Investigation of a practical assessment index to capture the clinical presentation of cachexia in patients with lung cancer.

Objective: Cancer cachexia constitutes a poor prognostic factor in patients with lung cancer. However, the factors associated with cancer cachexia remain unclear. This study aimed to identify factors that influence cancer cachexia in patients with lung cancer.

Methods: In this retrospective observational study conducted at the Kansai Medical University, 76 patients with lung cancer were evaluated for physical function, nutritional status (Mini Nutritional Assessment-Short Form) and physical activity (International Physical Activity Questionnaire-Short Form) at the first visit to the rehabilitation outpatient clinic. The patients were divided into cachexia and noncachexia groups. The log-rank tests and Cox proportional hazards model were used to investigate the relationship between cachexia and prognosis. To examine the factors that influence cachexia, multivariate regression analysis with significant (P < 0.05) variables in the univariate logistic regression analysis was performed. Spearman's correlation analysis was performed to investigate the association between International Physical Activity Questionnaire-Short Form and performance status.

Results: Overall, 42 patients (55.2%) had cachexia associated with survival time since their first visit to the outpatient rehabilitation clinic, even after confounders adjustment (hazard ratio: 3.24, 95% confidence interval: 1.12-9.45, P = 0.031). In the multivariate analysis, Mini Nutritional Assessment-Short Form (odds ratio: 20.34, 95% confidence interval: 4.18-99.02, P < 0.001) and International Physical Activity Questionnaire-Short Form (odds ratio: 4.63, 95% confidence interval: 1.20-17.89, P = 0.026) were identified as independent factors for cachexia. There was no correlation between International Physical Activity Questionnaire-Short Form and performance status (r = 0.155, P = 0.181).

Conclusion: Malnutrition and low physical activity were associated with cachexia in patients with lung cancer. The International Physical Activity Questionnaire-Short Form may be a useful indicator of physical activity in cachexia. Regularly assessing these factors and identifying suitable interventions for cachexia remain challenges to be addressed in the future.