Breast self-exams found not to prevent deaths

Study follows others that challenged practice of checking for cancer

October 02, 2002|By Jonathan Bor and Erika Niedowski | Jonathan Bor and Erika Niedowski,SUN STAFF

Teaching women to examine their breasts for early signs of cancer does not appear to save lives, according to a decade-long study of Chinese women that is sure to fan the debate over early detection of the disease.

Scientists who studied 266,000 female factory workers in Shanghai found that instruction in self-examination led to more biopsies of benign lumps but did not prevent breast-cancer deaths. The study, the largest controlled trial of self-exams ever conducted, included women who generally did not have access to screening mammograms, which are widely available and encouraged in the United States.

The Seattle scientist who led the study called for research in this country to determine if self-examination is a useful addition to annual mammograms and clinical exams by doctors. But he added that there is no evidence that the technique - long advocated by the American Cancer Society and other health organizations - works.

"If you're going to do it, do it well, and be aware that it might not work and it might increase the chance of a benign breast biopsy," said Dr. David Thomas, an epidemiologist with the Fred Hutchinson Cancer Research Center in Seattle and lead author of an article in today's Journal of the National Cancer Institute.

During the past year, several studies have challenged the benefits of accepted screening practices for breast cancer, provoking sharp disagreements among researchers and clinicians and confusing women about what to do.

A Canadian government review panel that looked at several studies of breast exams in Russia, China, Britain and Canada concluded last year that self-exams did not save lives and should not be promoted as a way to detect early breast cancers. Some scientists questioned those conclusions.

Then two Danish researchers stirred controversy last October by writing that the most widely cited studies supporting annual mammograms were so flawed they should be discarded. The authors, writing in a British medical journal, said the scans turn up many benign lumps along with slow-growing cancers that would not prove fatal, and do not detect fatal cancers early enough to reduce the risk of dying.

But the U.S. Preventive Services Task Force, a government panel charged with reviewing clinical studies, later concluded that the case for annual scans was indeed strong. The federal government then strengthened its recommendation for women to obtain annual mammograms, urging them to begin at age 40 rather than 50.

Yesterday, Thomas said that women should not consider self-examination a substitute for screening mammograms, which he supports. An accompanying editorial in the journal argues that American physicians can stop spending time routinely teaching women to conduct self-exams and spend more time on clinical exams.

"Routinely teaching BSE [breast self-exam] may be dead, but giving women information - and continuing research on the effectiveness of excellent physical examination - should live on," wrote Dr. Russell Harris and Dr. Linda S. Kinsinger of the University of North Carolina School of Medicine.

Checks are defended

Already, the study has drawn sharp rebukes from doctors who said the exams - though far from perfect - can help to flag tumors that appear in the intervals between mammograms and doctor visits.

"We know you can't have people doing it perfectly or with perfect regularity," said Dr. Gauri Bedi, a breast surgeon at Mercy Medical Center. "But whatever they do will only help."

In the study, scientists recruited 266,000 female factory workers and randomly assigned them either to receive instruction in self-examination or to get no training. The women in the "self-exam" group were taught a technique that is widely advocated in the United States. It involves palpating each breast in a circular motion while standing and while lying down, squeezing each nipple for discharge, and looking in the mirror for signs of dimpling or asymmetry.

After their initial instruction, women were taught again one and three years later and were asked to practice frequently before a factory medical worker. Though Thomas said the technique should, in theory, turn up small tumors that can be treated and cured, he said these women died just as frequently of breast cancer as women who received no instruction.

A leading official with the National Cancer Institute said yesterday that the agency doesn't urge self-examination because evidence that it works has been lacking.

Dr. Peter Greenwald, the NCI's chief of cancer prevention, said self-exams made sense in the 1970s because many cancers that doctors diagnosed were initially discovered by women themselves. "As we got more and more studies, the studies did not give a clear picture of a benefit against mortality," Greenwald said. "They did show benefits of both mammograms and a careful clinical examination" by a doctor.

Mammography urged

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