Prognostic importance of body fat ratio on lung cancer patients

ABSTRACT Introduction: Lung cancer, the most common malignancy seen in male and female population, remains the leading cause of death despite new diagnostic and therapeutic approach. Prognostic factors associated with overall survival include tumor grade, presence of comorbid disease, performance status, age, gender, cigarette smoking, histology, body mass index (BMI) and weight loss. In this study, we aim to evaluate the association between body fat mass and prognosis as well as with other factors affecting the survival. Materials and Methods: Patients with diagnosis of lung cancer between period of September 2014 and July 2015 in Dicle University Faculty of Medicine Oncology Department Outpatient Clinic were included in this study. Body fat mass and body mass index (BMI) were evaluated by Tanita Body Composition Analyzer. Patients gender, age, presence of comorbid disease, cigarette smoking, weight loss, performance status, histology, tumor grade and overall survival were recorded. Prognostic factors were seperately analysed in both metastatic and early stage lung cancer patients. Results: Results: 200 patients were included in this study. 36 (%18) patients women and 164 (%82) were men. The median age of patients was 56.5 years. 47 (%23.5) patients SCLC and 153 (%76.5) were NSCLC. No statistically significant role of gender, age (<65,>65), histology (SCLC, NSCLC), cigarette smoking, body fat ratio (>%30, <%30) on overall survival was found in all patients including early stage lung cancer(p>0.05). The role of Body mass index (BMI<30 MS: 21.1 mo, BMI>30 MS: 41,5 mo) (p=0.042), performance status (P1, MS: 21.1 mo, P2, MS: 20.4 mo, P3, MS:11.2 mo) (p=0,001), TNM grade (M0, MS: 31.2 mo, M1, MS: 17.6 mo) (p<0.001), weight loss within the last 6 months (negative, MS: 26.3 mo, positive , MS: 20.4 mo) (p=0,021) and comorbid disease status ( present, MS: 16.1 mo, absent, MS: 25.4 mo) (p=0,001) on overall survival were statistically significant.In early stage lung cancer patients, performans status (P1; MS 26.3 mo, P2; MS 26 mo, P3; MS 20.1 mo (p: 0.001)), status of comorbid conditions ( 26.7 mo if present, 34.6 mo if absent (p=0.018)), weight loss in the last six months ( absence of weight loss, median 29.2 mo; presence of weight loss, median 25.7 mo (p: 0.016)) were found to be statistically significant effect on survival rate. In metastatic patients analysis, no statistically significant affect of gender, age (<65,>65), histology (SCLC, NSCLC), cigarette smoking, performance status, weight loss within the last 6 months and body mass index (>30, <30) on overall survival were found (p>0.05), but comorbid disease status ( present, MS: 11.4 mo, absent, MS: 19.2 mo) (p=0.012), body fat ratio (<%30, MS: 16.4 mo; >%30, MS: 29.2 mo)(p=0.038). In multivariate analysis, no statistically significant affect of gender, age (<65,>65), histology (SCLC, NSCLC), cigarette smoking, performance status, weight loss within the last 6 months and body mass index (>25, <25) on overall survival were found (p>0.05), but comorbid disease status (p=0.01) and body fat ratio (p=0.033). Conclusion: In this study, in patients with metastatic lung cancer, it demonstrated that body fat mass may be more important prognostic faktor than BMI and weigth loss. Keywords; lung cancer, prognostic factors, body fat mass