Table 3.

Cox proportional hazards regression models of RFS among patients with invasive cancer

VariableModel 1
Model 2
Model 3
Model 4
All patients, RR (95% CI)Patients with ER-positive tumors, RR (95% CI)Patients with ER-negative tumors, RR (95% CI)Adjusted for all biomarkers, RR (95% CI)
Unadjusted
    Method of detection
        Screen detected1.001.001.00
        Symptom detected2.40 (2.00-2.87)*2.03 (1.60-2.59)*2.42 (1.77-3.31)*
        P<0.001<0.001<0.001
        No. recurrences or deaths/total (%)626/5,481 (11.4)304/3,843 (7.9)281/1,407 (20.0)
Adjusted
    Method of detection
        Screen detected1.001.001.001.00
        Symptom detected1.34 (1.09-1.66)1.18 (0.90-1.56)1.60 (1.14-2.25)1.29 (0.89-1.87)
        P0.0060.2330.0070.181
Age (per 10-y increase)
Race
    Non-African American1.00
    African American1.56 (1.02-2.39)
Tumor size
    T11.001.001.001.00
    T21.68 (1.34-2.10)*1.61 (1.19-2.19)1.78 (1.27-2.50)*1.76 (1.18-2.63)
    T32.76 (2.02-3.78)*2.79 (1.81-4.29)*2.77 (1.72-4.46)*2.87 (1.72-4.78)*
    T43.42 (2.54-4.61)*3.43 (2.23-5.28)*3.69 (2.41-5.67)*3.68 (2.24-6.06)*
Nodal status
    Negative1.001.001.001.00
    Positive1.89 (1.53-2.32)*1.75 (1.31-2.33)*2.00 (1.49-2.69)*1.90 (1.33-2.72)*
Nuclear grade
    Well/moderately differentiated
    Poorly differentiated
Lymphatic/vascular invasion
    No1.001.001.001.00
    Yes1.60 (1.33-1.94)*1.42 (1.08-1.86)1.90 (1.46-2.48)1.55 (1.10-2.18)
Surgery and radiation
    Breast-conserving surgery alone2.37 (1.65-3.42)*1.95 (1.20-3.17)3.40 (1.95-5.94)*
    Breast-conserving surgery + radiation0.81 (0.64-1.03)0.76 (0.55-1.06)0.85 (0.60-1.21)
    Mastectomy alone1.001.001.00
    Mastectomy + radiation1.08 (0.84-1.38)1.06 (0.76-1.48)1.03 (0.71-1.49)
Adjuvant chemotherapy
    No1.001.00
    Yes0.75 (0.63-0.91)0.68 (0.52-0.88)
Adjuvant endocrine therapy
    No1.001.001.001.00
    Yes0.47 (0.37-0.59)*0.44 (0.33-0.58)*0.48 (0.32-0.73)*0.37 (0.24-0.55)*
ER status
    ER positive1.001.00
    ER negative1.60 (1.27-2.02)*1.20 (0.75-1.91)
PR status
    PR positive1.001.00
    PR negative1.37 (1.06-1.77)0.95 (0.64-1.39)
HER-2/neu immunohistochemistry score
    0 or 1+1.00
    2+0.58 (0.33-1.01)
    3+0.94 (0.64-1.38)
Ki-67 expression
    <10%§§§1.00
    10-30%§§§1.29 (0.78-2.14)
    >30%§§§1.86 (1.09-3.18)
No. recurrences or deaths/total (%)536/5,110 (10.5)280/3,752 (7.5)254/1,340 (19.0)166/1,810 (9.2)
  • * P < 0.001.

  • P ≥ 0.001 and P < 0.05.

  • The variable was included in the original full model but it was not statistically significant (P ≥ 0.05). Thus, it was not included in the reduced model. A variable representing whether a patient received neoadjuvant chemotherapy was excluded for the same reason. The original full model included method of detection, age, race, tumor size, nodal status, nuclear grade, lymphatic/vascular invasion, surgery and radiation, adjuvant chemotherapy, neoadjuvant chemotherapy, adjuvant endocrine therapy, ER status, PR status, and HER-2/neu immunohistochemistry score.

  • § The variable was not included in the full model.