Ann H. Partridge, MD, MPH, discusses the incidence of second primary breast cancer in young patients with a history of breast cancer.
Ann H. Partridge, MD, MPH, vice chair, Medical Oncology, founder and director, Program for Young Adults with Breast Cancer, director, Adult Survivorship Program, Eric P. Winer, MD, Chair in Breast Cancer Research, senior physician, Dana-Farber Cancer Institute; professor, medicine, Harvard Medical School, discusses the incidence of second primary breast cancer in young patients with a history of breast cancer.
The risk of contralateral breast cancer is higher among patients who are under the age of 40 at their primary breast cancer diagnosis, although this risk differs based on primary tumor traits, genetic risk, and treatments.
The Young Women’s Breast Cancer Study aimed to determine the incidence of second primary breast cancer in patients aged 40 years and under at diagnosis who received lumpectomy or unilateral mastectomy after their primary breast cancer diagnosis between 2006 and 2016. At a median follow-up of 10 years, of the 685 patients included in the study, 526 were alive without recurrence, 45 had local recurrence, 94 had metastases, 3 had died from causes unrelated to breast cancer, and 17 had second primary breast cancer.
This retrospective study showed that among all patients, the risk of developing a new primary breast cancer was higher in patients with a genetic predisposition for breast cancer, such as a BRCA1 or BRCA2 pathogenic variant compared with those who were not pathogenic variant carriers, Partridge says. The 5- and 10-year risks of developing a second primary breast cancer were 6.1% and 9.1% in patients with pathogenic variants vs 1.1% and 1.7% in those without pathogenic variants.
The risk of developing a second primary breast cancer was relatively low in younger patients when pathogenic variant carriers were removed from the study population, Partridge emphasizes. These findings can be helpful for patients as they make local therapy decisions after a diagnosis of unilateral breast cancer, Partridge concludes.