A comparison of pectoralis versus lumbar skeletal muscle indices for defining sarcopenia in diffuse large B-cell lymphoma - two are better than one

// Se-Il Go 1, * , Mi Jung Park 2, * , Haa-Na Song 3 , Hoon-Gu Kim 1, 4 , Myoung Hee Kang 1, 4 , Jung Hun Kang 3, 4 , Hye Ree Kim 3 and Gyeong-Won Lee 3, 4 1 Division of Hematology-Oncology, Department of Internal Medicine, Gyeongsang National University Changwon Hospital, Gyeongsang National University College of Medicine, Changwon, Republic of Korea 2 Department of Radiology, Gyeongsang National University Hospital, Gyeongsang National University College of Medicine, Jinju, Republic of Korea 3 Division of Hematology-Oncology, Department of Internal Medicine, Gyeongsang National University Hospital, Gyeongsang National University College of Medicine, Jinju, Republic of Korea 4 Institute of Health Science, Gyeongsang National University College of Medicine, Jinju, Republic of Korea * These authors have contributed equally to this work Correspondence to: Gyeong-Won Lee, email: brightree24@gmail.com Keywords: sarcopenia, diffuse large B-cell lymphoma, muscle, drug toxicity, prognosis Received: February 04, 2017     Accepted: February 28, 2017     Published: March 24, 2017 ABSTRACT Backgrounds: Sarcopenia is known to be associated with poor clinical outcome in patients with diffuse large B-cell lymphoma (DLBCL). There is no consensus concerning the optimal method to define sarcopenia in DLBCL. Methods: We retrospectively reviewed 193 DLBCL patients treated with rituximab plus cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP) therapy. Sarcopenia was classified by the region where the pretreatment skeletal muscle index (SMI) was measured. Results: Both the sarcopenia-L3 and sarcopenia-pectoralis muscle (PM) groups had increased incidences of severe treatment-related toxicities and treatment discontinuation compared with the non-sarcopenia-L3 and non-sarcopenia-PM groups, respectively. The sarcopenia-L3 and non-sarcopenia-L3 groups had 5-year overall survival (OS) rates of 40.5% and 67.8% ( p < 0.001), respectively. The sarcopenia-PM and non-sarcopenia-PM groups had 5-year OS rates of 35.9% and 69.0% ( p < 0.001), respectively. When the sarcopenia-L3 alone and sarcopenia-PM alone groups were compared, there were no differences in baseline characteristics, treatment toxicity, or survival. In multivariate analysis, when compared with the non-sarcopenia-both group, OS was significantly worse in the sarcopenia-both group (HR, 2.480; 95% CI, 1.284 – 4.792; p = 0.007), but not in patients with either sarcopenia-L3 alone or sarcopenia-PM alone ( p = 0.151). Conclusions: L3- and PM-SMIs are equally useful to define sarcopenia, which is related to intolerance to R-CHOP therapy and to worse survival in patients with DLBCL. More prognostic information can be obtained when these two SMIs are combined to define sarcopenia.