Effect of primary radiotherapy on the survival rate of stage IVB cervical cancer patients and factors related to their survival: a real-world study based on SEER database

This study aimed to investigate the survival and influence factors of radiation therapy on primary tumors in patients with stage IVB cervical cancer. The data of 3129 stage IVB cervical cancer patients diagnosed from 2000 to 2018 in the Surveillance, Epidemiology and End Results (SEER) database were retrieved, and the propensity score matching (PSM) was used to balance variate and eliminate selection bias. The Kaplan-Meier (K-M) method was used to plot surviving profile. Univariate and multivariate analyses were used to estimate influencing factors of surviving time of stage IVB cervical cancer. After screening the SEER database, 3129 stage IVB cervical cancer patients were selected, including 2166 cases (69.2%) cases with and 963 without primary radiotherapy. PSM analysis identified 860 pairs of patients were one-to-one matched and further enrolled of radiotherapy part as well as non-radiotherapy part (control group) respectively for survival analysis. The K-M curve was compared among the two groups, and radiation therapy was found to be associated with longer survival before (Hazard ratio (HR) = 0.54,95% confidence interval (95% CI): 0.50-0.59, p < 0.001) and after (HR = 0.71, 95% CI: 0.64-0.79, p < 0.001) PSM. Multivariate Cox analysis confirmed that patients treated with radiotherapy, chemotherapy and local surgery had greater survival benefits, while high-grade tumor lesions, bone metastases, liver metastases and lung metastases were associated with significantly increased mortality. The survival rates varied among different races and were statistically different (p < 0.05). Conclusion: Primary radiotherapy could prolong the overall survival (OS) of stage IVB cervical cancer patients.