Analysis of postoperative weight loss associated with prognosis after lobectomy for lung cancer

OBJECTIVES: Weight assessment is an easy-to-understand method of health checkup. The present study investigated the association between weight loss (WL) after lung cancer (LC) surgery and short-mid-term prognosis. METHODS: The data of patients who underwent radical lobectomy for primary LC were assessed between December 2017 and June 2021. Percentage weight gain or loss was determined at 3, 6 and 12 months postoperatively based on preoperative weight. The timing of decreased weight was divided into 0-3, 3-6 and 6-12 months. We also evaluated the relationship between severe WL (SWL) and prognosis. RESULTS: We reviewed 269 patients, of whom 187 (69.5%) showed WL within 1 year after surgery. The interquartile range for maximal WL was 2.0-8.2% (median 4.0%). Furthermore, we defined SWL as WL >= 8%. Twenty-five patients (9.3%) died: 9 from primary LC and 16 from non-LC causes. Cancer recurrences occurred in 45 patients (16.7%). WL occurred from 6 to 12 months postoperatively was associated with poor overall survival and recurrence-free survival (P < 0.05, both). Body mass index <18.5 kg/m(2) and idiopathic pulmonary fibrosis were predictive factors (P < 0.05, all). In the SWL group, overall survival, recurrence-free survival and non-cancer-specific were worse (P = 0.001, 0.005 and 0.019, respectively). Age >= 70 years and severe postoperative complications were predictive factors for SWL (P < 0.05, all). CONCLUSIONS: WL from 6 to 12 months postoperatively and SWL were associated with poor prognosis. Ongoing nutritional management is important to prevent life-threatening WL in patients with predictive factors.