The mid-arm muscle circumference measurement and the prognosis of stage IV non-small cell lung cancer patients.

Abstract

e18058 Background: Patients with stage IV non-small cell lung cancer (NSCLC) comprise a very heterogenous population in relation to overall survival (OS). Strong prognostic factors are still needed to improve decisions regarding standard treatment options, to stratify patients for inclusion in innovative therapeutic trials and to identify patients best served by palliative care without systemic chemotherapy. The mid-arm muscle circunference (MAMC) is a bedside anthropometric measurement that estimates somatic protein reserve which is an early indicator of nutritional depletion. The measurement of MAMC is simple, non-invasive, objective, and inexpensive. We evaluated MAMC as a potential prognostic factor in patients with stage IV NSCLC. Methods: A prospective OS analysis of 56 (29 women) non-selected consecutive patients (Karnofsky status range 30-90) with stage IV NSCLC who had their MAMC measured as part of the nutritional evaluation. The MAMC results were expressed as a percentage of the expected reference values, adjusted for sex and age. Patients were categorized as normal (MAMC > = 90%) or depleted (MAMC < 90%). The study was approved by the Ethics Comitte and all patients signed the informed consent form. Results: The mean age of patients was 63 years (range 47-80) and mean MAMC was 89 (range 66–122), with 55% of patients (31) classified as depleted. Median OS of all patients was 6.2 months (95%CI: 5.1–7.3). In the subgroup with normal MAMC, median OS was 10.2 months (95% CI: 9.2–11.1). In patients classified as depleted, the median OS was 5.0 months (95%CI: 4.2–5.8). The OS difference between these two subgroups was highly statistically significant (p < 0.001 by the logrank test, HR = 0.21, 95%CI: 0.09–0.5 for patients with normal MAMC). In a multivariated analysis with the Karnofsky status, age and sex as covariates, the OS difference between MAMC groups remained statistically significant (p < 0.001 by the Cox proportional hazards method). Conclusions: MAMC is a strong independent prognostic factor in stage IV NSCLC patients. In our series, patients with MAMC < 90% of the expected value had poor overall survival. No significant financial relationships to disclose.