Long-term changes in psoas muscle mass after lobectomy and segmentectomy for early-stage lung cancer.

Abstract

Segmentectomy is considered a less invasive procedure than lobectomy for patients with non-small cell lung cancer (NSCLC); however, little is known about the physiological mechanism underlying the lower invasiveness of segmentectomy. This study is aimed to compare the differences in the long-term changes in the psoas muscle mass after segmentectomy and lobectomy in patients with NSCLC. Overall 315 recurrence-free patients who underwent segmentectomy (n=93) or lobectomy (n=222) for clinical stage 0-I NSCLC between January 2016 and December 2018 and underwent computed tomography during the entire period of 6months≤postoperative year (POY) 0.5<12months, 12months≤POY 1<24months, 24months≤POY 2<36months, and 36months≤POY 3<48months were included. Bilateral psoas muscle area (PMA) at the L3 level was measured using each cross-sectional computed tomography scan. Differences between the segmentectomy and lobectomy groups in the mean change of postoperative PMA from the preoperative period were analysed using Student's t-test and mixed analysis of variance. Multivariableanalysis was performed to identify the risk factors for PMA loss on POY 3 using logistic regression analysis. The lobectomy group had a significantly larger PMA change than the segmentectomy group during each postoperative period (P<0.001). Mixed analysis of variance revealed that the mean PMA change was significantly smaller in the segmentectomy group than in the lobectomy group during the observation period (P<0.001). The mean change in the PMA was significantly larger from POY1 (-2.5%) to POY2 (-3.9%) and POY3 (-4.7%) in the lobectomy group (P=0.003 and P<0.001). However, PMA remained unchanged during the postoperative observation period in the segmentectomy group. In the multivariable analysis, the risk factors for PMA change ≤-3.3% (cut-off: mean change of PMA) at POY3 included lobectomy [odds ratio (OR), 3.32; 95% confidence interval (CI), 1.90-5.82; P<0.001], male sex (OR, 1.92; 95% CI, 1.02-3.62; P=0.044) and open thoracotomy (OR, 1.84; 95% CI, 1.11-3.05; P=0.017). After propensity score matching, the mean change in PMA was smaller in the segmentectomy group (n=75) than in the lobectomy group (n=75) during the postoperative observation period (P<0.001). Psoas muscle mass was better maintained during the postoperative period by segmentectomy than by lobectomy. Psoas muscle mass reduction progressed over a long postoperative period after lobectomy. Segmentectomy via complete video-assisted thoracic surgery is associated with a lower likelihood of sarcopenia progression.