The Department of Health and Human Services has neglected for more than five months the advice of its own task force to warn women exposed to the drug DES of recently revealed cancer risks, a consumer group charged yesterday.

A task force's report was submitted to HHS Secretary Margaret M. Heckler on Feb. 8 but was neither released nor acted on, according to Dr. Sidney M. Wolfe, director of the Public Citizen Health Research Group. Wolfe made a copy of the report public yesterday.

"I don't have any idea why Secretary Heckler has withheld from the public, from mothers, daughters and physicians, the recommendations which were made by her own scientists," Wolfe said.

HHS offered no comment yesterday when called for a response.

Last January a panel of scientists, after reviewing new evidence, urged the department to take "early actions" to alert the women and their doctors. These included writing articles for bulletins published by the Food and Drug Administration and the Centers for Disease Control in Atlanta and revising pamphlets on DES to reflect the findings.

The task force's recommendations were based on research showing an increased risk of breast cancer in women who took the drug while pregnant, and of precancerous changes of the cervices in their daughters.

From the 1940s until the 1970s, DES, or diethylstilbestrol, was widely prescribed for preventing miscarriages. It is estimated that 6 million Americans -- women and their unborn daughters and sons -- were exposed to the medication.

Since 1971, the drug has been implicated in more than 300 cases of a rare vaginal cancer affecting women whose mothers took it. It has also been linked to pregnancy complications in "DES daughters" and to reproductive-tract abnormalities in "DES sons."

Heckler convened the task force in response to reports last year indicating that breast cancer and cervical cancer might also be increased.

One study that followed more than 3,000 women who had taken DES while pregnant found that their risk of breast malignancies was about 50 percent greater than that of unexposed women.

Another study looked at more than 700 women exposed to the drug as fetuses, and found that they had twice the normal incidence of cell changes that sometimes progress to cervical cancer.

HHS' task force said that women who took DES should examine their breasts monthly and undergo mammograms according to a doctor's schedule. It advised women exposed before birth to have a pelvic examination and Pap smear (a test for cervical cancer) at least yearly.