Gender differences in the correlation between prognosis and postoperative weight loss in patients with non-small cell lung cancer.

OBJECTIVES

The aim of this study was to investigate gender differences in the relationship between preoperative body mass index (BMI), postoperative body weight change and prognosis in patients with non-small cell lung cancer (NSCLC).

METHODS

Two hundred and sixty-three patients with NSCLC were enrolled in this study. Preoperative BMI was categorized based on WHO definition as follows: underweight (BMI <18.5): 21 patients (8.0%), normal (18.5 ≦ BMI <25): 179 patients (68%), overweight and obese (BMI ≧25): 63 patients (24%). Several factors such as age, sex, cancer stage, body weight change and BMI were recorded and correlated to the postoperative overall survival (OS).

RESULTS

For male patients, those in the low-BMI group had the worst prognosis (P < 0.05) whereas female patients with low BMI did not. Male patients with low BMI had statistically significant poorer prognosis compared to corresponding female patients (P < 0.05). Male patients with more than 5% body weight loss within 1 year after operation when compared to preoperative body weight had poorer prognosis than those with less than 5% body weight loss (P < 0.001). Furthermore, these male patients had statistically significant worse prognosis than the corresponding female patients (P < 0.05). In multivariable analysis, gender, more than 5% of body weight loss compared to preoperative body weight, and pathological stage were independent prognostic factors in NSCLC.

CONCLUSIONS

This study illustrates significant gender differences in the relationship between prognosis and BMI or body weight change in patients with postoperative NSCLC.