Abstract
BACKGROUND: Oesophageal cancer survivorship is afflicted by cancer cachexia related weight loss and nutrition impact symptoms. Identifying the factors which predict cancer cachexia specifically is warranted in order to identify those at risk and render the right kind of support. We aimed to assess if preoperative and postoperative body mass index (BMI) adjusted weight loss grading system (WLGS) is predictive of cancer cachexia at one year after surgery for oesophageal cancer. METHODS: Data were used from a prospective nationwide cohort study on patients operated on for oesophageal cancer in Sweden between 2013 and 2018 included at one year after surgery. The study exposure is BMI adjusted weight loss graded into one of five distinct weight loss grades (grades 0-4), defined in accordance with the WLGS by combining BMI and percentage weight loss, assessed at two clinical time points: preoperative and at 6 months post-surgery for oesophageal cancer. The study outcome is subjective measures of cancer cachexia one year after surgery, assessed using the cancer-cachexia specific questionnaire EORTC QLQ-CAX24. Multivariable linear regression models calculated mean score differences (MD) with 95% confidence intervals (CI) adjusted for predefined confounders. Statistical significance at p < 0.05 together with a clinically relevant difference of 10-points in mean scores was considered as a significant difference. RESULTS: Among a total of 232 patients, the highest grade of preoperative WLGS 4 was associated with significantly worse physical decline than lower grades of WLGS 1 (MD -10, 95% CI: -20 to -1) and WLGS 2 (MD -11, 95% CI: -20 to -2). Those with preoperative WLGS 2, 3 and 4 reported lower scores on the adequacy of information on weight loss provided to them than those with preoperative WLGS 0. Those with the highest postoperative WLGS 4 had greater eating and weight loss worry than WLGS 2 (MD -17, 95% CI: -32 to -3) and WLGS 3 (MD -11, 95% CI: -21 to -2) and worse physical decline than WLGS 0 (MD -14, 95% CI: -25 to -2). CONCLUSIONS: Higher grades of both preoperative and postoperative WLGS are predictive of cancer cachexia related physical decline one year after surgery for oesophageal cancer. Additionally, preoperative and postoperative WLGS were also predictive of inadequate information concerning weight loss and more worry regarding eating and weight loss, respectively. The WLGS may be an effective risk prediction tool for postoperative cachexia related physical decline in patients undergoing treatment for oesophageal cancer emphasizing its usability in the clinical setting.