Effect of progressive sarcopenia during postoperative 6 months on long-term prognosis of completely resected lung cancer

Abstract

Background: Preoperative sarcopenia has been indicated to be a potential prognostic factor for patients after complete resection of lung cancer. This study evaluated whether changes in the skeletal muscle mass index (SMI) over postoperative 6 months could predict long-term prognosis from 6 months after complete resection of non-small cell lung cancer (NSCLC). Methods: This retrospective study analyzed data of 468 patients who underwent curative lobar resection for non-small cell lung cancer at our hospital. The 6-month postoperative change in SMI was calculated, and associations between clinicopathological factors (including the change in SMI) and postoperative mortality were examined. Results: Rates of overall survival were 90.6% after 3 years and 80.7% after 5 years. The median 6-month change in SMI was-3.4% (range,-22.3% to 14.7%). Multivariate analysis revealed that poor outcomes were independently predicted by a large change in SMI, age, pathological stage, lymphovascular invasion, and a Brinkman index of ≥600. Through the analysis in training and validation sets, we determined a cutoff value of-9.9% for the 6-month postoperative change in SMI. Subgroup analysis showed that depletion of SMI during postoperative 6 months was a risk factor for poorer prognosis only in heavy smokers with a Brinkman index of ≥600. Conclusions: A reduction in SMI during the 6 months after complete resection of non-small cell lung cancer significantly predicted prognosis, especially in heavy smokers. These results suggest that attention should be given to prevent the perioperative progression of sarcopenia after curative resection of lung cancer. Thoracic surgeons should take how to manage perioperatively against sarcopenia into consideration.

Risk factors for progressive sarcopenia 6 months after complete resection of lung cancer: what can thoracic surgeons do against sarcopenia?

“…As indicated by the currently proposed definitions and severity grading systems for both generic and cancer cachexia (1,2), an absolute value of a surrogate marker for cachexia should be considered alongside a decrease in value. In our former study (14), preoperative BMI was not identified as a risk factor. In the present study, the influence of the preoperative BMI was clarified mainly because we focused on large population of heavy-smoking males.…”

“…In our previous study (14), the optimal cut-off value of the 6-month SMI change in heavy smokers with BI ≥600 (N=196) was −10.2%. Similarly, in this study, the ROC analysis for mortality indicated the optimal cut-off value for the 6-month change in SMI was −10.0% [area under the curve (AUC): 0.56…”

“…Details of the operative procedure, postoperative followup, and definition of recurrence were reported previously (14).…”

“…SMI changes were calculated as described previously (14). We changed only the application used for calculation.…”

“…Nevertheless, these studies have only demonstrated that sarcopenia is a risk factor for poor prognosis and may not suggest the actions to take based on the results. We reported that reduction in the SMI during the 6 months following complete resection of NSCLC is a significant prognostic factor after the postoperative 6-month follow-up, especially in heavy smokers (14). These results could justify acting to prevent postoperative progression of sarcopenia after curative resection of lung cancer for heavy smokers, although there is no current treatment for sarcopenia that has been demonstrated to improve long-term prognosis (6,(15)(16)(17).…”