BRIEF COMMUNICATION RIEF COMMUNICATION Body Size and Composition and the Risk of Lymphohema-

Reports of associations between body size and composition and risk of lym-phohematopoietic malignancies have been inconsistent. In a prospective study of 40 909 people aged 27 – 75 years and followed up for an average of 8.4 years, we measured fat mass and fat-free mass (using bioelectrical impedance analysis) and measured waist circum-ference directly. All malignancies were ascertained via the population cancer registry. The risk of myeloid leukemia was positively associated with body mass index (compared with those <25 kg/m 2, overweight and obese per-sons ’ hazard ratios [HRs] = 5.3, 95% confi dence interval [CI] = 1.9 to 15.2 and HR = 5.0, 95 % CI = 1.6 to 15.5, respectively; P =.006), fat-free mass (per 10-kg increase HR = 1.83, 95% CI = 1.15 to 2.90; P =.01), and waist circumference (per 10-cm increase HR = 1.35, 95 % CI = 1.06 to 1.72; P =.02). Lymphoproliferative malignan-cies and subgroups showed little rela-tionship with body size. [J Natl Cancer Inst 2005;97:1154 –7] Whether certain aspects of body size and composition are associated with risk of lymphohematopoietic malignancies is uncertain ( 1 – 13). Only one study has reported results for measures other than height, weight, or body mass index (BMI; kg/m 2) ( 5, 6) , and apart from two studies ( 3, 4) , measurement of obesity was based on self-reported measures ( 1, 2, 5 – 7, 10, 13) or on hospital discharge diagnoses of obesity ( 8, 9, 12). We examined whether direct measurements of body size were associated with the incidence of lympho-hematopoietic malignancies using a pro-spective cohort study of adults. The Melbourne Collaborative Cohort Study recruited 41 528 people between 1990 and 1994 ( 14 – 16) to investigate the role of nutritional and other lifestyle fac-tors in cancer. The study was approve