Analysis of circulating tumor DNA (ctDNA) is emerging as a powerful tool for guiding targeted therapy and monitoring tumor evolution in patients with non-small cell lung cancer (NSCLC), especially when representative tissue biopsies are not available. Here, we have compared the ability of four leading technology platforms to detect epidermal growth factor receptor (EGFR) mutations (L858R, exon 19 deletion, T790M and G719X) in ctDNA from NSCLC patients. Two amplification refractory mutation systems (cobas-ARMS and ADx-ARMS), a droplet digital polymerase chain reaction (ddPCR) and a next-generation sequencing (Firefly NGS) platform were included in the comparison. Fifteen EGFR mutations across twenty NSCLC patients were identified. Firefly NGS, cobas-ARMS and ddPCR all displayed superior sensitivity while ADx-ARMS was better suited for the qualitative detection of EGFR mutations with allele frequency higher than 1% in plasma and tissue samples. We observed high coincidence between the plasma and tissue EGFR mutational profiles for three driver mutations (L858R, exon 19 deletion and G719X) that are known targets of first generation EGFR-TKI therapies among patients who relapsed. Discrepancies between tissue and plasma EGFR mutational profiles were mainly attributable to spatial and temporal tumor heterogeneity, mutation inhibition due to therapy response and drug resistance (T790M). This study illustrates the challenges associated with selection of a technology platform for EGFR ctDNA analysis in the context of treatment evaluation and drug resistance detection.

PURPOSE: Neoadjuvant immune checkpoint blockade with nivolumab plus ipilimumab improves overall survival (OS) in non–small cell lung cancer (NSCLC); however, randomized data for resectable lung cancer are limited. We report results from the exploratory concurrently randomized nivolumab plus ipilimumab and chemotherapy arms of the international phase III CheckMate 816 trial. METHODS: Adults with stage IB-IIIA (American Joint Committee on Cancer seventh edition) resectable NSCLC received three cycles of nivolumab once every 2 weeks plus one cycle of ipilimumab or three cycles of chemotherapy (on day 1 or days 1 and 8 of each 3-week cycle) followed by surgery. Analyses included event-free survival (EFS), OS, pathologic response, surgical outcomes, biomarker analyses, and safety. RESULTS: A total of 221 patients were concurrently randomly assigned to nivolumab plus ipilimumab (n = 113) or chemotherapy (n = 108). At a median follow-up of 49.2 months, the median EFS was 54.8 months (95% CI, 24.4 to not reached [NR]) with nivolumab plus ipilimumab versus 20.9 months (95% CI, 14.2 to NR) with chemotherapy (HR, 0.77 [95% CI, 0.51 to 1.15]); 3-year EFS rates were 56% versus 44%. Higher rates of EFS events were initially seen, with later benefit favoring nivolumab plus ipilimumab; 3-year OS rates were 73% versus 61% (HR, 0.73 [95% CI, 0.47 to 1.14]); pathologic complete response rates were 20.4% versus 4.6%, respectively. In the respective arms, 83 (74%) and 82 patients (76%) underwent definitive surgery. Grade 3-4 treatment-related adverse events occurred in 14% and 36% of patients, respectively. CONCLUSION: Neoadjuvant nivolumab plus ipilimumab showed potential long-term clinical benefit versus chemotherapy, despite early crossing of EFS curves in the preoperative phase and a lower rate of high-grade toxicity.

Purpose:HOX genes are vital for all aspects of mammalian growth and differentiation, and recent data have shown that their deregulated expression is related to carcinogenesis. To date, there has been no systemic study on expression of HOX genes in esophageal carcinoma. We investigated the expression pattern of 39 known HOX genes in cancerous and noncancerous tissue from 36 patients with esophageal squamous cell carcinoma to determine whether their expression is altered in esophageal cancer. Experimental Design: Thirty-six patients with resectable esophageal squamous cell carcinoma (ESCC) were enrolled in this study. Specific primers were designed for each of 39 HOX genes, and reverse transcription-PCR was done in cancerous and noncancerous samples of these 36 patients. Furthermore, the expression of HOXA9 protein was subjected to Western blot analysis in all 36 paired tissue samples. Results: Eight of 39 HOX genes were expressed in cancerous but not in noncancerous tissue. Five of 39 HOX genes were expressed both in cancerous and noncancerous tissue. Of the latter, expression of HOXA7, HOXA9, and HOXC6 was significantly higher in cancerous tissue (P < 0.05). The remaining 26 HOX genes were not detected in either types of tissue. HOXA9 protein was expressed in both kinds of tissue (cancer tissue versus noncancerous mucosa: 0.34 ± 0.32 versus 0.24 ± 0.27, P = 0.121). Conclusions: This is the first comprehensive survey of 39 HOX gene expression in ESCC and noncancerous mucosa. Five of the 39 HOX genes were expressed in both types of tissue indicating their possible role in maintaining normal structure and function of adult esophageal mucosa. Eleven of the 39 HOX genes were deregulated in cancer tissue. These genes possibly participate in the carcinogenesis of ESCC.