Sublobar resection versus lobectomy for patients with stage T1-2N0M0 pulmonary typical carcinoid tumours: a population-based propensity score matching analysis

Abstract

Objectives It is widely accepted that surgical resection of localized pulmonary typical carcinoid (TC) tumours remains the primary curative modality. However, the optimal extent of resection remains controversial. This study aimed to investigate the survival rates of patients with stage T1-2N0M0 TC tumours who underwent sublobar resection or lobectomy. Methods We queried the Surveillance, Epidemiology, and End Results database for patients who underwent surgery after being diagnosed with stage T1-2N0M0 TCs from 2004 to 2016. Propensity score matching (PSM) analysis was used to equalize baseline characteristics between the sublobar resection group and the lobectomy group. Kaplan–Meier analysis and the Cox proportional hazard model were performed for survival analysis. Results Of the 2469 patients included, 658 (26.65%) underwent sublobar resection and 1811 (73.35%) underwent lobectomy. All 2469 patients were analysed with PSM and, following PSM, 812 patients were included in the final analysis, divided into two groups of 406 patients. In the matched cohort, Kaplan–Meier analysis demonstrated no significant difference in survival curves between the sublobar resection and lobectomy groups in patients with stage T1-2N0M0 TC tumours (5-year OS = 90.78% versus 93.30%; HR 1.18, 95% CI: 0.77–1.80; P = 0.505). Subgroup analysis by tumour size showed that the sublobar resection group was identical to the lobectomy group in overall survival (OS) for tumours ≤3.0 cm. In addition, no difference in OS between surgical groups was observed in any subgroups. In multivariable Cox analysis, age ≤ 65y, female sex, married status, and adequate lymph node assessment (≥5) were associated with improved OS, whereas the extent of resection was not. Conclusions Sublobar resection seems to be associated with similar survival to lobectomy for stage T1-2N0M0 TC tumours if lymph node assessment is performed adequately. This analysis suggests sublobar resection should be considered an appropriate alternative for stage T1-2N0M0 TC tumours. However, further validations are needed in large, multicentre prospective studies.

Does Examined Lymph Node Count Influence Survival in Surgically Resected Early‑stage Pulmonary Typical Carcinoid Tumors?

“…When analyzed in the subgroup analysis stratified by surgical method, this survival trend was observed in patients who received lobectomy or sublobar resection and was consistent with the findings of previous studies. 5,14,15 However, in this study, we found that patients who received sublobar resection had fewer ELNs, compared with those who underwent lobectomy. The proportion of patients undergoing sublobar resection with ELNs < 4 was 80.18% (526/656), whereas for those undergoing lobectomy, this proportion decreased to 27.57% (435/1578).…”

“…However, as surgical technologies continue to advance, the clinical application of sublobar resection has gradually increased. Moreover, studies 14,15 have increasingly confirmed that sublobar resection confers a noninferior survival benefit and safety compared with lobectomy in early-stage TCs. Moreover, TCs is an indolent tumor, which is less prone to LN and distant metastases and has good long-term survival.…”

“…To decrease the possibility of intergroup bias, a 1:1 nearest neighbor propensity score matching (PSM) scheme (caliper = 0.02) was used to obtain a matched cohort. 5,14,18 Propensity scores were calculated through a logistic regression analysis in a model that included age, sex, laterality, marital status, race, histologic grade, primary tumor site, tumor size, adjuvant chemotherapy, radiotherapy, and the surgical method. Comparisons between categorical variables were evaluated using McNemar tests, whereas the paired t test or the nonparametric Wilcoxon signed-rank test was used for continuous variables.…”

“…Similar to that of non-small cell lung cancer (NSCLC), the standard surgical procedure of operable TC comprises anatomic lobectomy with systematic mediastinal lymphadenectomy 11–13. However, with rapid and sustained improvements in surgical techniques, the clinical application of sublobar resection has gradually increased, given the similar prognostic outcome and safety as that of lobectomy in patients with early-stage TC 6,14,15. Therefore, accurate LN examination could determine the postoperative pathologic stage and predict the survival of TC patients16 as the absence of lymphatic metastasis indicates a relatively better prognosis.…”

“…[11][12][13] However, with rapid and sustained improvements in surgical techniques, the clinical application of sublobar resection has gradually increased, given the similar prognostic outcome and safety as that of lobectomy in patients with early-stage TC. 6,14,15 Therefore, accurate LN examination could determine the postoperative pathologic stage and predict the survival of TC patients 16 as the absence of lymphatic metastasis indicates a relatively better prognosis. In a study with 1495 participants treated with sublobar resection and lobectomy for clinical stage T1aN0M0 TC tumors, Brown et al 16 showed that LN assessment is important to identify LN upstaging and significantly affects the prognosis.…”