Body composition and bone mass in survivors of childhood cancer

Background. The number of survivors of childhood cancer has increased. Several studies in children and adults have shown relationships between lean mass (LM), fat mass (FM), and bone mineral content (BMC). The objective of the study was to examine the association between body composition and bone mass in young survivors of childhood cancer. Methods. Sixty-eight postpubertal participants (31 females and 37 males) aged between 15.5 and 27 years who were at least 5 years after completion of treatment for leukemia (n=30), lymphoma (n=28), or solid tumors (n=10) were studied. Anthropometry was performed and dual energy X-ray absorptiometry (DXA) was used to assess BMC in the total body (T) and lumbar spine (S), FM, and LM. Results. There were no observed differences in age or time for cessation of treatment. Body mass index (BMI) was a strong determinant of bone mass in both sexes. TBMC correlated positively with LM (males r=0.9 and females r=0.76; P < 0.0001, respectively) and with FM (r=0.54; P < 0.01 in males and r=0.8; P < 0.00001 in females). SBMC correlated with LM in both sexes (in males r=0.77 and in females r=0.64; P < 0.0001, respectively) but only in females, SBMC also correlated positively with FM (r=44 P=0.03). There were no differences between patients who received radiation and those who did not. Conclusions. The associations between bone mass and body composition differ by sex and skeletal site, however, they are similar in survivors of childhood cancer and compared to healthy individuals during growth. Further prospective research is needed in cancer survivors to determine the long-term effect of anti-cancer therapy on body composition and bone mass.