Hormone lowers cancer risk
2009-01-01 16:28
New York - High levels of a hormone that is produced in early pregnancy may lower a woman's risk of breast cancer, according to new research.
In a study published in the American Journal of Epidemiology researchers in Europe and the United States found that high levels of human chorionic gonadotropin (hCG) seems to have a protective impact against breast cancer.
"Although the results of the current study must be regarded as suggestive and should be interpreted with caution, they are consistent with a protective effect of elevated hCG levels during pregnancy on long-term risk of breast cancer," the researchers said in the study.
Scientists know that childbearing provides some protection against breast cancer, but the biological reasons for the benefit are not understood.
The researchers, led by Dr Annekatrin Lukanova at the German Cancer Research Centre in Heidelberg, used data from the Northern Sweden Maternity Cohort to study whether elevations in circulating hCG and another hormone called alpha-fetoprotein during the first trimester of pregnancy have a long-term protective effect against breast cancer risk.
Lower risk
The researchers found no overall association between breast cancer and either hormone. But they did find that there was a trend toward lower breast cancer risk for women with the highest hCG levels, compared with women with the lowest levels.
The protection afforded by higher hCG levels was limited to women diagnosed after the average lag time to cancer diagnosis, which was 14 years, the report indicates.
Alpha-fetoprotein concentrations were not associated with breast cancer risk in any of the overall or subgroup analyses.