Association between childhood adiposity and gynecologic cancers: a mendelian randomization analysis

The causal relationship between childhood adiposity and gynecologic cancers remains unclear. We performed a two-sample Mendelian randomization (MR) study to elucidate the association between childhood adiposity and the risk of gynecologic cancers.

The three distinct indicators of childhood adiposity that constitute the exposures were childhood body mass index (CBMI), childhood body size at age 10 (CBS-10) and childhood obesity (COBE). In tandem, the study scrutinized the outcomes encompassing gynecologic cancers, including ovarian cancer (OC), endometrial cancer (EC), cervical cancer (CC) and their subtypes.

The results of the inverse variance weighted (IVW) method suggested that CBMI was positively associated with OC (OR = 1.219, 95% CI, 1.084-1.370, q-value = 9.45E-04), EC (OR = 1.417, 95% CI, 1.272-1.702, q-value = 2.04E-07) and some of their subgroups. There were positive association between CBS-10 and invasive mucinous ovarian cancer (IMOC) (OR = 1.923, 95% CI, 1.184-3.125, q-value = 0.008), EC (OR = 1.727, 95% CI, 1.396-2.137, q-value = 4.80E-07) and its subtypes as indicated by IVW. And it is suggested by IVW that COBE was positively associated with EC (OR = 1.088, 95% CI, 1.019-1.163, q-value = 0.012). Additionally, there was no association between CBMI, CBS-10 and COBE and the risk of CC.

Overall, this study indicates that childhood adiposity is causally associated with ovarian and endometrial cancers at the genetic level, but childhood adiposity is not causally associated with cervical cancer.