%0 Journal Article
%T Effect of adjuvant radiotherapy on overall survival and breast cancer-specific survival of patients with malignant phyllodes tumor of the breast in different age groups: a retrospective observational study based on SEER.
%A Yang P
%A Zhang G
%A Zhang Y
%A Zhao W
%A Tang J
%A Zeng S
%A Lv X
%A Lv L
%J Radiat Oncol
%V 19
%N 1
%D 2024 May 21
%M 38773616
%F 4.309
%R 10.1186/s13014-024-02442-5
%X OBJECTIVE: Malignant phyllodes tumor of the breast (MPTB) is a rare type of breast cancer, with an incidence of less than 1%. The value of adjuvant radiotherapy (RT) for MPTB has been controversial. The aim of the study was to explore the effect of radiotherapy on the long-term survival of female patients with MPTB at different ages.
METHODS: Female MPTB patients were selected from the Surveillance, Epidemiology, and End Results (SEER) database between 2000 and 2020. A Kaplan-Meier survival analysis was conducted to investigate the value of RT for the long-term survival of MPTB patients in different age groups. Additionally, univariate and multivariate Cox regression analyses were performed for overall survival (OS) and breast cancer-specific survival (BCSS) of MPTB patients. Furthermore, propensity score matching (PSM) was also performed to balance the differences in baseline characteristics.
RESULTS: 2261 MPTB patients were included in this study, including 455 patients (20.12%) with RT and 1806 patients (79.88%) without RT. These patients were divided into four cohorts based on their ages: 18-45, 46-55, 56-65, and 65-80. Before adjustment, there was a statistically significant difference in long-term survival between RT-treated and non-RT-treated patients in the younger age groups (age group of 18-45 years: OS P = 0.019, BCSS P = 0.016; age group of 46-55 years: OS P < 0.001, BCSS P < 0.001). After PSM, no difference was found in long-term survival of patients in both younger and older groups regardless of whether they received RT (age group of 18-45 years: OS P = 0.473, BCSS P = 0.750; age group of 46-55 years: OS P = 0.380, BCSS P = 0.816, age group of 56-65 years: OS P = 0.484, BCSS P = 0.290; age group of 66-80 years: OS P = 0.997, BCSS P = 0.763). In multivariate COX regression analysis, RT did not affect long-term survival in patients with MPTB.
CONCLUSIONS: There is no evidence that long-term survival of MPTB patients in specific age groups can benefit from RT.