Heat shock protein 70 as a predictive marker for platinum-based adjuvant chemotherapy in patients with resected non-small cell lung cancer

Abstract

Objectives: Although adjuvant platinum-based chemotherapy improves survival in completely resected non-small cell lung cancer (NSCLC), its effect is limited. We evaluated whether the expression of heat shock protein 70 (Hsp70) is associated with clinical outcomes in patients with completely resected NSCLC who were treated with or without adjuvant platinum-based chemotherapy.

Patients and methods: Patients who underwent curative resection for NSCLC and diagnosed as stage IIA through IIIA were included. Immunohistochemical staining for Hsp70 was performed on surgical specimens and survival rates were compared by Hsp70 expression and adjuvant platinum-based chemotherapy.

Results: Of 327 enrolled patients, Hsp70 expression was positive in 220 (67.3%). For patients who did not receive adjuvant chemotherapy, Hsp70 expression did not significantly affect survival. However, for patients who received adjuvant chemotherapy, those with Hsp70-positive tumors had a longer disease-free survival outcome than cases with Hsp70-negative tumors (not reached vs. 27.3 months; P=0.002), although there was no significant difference in overall survival (97.0 vs. 58.9 months, P=0.080). In the adjuvant chemotherapy group, multivariate modeling showed that patients with Hsp70-postitive tumors had a lower risk of recurrence and death after adjusting for age, sex, performance status, pathologic stage, and histological type (disease-free survival: adjusted hazard ratio, 0.537; 95% CI, 0.362-0.796; P=0.002; overall survival: adjusted hazard ratio, 0.663; 95% CI, 0.419-1.051; P=0.080).

Conclusion: Hsp70 is a positive predictive factor in completely resected NSCLC with received platinum-based adjuvant chemotherapy.

Keywords: Adjuvant chemotherapy; Biologic markers; Heat shock protein 70; Non-small cell lung cancer; Survival analysis; Treatment outcome.