A recent cohort study, published in JAMA Network Open, has revealed that women diagnosed with breast cancer at the age of 35 or younger face an elevated risk of developing contralateral breast cancer in comparison to their older counterparts.
The study, conducted by Dr. Hakyoung Kim and colleagues at the University of Ulsan College of Medicine’s Asan Medical Center and Dongguk University College of Medicine at Dongguk University Ilsan Hospital in Goyang, South Korea, emphasizes the importance of recognizing and educating young breast cancer patients about the increased risk of contralateral breast cancer prior to deciding on a treatment plan.
The cohort study involved 16,251 Korean women, with a mean age of 48.6 years, diagnosed with stage 0 to III breast cancer who underwent surgery for unilateral nonmetastatic breast cancer between 1999 and 2013 at Asan Medical Center. The participants were categorized into two groups based on age: younger (aged 35 or below, n = 1,318) and older (aged above 35, n = 14,933).
Over a median follow-up period of 107 months, younger women exhibited a higher 10-year cumulative incidence (7.1% vs. 2.9%; P < .001) and a heightened risk for contralateral breast cancer (HR = 2.1; 95% CI, 1.62-2.74) compared to their older counterparts.
The study also delved into specific breast cancer subtypes, finding that in women with the hormone receptor-positive/ERBB2-negative subtype, the risk for contralateral breast cancer increased continuously over time for both age groups. For those with the triple-negative subtype, the risk peaked around year 10 before decreasing for both age groups. However, women with the hormone receptor-positive/ERBB2-positive subtype experienced an earlier peak in contralateral breast cancer risk, occurring at 1.7 years post-surgery for younger women and 4.8 years for older women.
The researchers highlight the potential implications of these findings in aiding physicians and patients in the decision-making process, particularly in considering contralateral prophylactic mastectomy. Nevertheless, they underscore the need for further research with larger sample sizes and multicenter studies to validate and confirm these results.
