Detection of oncogenic mutations in resected bronchial margins by next-generation sequencing indicates early relapse in stage IA lung adenocarcinoma patients

Recurrence/prognosis estimation using a molecularly positive surgical margin-based model calls for alternative curative strategies in pIIIA/N2 NSCLC

Stage pIIIA/N2 non-small cell lung cancer (NSCLC) is primarily treated by complete surgical resection combined with neoadjuvant/adjuvant therapies. However, up to 40% of patients experience tumor recurrence. Here, we studied 119 stage pIIIA/N2 NSCLC patients who received complete surgery plus adjuvant chemotherapy (CT) or chemoradiotherapy (CRT). The paired tumor and resection margin samples were analyzed using next-generation sequencing (NGS). Although all patients were classified as negative resection margins by histologic methods, NGS revealed that 47.1% of them had molecularly positive surgical margins. Patients who tested positive for NGS-detected residual tumors had significantly shorter disease-free survival (DFS) (P = 0.002). Additionally, metastatic lymph node ratio, erb-b2 receptor tyrosine kinase 2 (ERBB2) mutations, and SWI/SNF-related, matrix-associated, actin-dependent regulator of chromatin, subfamily a, member 4 (SMARCA4) mutations were also independently associated with DFS. We used these four features to construct a COX model that could effectively estimate recurrence risk and prognosis. Notably, mutational profiling through broad-panel NGS could more sensitively detect residual tumors than the conventional histologic methods. Adjuvant CT and adjuvant CRT exhibited no significant difference in eliminating locoregional recurrence risk for stage pIIIA/N2 NSCLC patients with molecularly positive surgical margins.

Distance between tumor and bronchial resection margin is an independent predictor of recurrence-free survival and overall survival in primary endobronchial neoplasm

BACKGROUND

The distance between tumor and bronchial resection margin (DBTM) had no clear standard in lung cancer surgery. We aimed to select the optimal cut-off value to provide a standard for surgery of the patients with primary endobronchial neoplasm.

METHODS

We retrospectively analyzed patients with primary endobronchial neoplasm who underwent surgical resection between 2005 and 2012. The receiver operating characteristic curves and the Youden index were used to calculate the optimal cut-off value of the DBTM. Propensity score matching was applied to reduce selection bias. Survival was assessed with Kaplan-Meier analysis, log-rank test and Cox proportional hazards model.

RESULTS

A total of 1048 patients comprised in the study cohort and 1.7 cm was determined the optimal cut-off value, including 531 grouped in DBTM ≤ 1.7 cm and 517 grouped in DBTM > 1.7 cm. Before propensity score matching, the 5-year recurrence-free survival was 38.7% in DBTM ≤ 1.7 cm group and 67.1% in DBTM > 1.7 cm (hazard ratio 0.48, P < 0.001), while the 5-year overall survival was 30.1% and 50.7%, respectively (hazard ratio 0.64, P < 0.001). After propensity score matching, the 5-year recurrence-free survival was 38.8% in DBTM ≤ 1.7 cm group and 66.1% in DBTM > 1.7 cm (hazard ratio 0.51, P < 0.001), while the 5-year overall survival was 34.7% and 50%, respectively (hazard ratio 0.81, P = 0.012). Multivariable cox model showed that the DBTM was an independent predictor for recurrence-free survival (hazard ratio 0.51, P = 0.001) and overall survival (hazard ratio 0.84, P = 0.026).

CONCLUSIONS

The DBTM was an independent predictor for outcomes in primary endobronchial neoplasm, and patients with the DBTM ≤ 1.7 cm should actively receive adjuvant therapy after surgery. The distance between tumor and bronchial resection margin (DBTM), the distance between the most proximal border of the macroscopic tumor and bronchial resection margin was measured by pathologist in the fresh specimens before formalin fixation. The DBTM less than 1.7cm had higher recurrence-free survival and overall survival and was an independent prognostic factor for patients with primary endobronchial neoplasm.

Ambient mass spectrometry for the molecular diagnosis of lung cancer

Lung cancer is one of the most common malignancies and the leading cause of cancer-related death worldwide. Among the technologies suitable for the rapid and accurate molecular diagnosis of lung cancer, ambient mass spectrometry (AMS) has gained increasing interest as it allows the direct profiling of molecular information from various biological samples (e.g., tissue, serum, urine and sputum) in real-time and with minimal or no sample pretreatment. This minireview summarizes the applications of AMS in lung cancer studies (including tissue molecular identification, the discovery of potential biomarkers, and surgical margin assessment), and discusses the challenges and perspectives of AMS in the clinical precision molecular diagnosis of lung cancer.

Molecular Analysis of Oncogenic Mutations in Resected Margins by Next-Generation Sequencing Predicts Relapse in Non-Small Cell Lung Cancer Patients

Objective

To investigate the genetic mutations in both tumor and marginal tissues in patients with non-small cell lung cancer (NSCLC), and to evaluate the potential prognostic value in patients with margins gene positive.

Methods

Next-generation sequencing (NGS) technique was used to detect genetic mutation in tumor and marginal tissues of the bronchus in 88 patients with NSCLC. Correlation of genetic mutations with pathology, lymph node metastasis, disease-free survival and overall survival was analyzed.

Results

Of the 88 patients, 83 cases (94.3%) had gene mutations in the tumor samples and 12 cases (13.6%) had genetic alterations in their margins. Most of the gene mutations detected were cancer drivers. Six common driver genes between tumor and marginal tissues were identified, including EGFR, TP53, CDKN2A, CTNNB1, BRAF, and NF1. Kaplan–Meier analysis revealed that the median disease-free survival (DFS) was significantly shorter in patients with detectable gene mutations in marginal tissues compared with patients without mutations in margins (30.7 versus 24.4 months, log-rank χ² = 4.78, P =0.029). Consistently, a shorter median OS was observed in patients harboring gene mutations in margins compared with patients with no mutations in margins (49.1 versus 32.2 months, log-rank χ² = 3.669, P =0.055).

Conclusion

These findings identify the presence of oncogenic alterations in microscopically negative margins in NSCLC patients associated with elevated risk of relapse and shorter survival time. Thus, examination of microscopically negative margins by NGS represents a valuable approach to predict the clinical outcome of NSCLC patients.