Proportional weight loss in six months as a risk factor for mortality in stage IV non-small cell lung cancer

OBJECTIVE: To evaluate different weight loss (WL) cut-off points as prognostic markers of 3-month survival after diagnosis of stage IV non-small cell lung cancer (NSCLC). METHODS: This was a prospective study involving 104 patients with metastatic (stage IV) NSCLC who were admitted to a cancer treatment center in southern Brazil between January of 2014 and November of 2016. We evaluated total WL and WL per month, as well as WL and WL per month in the 6 months preceding the diagnosis. The patients were followed for 3 months after diagnosis. A Cox proportional hazards regression model and Kaplan-Meier curves were used in order to evaluate 3-month survival. RESULTS: The median WL in the 6 months preceding the diagnosis was 6% (interquartile range, 0.0-12.9%). Patients with WL ≥ 5% had a median survival of 78 days, compared with 85 days for those with WL < 5% (p = 0.047). Survival at 3 months was 72% for the patients with WL ≥ 5% (p = 0.047), 61% for those with WL ≥ 10% (p < 0.001), and 45% for those with WL ≥ 15% (p < 0.001). In the multivariate analysis, the hazard ratio for risk of death was 4.51 (95% CI: 1.32-15.39) for the patients with WL ≥ 5%, 6.34 (95% CI: 2.31-17.40) for those with WL ≥ 10%, and 14.17 (95% CI: 5.06-39.65) for those with WL ≥ 15%. CONCLUSIONS: WL in the 6 months preceding the diagnosis of NSCLC is a relevant prognostic factor and appears to be directly proportional to the rate of survival at 3 months.