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Science Friday > Archives > 2001 > March > March 23, 2001:

Hour Two: Hormone Replacement Therapy / Hominid Skull

Anthropologist Meave Leakey and colleagues report this week that they have found a 3.5 million year old fossil hominid skull in Kenya -- the skull of a hominid that could challenge the 'ancestor' status of the 'Lucy' skeleton found by Donald Johanson in Ethiopia in 1974. The find has been classified as a new genus and species, Kenyanthropus platyops, or the 'flat-faced man of Kenya.' Scientists feel the find is significantly different in several regards from Lucy (Australopithecus afarensis), including a flattened face and small molar teeth. In the paper, published in this week's journal Nature, the researchers do not argue which hominid might have evolved into modern humans, merely saying that now there is more than one possibility to be considered. We'll talk about the find and what it means.

The 3.5 million year old skull of Kenyanthropus platyops. Photo by Fred Spoor, © National Museums of Kenya. (larger image)

Then, we'll turn our attention forward several million years. Many women going through menopause use hormone replacement therapy. In fact, estrogen, one of the hormones used in the treatment, is the most-prescribed drug in the United States today. Hormone replacement therapy can help mitigate symptoms of menopause such as hot flashes and vaginal dryness. Over the long term, it may help delay osteoporosis and protect against heart disease.

However, deciding whether to begin hormone replacement therapy or not is difficult for many women. "Unopposed" therapies (using just estrogen without progestin, a type of treatment now rarely used) may increase uterine cancer risks. Some studies have indicated that hormone replacement may increase breast cancer risks. And a new report, published this week in the Journal of the American Medical Association, links long term hormone replacement therapy using the older, unopposed treatment with an increased risk of ovarian cancer -- although the risk is still quite small.

In this hour of Science Friday, we'll take a look at some of the issues surrounding this controversial treatment. Call in with your questions and comments at 1-800-989-8255, and share your opinions online in our Listeners' Lounge (registration required)

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Guests:
Daniel E. Lieberman
Associate Professor, Department of Anthropology
George Washington University
Washington, DC

Dr. Graham Andrew Colditz
Professor of Medicine
Nurses' Health Study
Harvard Medical School
Boston, Massachusetts

Dr. Roberta Ness
Associate Professor, Epidemiology, Medicine, Obstetrics and Gynecology
Director, Women's Health Programs
University of Pittsburgh
Pittsburgh, Pennsylvania

Books/Articles Discussed:

"New hominin genus from eastern Africa shows diverse middle Pliocene lineages." M. Leakey, et al. Nature 410, 433-440 (22 March 2001) "Estrogen Replacement Therapy and Ovarian Cancer Mortality in a Large Prospective Study of US Women Carmen Rodriguez, et al.Vol. 285 No. 11, March 21, 2001. (find more SciFri books here)

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Related Links:
National Geographic News - New Face Added To Humankind's Family Tree National Museums of Kenya

National Institute on Aging - Hormone Replacement Therapy
Estrogen Replacement Therapy and Ovarian Cancer Mortality in a Large Prospective
Study of US Women
National Cancer Institute:Menopausal Hormone Replacement Therapy
North American Menopause Society
WOMEN'S HEALTH INITIATIVE
AMWA: Q & A on Hormone Replacement Therapy and Breast Cancer Risk
OnHealth: Hormone Replacement Therapy: Should Women Take It?
InteliHealth: Hormone Replacement Therapy: A Difficult Decision