Value of Cancer Screening
in Older Women Doubted

Women over 70 are having an increasing number of mammograms and Pap smears despite a lack of scientific evidence to support widespread testing of older women, a new study contends.

Considering the "substantial" societal costs of continuing to perform breast and cervical cancer tests in the oldest age groups, extensive testing may not be justified, argue researchers from Duke University Medical Center.

"We are questioning, is this really a good use of health-care resources," says Dr. Truls Ostbye, a professor in Duke's department of community and family medicine and the lead author of the paper. "We're not necessarily saying it is not, but certainly a lot of money is being spent."

Some 4.6 million screening mammograms and 3.7 million Pap tests were performed in 2000 on women 70 and older for a total cost of $507 million, the authors estimate. That's up from an estimated 3.7 million mammograms and 2.8 million Pap tests in 1996 at a cost of $411 million. The dollar estimates do not include any follow-up evaluation and care that women may require.

The study, based on a review of existing data, appears in the November/December issue of the Annals of Family Medicine.

The Duke study fuels an ongoing debate over the value of common cancer screenings in older women. Some researchers say the benefits outweigh the cost, while others see little value.

Ostbye and colleagues suggest early detection isn't as lifesaving for older women as it is for younger and middle-age women.

"As you get older, the number of years that you have left is short and, unfortunately, there are very many other diseases that are competing for your health," he says.

So it becomes "more doubtful" that extensive screening among these women "can postpone death," he adds.

Research as fresh as last week, however, seems to contradict him. A study reported last week found that, in general, the benefits of screening women over 65 for breast cancer every two years outweigh the costs and possible side effects. The exception may be women who suffer from serious chronic health conditions or who aren't expected to live very long, it said.

The debate rages on in part because there are few rigorous studies involving older women. As a result, clinical guidelines on cancer screening are "ambiguous and inconsistent for elderly women," the Duke authors write.

The American Cancer Society, the nation's leading voice on the war on cancer, recommends annual mammograms beginning at age 40 and sets no upper age limit on breast cancer screenings. It does say further research is needed on the risks and benefits for women with serious chronic health problems or short life expectancy.

As for Pap smears, it says women 70 years or older can choose to stop those screenings if they've had at least three normal Pap tests in a row and no abnormal Pap results in the last decade. The exceptions are women with a history of cervical cancer, DES exposure before birth, HIV infection, or a weakened immune system. These women should continue having Pap tests as long as they are in good health, it recommends.

To assess the frequency of breast and cervical cancer screenings, Ostbye and colleagues examined data collected from two earlier studies funded by the National Institute on Aging. The data covered the period from 1993 to 2000.

Among women aged 50 to 64, roughly 70 percent to 80 percent had a mammogram in the previous two years and 75 percent had received a Pap smear over the same time frame. Screening rates dropped for women 85 to 90 years of age, with 40 percent receiving mammograms and 25 percent having Pap smears.

Breast and cervical cancer testing rates increased in all groups, including older women, from 1995-1996 to 2000.

Without specific cancer screening guidelines, doctors are erring on the side of caution by testing women who may not benefit, the paper notes. For example, according to an earlier study cited in the paper, as many as 240 "very healthy" 80-year-olds would need to have mammograms to prevent one breast cancer death.

"This is the best-case scenario," Ostbye says. "You would have to screen many more 80-year-olds because most aren't very healthy."

He and his Duke colleagues argue that screening of the elderly "should be better and more specifically addressed in national clinical guidelines."

But Robert Smith, director of cancer screening at the American Cancer Society, defends national guidelines.

While some women who receive these tests might not need them, he believes "under-screening" is a larger problem than "over-screening," as physicians start withholding or neglecting preventive care for older women.

"The fact of the matter is there's no way to avoid some degree of waste because you inevitably contribute to deaths that you otherwise would have wanted to avoid," he says. "There's always going to be a cost to reducing deaths from cancer."

More information

To learn more about screening for breast cancer and cervical cancer.

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