In an update from the WECARE (Women’s Environmental Cancer and Radiation Epidemiology) study reported in the Journal of Clinical Oncology, Reiner et al found that women with invasive breast cancer are at increased risk of contralateral breast cancer even in the absence of deleterious mutations if they have a first-degree relative with breast cancer.
The WECARE study is a population-based case-control study including 1,521 women with contralateral breast cancer and 2,212 individually matched unilateral breast cancer controls from the United States and Denmark. Participants were aged < 55 years when diagnosed with a first invasive breast cancer between 1985 and 2008.
A subset of the population was screened for deleterious mutations in BRCA1/2, ATM, CHEK2*1100delC, and PALB2. Cumulative absolute risk was estimated by combining relative risks from the WECARE Study and population-based SEER*Stat cancer incidence data.
Risk of Contralateral Breast Cancer
The cumulative 10-year absolute risk of contralateral disease for participants without family history of breast cancer was 4.3%. Women with any first-degree relative with breast cancer had a 10-year absolute risk of 8.1% for contralateral disease. Absolute risk was high if the relative was diagnosed at age < 40 years (10-year absolute risk = 13.5%) or had contralateral disease (10-year absolute risk = 14.1%). These risks were comparable to the risk of contralateral disease observed in carriers of deleterious BRCA1/2 mutations (10-year absolute risk = 18.4%). In the subset of women negative for deleterious mutations in BRCA1/2, ATM, CHEK2*1100delC, and PALB2, 10-year absolute risk was 8.3% among those with any first-degree relative with breast cancer and 14.5% among those with a first-degree relative diagnosed at age < 40 years. Adjustment for known breast cancer single-nucleotide polymorphisms did not affect estimates of risk.
The investigators concluded, “Breast cancer family history confers a high [contralateral breast cancer] risk, even after excluding women with deleterious mutations. Clinicians are urged to use detailed family histories to guide treatment and future screening decisions for young women with breast cancer.”
The study was supported by grants from the National Institutes of Health.
Anne S. Reiner, MPH, of Memorial Sloan Kettering Cancer Center, is the corresponding author for the Journal of Clinical Oncology article.
The content in this post has not been reviewed by the American Society of Clinical Oncology, Inc. (ASCO®) and does not necessarily reflect the ideas and opinions of ASCO®.