More than half of women with locally advanced breast cancer are likely to relapse within 5 years despite chemotherapy and radiotherapy and one in five low risk disease patients will develop a secondary cancer within 10 years. Unfortunately doctors are often unable to predict which women are more at risk, but preliminary results of research into a possible new test to resolve this problem will be announced at the European Society of Medical Oncology conference in Hamburg today (16 October 2000).
The findings will be presented by Dr. Pier Francesco Ferrucci of the European Institute of Oncology in Milan, and suggest that the key to recognising and giving more intensive care to women whose cancer is more likely to relapse may be a protein called maspin, produced by cells within the breast called epithelial cells.
Dr. Ferrucci's research has involved studying a group of 48 women who have had surgery and aggressive chemotherapy to treat their high risk breast cancer. All these patients were tested for the presence of breast epithelial cells in the bone marrow and peripheral blood system by various methods and all were found to have a micrometastatic disease. (That is they have tiny secondary tumours, typically in the bone marrow, that would not show up as a solid mass but that could be seen under a microscope on tissue samples.) For women such as these the outlook is generally not good.
The researchers measured the expression of a range of substances associated with breast cancer in the tissue and blood samples by various molecular and hystological methods. These substances included cytokeratins (which comfirm the presence of epithelial cells) and mammaglobin (which shows the presence of cells deriving from breast tissue) as well as the protein maspin, which has only recently been shown to have the ability to suppress tumours (probably as a result of inhibiting the growth of new blood vessels needed to feed the cancer cells). Dr. Ferrucci and his colleagues found that in general, women with higher levels of maspin were less likely to relapse. And the effect was particularly pronounced in ten of the women, who all had 20 or more lymph nodes affected by the disease. After around 15 months observation, eight of these women had not relapsed and all had high maspin levels. The two women in this group with low maspin levels had developed secondary cancers of the liver and lung.
Commenting on the research, Dr. Ferrucci said, "In our study we have simply found an association between the amount of maspin produced by breast cells and reduced risk of relapse in a particular group of high risk breast cancer patients. Our findings are backed-up by similar results recently published on other tumors derived from epithelial cells. With further evaluation, this has the possibility of becoming a test that could routinely help doctors identify at least some of the women more at risk of relapse so that they can be given more appropriate care and treatment. But it is important to stress that these results are preliminary. More trials on bigger groups of patients need to be done to confirm our findings."