S., Slattery M. L., Potter J. D., Leppert M. F. BAT-26 and BAT-40 instability in colorectal adenomas and carcinomas and germline polymorphisms. Am. J. Pathol., 154: 1637-1641, 1999.[Abstract/Free Full Text]
  33. Samowitz W. S., Slattery M. L. Transforming growth factor ß receptor type 2 mutations and microsatellite instability in sporadic colorectal adenomas and carcinomas. Am. J. Pathol., 151: 33-35, 1997.[Abstract]
  34. Brownstein M. J., Carpten J. D., Smith J. R. Modulation of non-templated nucleotide addition by Taq DNA polymerase: primer modifications that facilitate genotyping. Biotechniques, 20: 1004-1010, 1996.[Medline]
  35. Hoang J. M., Cottu P. H., Thuille B., Salmon R. J., Thomas G., Hamelin R. BAT-26, an indicator of the replication error phenotype in colorectal cancers and cell lines. Cancer Res., 57: 300-303, 1997.[Abstract/Free Full Text]
  36. Boland C. R., Thibodeau S. N., Hamilton S. R., Sidransky D., Eshleman J. R., Burt R. W., Meltzer S. J., Rodriguez-Bigas M. A., Fodde R., Ranzani N., Srivastava S. A national cancer institute workshop on microsatellite instability for cancer detection and familial predisposition: development of international criteria for the determination of microsatellite instability in colorectal cancer. Cancer Res., 58: 5248-5257, 1998.[Abstract/Free Full Text]
  37. Samowitz W. S., Holden J. A., Curtin K., Edwards S. L., Walker A. R., Robertson M. A., Nichols M. F., Gruenthal K. M., Lynch B. J., Leppert M. F., Slattery M. L. Inverse relationship between microsatellite instability and Ki-ras and p53 gene alterations in colonic cancer. Am. J. Pathol., 158: 1517-1524, 2001.[Abstract/Free Full Text]
  38. Smyrk T. C. Cancer syndrome meets molecular biology meets histopathology. Am. J. Pathol., 145: 1-6, 1994.[Medline]
  39. Lothe R. A., Peltomaki P., Meling G. I., Aaltonen L. A., Nystom-Lahti M., Pylkkanen L., Heimdal K., Andersen T. I., Moller P., Rognum T. O., Fossa S. D., Haldorsen T., Langmark F., Brogger A., Chapelle A., Borresen A. L. Genomic instability in colorectal cancer: relationship to clinicopathological variables and family history. Cancer Res., 53: 5849-5852, 1993.[Abstract/Free Full Text]
  40. Hemminki H., Mecklin J-P., Jarvinen H., Aaltonen L. A., Joensuu H. Microsatellite instability is a favorable prognostic indicator in patients with colorectal cancer receiving chemotherapy. Gastroenterology, 119: 921-928, 2000.[Medline]
  41. Offit K. Genetic prognostic markers for colorectal cancer. N. Engl. J. Med., 342: 124-125, 2000.[Free Full Text]



This article has been cited by other articles:


Home page
 GutHome page
M W M D Lutgens, F P Vleggaar, M E I Schipper, P C F Stokkers, C J van der Woude, D W Hommes, D J de Jong, G Dijkstra, A A van Bodegraven, B Oldenburg, et al.
High frequency of early colorectal cancer in inflammatory bowel disease
Gut, September 1, 2008; 57(9): 1246 - 1251.
[Abstract] [Full Text] [PDF]

Home page
 JAMAHome page
J. A. Chan, J. A. Meyerhardt, D. Niedzwiecki, D. Hollis, L. B. Saltz, R. J. Mayer, J. Thomas, P. Schaefer, R. Whittom, A. Hantel, et al.
Association of Family History With Cancer Recurrence and Survival Among Patients With Stage III Colon Cancer
JAMA, June 4, 2008; 299(21): 2515 - 2523.
[Abstract] [Full Text] [PDF]

Home page
 GutHome page
S Le Gouvello, S Bastuji-Garin, N Aloulou, H Mansour, M-T Chaumette, F Berrehar, A Seikour, A Charachon, M Karoui, K Leroy, et al.
High prevalence of Foxp3 and IL17 in MMR-proficient colorectal carcinomas
Gut, June 1, 2008; 57(6): 772 - 779.
[Abstract] [Full Text] [PDF]

Home page
 CA Cancer J ClinHome page
F. L. Greene and L. H. Sobin
The Staging of Cancer: A Retrospective and Prospective Appraisal
CA Cancer J Clin, May 1, 2008; 58(3): 180 - 190.
[Abstract] [Full Text] [PDF]

Home page
 Biol Res NursHome page
E. L. Kurnat-Thoma
Hereditary Nonpolyposis Colorectal Cancer (Lynch Syndrome): Molecular Pathogenesis and Clinical Approaches to Diagnosis and Management for Nurses
Biol Res Nurs, January 1, 2008; 9(3): 185 - 199.
[Abstract] [PDF]

Home page
 Clin. Cancer Res.Home page
A. Malesci, L. Laghi, P. Bianchi, G. Delconte, A. Randolph, V. Torri, C. Carnaghi, R. Doci, R. Rosati, M. Montorsi, et al.
Reduced Likelihood of Metastases in Patients with Microsatellite-Unstable Colorectal Cancer
Clin. Cancer Res., July 1, 2007; 13(13): 3831 - 3839.
[Abstract] [Full Text] [PDF]

Home page
 JNCI J Natl Cancer InstHome page
W. S. Samowitz, H. Albertsen, C. Sweeney, J. Herrick, B. J. Caan, K. E. Anderson, R. K. Wolff, and M. L. Slattery
Association of Smoking, CpG Island Methylator Phenotype, and V600E BRAF Mutations in Colon Cancer
J Natl Cancer Inst, December 6, 2006; 98(23): 1731 - 1738.
[Abstract] [Full Text] [PDF]

Home page
 JCOHome page
G. Y. Locker, S. Hamilton, J. Harris, J. M. Jessup, N. Kemeny, J. S. Macdonald, M. R. Somerfield, D. F. Hayes, and R. C. Bast Jr
ASCO 2006 Update of Recommendations for the Use of Tumor Markers in Gastrointestinal Cancer
J. Clin. Oncol., November 20, 2006; 24(33): 5313 - 5327.
[Abstract] [Full Text] [PDF]

Home page
 GutHome page
J M Carethers
Prospective evaluation of fluorouracil chemotherapy based on the genetic makeup of colorectal cancer.
Gut, June 1, 2006; 55(6): 759 - 761.
[Full Text] [PDF]

Home page
 GutHome page
R Jover, P Zapater, A Castells, X Llor, M Andreu, J Cubiella, V Pinol, R M Xicola, L Bujanda, J M Rene, et al.
Mismatch repair status in the prediction of benefit from adjuvant fluorouracil chemotherapy in colorectal cancer
Gut, June 1, 2006; 55(6): 848 - 855.
[Abstract] [Full Text] [PDF]

Home page
 JCOHome page
G. Lanza, R. Gafa, A. Santini, I. Maestri, L. Guerzoni, and L. Cavazzini
Immunohistochemical Test for MLH1 and MSH2 Expression Predicts Clinical Outcome in Stage II and III Colorectal Cancer Patients
J. Clin. Oncol., May 20, 2006; 24(15): 2359 - 2367.
[Abstract] [Full Text] [PDF]

Home page
 Clin. Cancer Res.Home page
P. Benatti, R. Gafa, D. Barana, M. Marino, A. Scarselli, M. Pedroni, I. Maestri, L. Guerzoni, L. Roncucci, M. Menigatti, et al.
Microsatellite Instability and Colorectal Cancer Prognosis
Clin. Cancer Res., December 1, 2005; 11(23): 8332 - 8340.
[Abstract] [Full Text] [PDF]

Home page
 J. Nutr.Home page
C. M. Ulrich, K. Curtin, W. Samowitz, J. Bigler, J. D. Potter, B. Caan, and M. L. Slattery
MTHFR Variants Reduce the Risk of G:C->A:T Transition Mutations within the p53 Tumor Suppressor Gene in Colon Tumors
J. Nutr., October 1, 2005; 135(10): 2462 - 2467.
[Abstract] [Full Text] [PDF]

Home page
 Cancer Res.Home page
P. Findeisen, M. Kloor, S. Merx, C. Sutter, S. M. Woerner, N. Dostmann, A. Benner, B. Dondog, M. Pawlita, W. Dippold, et al.
T25 Repeat in the 3' Untranslated Region of the CASP2 Gene: A Sensitive and Specific Marker for Microsatellite Instability in Colorectal Cancer
Cancer Res., September 15, 2005; 65(18): 8072 - 8078.
[Abstract] [Full Text] [PDF]

Home page
 JCOHome page
J. L. Westra, M. Schaapveld, H. Hollema, J. P. de Boer, M. M.J. Kraak, D. de Jong, A. ter Elst, N. H. Mulder, C. H.C.M. Buys, R. M.W. Hofstra, et al.
Determination of TP53 Mutation Is More Relevant Than Microsatellite Instability Status for the Prediction of Disease-Free Survival in Adjuvant-Treated Stage III Colon Cancer Patients
J. Clin. Oncol., August 20, 2005; 23(24): 5635 - 5643.
[Abstract] [Full Text] [PDF]

Home page
 Cancer Res.Home page
W. S. Samowitz, C. Sweeney, J. Herrick, H. Albertsen, T. R. Levin, M. A. Murtaugh, R. K. Wolff, and M. L. Slattery
Poor Survival Associated with the BRAF V600E Mutation in Microsatellite-Stable Colon Cancers
Cancer Res., July 15, 2005; 65(14): 6063 - 6069.
[Abstract] [Full Text] [PDF]

Home page
 Cancer Res.Home page
J. S. Edmiston, W. A. Yeudall, T. D. Chung, and D. A. Lebman
Inability of Transforming Growth Factor-{beta} to Cause SnoN Degradation Leads to Resistance to Transforming Growth Factor-{beta}-Induced Growth Arrest in Esophageal Cancer Cells
Cancer Res., June 1, 2005; 65(11): 4782 - 4788.
[Abstract] [Full Text] [PDF]

Home page
 JCOHome page
S. Popat, R. Hubner, and R.S. Houlston
Systematic Review of Microsatellite Instability and Colorectal Cancer Prognosis
J. Clin. Oncol., January 20, 2005; 23(3): 609 - 618.
[Abstract] [Full Text] [PDF]

Home page
 GutHome page
C M Wright, O F Dent, R C Newland, M Barker, P H Chapuis, E L Bokey, J P Young, B A Leggett, J R Jass, and G A Macdonald
Low level microsatellite instability may be associated with reduced cancer specific survival in sporadic stage C colorectal carcinoma
Gut, January 1, 2005; 54(1): 103 - 108.
[Abstract] [Full Text] [PDF]

Home page
 Ann OncolHome page
A. Emterling, A. Wallin, G. Arbman, and X.-F. Sun
Clinicopathological significance of microsatellite instability and mutated RIZ in colorectal cancer
Ann. Onc., February 1, 2004; 15(2): 242 - 246.
[Abstract] [Full Text] [PDF]

Home page
 GutHome page
M Ponz de Leon, P Benatti, F Borghi, M Pedroni, A Scarselli, C Di Gregorio, L Losi, A Viel, M Genuardi, G Abbati, et al.
Aetiology of colorectal cancer and relevance of monogenic inheritance
Gut, January 1, 2004; 53(1): 115 - 122.
[Abstract] [Full Text] [PDF]

Home page
 Cancer Epidemiol. Biomarkers Prev.Home page
M. L. Slattery, S. Edwards, K. Curtin, D. Schaffer, and S. Neuhausen
Associations between Smoking, Passive Smoking, GSTM-1, NAT2, and Rectal Cancer
Cancer Epidemiol. Biomarkers Prev., September 1, 2003; 12(9): 882 - 889.
[Abstract] [Full Text] [PDF]

Home page
 JCOHome page
G.M. Nash, M. Gimbel, J. Shia, A.T. Culliford, D.R. Nathanson, M. Ndubuisi, Y. Yamaguchi, Z.S. Zeng, F. Barany, and P.B. Paty
Automated, Multiplex Assay for High-Frequency Microsatellite Instability in Colorectal Cancer
J. Clin. Oncol., August 15, 2003; 21(16): 3105 - 3112.
[Abstract] [Full Text] [PDF]

Home page
 Ann OncolHome page
F. Graziano and S. Cascinu
Prognostic molecular markers for planning adjuvant chemotherapy trials in Dukes' B colorectal cancer patients: how much evidence is enough?
Ann. Onc., July 1, 2003; 14(7): 1026 - 1038.
[Abstract] [Full Text] [PDF]