Prognostic impact of lymphadenectomy on outcomes of sublobar resection for non-small cell lung cancer ≤1 or >1 to 2 cm

Conditional Survival of Patients With Early-Stage Non-Small Cell Lung Cancer Who Undergo Lobectomy, Segmentectomy, or Wedge Resection Using the NCDB

BACKGROUND AND OBJECTIVES

Randomized clinical trials have shown that sub-lobar resection for clinical stage (cStage) IA non-small cell lung cancer (NSCLC) is non-inferior to lobar resection. We evaluated traditional and conditional survival differences between lobectomy, wedge resection, and segmentectomy in patients with cStage IA NSCLC.

METHODS

The National Cancer Database (2004-2019) was queried for patients with cStage IA (≤ 2 cm) NSCLC who underwent upfront lobectomy, segmentectomy, or wedge resection. Patients were stratified by extent of resection. Propensity-matched traditional (TSA) and conditional (CSA) survival analyses were performed. Propensity score included age, gender, histology, tumor grade, and Charlson-Deyo score. Number of lymph nodes (LN) harvested was also compared between groups.

RESULTS

There were 46 395 patients who met the inclusion criteria, of whom 32 599 (70.3%) received lobectomy, 11 181 (24.1%) wedge resection, and 2615 (5.6%) segmentectomy. Following propensity matching, all groups contained 2615 patients. In the TSA, segmentectomy (hazard ratio [HR]: 1.19, 95% confidence interval [CI]: 1.08-1.32) and wedge resection (HR: 1.41, CI: 1.28-1.56) were associated with worse 5-year survival. This remained significant in CSA at 3- and 5-years post-resection in patients who underwent segmentectomy (HR: 1.24, CI: 1.08-1.43 and HR: 1.23, CI: 1.02-1.49, respectively) and wedge resection (HR: 1.42, CI: 1.24-1.63 and HR: 1.33, CI: 1.11-1.59, respectively). Wedge resection and segmentectomy were associated with a lower number of harvested LN (median = 4 and 6, respectively) compared to lobectomy (8, p < 0.001).

CONCLUSION

Analysis of real-world data suggests that lobectomy is associated with improved traditional and conditional 5-year survival as well as LN harvest.

Impact of the number of dissected lymph nodes on machine learning-based prediction of postoperative lung cancer recurrence: a single-hospital retrospective cohort study

BACKGROUND

The optimal number of lymph nodes to be dissected during lung cancer surgery to minimise the postoperative recurrence risk remains undetermined. This study aimed to elucidate the impact of the number of dissected lymph nodes on the risk of postoperative recurrence of non-small cell lung cancer (NSCLC) using machine learning algorithms and statistical analyses.

METHODS

We retrospectively analysed 650 patients with NSCLC who underwent complete resection. Five machine learning models were trained using clinicopathological variables to predict postoperative recurrence. The relationship between the number of dissected lymph nodes and postoperative recurrence was investigated in the best-performing model using Shapley additive explanations values and partial dependence plots. Multivariable Cox proportional hazard analysis was performed to estimate the HR for postoperative recurrence based on the number of dissected nodes.

RESULTS

The random forest model demonstrated superior predictive performance (area under the receiver operating characteristic curve: 0.92, accuracy: 0.83, F1 score: 0.64). The partial dependence plot of this model revealed a non-linear dependence of the number of dissected lymph nodes on recurrence prediction within the range of 0-20 nodes, with the weakest dependence at 10 nodes. A linear increase in the dependence was observed for ≥20 dissected nodes. A multivariable analysis revealed a significantly elevated risk of recurrence in the group with ≥20 dissected nodes in comparison to those with <20 nodes (adjusted HR, 1.45; 95% CI 1.003 to 2.087).

CONCLUSIONS

The number of dissected lymph nodes was significantly associated with the risk of postoperative recurrence of NSCLC. The risk of recurrence is minimised when approximately 10 nodes are dissected but may increase when >20 nodes are removed. Limiting lymph node dissection to approximately 20 nodes may help to preserve a favourable antitumour immune environment. These findings provide novel insights into the optimisation of lymph node dissection during lung cancer surgery.

Outcomes after sublobar resection versus lobectomy in non-small cell carcinoma in situ

OBJECTIVE

Guidelines for treatment of non-small cell lung cancer identify patients with tumors ≤2 cm and pure carcinoma in situ histology as candidates for sublobar resection. Although the merits of lobectomy, sublobar resection, and lymphoid (LN) sampling, have been investigated in early-stage non-small cell lung cancer, evaluation of these modalities in patients with IS disease can provide meaningful clinical information. This study aims to compare these operations and their relationship with regional LN sampling in this population.

METHODS

The National Cancer Database was used to identify patients diagnosed with non-small cell lung cancer clinical Tis N0 M0 with a tumor size ≤2 cm from 2004 to 2017. The χ2 tests were used to examine subgroup differences by type of surgery. Kaplan-Meier method and Cox proportional hazard model were used to compare overall survival.

RESULTS

Of 707 patients, 56.7% (401 out of 707) underwent sublobar resection and 43.3% (306 out of 707) underwent lobectomy. There was no difference in 5-year overall survival in the sublobar resection group (85.1%) compared with the lobectomy group (88.9%; P = .341). Multivariable survival analyses showed no difference in overall survival (hazard ratio, 1.044; P = .885) in the treatment groups. LN sampling was performed in 50.9% of patients treated with sublobar resection. In this group, LN sampling was not associated with improved survival (84.9% vs 85.0%; P = .741).

CONCLUSIONS

We observed no difference in overall survival between sublobar resection and lobectomy in patients with cTis N0 M0 non-small cell lung cancer with tumors ≤2 cm. Sublobar resection may be an appropriate surgical option for this population. LN sampling was not associated with improved survival in patients treated with sublobar resection.

Outcomes of sublobar resection vs lobectomy for invasive clinical stage T1N0 non-small-cell lung cancer: A propensity-match analysis

BACKGROUND

The role of sub lobar resection (SLR; either segmentectomy or wedge resection) vs lobectomy (LBCT) for invasive clinical stage T1N0 non-small-cell-lung-cancer (NSCLC) has not been fully established yet.

AIM

We aimed to characterize the preoperative parameters leading to selecting SLR and compare the overall survival (OS) and disease-free survival (DFS) of these two surgical approaches.

METHODS

Clinical data on 162 patients (LBCT-107; SLR-55) were prospectively entered in our departmental database. Preoperative parameters associated with the performance of SLR were identified using univariate and multivariate cox regression analysis. The Kaplan-Meier method was used to compute OS and DFS. Comparison between LBCT and SLR groups and 32 propensity-matched groups was performed using Log-rank test.

RESULTS

Median follow-up time for the LBCT and SLR groups was 4.76 (Inter-quartile range [IQR] 2.96 to 8.23) and 3.38 (IQR 2.9 to 6.19) years respectively. OS and DFS rates were similar between the two groups in the entire cohort (OS-LBCT vs SLR P = .853, DSF-LBCT vs SLR P = .653) and after propensity matching (OS-LBCT vs SLR P = .563 DSF-LBCT vs SLR P = .632). Specifically, Two- and five-year OS rates for LBCT and SLR were 90.6.% vs 92.7%, 71.8% vs 75.9% respectively. Independent predictors of selecting for SLR included older age (P < .001), reduced FEV1% (P = .026), smaller tumor size (P = .025), smaller invasive component (P = .021) and higher American Society of Anesthesiology scores (P = .014).

CONCLUSIONS

In 162 consecutive and 32 matched cases, SLR and lobar resection had similar overall and disease-free survival rates. SLR may be considered as a reasonable oncological procedure in carefully selected T1N0 NSCLC patients that present with multiple comorbidities and relatively small tumors.