490 Impact of Sarcopenia on Short- and Long-Term Outcomes in Patients Undergoing Curative Intent Resection for Pancreatic Adenocarcinoma: A New Tool

Abstract

Background: Sarcopenia, defined as loss of muscle mass, may be a more objective means to determine peri-operative performance status. Traditionally, sarcopenia has exclusively been characterized using total psoas area (TPA). Defining sarcopenia using only a single axial cross-sectional image may, however, be inadequate. We sought to evaluate total psoas volume (TPV) as a new tool to define sarcopenia and compared TPV with traditional TPA. Method: Sarcopenia was assessed in 763 patients who underwent pancreatectomy for pancreatic adenocarcinoma between 1996-2014. Sarcopenia was defined as the TPA and TPV in the lowest sex-specific quartile. The impact of TPA and TPV sarcopenia on overall morbidity and mortality was assessed using multivariable analysis. Result: Median patient age was 67 years and 54.8% (n= 418) was male. Median TPA and TPV were both lower in women (506.3mm2/m2 and 22.4 cm3/m2, respectively) versus men (685.1mm2/m2 and 33.0 cm3/m2, respectively)(both P<0.001). 192 (25.1%) patients had sarcopenia by TPA, while 152 patients (19.9%) had sarcopenia according to TPV. Post-operatively, 369 (48.4%) patients had a complication. While TPA-sarcopenia was not associated with the risk of morbidity (OR=1.06; P= 0.72), sarcopenia defined by TPV was associated with a higher odds of complications (OR= 1.79; P= 0.002). In fact, patients with sarcopenia according to TPV had a higher risk of a major complication (Clavien grade ≥3)(22.4% vs. 15.1%; P= 0.03) and a longer length-of-stay (10 days vs. 8 days; P=0.002). On multivariable analysis, TPV-sarcopenia remained independently associated with an increase risk of post-operative complication (OR= 1.69; P= 0.006). In addition, after controlling for competing risk factors, sarcopenia defined by TPV was associated with a higher odds of long-term death (HR=1.46; P= 0.006). Conclusion: The use of TPV to define sarcopenia was associated with both shortand long-term outcomes following resection of pancreatic cancer. Assessment of the entire volume of the psoas muscle (TPV) may be a better means to define sarcopenia rather than a single axial image (TPA).