Abstract 2556: The predictive role of tumor-associated macrophages in stage IIIA pN2 non-small cell lung cancer after neoadjuvant chemotherapy and surgery

Abstract

Abstract Introduction: Neoadjuvant chemotherapy improves survival in patients with pN2 stage IIIA non-small cell lung cancer (NSCLC). However, the majority relapse eventually even with mediastinal downstaging. Our study investigated the predictive role of tumor-associate macrophages (TAMs) in these patients. Methods: Between 2005 and 2008, twenty-two pN2 stage IIIA NSCLC patients underwent cisplatin/docetaxel neoadjuvant chemotherapy and surgery were retrospectively enrolled. Immunohistochemical staining of CD68 was used to identify macrophages in stored tissues. Results: The objective response rate was 68%, overall median disease-free survival (DFS) was 13.1 months (95% CI 6.1-20.2 months) and median overall survival (OS) 48.0 months (95% CI 24.0-72.1 months). Multiple Cox regression analysis showed mediastinal downstaging to pN0 (HR=0.039, 95% CI 0.004-0.349, p=0.004) and high total macrophage numbers (HR=1.01, 95% CI 1.002-1.017, p=0.012) were independent factors for DFS. In the 16 patients downstaged to pN0, those with low total macrophage numbers had longer DFS (median 33.4 months), compared with those with high numbers (13.4 months, p=0.037). Conclusions: Low total macrophage numbers were also an independent factor for better DFS in pN2 stage IIIA NSCLC patients receiving neoadjuvant chemotherapy and surgical resection, which association was kept in patients downstaged to pN0. Further prospective study is warranted to confirm the predictive role of TAM in these patients. Citation Format: Po-Hao Feng, Chih-Teng Yu, Chin-Yang Wu, Tzung-Hai Yen, Kang-Yun Lee. The predictive role of tumor-associated macrophages in stage IIIA pN2 non-small cell lung cancer after neoadjuvant chemotherapy and surgery. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 2556. doi:10.1158/1538-7445.AM2014-2556