Markers that can predict cancer spread could save women from unnecessary chemotherapy

Women with early breast cancer could avoid needless chemotherapy thanks to work carried out in Chicago on identifying biochemical markers which indicate whether or not cancer is likely to spread to other parts of the body, the 3rd European Breast Cancer Conference in Barcelona heard today (Saturday 23 March).

Ruth Heimann, Associate Professor in the department of radiation and cellular oncology at the University of Chicago, USA, said that patients with early breast cancer which has not spread to the lymph nodes (node-negative) are usually offered chemotherapy as a safety precaution, even though they have a 70-80% chance of being cured of the disease by just having the tumour surgically removed without any follow-up therapy.

“With the available prognostic markers we cannot identify those patients who will develop metastatic disease,” she said.

However, Prof Heimann has now discovered four biochemical markers that appear to be significant in predicting a woman’s likelihood of developing metastatic disease.

She studied tissue taken from women with node-negative breast cancer who had been treated by surgery alone up to an average of 14 years ago. She looked for the markers which are already known to play a role in cancer metastasising, and found that markers for p53 (the tumour suppressor gene which is involved in many cancers), E-cadherin (the gene involved in making cells stick together), and nm23H1 and MMP-2 (two genes involved in cell invasion), were detectable in the tissues and could be used to predict the outcome of node-negative breast cancer.

“These markers were independent predictors of outcome, whereas the traditional indicators of tumour size and grade, were not independent,” said Prof Heimann. “With these markers we can, on one hand, identify node-negative patients with very low likelihood of metastasis, and on the other hand, a group with a very high likelihood of metastasis.

“If we have a more accurate knowledge of the risk of metastasis in an individual patient, based on these biomarkers, we could tailor treatments, and give chemotherapy only to the women who really need it.

“However, despite the fact that we can identify women with a low probability of metastasis and a high probability, there is still a middle group of women in whom further work needs to be done.”