Effect Of Radiation Therapy On Early Stage Breast Cancer In Elderly Women

Object:The ageing of the population had intensified and the incidence of breast cancer in the elderly had increased year by year.However,the best treatment for elderly breast cancer was not yet clear.Randomized clinical trials had shown that adjuvant radiotherapy could reduce local recurrence but had no survival benefit in early-stage(T1 or tumor<3cm)breast cancer patients with good clinical characteristics.For the controversy over adjuvant radiotherapy,a large sample retrospective study was conducted to investigate the effect of radiotherapy on prognosis in elderly patients with breast cancer.Method:Data from the US Surveillance Epidemiology and End Result(SEER)database were collected and retrospectively analyzed among women aged 66-80 years diagnosed as T1/T2N0M0 breast cancer which were diagnosed between 2010 and 2012.Population characteristics,clinicopathology and treatment information were grouped by radiotherapy and non-radiotherapy.SPSS software was used to analyze the distribution and survival of the groups.Results:The chi-square test showed whether adjuvant radiotherapy was associated with patient age,race,histological grade,T stage,surgery,and radiotherapy(p<0.001),regardless of the primary tumor location(left or right)(p = 0.102).The overall survival(OS)and breast cancer-specific survival(BCSS)in the radiotherapy group were better than those in the non-radiotherapy group(p<0.001),but the average survival time was not significantly different.Cox univariate regression analysis showed that advanced age(76-80 years)(p<0.001),T2(p<0.001),non-radiotherapy(p<0.001),and total breast resection(p = 0.011)were independent risk factors.Subgroup analysis showed that in all T-stage subgroups of patients undergoing breast-conserving surgery,the radiotherapy group had a better prognosis.There was little difference in survival in the T1a,T1b,and T1c subgroups.The mean OS of T2 stage breast-advancing patients in the radiotherapy group was 45.48 months[95%confidence interval(CI)44.91-46.05].In non-radiotherapy group,OS was 41.88 months in the group(95%CI 40.29-43.49).Cox multivariate regression.showed that the hazard ratio(HR)of radiotherapy group compared with non-radiotherapy group was 0.327(95%CI 0.194-0.553,p<0.001).Conclusion:In elderly patients with early-stage breast cancer,adjuvant radiotherapy after breast-conserving surgery could achieve survival benefits.Among them,radiotherapy brought little survival benefits of T1 stage patients,but improved the survival of T2 patients significantly.Therefore,we should be cautious about whether adjuvant radiotherapy can be ignored in T2 elderly breast cancer patients.