Prognostic value of preoperative psoas muscle index as a measure of nutritional status in patients with esophageal cancer receiving neoadjuvant therapy.

ABSTRACT

OBJECTIVES: It has been reported that preoperative nutritional status in some gastrointestinal cancers has a significant effect on postoperative prognosis. However, there are few reports on esophageal cancer, especially for esophageal cancer patients who have undergone neoadjuvant therapy and surgery. Psoas muscle index (PMI) is widely known as an index for assessing preoperative nutritional status, and has recently been reported for its prognostic value in many malignancies. The aim of this study was to investigate and evaluate the clinical results in our hospital using the PMI method. METHODS: We retrospectively investigated esophageal cancer in patients (clinical stage II or III) who underwent neoadjuvant therapy and surgical treatment (R0 cases) from January 2008 to December 2015. Applicable 63 cases were entered accordingly. In our hospital, nutritional supplements are used for nutritional management during preoperative adjuvant therapy, and these are administered to patients who have difficulty ingesting nutrition by feeding tube or total parenteral nutrition. The target value for nutritional supplement administration was 36 kcal/kg. Taking into account that chemotherapy for esophageal cancer was being performed using Harris-Benedict's basal energy expenditure (25 kcal/kg), we multiplied by 1.44 (active factor; 1.2, stress factor; 1.2) and set 36 kcal/kg as a guide. PMI was evaluated before neoadjuvant therapy and before surgery. We defined sarcopenia by PMI of the third lumbar vertebra (L3) by a computed tomography (CT) examination using 3-dimensional image analysis software, <6.36 for men and <3.92 for women, and investigated the effect of each on prognosis. RESULTS: The prevalence of sarcopenia decreased from 74.6% (47 of 63) to 69.84% (44 of 63) during the pretherapeutic to preoperative period (P = 0.691), suggesting improved nutritional status. Regarding PMI divided by cutoff value for each sex (the cutoff value was the PMI mean value -2 SD [6.36 cm2 m2 for men and 3.92 cm2/m2 for women] of healthy individuals <50 y of age, which was reported as a standard for low skeletal muscle mass in Japanese individuals), there was an improvement observed in the preoperative compared to pretherapeutic period, but it was not obtained as a significant difference (pretherapeutic PMI; 0.87 ± 0.06 [mean ± SD], preoperative PMI; 0.89 ± 0.06 [mean ± SD], P = 0.18). In overall survival (OS) and disease-free survival (DFS), there was no significant difference in the short-term results with and without sarcopenia in the pretherapeutic group (both OS and DFS, P = 0.17). There was a significant difference with and without sarcopenia in the preoperative group in terms of OS and DFS (OS, P = 0.045; DFS, P = 0.043), which was short term due to nutritional intervention during preoperative adjuvant therapy. It was suggested that the results would be improved. CONCLUSIONS: Improving nutritional status before surgery was shown to improve short-term prognosis in patients with esophageal cancer. It is hence suggested that it is important to maintain or improve nutritional status by intervention from the time of neoadjuvant therapy.