Early hormone levels may lead to cancer.

Researchers have found preliminary evidence suggesting a man's lifetime risk of prostate cancer may be linked to the amount of the male hormone testosterone circulating in his body as early as puberty or even in utero, although direct evidence of this link remains to be shown. The two possible risk factors they found--high free testosterone levels in adulthood and a small shoulder span in relation to body size--appear to be unrelated to one another. However, they are both tied to hormone levels at various stages of development, notes Wendy Demark-Wahnefried, associate professor of surgery, Duke University Medical Center, Durham, N.C. Free testosterone refers to a type of hormone that is not bound to a protein and thus can freely enter cells throughout the body.

"We have to look at how hormone levels at different points in time actually determine the risk of prostate cancer. It is hypothesized that hormone levels throughout life--ranging from in utero to old age--drive such events as skeletal and muscle formation, fat deposition, baldness, and that these events may provide the initial stimuli and promotion for prostate cancer."

Demark-Wahnefried set out to measure the link between prostate cancer and factors such as height, weight, musculature, and baldness--all of which are related to hormones. She and her colleagues at the Duke Comprehensive Cancer Center found nearly a twofold increase in the risk of prostate cancer among men with...