In a South Korean single-center retrospective cohort study reported in JAMA Surgery, Cheun et al identified locoregional recurrence patterns according to molecular subtypes of breast cancer among women undergoing surgery for the disease.
The study involved data from 16,462 women who underwent breast cancer surgery at Seoul National University Hospital, South Korea, between January 2000 and December 2018. Median patient age at surgery was 49 years (interquartile range = 43–57 years).
Key Findings
Among all patients, the rates for 10-year ipsilateral breast tumor recurrence–free, regional recurrence–free, and contralateral breast cancer–free survival were 95.9%, 96.1%, and 96.5%, respectively. Compared with patients with the hormone receptor–positive/HER2-negative subtype, those with the hormone receptor–negative/HER2-positive subtype had the poorest ipsilateral breast tumor recurrence–free survival (hazard ratio [HR] = 2.95, 95% confidence interval [CI] = 2.15–4.06) and those with the hormone receptor–negative/HER2-negative subtype had the worst regional recurrence–free (HR = 2.95, 95% CI = 2.37–3.67) and contralateral breast cancer–free survival (HR = 2.12, 95% CI = 1.64–2.75).
Analysis of annual recurrence patterns showed that ipsilateral breast tumor recurrence patterns of the hormone receptor–negative/HER2-positive and hormone receptor–negative/HER2-negative subtypes exhibited double peaks at approximately 2 and 9 years, whereas the hormone receptor–positive/HER2-negative subtype exhibited a steady increase with no discernible peaks. The hormone receptor–positive/HER2-negative subtype exhibited a steady regional recurrence pattern; the other subtypes exhibited the highest regional recurrence incidence at 1 year, followed by a steady decrease. The annual incidence of contralateral breast cancer gradually increased among all subtypes, with patients who had the hormone receptor–negative/HER2-negative subtype showing the highest 10-year incidence.
Overall, women aged ≤ 40 years exhibited greater differences in ipsilateral breast tumor recurrence, regional recurrence, and contralateral breast cancer patterns among subtypes compared with older patients.
The investigators concluded: “In this study, locoregional recurrence occurred with different patterns according to [breast cancer] subtypes, with younger patients having greater differences in patterns among subtypes than older patients. The findings suggest that tailoring surveillance should be recommended regarding differences in locoregional recurrence patterns according to tumor subtypes, particularly for younger patients.”
Han-Byoel Lee, MD, PhD, of the Department of Surgery, Seoul National University College of Medicine, Seoul, is the corresponding author of the JAMA Surgery article.
Disclosure: The study was supported by grants from the Korea Health Technology R&D Project through the Korea Health Industry Development Institute, which is funded by the Ministry of Health and Welfare. For full disclosures of the study authors, visit jamanetwork.com.
