Increased skeletal muscle loss as a predictor of recurrence in postoperative lung cancer patients

Skeletal muscle loss and sarcopenia are associated with adverse outcomes in patients with non-small cell lung cancer (NSCLC). However, the relationship between longitudinal postoperative changes in CT-derived skeletal muscle mass and cancer recurrence remains insufficiently explored.

To evaluate longitudinal changes in CT-derived skeletal muscle mass at the T4 vertebral level after curative-intent resection for NSCLC and investigate their association with cancer recurrence.

Patients who underwent anatomic or non-anatomic lung resection for NSCLC between January 2016 and December 2019 and were followed at the same institution were included. Preoperative and recurrence or last follow-up CT images were evaluated for skeletal muscle mass at the T4 level using the open-source software 3D Slicer.

Sixty-three patients were evaluated, including 44 with recurrence and 19 without recurrence. Mean time to recurrence was 21.1 ± 17.6 months, and mean follow-up in controls was 41.5 ± 10.0 months. Initial and recurrence/last follow-up skeletal muscle mass measurements were comparable between groups. However, mean monthly total skeletal muscle mass loss was significantly greater in patients with recurrence than in controls (135.68 ± 285.52 vs. 16.31 ± 31.53, respectively; p = 0.015). A monthly back muscle mass loss cut-off of ≥ 250.29 showed 79.5% sensitivity, 84.2% specificity, and an area under the curve of 0.840 for detecting recurrence. Loss above this cut-off was independently associated with recurrence (odds ratio = 12.583; 95% confidence interval: 2.41-65.66).

Accelerated postoperative skeletal muscle loss was associated with NSCLC recurrence. Serial T4-level muscle assessment on routine surveillance CT may provide a practical supplementary marker for identifying patients at increased risk of recurrence.