Sex-Based Heterogeneity in the Clinicopathological Characteristics and Prognosis of Breast Cancer: A Population-Based Analysis

Abstract

PurposeTo better understand the differences in clinicopathological features and prognosis between male breast cancer (MBC) and female breast cancer (FBC).Material and MethodsData on patients diagnosed with breast cancer from January 1, 2010, to December 31, 2016, were obtained from the Surveillance, Epidemiology, and End Results database. Selected patients were classified into MBC and FBC, of which population demographics and clinicopathological features at baseline were successively extracted for analysis. Comparative analysis was performed to explore the differences in baseline characteristics, followed by propensity-score matching to calibrate the objective distinctions for adjusted analysis. Survival analysis was carried out to investigate divergences presented in prognosis from the two cohorts, and risk factors for prognosis were successively identified using univariate and multivariate COX regression analyses.ResultsA total of 407341 individuals were eligible, including 3111 MBC (0.7%) and 404230 FBC (99.3%) patients. Comparatively, patients with MBC tended to be older at diagnosis, with a higher confirmation of ductal carcinoma, a higher histological grade, a higher TNM stage, a higher proportion of luminal-like subtype, a higher rate of lung metastasis, a lower incidence of liver involvement, and a lower rate of surgical, radiation, and chemotherapeutic delivery. The overall prognosis of MBC was significantly worse than that of FBC, with a decreasing divergence both in median overall survival (65.5 months vs. 72.7 months, P<0.0001) and median breast cancer-specific survival (75.4 months vs. 77.8 months, P<0.0001). However, these discrepancies were not consistent among patients from different subgroups stratified by molecular subtype, age at diagnosis, or disease stage.ConclusionIn this study, sex-based heterogeneity in clinicopathological characteristics and prognostic profiles was observed in the overall population of patients with breast cancer and was significantly variable among different subgroups. A male-specific design with reasonable endpoints for a clinical trial protocol will be warranted in the future.

Analysis of the distinct features of metastasis male breast cancer and its effect on overall survival based on the SEER database compared with female breast cancer

“…This current study compared the distant metastases of MBC and FBC patients and found that the rates of bone, lung, liver, and brain metastases in patients with metastatic MBC were 40.3%, 6.7%, 9.7%, and 13.4% respectively, while for FBC, they were 41.8%, 4.0%, 11.2%, and 15.7%, respectively (P>0.05). In MBC, bone was the most common site of metastasis, and the brain the least common; both findings are consistent with previous studies ( 21 , 22 ). In MBC, although the incidence of isolated brain metastasis was only 6.7%, brain combined with other sites of organ metastases accounted for 11.9%.…”

Role of sex in liver tumor occurrence and clinical outcomes: A comprehensive review

“…[199,[201][202][203][204] In one study, the rate of LM of breast cancer was significantly lower in males than in females (10.5% vs. 24.5%). [205] Regardless, breast cancer survival is significantly worse in men than in women regardless of the age at diagnosis, race, marital status, disease stage, lymph node and ER involvement, grade, geographic region, and surgery type. [206] CONCLUSIONS AND FUTURE DIRECTIONS Sex differences in the incidence, prevalence, clinical outcomes, and treatment response of many liver tumors have been reported.…”

“…The role of sex in the development of LM is rarely analyzed in breast cancer studies because of the low prevalence of this cancer in males 199,201–204 . In one study, the rate of LM of breast cancer was significantly lower in males than in females (10.5% vs. 24.5%) 205 . Regardless, breast cancer survival is significantly worse in men than in women regardless of the age at diagnosis, race, marital status, disease stage, lymph node and ER involvement, grade, geographic region, and surgery type 206 …”