Scientists find a way to detect which breast abnormalities may develop into cancer

Scientists at the Royal Liverpool University Hospitals in the UK have found a way of testing whether certain abnormalities in a woman’s breast are likely to go on to develop into breast cancer, the 3rd European Breast Cancer Conference in Barcelona heard today (Wednesday 20 March).

Armed with information from the test, doctors could then consider whether the at-risk women should be offered prophylactic anti-oestrogen treatment such as tamoxifen or more frequent screening.

However, Dr Abeer M. Shaaban, a Specialist Registrar in the hospital’s department of Cellular and Molecular Pathology, warned that, while the test itself was fairly straightforward to do, it might be many years before it could lead to the development of prophylactic treatments, especially as clinical trials are still being run to test the effectiveness of anti-oestrogens such as tamoxifen in preventing breast cancer.

Hyperplasia of usual type (HUT) is a benign abnormality in the breast. Although it is formed by cell proliferation, it is not cancer, but it is associated with a slightly increased risk of cancer developing subsequently. Women who have HUT have a risk of developing breast cancer of between 1.5 and 2 times that of the general population. Normally HUT cannot be detected by self-examination, and is usually spotted during screening and diagnosed following a biopsy.

Dr Shaaban, working with Professor Christopher S. Foster, head of the hospital’s Pathology Laboratories, studied 674 biopsies from a 20-year period between 1979 and 1999 to see whether those samples that belonged to patients who had subsequently developed breast cancer contained different biological signals to samples from women who did not develop cancer. The biopsies included cases from 120 women who subsequently developed cancer and 382 who did not during the 20-year follow-up.

She found that in samples from women who had developed breast cancer subsequently, there was a high proportion of cells with receptors for the signals given out by ER alpha (an oestrogen receptor protein), Ki-67 (a nuclear protein which is only expressed in dividing cells), and hsp27 (an oestrogen-related heat shock protein).

Dr Shaaban said: “Our data show that there are clear differences between various types of HUT. By identifying those cases of HUT which show a high proportion of cells which have positive signals for ER alpha, Ki-67 and hsp27, it is possible to point to a subset of women with HUT who are at high risk of developing breast cancer.

“This study is an early step on the way to refining breast cancer risk. HUT has been reported increasingly since the advent of mammography. By identifying lesions likely to progress to breast cancer early in patients` lifetimes, prophylactic anti-oestrogen therapy could be offered to this particularly high-risk group. Moreover, for those who prove not to be at high risk, regular mammographic screening might not be a necessity. However, several years of clinical trials with long follow-up periods lie ahead before anti-oestrogens could be used as an effective preventive tool.”