Still Too Few Women in Cancer Trials

June 9 -- MONDAY, June 8 (HealthDay News) -- Women are underrepresented in clinical cancer research published in the world's most influential medical journals, a new study says.

The findings raise concerns that scientists aren't learning all they can about gender differences in response to chemotherapy and other cancer treatments.

Researchers analyzed 661 prospective studies about types of cancer that afflict both genders at relatively equal rates, including colon cancer, oral cancers, lung cancer, brain tumors and lymphomas. The studies included more than one million participants in all.

Women made up 37 percent of participants in studies not receiving government funding. Studies receiving government funding had a slightly better record of including women, with women representing 41 percent of participants, the analysis showed.

"In the vast majority of individual studies we analyzed, fewer women were enrolled than we would expect given the proportion of women diagnosed with the type of cancer being studied," study author Dr. Reshma Jagsi, assistant professor of radiation oncology at the University of Michigan Medical School, said in a university news release.

"It's so important that women are appropriately represented in research. We know there are biological differences between the sexes, as well as social and cultural differences. Studies need to be able to assess whether there are differences in responses to treatment," she added.

In the report, published in the July 15 issue of the journal Cancer, the researchers looked at all original clinical cancer research published in 2006 in five major cancer journals (the Journal of Clinical Oncology, the Journal of the National Cancer Institute, The Lancet Oncology, Clinical Cancer Research and Cancer) and three major general medical journals (the New England Journal of Medicine, the Journal of the American Medical Association and The Lancet).

The importance of including women in clinical research is stressed in the U.S. National Institutes of Health's Revitalization Act of 1993, which states that enrolling adequate numbers of women in clinical trials allows for subgroup analysis.