Cancer Research UK-funded scientists have shown that an early chemotherapy drug invented in the 1940s has the potential to work against a genetic fault called HNPCC which is linked to bowel and other cancers. HNPCC is a hereditary condition involved in around five per cent of all bowel cancer cases. As well as bowel cancer, it puts people at increased risk of developing stomach, womb, ovarian, kidney and other cancers. Almost 40 per cent of people with HNPCC have a faulty MSH2 gene.

Scientists at the Breakthrough Breast Cancer Research Centre at The Institute of Cancer Research (ICR) in London sought to improve treatments for people with cancer caused by HNPCC by finding drugs which selectively kill cells containing the damaged MSH2 gene. In this study, the scientists tested a range of drugs on cells with the faulty MSH2 gene. They found that a drug called methotrexate worked particularly well in destroying these cells.

This study suggests that methotrexate could help to treat people whose cancer is driven by the MSH2 genetic fault, potentially opening the door to a more targeted treatment option. A new clinical trial has begun at The Royal Marsden NHS Foundation Trust to see how well methotrexate treats patents with advanced bowel cancer following this study.

Methotrexate is similar to a normal molecule called folinic acid, which is required for copying DNA. The drug prevents cells from making and repairing DNA - a process needed for cancer growth. It was one of the first chemotherapy drugs to be invented in the 1940s and is still used to treat a number of cancers today. But until now, it has not commonly been used to treat people with HNPCC.

The Institute of Cancer Research