The positive threshold of the immunohistochemical parameter Ki67 for predicting the recurrence of cervical cancer

Objective To find the optimal threshold of Ki67 and evaluate its significance in predicting recurrence of stage I-II cervical cancer. Methods A total of 1130 patients were included after screening. Univariate and multivariate Cox regression analysis were used to select factors associated with recurrence of cervical cancer. The receiver operating characteristic (ROC) curve was used to assess the optimal threshold of Ki67. The differences of clinicopathological parameters and the survival analysis between the two groups divided based on the optimal threshold of Ki67 were compared. Results Multivariate Cox regression analysis showed that Ki67 (p < 0.001) was significant prognostic predictor for recurrence of cervical cancer. The optimal threshold of Ki67 was 42%. The recurrence-free survival (RFS) and the overall survival (OS) of cervical cancer patients in the high-Ki67 group (Ki67 >= 42%) were much lower than those in the low-Ki67 group (Ki67<42%) (p < 0.001, p < 0.001). Among the 380 patients with low-risk cervical cancer, the RFS and OS of patients in the high-Ki67 group were also lower than those in the low-Ki67 group (p < 0.001, p < 0.001). Conclusion The Ki67 was a useful prognostic factor in patients with stage I-II cervical cancer, and the Ki67 labeling index 42.0% was optimal threshold for predicting recurrence.