'Male' Hormone Tied to Early Puberty in Girls
March 26, 2001 (New Orleans) --Low levels of the "male" hormone testosterone in young girls may play a key role in the early onset of puberty, which in turn might increase their risk for breast cancer, according to new research. This finding comes out of research aimed at understanding how commonly found genetic differences among people influence their risk of developing diseases such as cancer.
You may have heard that some cancers, including breast cancer, can run in families because certain rare gene mutations greatly increase the risk of developing the disease. What you may not know is that countless variations, or differences, in genetic makeup that occur in a large portion of the population also have an impact, albeit quite small, on the risk of developing cancer and other diseases.
One of the many outgrowths of the Human Genome Project is to identify some of these variations to see what kind of effect they have on health as a way to better understand how and why cancer develops, as well as to help direct prevention, early detection, and treatment strategies.
This study, reported at the annual meeting of the American Association for Cancer Research, is a prime example of how a very common genetic variation may lead to a slightly increased cancer risk.
At a press conference, expert Christine B. Ambrosone, PhD, said that the field of molecular epidemiology, which involves looking at how genetic differences affect health, is really starting to get off the ground. This study is one of several groundbreaking findings in this area. Ambrosone is a cancer epidemiologist at the Derald H. Ruttenberg Cancer Center of Mount Sinai School of Medicine in New York. She was not involved in the study.
Cancer researchers have found that girls who start their first period or start puberty at a relatively early age have a higher risk for breast cancer than girls who develop later. This suggests that hormones play a role in the development of breast cancer, begging the questions, which hormones are involved and how do they impact on cancer risk?
The hormone estrogen is most abundant in women and associated with the development of 'female' characteristics, like breasts. Testosterone, on the other hand, is seen in its highest proportions in men and is associated with 'male' characteristics, like muscle development and body hair. Both hormones, however, are found to some degree in both men and women.
Until recently, it was assumed that estrogen is a key player in puberty in young girls, but this new research points the finger at testosterone. Does that mean that testosterone levels affect cancer risk?
To help unravel the association between testosterone and puberty, Fred F. Kadlubar, MD, director of the division of molecular epidemiology at the FDA National Center for Toxicological Research in Jefferson, Ark., and colleagues studied nearly 200 white, black, and Hispanic girls aged 9-10. The researchers noted when the girls started puberty and recorded information about their diet, weight, and environment. Genetic testing also was used to identify any genetic differences among the girls that would explain how their hormones would affect their health.