Teenage Obesity Ups Colorectal Cancer Risk
Data for over 2 million Israeli men and women were collected as part of the study.
HealthDay News — Obesity even in adolescence may raise the odds for colon and rectal cancers in adulthood, according to research published online in Cancer.
The new study was led by Zohar Levi, MD, of the Rabin Medical Center in Petah Tikva, Israel. Levi's team collected data on 1,087,358 Israeli men and 707,212 Israeli women. They had weight assessments at ages 16 to 19 between 1967 and 2002. Follow-up continued until 2012. The final sample included 1,794,570 participants.
Over an average follow-up of 23 years, 2967 participants developed colorectal cancer, the researchers found. Among men, 1403 had colon cancer, and 574 had rectal cancer. Among women, 764 had colon cancer, and 226 had rectal cancer. Overweight and obese teens in Israel had about a 53% higher risk for colon cancer as adults (for men: hazard ratio [HR] for overweight, 1.53; 95% CI, 1.28-1.84; HR for obesity, 1.54; 95% CI, 1.15-2.06; statistically significant from a BMI of 23.4 kg/m² [spline analysis]; for women: HR for overweight, 1.54; 95% CI, 1.22 to 1.93; HR for obesity, 1.51; 95% CI, 0.89 to 2.57; significant from a BMI of 23.6 kg/m²). For rectal cancer, obesity — but not overweight — was tied to more than double the risk for girls (HR, 2.03; 95% CI, 0.90-4.58; significant from a BMI of 30.6 kg/m²), and 71% percent higher odds for boys (HR, 1.71; 95% CI, 1.11-2.65; significant from a BMI of 29.6 kg/m²), compared to normal-weight teens.
"Notably, a high CDC healthy-range weight in adolescence might be associated with an increased risk of colon cancer in men; this observation needs further verification," the authors write.
Levi Z, Kark JD, Katz LH; et al. Adolescent body mass index and risk of colon and rectal cancer in a cohort of 1.79 million Israeli men and women: A population-based study [published online July 24, 2017]. Cancer. doi:10.1002/cncr,30819