Table 2.

Characteristics of randomized trials and observational studies addressing the association of gastric cancer with tamoxifen therapy

Tamoxifen-treated groupTamoxifen-untreated group
Authors, year (reference)Country in which conductedStudy name or target populationStudy TypeMedian follow-up time in yearsAge range or menopausal statusTreatment regimen (daily dose and duration)Gastric cancer casesn/women-years at riskTreatment regimenGastric cancer casesn/women-years at risk
Ribeiro and colleagues 1992 (48)United KingdomThe Christie Hospital Adjuvant Tamoxifen trialRCT10PostmenopausalTAM (20 mg/1 y)2282/2,820No treatment0306/3,060
Ryden and colleagues 1992 (55)SwedenThe Southern Sweden Breast Cancer TrialRCT9PostmenopausalRT + TAM (30 mg/1 y)2239/1,847aRT0236/1,812a
Cummings and colleagues 1993 (56)United StatesEasternCooperative Oncology GroupRCTTAM: 7.4 placebo: 4.465–84TAM (20 mg/1 y)185/629Placebo183/365
Rivkin and colleagues 1994 (57)United StatesThe SouthernOncology Group StudyRCT6.5PostmenopausalCHEMO + TAM (20 mg/1 y)1303/1,970CHEMO0300/1,950
Rutquvist and colleagues 1995 (52)SwedenThe StockholmBreast Cancer Study GroupRCT9PostmenopausalTAM (40 mg/2 or 5 y)51372/9,610No treatment21357/9,378
Fisher and colleagues 1996 (50)United States and Canada(NSABP) B-14RCT10.4 (mean)Mean age: 55 yTAM (20 mg/5 or 10 y)41404/14,602Placebo21414/14,706
Cuzick and colleagues 2002 (58)United KingdomThe International Breast Cancer Intervention Study (IBIS-I)RCT4.235–70TAM (20 mg/5 y)13578/15,028Placebo33574/15,011
Fisher and colleagues 2005 (59)United StatesThe National Surgical Adjuvant Breast and Bowel Project Breast Cancer Prevention trial (P-1)RCT6.2 (mean)≥35TAM (20 mg/5 y)26,681/40,844Placebo (including crossovers after unblinding)26,707/40,648
Veronesi and colleagues 2007 (60)ItalyItalian Randomized Tamoxifen Prevention TrialRCT9.1 (mean)35–70TAM (20 mg/5 y)12700/30,303Placebo42,708/30,310
Curtis andcolleagues 1996 (53)United StatesCancer registration data from 1980 to 1992Cohort12(maximum)≥50 yHormone therapy for their first course of therapy1514,358/39,736No hormonal therapy/unknown11872,965/348,393
Matsuyamaand colleagues 2000 (61)Japan9 medical institutionsCohortTAM: 7.64 Non-TAM: 8.1Adult womenTAM (20 mg/≤2 y mainly)323,497/26717CHEMO or no further treatment192,529/20,485
Ursic-Vrscaj and colleagues 2001 (62)SloveniaPopulation-based registry from 1987 to 1994Cohort8.5 (mean); 5–12 (range)≥55 yTAM (20 mg/3.33 y, median)2440/3,740No TAM0190/1,615
Fowble and colleagues 2001 (63)United StatesUniversity of Pennsylvania or Fox Chase Cancer CenterCohortTAM: 7.4 Non-TAM: 9.6Pre- and postmenopausalbTAM (-/1 y)0234/1,732No TAM1681/6,538
Andersson and colleagues 2008 (46)DenmarkPatients registered by the population based Danish Breast Cancer Cooperative Group (DBCG)Cohort7.819–89TAM (-/1 y)197,204/47,465Other treatment3824,614/209,098

Abbreviations: RCT, randomized clinical trial; RT, radiotherapy; TAM, tamoxifen; CHEMO, chemotherapy.

Italicized numbers were approximated based on reported data.

  • aPerson-time estimates taken from Rutquvist and colleagues 1995 (52).

  • bAll women received radiotherapy.