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Published on: February 12, 2017
Predictive value of Ki-67 expression in predicting pathological response to neoadjuvant chemotherapy combined with
Yongliang Niu1,2, Junguo Li3, Bowen Ding4
1Department of Respiratory and Critical Care Medicine, Second Affiliated Hospital of Anhui Medical University, Hefei, Anhui, China.
Background:
Neoadjuvant chemoimmunotherapy is standard for locally advanced lung squamous cell carcinoma (SCC), but reliable predictive biomarkers for pathological response are lacking. Ki-67 has shown promise in advanced disease, yet its role in the neoadjuvant setting remains undefined.
Methods:
We retrospectively analyzed 137 patients with stage IIIA-IIIB lung SCC who received neoadjuvant PD-1 inhibitors plus platinum-based chemotherapy followed by surgery (2022-2025). Major pathological response (MPR) and pathological complete response (pCR) were assessed per IASLC criteria and combined as MPR/pCR. Ki-67 expression was measured by immunohistochemistry (clone UMAB107). ROC curve, univariate and multivariate logistic regression were used to evaluate predictive performance.
Results:
MPR/pCR was achieved in 77/137 patients (56.2%). The optimal Ki-67 cutoff was 55% (AUC = 0.785, 95%CI: 0.707-0.862, P<0.001). High Ki-67 (≥55%) was associated with a significantly higher MPR/pCR rate than low Ki-67 (69.6% vs. 27.9%, P<0.001). In multivariate analysis, Ki-67 expression (adjusted OR per 1% increase =1.069, 95%CI: 1.043-1.096, P<0.001) and smoking status (adjusted OR = 5.405, 95%CI: 1.515-19.280, P = 0.009) were independent predictors of MPR/pCR. PD-L1 expression showed no significant association (P = 0.607).
Conclusions:
Pretreatment Ki-67 expression (optimal cutoff 55% in this cohort) is a robust independent predictor of pathological response to neoadjuvant chemoimmunotherapy in locally advanced lung SCC. Smoking status is also an independent predictor. Ki-67 assessment may help identify patients likely to benefit from neoadjuvant therapy, but prospective multi-center validation is required before routine clinical application.