Table 1.

Characteristics of DCIS cohort and crude rates of second cancer in the ipsilateral and contralateral breasts

Characteristic (at index DCIS)All DCIS patients (n = 935)Second breast cancer
Ipsilateral* (n = 164)Contralateral (n = 59)
NPercentpyNRate per 1,000 pyNRate per 1,000 py
Age at diagnosis
    <4511512.3%905.52830.955.5
    45-5425827.6%2,070.14622.2188.7
    ≥5556260.1%4,305.49020.9368.4
Diagnosis year
    1990-199114915.9%1,413.13222.696.4
    1992-199320722.1%1,733.83218.51810.4
    1994-199527429.3%2,078.95124.5178.2
    1996-199730532.6%2,055.14923.8157.3
Race/Ethnicity
    Asian10411.1%795.91518.81012.6
    Black687.3%545.51629.359.2
    Hispanic606.4%499.3918.036.0
    White70074.9%5,420.912422.9417.6
    Unknown30.3%19.400.000.0
Mode of Detection
    Other30.3%33.6129.700.0
    Routine mammogram75981.2%5,998.612621.0488.0
    Symptom/Exam16918.1%1,209.23730.6119.1
    Unknown40.4%39.600.000.0
BMI
    <2539041.7%3,041.28427.6206.6
    25 to <3029231.2%2,307.34419.1177.4
    ≥3019520.9%1,519.63120.41811.8
    Unknown586.2%412.7512.149.7
Radiotherapy
    No44647.7%3,251.010933.5226.8
    Yes48551.9%4,005.45513.7379.2
    Unknown40.4%24.600.000.0
Hormonal therapy
    No89195.3%6,943.615922.9557.9
    Yes444.7%337.4514.8411.9
  • *Excludes second cancers (n = 5) that were regional or distant metastases without ipsilateral breast involvement.