Table 1.

Selected characteristics of the study population at diagnosis

All cases (N = 603) mean (SD)Premenopausal (n = 235) mean (SD)Postmenopausal (n = 368) mean (SD)
Personal variables
    Age (y)54.5 (11.0)43.1 (5.7)61.8 (6.8)
    Family history of breast cancer*15.9%11.3%18.8%
    Number of children2.4 (1.8)1.8 (1.2)2.8 (2.0)
    Age menstruation began12.9 (1.7)12.6 (1.4)13.0 (1.8)
Body size and shape variables
    Body mass index26.0 (4.6)25.3 (4.7)26.4 (4.5)
    Waist-to-hip ratio0.80 (0.07)0.79 (0.06)0.82 (0.07)
Demographic variables (%)
    Employed46.7%70.2%31.6%
    Marital status
        Single5.3%9.8%2.4%
        Married68.3%70.6%66.8%
        Widowed11.6%1.3%18.2%
        Divorced14.8%18.3%12.5%
    Ethnicity
        Caucasian88.4%83.4%91.6%
        Asian7.1%10.2%5.2%
        E. Indian2.2%1.7%2.4%
        Black0.3%0.9%0.0%
        Other2.0%3.8%0.8%
Prognostic variables (%)
    Tumor grade
        Well differentiated7.6%8.8%6.8%
        Moderately differentiated46.4%37.8%51.9%
        Poorly differentiated46.0%53.5%41.3%
    Tumor size (cm)
        0-1.020.6%16.3%23.8%
        1.1-2.023.5%20.9%25.4%
        2.1-5.047.1%54.7%41.7%
        5.1-9.98.7%8.1%9.2%
    Nodal status
        No axillary dissection11.1%13.6%9.5%
        No positive nodes57.5%53.2%60.3%
        Positive nodes27.9%29.4%26.9%
        Unknown3.5%3.8%3.3%
    Estrogen receptor positive76.4%69.0%81.3%
    Systemic treatment
        None40.1%32.7%44.7%
        Tamoxifen only21.9%4.0%33.1%
        Chemotherapy only14.7%31.8%3.9%
        Both21.4%28.7%16.9%
        Other hormone1.9%2.6%1.4%
    Local treatment
        Lumpectomy alone4.6%5.3%4.2%
        Lumpectomy + RT14.6%11.9%16.3%
        Complete mastectomy alone59.6%59.3%59.8%
        Complete mastectomy + RT10.0%10.6%9.6%
        Other§11.2%12.8%10.1%
  • Abbreviation: RT, radiation therapy.

  • * Family history is defined as breast cancer in any first-degree relative.

  • kg/m2.

  • Missing values: WHR (17), family history (10), employment status (1), estrogen receptor status (180).

  • § For example, a lumpectomy followed by a complete mastectomy.