The Effect of Body Mass Index on Survival in Lung Cancer.

The prognostic significance of body mass index in lung cancer and the direction of this relationship are not yet clear. This study aimed to evaluate the relationship between BMI and overall survival time of advanced-stage lung cancer patients treated in a center in Turkey, a developing country. In this study, the data of 225 patients diagnosed with stage III or stage IV lung cancer between 2016 and 2020 were analyzed. The effects of BMI and other variables on survival were examined by Cox regression analysis for NSCLC and SCLC. For NSCLC and SCLC, being underweight compared to the normal group, being diagnosed at a more advanced stage, and having a worse performance score were associated with a significantly higher risk of death. Other variables significantly associated with survival were gender, type of radiotherapy for NSCLC, age group, and family history for SCLC. This study showed that being underweight relative to the normal group was associated with worse survival for NSCLC and SCLC but did not support the obesity paradox. Studies that are representative of all BMI categories and free of bias are needed to understand the BMI-lung cancer survival relationship clearly.