PQA 07 - PQA 07 Gastrointestinal Cancer and Sarcoma/Cutaneous Tumors Poster Q&A
3100 - Sarcopenia as an Independent Prognostic Factor for Neoadjuvant Chemoradiation Efficacy in Locally Advanced Rectal Cancer: A Retrospective Analysis
J. Y. Wu1,2, and C. Y. E. Su1,3; 1Graduate Institute of Biomedical Informatics, College of Medical Science and Technology, Taipei Medical University, Taipei, Taiwan, 2Wan Fang Hospital, Taipei Medical University, Department of Radiation Oncology, Taipei, Taiwan, 3Clinical Big Data Research Center, Taipei Medical University Hospital, Taipei, Taiwan
Purpose/Objective(s): Rectal cancer is one of the major causes of cancer-related mortality worldwide. The current standard of care for locally advanced rectal cancer (LARC) includes neoadjuvant chemoradiation therapy to downstage the tumor, followed by surgical resection. This research was conducted to evaluate the effect of sarcopenia, determined by computed tomography, on the response to neoadjuvant chemoradiation among individuals with LARC. Despite established prognostic indicators like clinical T/N stage, this study aimed to ascertain if sarcopenia is an independent prognostic factor.Materials/
Methods: Under the authorization of TMU-JIRB (Protocol Number: N201809032), a retrospective analysis included 175 LARC patients diagnosed between January 2011 and December 2016. The collected data included demographics, tumor markers, treatment regimens, and clinical outcomes. The skeletal muscle index (SMI) was assessed from CT scans. SMI thresholds for sarcopenia were set at one standard deviation below the mean for the study population, stratified by gender. Progression-free survival (PFS) and overall survival (OS) were defined and calculated, with the duration from treatment initiation to any recurrence or metastasis, and the latter from initiation to death from any cause. For statistical analysis, uni- and multivariate logistic regression models were employed to evaluate the influence of sarcopenia on survival outcomes. Kaplan-Meier survival analysis was conducted to illustrate the difference in survival probabilities between sarcopenic and non-sarcopenic patients, with the log-rank test used to assess the statistical significance of the differences observed. Results: In the cohort of 175 patients (104 male, 71 female), with an average follow-up of 7.1 years, 32 patients (17.3%) achieved pCR, with cT3 staging and nodal positivity being prevalent. The median age was 58.6 for males and 56.1 for females. Sarcopenia was identified in 45 (25.5%) patients. Treatment response was observed in 93 (52.8%) patients, with 33 (18.2%) achieving TRG 0. Age, clinical T stage, sarcopenia, and tumor distance from the anal verge were significant in univariate analysis, with sarcopenia and T stage maintaining significance in multivariate contexts (odds ratios: 2.83 and 2.11, respectively). Kaplan-Meier survival curves further underscored the detrimental impact of sarcopenia on survival, with a clear separation between the curves for sarcopenic and non-sarcopenic patients(p<0.05). Conclusion: Sarcopenia is an independent predictor of long-term survival in patients with LARC. This study advocates for the inclusion of sarcopenia in the pre-treatment assessment of LARC patients to enhance prognostic accuracy and guide treatment personalization. Future research is essential to validate these findings and to establish a standardized SMI cutoff that could be universally applied in clinical practice for patients with LARC.
