BACKGROUND:Currently, the proportion of standard chemotherapy for elderly patients is much lower than that for young patients, with little evidence from clinical trials supporting the use of chemotherapy for elderly patients. The effectiveness of chemotherapy for the elderly suffering from breast cancer remains to be further verified. METHODS:A total of 75,525 female breast cancer patients aged 70 years or older were hereby identified, all from the Surveillance, Epidemiology, and End Results (SEER) database from January 1, 2010 to December 31, 2016. Kaplan-Meier analysis and multivariable Cox proportional model were performed to evaluate the effectiveness of chemotherapy on overall survival (OS) and breast cancer-specific survival (BCSS). Propensity score matching (PSM) (PSM ratio: 1:1, caliper: 0.2 standard deviation of propensity score) was applied to construct balanced cohorts with or without chemotherapy based on demographic and pathophysiological characteristics. RESULTS:A total of 33,177 eligible patients were included, with 5273 (15.89%) receiving chemotherapy. Through PSM, 8360 patients were successfully matched, and balances between groups were almost reached. In the matched data set, multivariable Cox analysis reveals that chemotherapy was associated with a 36% and 21% risk reduction on OS (HR = 0.64, 95% CI 0.58 to 0.71) and BCSS (HR = 0.79, 95% CI 0.69 to 0.91), respectively. Furthermore, subgroups with more adjacent lymph nodes involved by tumor, or nonluminal A, were inclined to benefit more from chemotherapy. Moreover, chemotherapy did not increase the chances of dying from heart disease. CONCLUSIONS:The present study provided evidence that chemotherapy may improve the prognosis of elderly breast cancer, especially for those subpopulations that benefit more from chemotherapy treatment.

PURPOSE:The treatment of advanced gallbladder cancer (GBC) remains controversial. Therefore, the purpose of this study was to explore treatment choices for advanced GBC. METHODS:We identified four different treatments from the surveillance, epidemiology, and end results (SEER) database: surgery, chemotherapy (CT), surgery and chemotherapy (Surgery + CT), and no surgery/no chemotherapy (No surgery/No CT). Kaplan-Meier method and Cox proportional hazards regression method were used to determine the risk factors for overall survival (OS) and cancer-specific survival (CSS). In addition, patients in AJCC stages III and IV stage were matched with 1:1 propensity score matching (PSM) for diagnosis age, race, marital status, histological type, tumor grade, and treatment pattern to decrease the possibility of selection bias. RESULTS:A total of 288 AJCC stage III patients and 4239 AJCC stage IV patients with advanced GBC were identified from the SEER database between 2004 and 2015. Treatment pattern was an independent risk factor for patients with advanced GBC. For all patient, AJCC stage III patients and AJCC stage IV patients, "Surgery + CT" treatment minimized the OS and CSS in advanced GBC patients. In addition, after the PSM analysis, the "Surgery + CT" treatment still significantly decreased patient OS and CSS. CONCLUSIONS:"Surgery + CT" treatment can provide survival benefits for patients with advanced GBC. In addition, "Surgery + CT" treatment was not fully utilized and may further improve the survival rate of GBC patients.