Predicting Late Recurrence in Male Estrogen Receptor-Positive Breast Cancer With Clinical Treatment Score Post-5 years: A SEER database analysis of 65,711 cases.

PURPOSE

Male breast cancer is an understudied disease with unique clinicopathological features. This study aims to evaluate the predictive value of the Clinical Treatment Score post-5 years (CTS5) in estimating late recurrence risk in estrogen receptor-positive (ER+) male breast cancer patients.

METHODS

This retrospective study includes 65,711 ER+ early male (n = 611) and female (n = 65,100) breast cancer patients from the Surveillance, Epidemiology, and End Results (SEER) database diagnosed between 2010 and 2018. The main outcome measured was breast cancer-specific survival (BCSS) after 5 years of diagnosis. The CTS5 was calculated using their clinicopathological features.

RESULTS

Male breast cancer was more likely to be diagnosed later in life, with more aggressive biological features, and higher tumor burden comparing to female counterparts. More male patients were CTS5 intermediate- or high-risk than female patients (high 7.9% vs. 6.3%, intermediate 41.1% vs. 24.6%, P < .001). The 5-year BCSS rate was 89.1% (95% CI, 86.4%-91.8%) in the male patients and 93.5% (95% CI, 93.3%-93.7%) in the female patients. At median follow up of 77 months, in the male breast cancer patients without progression after 5 years of diagnosis, BCSS rate was significantly lower in the CTS5 high-risk group (HR 6.44; 95% CI, 1.54-26.97; P = .011) and intermediate-risk group (HR 5.61; 95% CI, 2.00-26.97; P = .001), when compared with the low-risk group.

CONCLUSIONS

Male breast cancer patients have distinct clinicopathological features and worse survival outcomes. The CTS5 could predict breast cancer recurrence beyond 5 years of diagnosis in ER+ male breast cancer patients, which may aid in personalized treatment decisions.