Cell-free DNA methylation profile potential in the diagnosis of lung squamous cell carcinoma.

Background: Aberrant methylation plays an essential role in early cancer development. In this study, we investigated methylation patterns in lung squamous cell carcinoma (LUSC) and matched non-tumor tissue and plasma samples to evaluate the potential of these patterns in the diagnosis of LUSC. Methods: The study group included 49 patients with stage I-III LUSC. We collected resected tumor tissue, paired peritumoral tissue, distant normal tissue, and corresponding plasma samples. A bespoke lung cancer bisulfite sequencing panel was used to profile the methylation level. Another 48 healthy volunteers provided control plasma samples. Results: Peritumoral and distant normal tissues presented similar methylation signatures, distinct from those in tumor tissue samples. A comparison of methylation profiles led to the identification of 871 tumor-specific differentially methylated blocks, including 847 hypermethylated and 24 hypomethylated blocks (adjusted P value <0.05). All top-ranked blocks were tumor-related. Tissue samples were analyzed for field cancerization to identify progressively aggravating aberrant methylations during tumor initiation and development. The analysis revealed that 221 blocks presented a stepwise increase in methylation levels, while seven blocks presented a stepwise decrease in methylation pattern as the sampling drew nearer to the tumor. The malignant contaminated ratio (MCR) confirmed the presence of distinct methylation patterns between tumor and peritumoral tissue samples. We then constructed a diagnostic panel using a combined diagnostic score of cell-free DNA (cfDNA) that showed high sensitivity and specificity. The healthy controls had a significantly lower combined diagnostic score (cd-score) than LUSC patients. Additionally, based on the methylation profiles, LUSC could be classified into two subgroups, C1 and C2. The methylation profile of the C2 group was not distinct from the healthy controls, which had a significantly lower cd-score than did the C1 group. Conclusions: LUSC-specific methylation patterns could potentially discriminate between peritumoral tissue, distant normal tumor tissue, and tumor tissues. This preliminary study also supported the potential utility of cfDNA methylation analysis in diagnosing LUSC.

Neo-adjuvant chemotherapy plus immunotherapy in resectable N1/N2 NSCLC.

BACKGROUND: Locally advanced non-small cell lung cancer (NSCLC) with N1/N2 lymph node metastasis is challenging with poor survival. Neo-adjuvant chemo-immunotherapy has gained benefits in a proportion of these patients. However no specific biomarker has been proved to predict the effect before therapy. In addition, the relationship of nodal status and survival after neo-adjuvant chemo-immunotherapy is still not well stated. METHODS: A total of 75 resectable NSCLC patients with N1/N2 stage who received neo-adjuvant chemo-immunotherapy plus surgery were retrospectively studied. The clinical characteristics, surgical information and safety parameters were collected. The correlations of major pathological response (MPR) and pathological complete response (pCR) with clinical data were analyzed. The progression free disease(PFS) and overall survival(OS) were evaluated with pathological response and nodal status. RESULTS: Of the 75 patients, 69 (92%) patients experienced treatment related adverse effects, while grade 3-4 adverse effects occurred in 8 (10%) patients. All the patients received surgical R0 resection with a MPR rate of 60% and a pCR rate of 36%. 67% of N1 patients and 77% of N2 patients had nodal clearance after neo-adjuvant treatment. A significant difference was observed between pathological response with age, histology and multiple lymph node metastasis. The PFS was better in the MPR cohort. The PFS was 90.1% and 83.6% at the nodal clearance group at the time of 12 and 18 months, compared with 70.1% and 63.7% at the nodal residual group. CONCLUSIONS: The neo-adjuvant chemo-immunotherapy for locally advanced NSCLC with nodal positive was safe and feasible. The patients with elder age and squamous-cell carcinoma (SCC) were more likely to have better pathological response, while multiple nodal metastasis was a negative predictor. The clearance of lymph node resulted in significantly longer PFS and OS.

Long-Term Outcomes of Selected Patients with IIIA-N2 Non-small Cell Lung Cancer Receiving Upfront Surgical Resection.

BACKGROUND: Stage IIIA non-small cell lung cancer (NSCLC) is a diverse group that requires multimodality treatment. The aim of this study was to report the long-term outcomes for patients with IIIA-N2 disease. METHODS: We conducted a retrospective review of cases with IIIA-N2 (T1-2N2) NSCLC who underwent upfront surgery. Kaplan-Meier curves and Cox proportional hazard analyses were used to assess the impact of various variables on survival. RESULTS: A total of 475 patients were ultimately included. With a median follow-up time of 108 months, the 5- and 10-year overall survival (OS) rates were 42.2% and 27.7%, respectively. R0 resection was found to be associated with improved progression-free survival (PFS) and OS compared with R1/R2 resection (p = 0.041 for PFS; p = 0.015 for OS). Patients with single-station N2 disease demonstrated significantly better PFS and OS than those with multiple-station N2 disease (p < 0.001 for PFS; p = 0.002 for OS). Following surgical resection, adjuvant therapy was significantly correlated with prolonged PFS and OS compared with those patients without any treatment. However, there was no significant difference in PFS and OS between chemotherapy and radiochemotherapy (p = 0.915 for PFS; p = 0.287 for OS). Patients with EGFR exon 19 deletion had significantly improved OS compared with those with L858R (p = 0.040). CONCLUSIONS: Our study shows promising long-term outcomes for selected patients with stage IIIA-N2 NSCLC treated with upfront surgery followed by adjuvant therapy, especially those with R0 resection and single-station N2. This study sheds light on the potential management and treatment options for this challenging population.