Scientists identify gene signature that predicts cancer spread
A team of scientists in the Netherlands has discovered a genetic protein marker that could save breast cancer patients from undergoing unnecessary chemotherapy treatment, reports the Lancet. The research conducted at the Erasmus medical school in Rotterdam identified a signature of 76 genes that predicted which patients would go on to develop cancer in another part of the body within five years. Currently, no reliable diagnostic tools exist to predict which breast cancer patients are most likely to relapse. John Foekens and his team focused on a condition called lymph-node negative breast cancer. If diagnosed in time (when the cancer has not spread to the lymph nodes), up to 70 per cent of breast cancer patients who are given surgery or radiotherapy for the disease are cured. However, the treatment is usually followed by chemotherapy of hormone treatment as a precaution to prevent recurrence. Yet many women do not actually need the follow-up therapy. With this new diagnostic tool, Dr Foekens hopes to spare low-risk patients from unnecessary treatment. The research team took tumour samples from 286 women whose breast cancer was confined to the breast (lymph-node negative) and who did not receive hormone treatment or chemotherapy after surgery. All the patients were given genetic testing and were monitored for an average of eight years. During that time, 33 per cent of women developed cancer recurrence in another part of their bodies. The researchers then analysed 115 of the tumours for a selection of markers and discovered a 76-gene signature that could predict which women are at high risk of recurrence. The gene signature was subsequently tested on the genetic profile of 171 lymph-node negative patients and was 93 per cent accurate in predicting those who had a recurrence within five years. It was less precise, however, in predicting patients whose cancer did not return in that time (48 per cent sensitivity). 'Since only 30 per cent to 40 per cent of untreated lymph-node negative patients develop tumour recurrence, our prognostic signature could provide a powerful tool to identify those patients at low risk preventing over-treatment in substantial numbers of patients,' said Dr Foekens. 'If confirmed in further studies, the recommendation of additional hormone or chemotherapy in patients with lymph-node negative breast cancer could be guided by this prognostic signature.' However, this is not the first time researchers identify genetic signatures for recurrent breast cancer. Critics warn that although this study is the largest of its kind, it may still be too small to offer a final selection of the right genes for analysis.
Countries
Netherlands