 |
Oct. 1, 2002 |
|||||||
|
Browse Archives n Lung n Breast n General n Prostate n Leukemia n Lymphoma n Colon n News/Issues |
Breast self-exams don't increase survival by Michael O'Leary SEATTLE -- Oct. 1, 2002 -- One of the largest populations studies ever undertaken has found that, women taught to practice breast self examination more often detected breast tumors than women who did not perform the exams, but did not detect the tumors early enough to make difference in survival. The finding runs counter to the theory that detecting breast tumors earlier when they are smaller and less likely to have spread beyond the breast would reduce breast cancer deaths. The research team led by Dr. David Thomas of the Fred Hutchinson Cancer Research Center, suggest there may be two reasons for the result. "It may be that either the women didn't practice breast self examination as diligently as we thought," Thomas said in interview. "Or the technique isn't sufficiently sensitive to make a difference." The final results of the mammoth Shanghai Breast Self Examination Trial were published today in the Journal of the National Cancer Institute. The trial involved 266,064 women associated with 519 textile factories in Shanghai who were followed for 12 years, making the study among the largest medical intervention studies ever attempted. Approximately half of the women were given comprehensive training in breast self-examination and video training reinforcement after 1 and 3 years. The other half were given information about breast self-examination, but were not given formal training. After 12 years 154 women in the instruction group developed breast cancer and died of breast cancer compared to 158 women in the comparison group. Women in the instruction group did have more breast biopsies and diagnoses of benign breast lesions than women in the control group, however, there was little evidence that cancers were detected at an earlier stage in the BSE instruction group. Likewise the number of women with lymph node involvement at the time of diagnosis was similar between the two groups. One limitation of the study, the researchers pointed to was an inability to ensure that the women in the instructional group actually did perform the exam monthly as instructed. "Although women were strongly urged to practice BSE monthly on their own, the frequency of the practice outside the clinic setting is unknown," the researchers wrote. "An attempt was made to ask a sample of women how frequently they practiced BSE, but the responses were uniformly "monthly" and hence not considered reliable. It can, however, be concluded with certainty that practicing BSE a minimum of every 5 months for 45 years did not have an effect on breast cancer mortality." Writing in an accompanying editorial, Russell Harris and Linda S. Kinsinger concluded that with the evidence of this well-designed, very large trial, breast self-examination cannot be substituted for regular mammography. "Teaching BSE seems like a good idea: it sounds inexpensive, simple, and potentially applicable to people without access to mammography," they wrote. "It allows women to take charge of their own health and teaches them about their bodies. But the evidence is increasingly clear and difficult to ignore: BSE is more expensive than it first appears. It is difficult to learn to do well, and it is difficult to continue to do long-term. "Most importantly, at least for the great majority of women whose BSE practice is not optimal, it does not reduce the risk of dying of breast cancer." Faced with this and earlier trials that produced essentially the same result, the Harris and Kinsinger conclude that the Shanghai BSE Trial should lead to a change in clinical practice. "Until we receive further evidence (one trial has not yet reported results) North American physicians can stop spending time routinely teaching women's fingers to do BSE." SOURCE: J Natl Cancer Inst 2002; 94: 1445-1457 |
Related Stories Anxiety over breast self-exams may lead to low compliance Canadian panel recommends women stop breast self-exams |
||||||
SUBSCRIBE
FREE