The association between sarcopenia and treatment outcomes in patients with pancreatic cancer undergoing chemoradiation.

Abstract

415 Background: Sarcopenia (Sp) or severe loss of muscle mass is a prognostic factor in cancer patients. We assessed the association between Sp and outcomes in borderline resectable or locally advanced/unresectable pancreatic cancer patients undergoing chemoradiation (CRT). Methods: We reviewed all patients who underwent CRT at an NCI-designated cancer center between 2007-2012. Patients with available pre-treatment imaging were included in the analysis. Sp was defined as a lumbar skeletal muscle area/height of < 55.4 cm2/m2 for males and < 38.9 cm2/m2for females. Sp was correlated to treatment toxicity, cause specific survival (CSS), and overall survival (OS). Analysis was performed using chi-square test for categorical variables and Mann-Whitney U test for continuous variables. Kaplan-Meier method and Cox regression was used for survival analysis. Results: A total of 86 patients met the inclusion criteria with 32 (37%) patients being sarcopenic. The median age was 70 (range 46-91) with a median follow-up of 14 months (3-68). The majority of patients were male (57%), had T3 disease (47%), or were borderline resectable (63%). Twenty nine (33.7%) patients underwent surgery. Sarcopenic patients were less likely to undergo surgery (p = 0.024) versus non-sarcopenic patients. Otherwise there was no difference in clinical or treatment factors. The 12-month actuarial OS for patients with and without Sp was 47.9% and 70.7%, respectively (p = 0.047). The 12-month actuarial CSS for patients with and without Sp was 48% and 76%, respectively (p = 0.007). On multivariable analysis, after controlling for T-stage, N-stage, resectability, gender, pre-treatment CA 19-9, and surgery, Sp was no longer associated with CSS (HR 0.284 95% CI 0.774-2.398) or OS (HR 1.077 95% CI 0.626-1.853). Surgery remained associated with CSS (HR 0.205 95% CI = 0.102-0.412) and OS (HR 0.187 95% CI 0.096-0.363). T-stage also remained associated with both CSS (HR 0.616 95% CI 0.410-0.925) and OS (HR 0.649 95% CI 0.440-0.957). Conclusions: The presence of Sp decreases the likelihood of undergoing curative surgery for pancreatic cancer. This may be another useful tool to identify poor prognosis patients.