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

Objective Due to the poor prognosis of stage ⅣB cervical cancer,the main purpose of treatment is to prolong survival and improve quality of life.The main therapeutic methods are systemic chemotherapy and palliative therapy.At present,there are few studies on the effect of radiotherapy on the primary lesion and related factors affecting prognosis.This study aimed to investigate the survival and influence factors of radiation therapy on primary tumors in patients with stage ⅣB cervical cancer.Methods All statistical analyses in our study were performed by R software and SPSS22.0.The data of 6230 stage IVB cervical cancer patients diagnosed from 2000 to2018 in the Surveillance,Epidemiology and End Results(SEER)database were retrieved,After excluding related unknown factors,3129 patients with stage ⅣB cervical cancer were selected for analysis.The matching ratio of propensity score was set as 1:1 with the nearest neighbor matching method,and the propensity score matching(PSM)was used to balance variate and eliminate selection bias.Kaplan-Meier method was used for survival analysis,and log-rank test was used for statistical comparison of survival curves.Univariate and multivariate analyses were performed on the data before and after PSM using Cox proportional hazard model to determine independent prognostic factors and to plot forest maps.It was considered that p<0.05 was statistically significant,therefore,to estimate the factors influencing the survival time of stage IV b cervical cancer.Results 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.p<0.001 was statistically significant.After PSM,the 5-year survival rates were 4.0% and 9.2% in the untreated and radiotherapy groups,respectively.Cox regression analysis of forest chart showed that stage ⅣB cervical cancer had survival benefits for primary radiotherapy,chemotherapy and local surgery,while high-grade lesions,bone metastases,liver metastases and lung metastases significantly increased mortality.Different races showed different survival rates.Compared with rural patients,urban patients had higher OS.P<0.05,there was statistical significance.Conclusion Primary radiotherapy could prolong the overall survival(OS)of stage IVB cervical cancer patients.In this study,chemotherapy,surgical treatment,high-grade tumor lesions,bone metastases,liver metastases,lung metastases,race,and place of residence were all related factors affecting the survival rate of patients with stage IVB cervical cancer.