Mammographic density and breast cancer after ductal carcinoma in situ.
Women with ductal carcinoma in situ (DCIS) are at substantially increased risk for a second breast cancer, but few strong predictors for these subsequent tumors have been identified. We used Cox regression modeling to examine the association between mammographic density at diagnosis of DCIS of 504 women from the National Surgical Adjuvant Breast and Bowel Project B-17 trial and risk of subsequent breast cancer events. In this group of patients, mostly 50 years old or older, approximately 6.6% had breasts categorized as highly dense (i.e., > or =75% of the breast occupied by dense tissue). After adjusting for treatment with radiotherapy, age, and body mass index, women with highly dense breasts had 2.8 (95% confidence interval [CI] = 1.3 to 6.1) times the risk of subsequent breast cancer (DCIS or invasive), 3.2 (95% CI = 1.2 to 8.5) times the risk of invasive breast cancer, and 3.0 (95% CI = 1.2 to 7.5) times the risk of any ipsilateral breast cancer, compared with women with less than 25% of the breast occupied by dense tissue. Our results provide initial evidence that the risk of second breast cancers may be increased among DCIS patients with highly dense breasts.
Division of Research, Kaiser Permanente Medical Care Program, Oakland, CA 94612, USA. lah@dor.kaiser.org.
Laurel A
LA
Habel
James J
JJ
Dignam
Stephanie R
SR
Land
Martine
M
Salane
Angela M
AM
Capra
Thomas B
TB
Julian
D000328:Adult; D000368:Aged; D001940:Breast / Q000473:pathology*; D001943:Breast Neoplasms / Q000000981:diagnostic imaging* / Q000453:epidemiology / Q000532:radiotherapy / Q000601:surgery; D002285:Carcinoma, Intraductal, Noninfiltrating / Q000000981:diagnostic imaging* / Q000453:epidemiology / Q000532:radiotherapy / Q000601:surgery; D015986:Confounding Factors, Epidemiologic; D005260:Female; D006801:Humans; D015994:Incidence; D008327:Mammography; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000000981:diagnostic imaging* / Q000453:epidemiology / Q000517:prevention & control; D016016:Proportional Hazards Models; D016032:Randomized Controlled Trials as Topic; D018570:Risk Assessment; D012307:Risk Factors; D016037:Single-Blind Method; D014481:United States / Q000453:epidemiology