Childhood Body Size At Age 13 Years And Associations With Ovarian Cancer In Adult Life

Background: Among women, body mass index (BMI; kg/m2) and attained height are positively associated with ovarian cancer. Few studies have, however, investigated associations with childhood body size. As such, it remains largely unknown if it is body size development in early life or adult life that contributes to these associations. Therefore, we examined if childhood BMI and height at age 13 years were associated with ovarian cancer in adult life. Methods: Individuals were girls in the Copenhagen School Health Records Register who were born between 1930 and1989 and had available measures of height and weight at age 13 years. BMI and height z-scores were calculated from an internal age-specific reference. Via a personal identification number, individuals were followed up for ovarian cancer diagnosis by linkage to the Danish Cancer Registry. Cox proportional hazard regressions were performed and stratified by birth cohort. Results: Among the included 137,416 girls, 1048 cases of ovarian cancer occurred during 5.2 million person-years of follow-up with a median age of diagnosis of 57 years (range: 19-83 years). BMI tended to be non-linearly associated with ovarian cancer such that only the heaviest girls had positive associations with ovarian cancer. Compared with a 13-year-old girl of average-size (BMI z-score = 0, corresponding to a weight of 45 kg and a height of 157 cm), an equally tall girl who was at least 9 kg heavier (corresponding to a BMI z-score u003e1.28) had a hazard ratio (HR) for ovarian cancer of 1.33 (95% confidence interval [CI]: 1.08-1.63). In analyses adjusted for childhood height, the association was only marginally attenuated (HR = 1.30, 95% CI: 1.06-1.60). Childhood height was positively and statistically significantly associated with ovarian cancer. At age 13 years, per height z-score (corresponding to approximately 7 cm), the HR for ovarian cancer was 1.07 (95% CI: 1.01-1.14). Conclusion: Body size in early life was associated with ovarian malignancies later in life suggesting that childhood height and BMI might impact if women are later diagnosed with ovarian cancer. As ovarian cancers vary widely in their etiologies, associations with childhood body size may differ depending on the tumor type, which will be investigated. Citation Format: Julie Aarestrup, Michael Gamborg, Nicolas Wentzensen, Lian G. Ulrich, Thorkild IA Sorensen, Jennifer L. Baker. Childhood body size at age 13 years and associations with ovarian cancer in adult life. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr LB-375.