Prognostic Factors in Postoperative Radiotherapy

The variables of patient demographic, clinicopathological, and treatment variables, were compared using the chi-squared test or Fisher's exact test upon receipt of postoperative RT. To reduce the potential confounding of retrospective studies, a 1:1 match including the variables mentioned above was conducted using propensity score matching (PSM) to create matched cohorts (17 , 18 (link)). BCSS curves were plotted using the Kaplan–Meier method and then compared with the log-rank test. Multivariate Cox proportional hazards models with the backward Wald method were used to assess the independent prognostic indicators related to BCSS. The hazard ratios (HRs) and their corresponding 95% confidence intervals (CIs) were calculated. Statistical analyses were carried out using SPSS 22.0 (IBM, Armonk, NY, USA). P < 0.05 was considered statistically significant.