BackgroundThis study was conducted to explore programmed cell death‐ligand‐1 (PD‐L1) expression and fibroblast growth factor receptor 1 (FGFR1) amplification in stage IIIB/IV lung squamous cell carcinoma (SQC). Correlations between PD‐L1 and FGFR1, and with clinicopathological characteristics, efficacy of platinum‐based chemotherapy, and prognosis were analyzed.MethodsOne hundred and twenty‐eight consecutive stage III/IV SQC patients were enrolled in this study from 2009 to 2014. Seventy‐eight patients received platinum‐based chemotherapy. Immunohistochemistry was used to assess PD‐L1 expression and fluorescence in situ hybridization was applied to detect FGFR1 amplification.Results PD‐L1 expression was detected in 61.7% (79/128) of lung SQC patients. Smokers had significantly higher PD‐L1 expression rates than non‐smokers (66.1% vs. 44.0%, P = 0.042, respectively). The objective response and disease control rates for platinum‐based chemotherapy were not significantly different between PD‐L1 negative and positive patients (43.3% vs. 36.2%, P = 0.434; 80.0% vs. 78.7% P = 0.840, respectively); however, overall survival in PD‐L1‐negative patients was significantly longer than in PD‐L1‐positive patients (41.5 vs. 19.3 months, P = 0.001). Twenty‐five percent (32/128) of patients displayed FGFR1 amplification, with a lower rate in stage III patients compared to stage IV (17.1% vs. 36.5%, P = 0.013, respectively). There was no significant difference in FGFR1 amplification levels between overall response, disease control or overall survival rates. No correlation was observed between PD‐L1 expression and FGFR1 amplification (P = 0.916).Conclusion PD‐L1 expression may function as a prognostic factor in Chinese stage III/IV SQC patients. FGFR1 amplification is more prevalent in late stage SQC patients but does not predict chemotherapy response. There is no apparent correlation between PD‐L1 expression and FGFR1 amplification.

Objective: With the rapid development of cancer genomics and immunomics, some new treatments of small cell lung cancer (SCLC) are emerging. However, there are limitations to the clinical use of tumor tissue. Our study aimed to evaluate the potential use of bronchial washing fluid (BWF) in the liquid biopsy of SCLC.Methods: Twenty-one extensive SCLC (ES-SCLC) patients were enrolled in this study. For all patients, four sample types, BWF supernatant (BWFs), BWF precipitate (BWFp), plasma and tumor tissue, were collected before receiving chemotherapy, and one type, plasma, was collected after chemotherapy. All samples were conducted to NGS using the 1021-gene panel. The concordance rates of genomic profiling using NGS in the four types of samples were evaluated. Multiple clinical information was analyzed for correlation.Results: We successfully tested 20 BWFs samples, 21 BWFp samples, 21 tumor tissue samples, 20 pre-treatment plasma, and 13 post-treatment plasma of these 21 patients. The detectability of somatic mutations was 100% for BWFs, BWFp, tumor tissues, and post-treatment plasma, and only one pre-treatment plasma was absent with any mutation. Matched tumor tissue, BWFs, BWFp, and pre-treatment plasma samples were subsistent for 19 patients. For these patients, 204 genomic alterations were identified in tissue samples, while 189 (92.6%), 175 (85.5%), and 163 (79.9%) alterations were detected in the matched BWFs, BWFp, and pre-treatment plasma, respectively. Moreover, we found that the three tumor markers associated with SCLC have a lower sensitivity than genomic alterations. The endocrine resistance pathway was found enriched in hyponatremia patients which may be related to the hyponatremia. The TMBs of BWF, BWFp, and pre-treatment plasma samples all had a strong correlation with that of tissue samples. Both the VAF and the MVAF of mutations in post-treatment plasma were less than those in pre-treatment plasma, which was in accordance with the evaluation of curative effect.Conclusions: For ES-SCLC patients, the liquid biopsy of BWF showed a highly potential advantage to identify DNA alterations, which suggested that genomic analysis of BWF liquid biopsy may have clinical value as a supplement for tissue and blood detection. Through the restricted validation, it can be widely used in routine clinical practice.

e21098 Background: With the rapid development of cancer genomics, the precision medicine of small cell lung cancer (SCLC) is emerging. However, there are limitations to the clinical use of tumor tissue and peripheral blood biopsies. The main purpose of this study was to evaluate the potential use of bronchial washing fluid (BWF) in the liquid biopsy of SCLC. Methods: Twenty-one SCLC patients diagnosed in 2019 were enrolled in this study. BWF (separated as supernatant and precipitate), treatment-naive plasma and tumor tissue samples were collected from all of patients and subjected to next-generation sequencing (NGS) using a 1021-gene panel. The concordance rates of genomic profiling using NGS in these four types of samples were evaluated. Results: Of these 21 patients, 20 BWF supernatant (BWFs) samples, 21 BWF precipitate (BWFp) samples, 21 tumor tissue samples and 20 plasma samples were successfully tested. The detectability of somatic mutations was 100% for BWFs, BWFp and tumor tissues, and only one plasma was absent with any mutation. Matched tumor tissue, BWFs, BWFp and plasma samples were subsistent for 19 patients. For these patients, 204 genomic alterations were identified in tissue samples, of which 189 (92.6%), 175 (85.5%) and 163 (79.9%) alterations were detected in the matched BWFs, BWFp and plasma samples, respectively. Moreover, tumor mutation burden (TMB) was also calculated. Compared with the proportion of TMB-H samples in tissue samples counting 61.9% (13/21), 60% (12/20) of BWFs samples and 52.38 % (11/21) of BWFp samples were TMB-H (defined as more than or equal to 9 mutations per megabase), which was a molecular biomarker that can be used in immunotherapy efficacy prediction. The TMBs of BWFs, BWFp and treatment-naive plasma samples all had strong correlation with that of tissue samples. The TMB of BWFs had the strongest correlation (Pearson r = 0.9512, p < 0.0001), and the TMB of treatment-naive plasma had relatively lower correlation (Pearson r = 0.8782, p < 0.0001) compared with those of BWFs (Pearson r = 0.936, p < 0.0001) and BWFp (Pearson r = 0.8782, p < 0.0001). Conclusions: For SCLC patients, the liquid biopsy of BWF showed high potential to identify DNA alterations and calculate TMB grades, which suggested that genomic analysis of BWF liquid biopsy may have clinical value in predicting the effectiveness of targeted therapy and immunotherapy. It can be widely used in routine clinical practice.

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The X-ray repair cross-complementation group 1 (XRCC1) protein plays an important role in base excision repair, and the genetic polymorphisms in the XRCC1 gene influence its function. XRCC1 codon 280 polymorphism is an Arg-His change in the XRCC1 gene. Many studies were published to investigate the association between XRCC1 codon 280 polymorphism and risk of lung cancer, but the results were inconsistent. We performed a meta-analysis of 16 studies with a total of 18,660 subjects (8,736 cases and 9,924 controls). The pooled odds ratios (OR) and corresponding 95 % confidence intervals (95 % CI) for the gene-disease association were calculated. Overall, there was a significant association between XRCC1 codon 280 polymorphism and increased risk of lung cancer (HisHis vs. ArgArg: OR = 1.53, 95 % CI 1.08-2.16, P = 0.016; HisHis vs. ArgArg/ArgHis: OR = 1.55, 95 % CI 1.10-2.19, P = 0.012). However, subgroup analysis by race failed to confirm the obvious association in Europeans and Asians. Therefore, there is a significant association between XRCC1 codon 280 polymorphism and increased risk of lung cancer. More studies with a large sample are needed to further evaluate the possible race-specific effect in the association above.