Body Composition at Diagnosis and Early Response in Pediatric Hodgkin Lymphoma

Background: The association between skeletal, muscle, and adipose tissue (body composition) and early response using PET in pediatric Hodgkin lymphoma remains unstudied. Methods: Patients enrolled on Children’s Oncology Group studies AHOD0031 (intermediate-risk Hodgkin lymphoma) and AHOD0831 (high-risk Hodgkin lymphoma) with digital abdominal CT scans at diagnosis and PET scans after 2 cycles (PET2) were included. Two consecutive slices at the third lumbar vertebra were identified, and skeletal muscle index (SMI; in cm²/ m²) and total adipose tissue index (TATI; in cm²/m²) were calculated using sliceOmatic and height at diagnosis. SMI and TATI were divided into quintiles [Q1 (lowest) to Q5 (highest)]. Body mass index (BMI) was calculated using height and weight at diagnosis. The association between baseline body composition (SMI, TATI, and BMI) and positive PET2 was examined using logistic regression, adjusting for age at diagnosis, sex, race/ ethnicity, stage, histology, bulk disease, and “B” symptoms. Results: Among 1,033 included patients, PET2 was positive in 314 (30.4%) patients. SMI was not associated with positive PET2. Extremes of TATI were associated with positive PET2, when compared with the middle TATI quintile [reference: Q3; OR_Q1 ¼ 1.63; 95% confidence interval (CI) ¼ 1.03–2.60; P ¼ 0.04; OR_Q2 ¼ 1.82; 95% CI ¼ 1.17–2.82; P ¼ 0.008; OR_Q5 ¼ 1.94; 95% CI ¼ 1.23–3.05; P ¼ 0.005]. The association between BMI in obesity range and positive PET2 trended toward significance (OR ¼ 1.42; 95% CI ¼ 0.98–2.04; P ¼ 0.06; ref ¼ normal weight). Conclusions: Extremes of adipose tissue at diagnosis influence early response among pediatric Hodgkin lymphoma. Impact: Validation of results from this study could inform studies investigating body composition–based chemotherapy dosing.