A comparative evaluation of the GINI index and the modified Glasgow prognostic score in predicting postoperative sarcopenia in rectal cancer patients undergoing NACRT
摘要
Postoperative sarcopenia following neoadjuvant chemoradiotherapy for locally advanced rectal cancer negatively affects recovery and oncological outcomes. Both the Global Immune Nutrition and Inflammation Index (GINI) and the modified Glasgow Prognostic Score (mGPS) are derived from routine laboratory data. There are no studies comparing the performance of these scores and indices in predicting sarcopenia in patients with CT-confirmed sarcopenia. The aim of this study is to determine which of these two indices is a more specific predictor of postoperative sarcopenia in patients who underwent surgery after NACRT in this patient population.
MethodsThis single-center retrospective cohort study (January 2019–December 2025) included 134 adults with locally advanced rectal adenocarcinoma who underwent total mesorectal excision after completing standard 5-fluorouracil/leucovorin/oxaliplatin-based neoadjuvant chemoradiotherapy (NACRT). GINI and mGPS values were calculated from fasting blood samples collected one month after NACRT. Postoperative sarcopenia was defined using gender-specific skeletal muscle index (SMI) cutoff values at the level of the third lumbar vertebra, as determined by CT scans performed three to six months after surgery.
ResultsThe prevalence of postoperative sarcopenia was 30.6% (41/134). Sarcopenic patients had lower albumin levels (35.76 vs. 38.07 g/L; p = 0.046) and higher GINI values (median 146.70 vs. 68.39; p = 0.018); there was no difference between mGPS categories (p = 0.558). The GINI index yielded an AUC value of 0.629 (95% CI 0.541–0.711; sensitivity 48.78%, specificity 79.57% when the cutoff value was > 156.25; Nagelkerke R² = 0.140), whereas mGPS showed no discriminatory power (AUC 0.551; p = 0.307). In the adjusted analysis, a high GINI value independently predicted sarcopenia (aOR 4.93, 95% CI 1.72–14.13; p = 0.003).
ConclusionIn patients with locally advanced rectal cancer, a high GINI value after NACRT was independently associated with sarcopenia assessed by postoperative CT, whereas no such association was found with mGPS. Moderate discriminatory performance and a wide 95% confidence interval indicate that the GINI, in its current form, is insufficient as a standalone clinical decision-making tool; therefore, these findings should be considered hypothesis-generating and must be supported by a prospective, multicenter validation study before being implemented in clinical practice.