Predictors and Outcomes of 21-Gene Testing in Breast Cancer

Patients’ baseline characteristics were compared according to the receipt of the 21-gene testing using chi-square tests. Multiple logistic regression models were used to determine the predictive factors related to the use of RS testing and chemotherapy. A multicollinearity test was used to assess the data collected. The Kaplan–Meier method was used to assess differences in BCSS and OS and compared by the log-rank test. Multivariable Cox proportional hazards models were performed to determine independent prognostic factors impacting BCSS and OS. A 1:1 propensity score matching (PSM) was used to balance the potential confounders. Statistical analyses were conducted using the SPSS version 25.0. A P value less than 0.05 was considered statistically significant.