Does breast self-examination reduce mortality from breast cancer?

Surprisingly, despite costly national publicity campaigns in Australia over the past two decades to educate women about the life-saving benefits of breast self-examination (BSE), convincing evidence of any benefit remains elusive, according to Associate Professor Val Clarke, of Deakin University's School of Psychology at Melbourne.

Dr Clarke, who has been working with the Victorian Anti-Cancer Council's Centre for Behavioural Research in Cancer, says the few international studies of the effectiveness of BSE have been inconclusive because of fundamental design flaws.

"Among women diagnosed with breast cancer, and comparisons of those who reported practicing BSE with those who did not, there was a 36 % survival advantage five years post-diagnosis. "

Practicing BSE is no guarantee that any cancer will be diagnosed early, but not failure to practice BSE clearly reduces the opportunity to detect cancer early.

In Victoria, the lifetime risk of a woman developing breast cancer is one in 13. Breast cancer is more common in older women, although diagnosis of a breast cancer in a woman during her 30s is not uncommon.

Australia pursues three different strategies for reducing breast cancer mortality through early detection when prognosis is more positive:

• breast self-examination (BSE)
• clinical breast examination (CBE) by doctors
• Mammograms

"A review of the literature indicated that when CBE is used in a diagnostic setting, its sensitivity is around 96% - that is, it will yield a diagnosis of breast cancer as opposed to some other medical condition. In contrast, the mammogram's sensitivity as a diagnostic technique is nowhere near as high."

"The question is not whether we should also be using mammography, BSE or CBE, but whether we should be using all three, in conjunction, for early breast cancer detection. "

"In Australia, there is a much greater emphasis on the benefits of mammography. Free two-yearly mammograms are heavily promoted to the 50-69 age group, but not to women in the 40-49 age group, or to women under 40, who are also eligible. "

The relevance of BSE and CBE, says Dr Clarke, is that some women simply refuse to have mammograms - BSE and CBE constitute a safety net for anyone who develops a breast lump in the two-year interval between mammograms.

Not In My Body

You're female, and still relatively young and healthy. Your friend has just had a Pap smear for cervical cancer, and suggests you should do the same. On brief reflection, you ignore her potentially life-saving suggestion.

What went on here? Health messages advising all sexually active women up to the age of 70 - including teenagers - to have regular Pap smears - continue to meet resistance, or fall on deaf ears.

How do the mindsets of the "screener" and the "non-screener" differ?

Fear seems to be a factor - screeners show less fear of cancer than non-screeners. Most screeners knew of people who had been diagnosed with cancer, treated and survived.

"The other significant finding was that many non-screeners believe they don't need to be tested," Dr Clarke said. "These women tend to have idiosyncratic beliefs about cancer, or about their personal behavior that, in their own minds, excludes them from risk.

"For example, some said that stress causes cancer, and because they weren't stressed, they weren't at risk. Others were using so-called alternative therapies ward off cancer, even though there is no scientific or medical evidence that these remedies work.

Dr Clarke says that while non-screeners in the 'idiosyncratic belief' category constitute around 5 per cent of women in the community, in Victoria's population of more than 4 million, this equates to about 100,000 women.

Dr Clarke says current psychological theories do not work well in predicting screeners vs non-screeners, because they assume rationality and a basic knowledge of cancer, whereas many of these decisions are made on the basis of emotional reactions and idiosyncratic beliefs.

"But some women have a different cognitive model - they have a totally different understanding of what cancer is, and what causes it. It takes the form of 'I'm totally in tune with my body, so I'm certain nothing is wrong'. That sort of belief is horrifying.

Another study is comparing women's recall of when they were last tested, against actual medical records. Irregular screeners are significantly more likely to underestimate the time of their last test - commonly, they will guess two years, when the interval is actually closer to 2.5 or 3 years.

Such research, says Dr Clarke, offers health authorities valuable insights into why screening programs do not work as well as they should.

The solution, she suggests, is to tailor the message to these different mindsets, to circumvent resistance - in particular, to break through the attitudes of sexually active teenage girls and young women.

"It's an optimistic belief that one's own health outcomes are likely better than anybody else's," she said.

"People see themselves as having a better health outcome in all circumstances, because they feel they know what they are doing.

"The problem is that they are incapable of making a realistic assessment of personal risk, based on their own knowledge of themselves."