Scientists in the Netherlands have developed a method of establishing which colon cancer patients would most benefit from chemotherapy after surgery.

The team, led by Professor Rob Tollenaar at Leiden University Medical Centre, analysed the full range of genes in the tumours of 121 patients with stage II colon cancer who had not received chemotherapy after their surgery, and announced their results at the 14th European Cancer Conference in Barcelona.

The patients were found to fall into two groups with distinct separate outcomes: The first were likely to survive for at least five years with no spread of the cancer, whereas the second were far less likely.

Thus a group with distinctly poor survival was established based solely on analysis of genetics; the first time this has happened for colon cancer. This means that the outcome of the disease can be predicted by genetic analysis of the tumour tissue in the future.

Addressing the guidelines laid down by the American Society of Clinical Oncology (ASCO), Professor Tollenaar suggested that their insistence that routine chemotherapy should not be given to patients post-surgery was too general, as his new method had the potential to accurately identify high risk patients who would benefit.

The team checked their findings against data from a different set of colon cancer patients, published in the Journal of Clinical Oncology in 2005, and found that it closely matched.

Refining their analysis further, a subset of 100 genes was identified which could predict the outcome just as accurately without the need for analysing the full range. Many of these are already thought to be related to the spread of colorectal cancer.

The Professor concluded that the research has great potential for more tailored anti-cancer treatment, though there is much more work to do.