RESUMO
Objective:To analyze the differences of clinicopathological features and prognosis between secretory breast carcinoma (SBC) and invasive ductal carcinoma (IDC), and to explore the influence of SBC on the prognosis of breast cancer.Methods:We retrieved data of patients diagnosed with SBC and IDC from The National Cancer Institute′s Surveillance, Epidemiology, and End Results (SEER) database between 1990 and 2016. 109 cases of SBC (SBC group) and 558 814 cases of IDC (IDC group) were collected. The clinicopathological features were compared between SBC and IDC groups. The tendency score matching method was used to match the balance confounding factors according to 1∶4 proportion. The breast cancer-specific survival time (BCSS) and overall survival time (OS) of the two histological types of breast cancer before and after matching were analyzed. The survival curve was drawn using the Kaplan-Meier method and compared with the log-rank test. Univariate and multivariate Cox regression analysis was used to determine the independent prognostic factors of breast cancer.Results:There were significant difference in diagnostic age, marital status, sex, histological grade, American Joint Committee on Cancer (AJCC) N stage, estrogen receptor (ER) and progesterone receptor (PR) expression between SBC and IDC group (all P<0.05). The BCSS of SBC group was similar to IDC group, and OS was better than IDC ( P<0.05). Univariate and multivariate regression analysis showed that diagnostic age, race, marriage, sex, location, histological grade, AJCC stage, treatment mode and ER, PR expression were all related factors affecting BCSS and OS (all P<0.05). SBC was an independent prognostic factor for OS ( P<0.05). After propensity score matching according to 1∶4, there was no significant difference in BCSS and OS between the two groups ( P<0.05). Cox regression analysis showed that AJCC T stage and PR negative expression were the influencing factors of BCSS (all P<0.05), and diagnostic age and AJCC T stage were the influencing factors of OS (all P<0.05). SBC was no longer an influencing factor of OS in breast cancer. Conclusions:There was no significant difference in prognosis between SBC and IDC. SBC was not an independent risk factor for breast cancer.
