Stromal PDGFR-β Expression is Associated with Postoperative Survival of Non-Small Cell Lung Cancer Patients Receiving Preoperative Chemo- or Chemoradiotherapy Followed by Surgery.

BACKGROUND: PDGFR-β is used as a stromal biomarker and is functional in mesenchymal cells of the tumor microenvironment. The significance of stromal PDGFR-β expression in non-small cell lung cancer (NSCLC) in patients undergoing preoperative chemo- or chemoradiotherapy had not been determined.

METHODS: Patients with NSCLC undergoing preoperative chemo- or chemoradiotherapy between 1996 and 2014 were assessed for expression of stromal PDGFR-β by immunohistochemistry using resected specimens. Relationships between stromal PDGFR-β expression and survival after operation were analyzed. Forty-three patients who underwent surgery without preoperative treatment in 2005 were also analyzed as a chemo-naïve control group.

RESULTS: The mean age of the 92 patients was 60.2 years. Seventy-eight (85%) were male, and 14 (15%) were female. Fifty-four patients (59%) underwent preoperative chemoradiotherapy, and 38 patients (41%) underwent preoperative chemotherapy. Regimens for preoperative chemotherapy were cisplatin (CDDP) based in 48 patients (52%) and carboplatin (CBDCA) based in 43 (42%). While stromal cells expressed PDGFR-β in 21 chemo-naïve patients (49%), stromal cells expressed PDGFR-β in 65 patients who underwent preoperative therapy (p = 0.02). The 5-year disease-free survival rate (DFS) of the PDGFR-β-positive group was significantly worse than that of the negative group (27 vs. 48%, p = 0.04). The 5-year disease-specific survival rate (DSS) in the stromal PDGFR-β-positive group was also significantly worse than in the negative group (43 vs. 70%, p = 0.01). On the other hand, stromal PDGFR-β expression did not influence survival in chemo-naïve patients.

CONCLUSIONS: Stromal PDGFR-β expression is negatively associated with DFS and DSS in patients with NSCLC undergoing preoperative chemo- or chemoradiotherapy.