Correspondence

Lobectomy versus limited resection in T1 N0 lung cancer

Lobectomy has been the standard treatment for stage I lung cancer in healthy patients, largely based on a randomized trial published in 1995. Nevertheless, research has continued regarding the role of sublobar resection. Three additional randomized trials addressing resection extent in healthy patients have recently been published. These 4 trials involve differences in design, eligibility, interventions, and intraoperative processes. Patients were ineligible if intraoperative assessment demonstrated stage > IA or inadequate resection margins. All trials consistently show no differences in perioperative morbidity, mortality, and postoperative changes in lung function between sublobar resection and lobectomy—consistent with other nonrandomized evidence. Long-term outcomes are generally encouraging of lesser resection, but some inconsistencies are apparent. The 2 larger recent trials demonstrated no overall survival difference while the others suggested better survival after lobectomy versus sublobar resection. Recurrence-free survival was found to be the same after lobectomy versus sublobar resection in 3 trials, despite higher locoregional recurrences after sublobar resection. The low 5-year recurrence-free survival (64%, regardless of resection extent) in 1 recent trial highlights the need for further optimization. Thus, there is high-level evidence that sublobar resection is a reasonable alternative to lobectomy in healthy patients. However, variability in long-term results suggests that aspects of patients, tumors and interventions need to be better understood. Therefore, we propose to apply sublobar resection cautiously; especially because there are no short-term benefits. Sublobar resection requires careful attention to intraoperative details (nodes, margins), and may be best suited for less aggressive (eg, ground glass, slow growing) tumors.

This study evaluated the prognostic effect of regional lymph node evaluation (LNE) in patients with non-small cell lung cancer (NSCLC) who underwent sublobar resection based on harvested node stations.

We retrospectively reviewed the data of patients with NSCLC who underwent sublobar resection at Asan Medical Center between 2007 and 2016. To adjust for the differences in confounding variables between the groups, propensity score–based inverse probability of treatment weighting (IPTW) was performed.

In the LNE group with pathological N0 disease (n = 522), 458 (87.7%) patients underwent both N1 and N2 LNE (N1 + N2 group) and 64 (12.3%) underwent only N2 LNE (N2 alone group). The N1 + N2 group had better prognosis before (P < .001) and after (P = .019) IPTW adjustment. Similar results were obtained even in patients with tumor size less than or equal to 2 cm (P = .032) or who underwent wedge resection (P = .041). According to IPTW-adjusted multivariable analysis, the performance of regional LNE was a significant prognostic factor for survival outcome (hazard ratio, 0.45; 95% confidence interval, 0.27-0.74; P = .002).

LNE is a critical process during sublobar resection in patients with NSCLC. Regional LNE during sublobar resection can significantly affect clinical outcomes even in patients with wedge resection or with tumor size less than 2 cm.

Pour un patient présentant un cancer bronchique non à petites cellules (CBNPC) de stade I ou II, la résection chirurgicale reste le traitement de choix pourvu que le patient soit opérable d’un point de vue fonctionnel. Une résection complète doit être effectuée. Fréquemment, une lobectomie est réalisable par une procédure minimalement invasive. La radiothérapie stéréotaxique est un traitement alternatif pour des patients avec une fonction cardiopulmonaire limitée. Par contre, en ce qui concerne les patients opérables au point de vue fonctionnel, il n’y a pas encore de réponse définitive car on ne dispose pas encore de résultats d’études randomisées avec un nombre suffisant de patients et un suivi à long terme. Pour cette raison, il est important de discuter chaque patient dans une réunion multidisciplinaire dans laquelle chirurgiens thoraciques et radiothérapeutes participent pour proposer une thérapie personnalisée prenant en considération la tumeur et son étendue, ainsi que les comorbidités et les fonctions respiratoire et cardiaque du patient.

For a patient with stage I or II non-small cell lung cancer (NSCLC) surgical resection remains the treatment of choice on condition that the patient is functionally operable. A complete resection should be obtained. Often lobectomy is feasible by a minimally invasive approach. For patients with compromised cardiopulmonary function stereotactic radiotherapy is an alternative treatment. For patients who are functionally operable, no definite recommendation can be made as no large, randomised studies have been performed with a sufficient number of patients and long-term follow-up. For this reason, it is important to discuss every patient within a multidisciplinary team with participation of thoracic surgeons and radiation oncologists. To provide personalised advice, the primary tumour, its extension, the patient's comorbidities and his respiratory and cardiac function have to be considered.

We investigated the association between survival and the number of examined lymph nodes after sublobar resection for node-negative non-small cell lung cancer with size of 2 cm or less.

The Surveillance, Epidemiology, and End Results database was used to identify patients diagnosed with non-small cell lung cancer 2 cm or less from 2004 to 2014 and underwent wedge resection or segmentectomy. Patients were stratified by the procedure (wedge resection, segmentectomy), the size of tumors (≤1 cm, 1 to 2 cm), and the number of lymph nodes examined (0, 1 to 3, 4 to 9, ≥10). The relationship between the number of resected lymph nodes and overall survival (OS)/lung cancer-specific survival (LCSS) was analyzed.

A total of 2,298 patients with wedge resection and 566 patients with segmentectomy were identified. Segmentectomy was performed for bigger tumors (1.43 cm versus 1.38 cm) and was associated with more lymph nodes resected (median number: 3 versus 1). Multivariable analysis after propensity score matching revealed that lymph node resection improved survival for patients undergoing wedge resection while not for patients undergoing segmentectomy. In the wedge resection group, 1 to 3 nodes resected improved OS and 4 to 9 nodes improved OS and LCSS compared with patients without nodes evaluated for lesions 1 cm or less. No survival benefit was observed when 10 or more nodes were resected. For lesions 1 to 2 cm, incremental improvement in survival appeared with the increase of examined lymph node number. More than 16 nodes resected conferred no additional survival benefit compared with patients with 10 to 16 nodes resected.

In wedge resection, 4 to 9 and 10 to 16 lymph nodes should be examined for lesions 1 cm or less and 1 to 2 cm, respectively. In segmentectomy, lymph node resection did not confer survival benefits for lesions 2 cm or less.