Clinical impact of number of lymph nodes dissected on postoperative survival in node-negative small cell lung cancer

The Clinical Role of Adjuvant Chemotherapy after Sublobar Resection for Non-Small-Cell Lung Cancer ≤ 20 mm with Lymph Node Metastases: A Propensity-Matched Analysis of the National Cancer Database

Sublobar resection is a standard surgical procedure for small-sized non-small-cell lung cancer (NSCLC). However, the clinical role of adjuvant chemotherapy for small-sized NSCLC with pathological lymph node (LN) metastasis after sublobar resection is unknown. The National Cancer Database was queried for NSCLC patients between 2004 and 2018. Eligibility included sublobar resection with pathological LN metastasis, R0 resection, Charlson comorbidity score = 0, clinical stage T1a-b, and tumor size ≤ 20 mm. The Kaplan-Meier method with a log-rank test and multivariable Cox proportional hazards analyses were used for assessing survival. The samples were evaluated before and after propensity score matching (PSM) with respect to age, sex, histologic type, and pathological LN status. Of 810 patients who met the eligibility criteria, 567 (70.0%) underwent adjuvant chemotherapy. After PSM, patients with adjuvant chemotherapy had a significantly longer survival than those without (median survival: 64.3 vs. 34.0 months, hazard ratio for death: 0.61, p < 0.0001). Multivariate analyses after PSM showed that younger age (p = 0.0206), female (p = 0.0005), and adjuvant chemotherapy (p < 0.0001) were independent prognostic factors for longer survival. Adjuvant chemotherapy has a prognostic impact in patients with small-sized NSCLC and pathological lymph node metastasis who undergo sublobar resection.

Impact of lymph node dissection on cancer-specific survival in non-small cell lung cancer patients: a SEER database analysis

Background

Non-small cell lung cancer (NSCLC) is the leading cause of cancer-related mortality worldwide, and lymph node dissection (LND) is a significant surgical procedure employed in its management. Although some studies suggest benefits of LND, the extent of its impact on survival, the optimal range of lymph nodes to be examined, and the specific patient groups that benefit most remain areas of active debate and investigation.

Methods

A population-based analysis was conducted using the Surveillance, Epidemiology, and End Results (SEER) database. Patients diagnosed with NSCLC between 2004 and 2017, undergoing primary tumor resection, were included. Descriptive, univariate, and multivariate analyses assessed the effect of LND on survival, and a restricted cubic spline method determined the optimal range for lymph node examination.

Results

This study of 37,323 NSCLC patients delved into the impact of LND on lung cancer-specific survival. Key findings revealed a median survival of 19.58 months, with 85% mortality. Baseline characteristics included a majority of White patients (81%), distant stage diagnoses (63%), and 64% with Grade IV tumors. LND emerged as a crucial predictor, influencing survival across age, gender, race, and tumor characteristics. Univariate analysis highlighted its significance, with higher T, N, and M categories, advanced stage, and poorer grade associating with elevated hazard ratios. Multivariate Cox proportional hazards (PH) analysis reinforced LND's impact, showcasing lower hazard ratios post-removal. Hazard ratios for biopsy/aspiration and removal of regional lymph nodes were 0.85 [95% confidence interval (CI): 0.81-0.89; P<0.001] and 0.43 (95% CI: 0.39-0.46; P<0.001), underscoring the protective effect. Visualizations and a U-shaped curve analysis identified an optimal range (24-32 nodes) for examination, emphasizing the nuanced benefits across NSCLC stages.

Conclusions

The study findings suggest that LND plays a critical role in improving cancer-specific survival in NSCLC patients, particularly when tailored to the early stages of the disease. The optimal range of lymph nodes examined, between 24 and 32, offers crucial insights for personalized NSCLC treatment strategies and may enhance overall survival. These results underscore the need for refined surgical guidelines that incorporate the extent of LND, supporting the utility of a more personalized approach in NSCLC management.

Robotic Anatomical Pulmonary Resections: An Australian Experience

BACKGROUND

Robotic thoracic surgery is a minimally invasive technique that allows the surgeon to perform delicate, accurate surgical manoeuvres within the chest cavity without rib spreading. Previous studies have suggested potential benefits of the robotic platform in nodal upstaging due to its versatility, seven degrees of freedom of movement, and superior vision. However, there is currently a paucity of robust clinical data from Australia.

AIMS

This study aimed to assess the perioperative safety and oncological efficacy of anatomical pulmonary resections performed using the robotic platform. Endpoints included mortality and major morbidity outcomes according to Clavien-Dindo classification and rate of pathological nodal upstaging compared with preoperative imaging using positron emission tomography.

METHODS

A single-surgeon retrospective analysis was performed using data collected from two institutions from July 2021 to May 2022, after ethics committee approval. Consecutive patients who underwent anatomical robotic resections were included in the study, with subsequent analysis of patients who had confirmed primary lung cancer.

RESULTS

A total of 52 patients underwent robotic anatomical pulmonary resection during the study period. Safety was demonstrated by 0% mortality and a 9.6% major complication rate, which was related to chest tube insertion for prolonged air leak or intensive care unit monitoring during treatment of atrial arrhythmia. After excluding patients who did not have primary lung cancer, 48 patients remained for further analysis; pathological nodal upstaging was observed in nine (18.8%) of these patients. On multivariate analysis, the total number of lymph nodes harvested was found to be a statistically significant predictor of nodal upstaging. Complete microscopic resection (R0) was achieved in 100% of patients.

CONCLUSIONS

This study represents the most extensive documentation of robotic thoracic procedures in Australia in the existing literature. It demonstrated a satisfactory safety profile with a relatively high rate of nodal upstaging, possibly reflecting the ability of the robotic instruments to perform comprehensive and complete nodal resection at the time of anatomical pulmonary resection.

Efficacy of immune checkpoint inhibitors in younger patients with non-small cell lung cancer

PURPOSE

Because patients younger than 40 years are rarely enrolled in clinical trials in non-small cell lung cancer (NSCLC), their survival benefit of immune checkpoint inhibitors (ICIs) needs to be clarified.

METHODS

The National Cancer Database was queried for patients who were diagnosed with stage IV NSCLC between 2016 and 2018. ICIs were administered in the first-line setting. The overall survival (OS) of patients with stage IV NSCLC according to the receipt of ICIs was compared in different age groups (< 40, 40-49, 50-59, 60-69, 70-79, and ≥ 80 years). Multivariate analyses identified the clinical characteristics predictive of OS. Propensity score matching (PSM) was conducted to reduce the biases arising from clinical characteristics.

RESULTS

This study included 126,476 patients with stage IV NSCLC. In univariate analysis, ICI treatment was not associated with a survival benefit in patients younger than 40 years with stage IV NSCLC relative to their ICI-naïve counterparts after PSM (median OS: 24.2 months vs. 24.0 months, hazard ratio [HR] = 1.01, 95% confidence interval [CI] = 0.81-1.27, P = 0.9031). Multivariate analysis revealed that ICI use was not an independent predictor of OS in patients with stage IV NSCLC < 40 years old (HR = 0.96, 95% CI = 0.76-1.21, P = 0.7230). Sequential improvement of the HR was observed with increasing age.

CONCLUSION

Our study suggested a poor survival benefit of ICIs in stage IV NSCLC patients younger than 40 years old, which should be validated in prospective studies.