Human Chorionic Gonadotropin Does Not Correlate with Risk for Maternal Breast Cancer: Results from the Finnish Maternity Cohort

Abstract

Human chorionic gonadotropin (hCG) is necessary for the maintenance of early pregnancy and promotes normal breast cell differentiation. Administered hCG reduces risk of carcinogen-induced breast cancer in animal models, and higher circulating hCG concentrations were associated with significantly lower long-term risk of breast cancer in a prior nested case-control study. In this study, we investigated early pregnancy hCG concentrations and subsequent breast cancer risk. We conducted a nested case-control study with 1,191 cases and 2,257 controls (matched on age and date at blood collection) in the Finnish Maternity Cohort (FMC), a cohort with serum samples from 98% of pregnancies registered in Finland since 1983. This study included women with a serum sample collected early (<140 days gestation) in their first pregnancy resulting in a live, term birth. Breast cancer cases were identified via the Finnish Cancer Registry. Age at breast cancer diagnosis ranged from 22–58 years (mean: 41 years). hCG was measured using a solidphase competitive chemiluminescence assay. Odds ratios (ORs) were calculated using conditional logistic regression. We observed no association between hCG and breast cancer risk, overall (Quartile 4 vs. 1, OR: 1.14 95% confidence interval [0.94–1.39]), by estrogen and progesterone receptor status, or by ages at first term birth or diagnosis. Associations did not differ by time between pregnancy and diagnosis (e.g., <5 years, ORQ4 vs. Q1: 1.10 [0.64–1.89]; ≥ 15 years, ORQ4 vs. Q1: 1.36 [0.86–2.13]; pheterogeneity=0.62). This large prospective study does not support an inverse relationship between early pregnancy serum hCG concentrations and breast cancer risk.

Maternal reproductive hormones and angiogenic factors in pregnancy and subsequent breast cancer risk

“…In contrast, higher concentrations were inversely associated with risk among women who were 40+ years at diagnosis (n = 91) or diagnosed 10 or more years after the pregnancy (n= 99). Our results for hCG are consistent with a recent, larger study in the Finnish Maternity Cohort, however, which found no association between hCG concentration and breast cancer overall, or by hormone receptor subtype, age at first-term birth, age at diagnosis, or time between blood collection and diagnosis [32]. …”

Human Chorionic Gonadotropin and Breast Cancer

“…Lukanova et al found that women with HCG levels in the top tertile tended to be at lower risk of breast cancer than women with HCG levels in the lowest tertile [ 77 ]. No such inverse relationship between early pregnancy serum HCG concentrations and breast cancer risk was found by other studies including in a recent large prospective study from Finland including 1191 women with invasive breast cancer and 2257 controls [ 78 ]. The beneficial effect of HCG was supported by the results of two studies examining the effect of treatment with recombinant HCG.…”

Good Guy or Bad Guy? The Duality of Wild-Type p53 in Hormone-Dependent Breast Cancer Origin, Treatment, and Recurrence

“…However, it is noted that not all studies supported hCG as a prospective treatment for breast cancer. In contrast, a large prospective study (1191 women with invasive breast cancer and 2257 controls) completed in Finland showed no correlation between early pregnancy hCG serum concentrations and breast cancer risk [ 57 ]. What is coming to light is that there are different forms of hCG, which may have opposing effects on breast cancer development, driving different outcomes in breast cancer risk [ 54 ].…”