BACKGROUND

Adult body size is related to ovarian cancer risks, but size in childhood may also influence risks. We investigated if childhood body mass index (BMI; kg/m2), height, and growth patterns were associated with ovarian cancer overall and by histologic subtypes, including effects of birthweight.

METHODS

A cohort of 155,958 girls from the Copenhagen School Health Records Register, born 1930-1989 with measured weights and heights from 7-13 years were included. During follow-up, 1,041 ovarian cancers were recorded. Overweight was defined using International Obesity Task Force criteria. Cox regressions were performed.

RESULTS

Compared with non-overweight girls, at most ages girls with overweight had increased risks of ovarian cancer overall (hazard ratio (HR) range: 1.24-1.34), mucinous, endometrioid and clear cell ovarian cancers, but not serous and other ovarian cancers. Childhood height had positive and significant associations with ovarian cancer overall (HR range: 1.07-1.10 per z-score) and the endometrioid subtype but not with the other sub-types. Adjusting for birthweight minimally altered the associations with childhood body size. In growth analyses, girls with overweight or who were tall at 7 and 13 years had increased risks of ovarian cancer overall compared with average-sized girls at both ages.

CONCLUSIONS

Ovarian carcinogenesis is linked to childhood overweight, tallness and growth, with variations across histological subtypes, suggesting that early life play a role in the origins of this disease.

CONCLUSIONS

These findings emphasize that healthy body size and growth during childhood are important as they may contribute to reducing ovarian cancer risks.