Abstract 6458: Adverse recurrence prognostic implications of tumor CD47 expression in resected non-small cell lung cancer
Authors: Xu Yan , Li Ji , Tong Bing , Wang Shuang , Zhong Wei , Chen Minjiang , Zhao Jing , Wang Mengzhao 
Published: September 2020

Background: Immunotherapy is one of the most promising advances in the field of oncology. However, limited information exists regarding characterization of the tumor associated macrophages (TAMs) related immune microenvironment in patients with non-small cell lung cancer(NSCLC), by which it may possible to predict the efficacy of novel immunotherapies.

Method: 191 resected NSCLC specimens were retrospectively studied for the CD47 expression & PD-L1 expression which were examined using immunohistochemistry (IHC). The infiltration of macrophages (M2-macrophages & M1-macrophages) and CD8+T-lymphocytes were evaluated using dual-IF staining. 46 cases of pulmonary infectious diseases were used as the control group. Targeted sequencing was performed on all 191 specimens using NovoSeq 6000 system. Bioinformatics analysis including somatic variant detection and statistical analysis were subsequently carried out. Finally, the pattern of immune infiltrates was depicted and their prognostic role of was assessed.

Results: Using IHC 2/3+ as cutoff, the prevalence of CD47 positive (CD47pos) expression in NSCLC was 33.0% (63/191), significantly higher than that in non-tumor lung tissues (17.4%, 8/46, Chi-squared test p-val=0.038). CD47pos expression was significantly higher in female, non-smoking, and adenocarcinoma (LUAD) patients (p-val=0.020, p-val&lt;0.001, and p-val&lt;0.001, respectively). With somatic mutations integrated, CD47pos expression significantly correlates with EGFR mutation (p-val&lt;0.001). When patients were stratified by LUAD and squamous cell carcinoma (LUSC), statistical correlation between EGRE mutation and CD47pos expression remains in LUAD (adjusted p-val=0.002) and LUSC patients group (adjusted p-val=0.0499). The expression of CD47 (H-score) in NSCLC was negatively correlated with both tumor PD-L1 expression (tumor proportion score, TPS) (p-val=0.0346) and tumor mutation burden (TMB) (p-val=0.0107). CD47pos expression independently correlates with worse disease free survival (DFS) for NSCLC patients in multivariate Cox regression (p-val=0.035). When CD47 and M2 were combined as combinatorial biomarkers, four groups of patients can be significantly separated with negative

CD47(CD47neg) expression / absence of M2 in tumor area being best DFS and CD47pos expression / M2 in tumor area being worst DFS. To link the pattern of immune infiltrates with patient better DFS, we performed an unsupervised clustering using major immune components (CD47, PD-L1, CD8, M1 and M2). 191 patients were clustered into three groups and patient's DFS of each group was significantly differentiated (Log-rank p-val=0.041). Briefly, the group of patients with worst DFS is characterized with high infiltration of M1 and M2 in tumor area.

Conclusions: To the best of our knowledge, this is the first study that extensively investigated the major immune modulators along with their association with genotype in NSCLC cohort. We elucidated the demographic characteristics, molecular characteristics, and immuno-microenvironment characteristics of CD47 expression in NSCLC. We further identified the tumor CD47pos expression as an independent adverse recurrence prognostic factor in NSCLC. Our study illustrates the idea of ‘precision medicine' by stratification of patients based on immuno-microenvironment characteristics.

Citation Format: Yan Xu, Ji Li, Bing Tong, Shuang Wang, Wei Zhong, Minjiang Chen, Jing Zhao, Mengzhao Wang. Adverse recurrence prognostic implications of tumor CD47 expression in resected non-small cell lung cancer [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 6458.