Nancy Baxter and her coauthors have shown that breast self-examination not only does no good but actually may cause harm.1 Perhaps the fault lies not in the concept itself, but in the way it is taught. Women are taught using plastic breast models to detect lumps (tumours) that are extremely small — from 5 mm to 10 mm in diameter. These tiny lumps, which women find in large numbers, are rarely cancers; this accounts, perhaps, for the harm in terms of false positives and related biopsies described by Baxter's team.2
Most of us do not fully appreciate the fact that 80% of breast cancers are detected by the woman herself or by her partner.3 When detected, the cancers are shockingly large, with average diameters of 30 mm.4,5 What's more, these large lumps are apparently discovered accidentally, even among women actively practising breast self-examination6 and participating in mammography screening programs.7 They are easy to feel and are noted by chance while bathing or showering, rolling over in bed or engaging in sexual activity. They can sometimes be seen by simple observation in a mirror. The only tools that seem to be necessary to detect these good-sized lumps are the hands and the eyes, tools that are available to all of the women in the world.
We have already proven that we know how to teach the technique of breast self-examination and I believe we now know what to teach women to look for: not tiny lumps that are rarely cancers, but the bigger, easier-to-detect lumps more likely to be malignant. Before we abandon breast self-examination, I think we should test it anew. Do we really want to abandon a technique that could help women find their tumours sooner than at present? Whether this early detection will change their outcomes may be debatable, but surely it is worth a try.
Signature
Leo Mahoney
Associate Professor of Surgery University of Toronto Toronto, Ont.
References
- 1.Baxter N, with the Canadian Task Force on Preventive Health Care. Preventive health care, 2001 update: Should women be routinely taught breast self-examination to screen for breast cancer? CMAJ 2001;164(13):1837-46. [PMC free article] [PubMed]
- 2.Thomas BD, Gao DL, Self SG, Allison CJ, Tao Y, Mahloch J, et al. Randomized trial of breast self-examination in Shanghai: methodology and preliminary results. J Natl Cancer Inst 1997: 89: 355-65. [DOI] [PubMed]
- 3.Ontario Division Breast Health Program. Breast health edu-kit. Toronto: Canadian Cancer Society Ontario Division; 1996. p. A-5.
- 4.Mahoney L, Csima A. Efficiency of palpation in clinical detection of breast cancer. CMAJ 1982: 127:729-30. [PMC free article] [PubMed]
- 5.Fisher B, Bryant J, Wolmark N, Mamounas E, Brown A, Fisher ER, et al. Effect of preoperative therapy on the outcome of women with operable breast cancer. J Clin Oncol 1998:16:2672-85. [DOI] [PubMed]
- 6.Anvinsen A, Elovainio L, Hakama M. Breast self-examination and survival from breast cancer: a prospective follow-up study. Breast Cancer Res Treat 1996:38(2):161-8. [DOI] [PubMed]
- 7.Miller AB, Baines CJ, To T, Wall C. Canadian National Breast Screening Study: 2. Breast cancer detection and death rates among women aged 50 to 59 years. CMAJ 1992;147(10):1477-88. [PMC free article] [PubMed]