Response to letter to editor by Safer et al.

Abstract

Dear Editor, We have read with interest the Letter to the Editor by Dr. Safer and colleagues regarding our manuscript [1]. Dr. Safer correctly pointed out that muscle mass measurements by cross sectional imaging alone (Total Psoas Area) might not be the optimal method for classification of sarcopenia in cancer patients. They indicated that lumbar skeletal muscle index was recently put forth in a consensus statement as a recommended method for measuring sarcopenia [2]. Our study agrees with this finding. In our study, sarcopenia was quantified using two endpoints. This included the Total Psoas Index (TPI), which is different from the Total Psoas Area in that it takes into account patient height. Similar to the consensus statement, it is an index calculation and not a gross measurement of muscle mass. We also utilized the Hounsfield Unit Average Calculation (HUAC), which is a measurement derived from the radiation attenuation of the psoas muscle in conjunction with the psoas area. The HUAC is representative of psoas muscle quality accounting for both muscle density and fatty infiltration. Therefore based on using the TPI and the HUAC we did not employ muscle mass measurement alone in our study. Using our database of patients with pancreatic ductal adenocarcinoma treated with pancreatectomy, we evaluated the impact of these endpoints on graded operative complications using multivariate analysis. Our results indicate that the HUAC was an independent predictor of numerous study endpoints, including overall and severe operative complications. The TPI only independently predicted length of hospital stay in our study. In the Discussion, we support the notion that TPI alone may not be as valuable as previously thought and that the HUAC, accounting for both muscle mass and density is something novel to be evaluated in future studies. Our conclusion highlights the HUAC as a proxy for the extent of a patient’s sarcopenia and discusses the potential clinical applicability of this measurement in cancer patients undergoing major operations. The European Consensus Definition of sarcopenia is the presence of low muscle mass and one of the following clinical variables—low muscle strength or low physical performance [3]. Future studies that build on the current body of literature should therefore include not only muscle indices measured by imaging, but also clinical parameters such as muscle strength, physical performance, and frailty [4]. Thank you very much for taking interest in our study.

DOI: 10.1002/jso.23968

Cite this paper

@article{Joglekar2015ResponseTL, title={Response to letter to editor by Safer et al.}, author={Savita Joglekar and James John Mezhir}, journal={Journal of surgical oncology}, year={2015}, volume={112 1}, pages={117} }