Sub-Lobar Resection: The New Standard of Care for Early-Stage Lung Cancer

The Lung Cancer Study Group previously established lobectomy as the standard of care for treatment of clinical T1N0 NSCLC. Advances in imaging technology and refinements in staging have prompted a re-investigation to determine the non-inferiority of sub-lobar resections to lobectomies. Two recent randomized studies, JCOG 0802 and CALGB 140503, are reviewed here in the context of LCSG 0821. The studies confirm non-inferiority for sub-lobar resection (wedge or segmentectomy) compared to lobectomy for peripheral T1N0 NSCLC less than or equal to 2 cm. Sub-lobar resection should therefore be considered the new standard of care in this sub-set of patients with NSCLC.

Comparison of Lobectomy and Sublobar Resection for Stage IA Elderly NSCLC Patients (≥70 Years): A Population-Based Propensity Score Matching's Study

Background

To investigate the differences in survival between lobectomy and sub-lobar resection for elderly stage I non-small-cell lung cancer (NSCLC) patients using the Surveillance, Epidemiology, and End Results (SEER) registry.

Method

The data of stage IA elderly NSCLC patients (≥ 70 years) with tumors less than or equal to 3 cm in diameter were extracted. Propensity-matched analysis was used. Lung cancer-specific survival (LCSS) was compared among the patients after lobectomy and sub-lobar resection. The proportional hazards model was applied to identify multiple prognostic factors.

Results

A total of 3,504 patients met criteria after propensity score matching (PSM). Although the LCSS was better for lobectomy than for sub-lobar resection in patients with tumors ≤ 3 cm before PSM (p < 0.001), no significant difference in the LCSS was identified between the two treatment groups after PSM (p = 0.191). Multivariate Cox regression showed the elder age, male gender, squamous cell carcinoma (SQC) histology type, poor/undifferentiated grade and a large tumor size were associated with poor LCSS. The subgroup analysis of tumor sizes, histologic types and lymph nodes (LNs) dissection, there were also no significant difference for LCSS between lobectomy and sub-lobar resection. The sub-lobar resection was further divided into segmentectomy or wedge resection, and it demonstrated that no significant differences in LCSS were identified among the treatment subgroups either. Multivariate Cox regression analysis showed that the elder age, poor/undifferentiated grade and a large tumor size were a statistically significant independent factor associated with survival.

Conclusion

In terms of LCSS, lobectomy has no significant advantage over sub-lobar resection in elderly patients with stage IA NSCLC if lymph node assessment is performed adequately. The present data may contribute to develop a more suitable surgical treatment strategy for the stage IA elderly NSCLC patients.

Surgery for advanced-stage non-small cell lung cancer: lobectomy or sub-lobar resection?

Background

Metastatic non-small cell lung cancer (NSCLC) has many comorbidities, such as chronic obstructive pulmonary disease, coronary heart disease, and older age-related comorbidities. A survival benefit was observed in such patients who underwent surgery for selected oligometastatic disease. However, to the best of our knowledge, there is no evidence to support whether lobectomy (compared with sub-lobar resection) would further prolong these patients' lives.

Methods

Patients with metastatic NSCLC who underwent primary tumor resection were identified from the Surveillance, Epidemiology, and End Results (SEER) database and then divided into lobectomy and sub-lobar resection groups. Propensity score matching (PSM, 1:1) was performed to match the baseline characteristics of the two groups. Cancer-specific survival (CSS) was estimated.

Results

In total, 24,268 patients with metastatic NSCLC were identified; 4,114 (16.95%) underwent primary tumor surgery, and of these, 2,045 (49.71%) underwent lobectomy and 1,766 (42.93%) underwent sub-lobar resection. After PSM, 644 patients in each group were included. Lobectomy was independently correlated with longer median CSS time [hazards ratio (HR): 0.70, 95% confidence interval (CI): 0.61-0.80, P<0.001]. The 1, 2, and 3-year survival rates after PSM also favored the lobectomy group. However, no significant survival difference was found for wedge resection and segmentectomy (HR: 0.96, 95% CI: 0.70-1.31, P=0.490). The 1-, 2-, and 3-year survival rates after PSM also exhibited no difference within the sub-lobar group. We explored whether lymph node dissection would provide additional survival benefits for stage IV NSCLC patients. According to the multivariate Cox analysis of the matched population, lymph node dissection was independently associated with better CSS (HR: 0.76, 95% CI: 0.66-0.88, P<0.001) and overall survival (OS) (HR: 0.74, 95% CI: 0.65-0.86, P<0.001). We confirmed this result in the different types of surgery and found that the lymph node dissection group consistently had better survival outcomes both in the lobectomy group and sub-lobar resection population. According to the subgroup analysis, with the exception of stage T4 and brain metastatic patients, all of the patient subtypes exhibited greater benefit from lobectomy than sub-lobar resection.

Conclusions

Lobectomy has a greater survival benefit in metastatic NSCLC patients compared with sub-lobar resection when radical treatment of primary site was indicated.

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.

Biopsy first: Lessons learned from Cancer and Leukemia Group B (CALGB) 140503

OBJECTIVE

Cancer and Leukemia Group B 140503 is an ongoing, multicenter randomized trial assessing whether sublobar resection is equivalent to lobectomy for the treatment of stage I A non-small cell lung cancer (NSCLC) ≤2 cm in diameter. The objective of this report is to determine the reasons precluding intraoperative randomization.

METHODS

From June 15, 2007, to March 22, 2013, 637 patients were preregistered to the trial. Three hundred eighty-nine were randomized successfully (61%), and 248 patients were not randomized (39%). We analyzed the reasons for nonrandomization among a subset of the nonrandomized patients (208) for whom additional data were available.

RESULTS

Of these 208 patients, undiagnosed benign nodules (n =104, 16% of all registered patients) and understaging of NSCLC (n =45, 7% of all registered patients) were the dominant reasons precluding randomization. Granulomas represent one-quarter of the benign nodules. The understaged patients had unsuspected nodal metastases (n =28) or other more advanced NSCLC. The rate of randomization was significantly greater in those patients who had a preoperative biopsy (P <.001).

CONCLUSIONS

In a carefully monitored cohort of patients with suspected small NSCLC ≤2 cm, a substantial number are misdiagnosed (benign nodules) or understaged. These patients may not have benefited from a thoracic surgical procedure. Preoperative biopsy significantly increased the rate of correct diagnosis. Preoperative biopsy of small suspected NSCLC will reduce the number of nontherapeutic or unnecessary thoracic procedures. Accuracy in preoperative diagnosis is increasingly important as more such small nodules are discovered through lung cancer screening.