Dorsal Muscle Attenuation May Predict Failure to Respond to Interleukin-2 Therapy in Metastatic Renal Cell Carcinoma.
To explore whether the sarcopenia body type can help predict response to interleukin-2 (IL-2) therapy in metastatic renal cell carcinoma (RCC).



Institutional review board approval was obtained for this Health Insurance Portability and Accountability Act-compliant retrospective cohort study of 75 subjects with metastatic RCC who underwent pretreatment contrast-enhanced computed tomography within 1 year of initiating IL-2 therapy. Cross-sectional area and attenuation of normal-density (31-100 Hounsfield units [HU]) and low-density (0-30 HU) dorsal muscles were obtained at the T11 vertebral level. The primary outcome was partial or complete response to IL-2 using RECIST 1.1 criteria at 6 weeks. A conditional inference tree was used to determine an optimal HU cutoff for predicting outcome. Bonferroni-adjusted multivariate logistic regression was conducted to investigate the independent associations between imaging features and response after controlling for demographics, doses of IL-2, and RCC prognostic scales (eg, Heng and the Memorial Sloan Kettering Cancer Center [MSKCC]).



Most subjects had intermediate prognosis by Heng (65% [49 of 75]) and the MSKCC (63% [47 of 75]) criteria; 7% had complete response and 12% had partial response. Mean attenuation of low-density dorsal muscles was a significant univariate predictor of IL-2 response after Bonferroni correction (P = 0.03). The odds of responding to treatment were 5.8 times higher for subjects with higher-attenuation low-density dorsal muscles (optimal cutoff: 18.1 HU). This persisted in multivariate analysis (P = 0.02). Body mass index (P = 0.67) and the Heng (P = 0.22) and MSKCC (P = 0.08) clinical prognostic scales were not significant predictors of response.



Mean cross-sectional attenuation of low-density dorsal muscles (ie, sarcopenia) may predict IL-2 response in metastatic RCC. Clinical variables are poor predictors of response.
University of Michigan Medical School, Ann Arbor, Michigan.
Bamidele
B
Otemuyiwa
Morphomics Analysis Group, University of Michigan, Ann Arbor, Michigan.
Brian A
BA
Derstine
Morphomics Analysis Group, University of Michigan, Ann Arbor, Michigan.
Peng
P
Zhang
Department of Surgery, Dartmouth-Hitchcock Medical Center, Lebanon, New Hampshire.
Sandra L
SL
Wong
Department of Surgery, University of Michigan Health System, Ann Arbor, Michigan.
Michael S
MS
Sabel
Department of Medicine, Division of Hematology/Oncology, University of Michigan Health System, Ann Arbor, Michigan.
Bruce G
BG
Redman
Morphomics Analysis Group, University of Michigan, Ann Arbor, Michigan; Department of Surgery, University of Michigan Health System, Ann Arbor, Michigan.
Stewart C
SC
Wang
Department of Medicine, Division of Hematology/Oncology, University of Michigan Health System, Ann Arbor, Michigan.
Ajjai S
AS
Alva
Department of Radiology, University of Michigan Health System, 1500 E. Medical Center Dr. B2-A209P, Ann Arbor, MI 48108; Department of Urology, University of Michigan Health System, Ann Arbor, Michigan; Michigan Radiology Quality Collaborative, Ann Arbor, Michigan. Electronic address: matdaven@med.umich.edu.
Matthew S
MS
Davenport
D000074322:Antineoplastic Agents, Immunological / Q000627:therapeutic use*; D064131:Back Muscles / Q000000981:diagnostic imaging*; D002292:Carcinoma, Renal Cell / Q000150:complications / Q000188:drug therapy* / Q000556:secondary; D003287:Contrast Media; D005260:Female; D006801:Humans; D007376:Interleukin-2 / Q000627:therapeutic use*; D007680:Kidney Neoplasms / Q000150:complications / Q000188:drug therapy* / Q000473:pathology; D008297:Male; D008875:Middle Aged; D016609:Neoplasms, Second Primary; D011237:Predictive Value of Tests; D011379:Prognosis; D066066:Response Evaluation Criteria in Solid Tumors; D012189:Retrospective Studies; D055948:Sarcopenia / Q000150:complications / Q000000981:diagnostic imaging*; D014057:Tomography, X-Ray Computed; D017211:Treatment Failure
D000074322:Antineoplastic Agents, Immunological; D003287:Contrast Media; D007376:Interleukin-2
Morphometry; interleukin-2; metastatic renal cell carcinoma; response prediction; sarcopenia