Abstract
BACKGROUND: Early skeletal muscle wasting has been demonstrated to be associated with chemotherapy-related toxicity in patients with cancer. Hounsfield unit average calculation (HUAC) or psoas muscle index (PMI) can be used to diagnose skeletal muscle wasting radiologically by calculations involving psoas muscle area. AIM: To evaluate ability of HUAC and PMI in predicting adjuvant chemotherapy (AC)-related and survival outcomes following pancreaticoduodenectomy for periampullary malignancy. METHODS: A retrospective study of patients who underwent pancreaticoduodenectomy for periampullary malignancy was conducted. HUAC and PMI were determined from preoperative computed tomography scans. Time to AC, completion of AC, survival, failure to initiate AC, mortality during AC, AC-related toxicity, cancer progression during AC and non-chemotherapy-related complications were the outcome measures. RESULTS: A total of 148 patients were included of whom 62.2% completed AC. The AC was terminated due to toxicity in 33.9%, cancer progression in 25.0%, non-chemotherapy-related complications in 16.1%, or poor performance status in 3.5% of the patients. The 1-,3-,5-years survival rates were 85.1%, 29.7% and 19.9%, respectively. The overall median survival was 22.6 (76.8) months. HUAC was an independent predictor of time to AC (P = 0.0005), AC-related toxicity (P = 0.0431), and completion of AC (P = 0.0486). However, HUAC did not predict 1-year (P = 0.8616), 3-years (P = 0.5941) or overall (P = 0.9206) survival. Being an octogenarian (P = 0.0009), Clavien-Dindo > III (P = 0.0184), and length of hospital stay (P = 0.0103) were independent predictors of failure to initiate AC. Moreover, being an octogenarian was an independent predictor of 3-years (P = 0.0201) and overall (P = 0.0433) survival. PMI did not predict any of the outcome measures. CONCLUSION: Unlike PMI, preoperative HUAC, determined from psoas muscle area and density, may predict time to AC, AC-related toxicity and completion of AC following pancreaticoduodenectomy for periampullary cancers. However, its ability to predict survival should be evaluated by future research.