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.