Australian scientists have discovered a defective gene MCC that aid in solving the age old mystery of why some colorectal cancer patients respond well to radiotherapy while others don't respond to the therapy at all.
The defective gene was a "double-edged sword" - it seemed to trigger the development of a tumor, but also make these less resistant and easier to kill off with radiotherapy, said Dr Laurent Pangon.
"Our findings show that MCC appears to be involved at a kind of DNA damage checkpoint, when the cell recognizes that there is DNA damage and that it needs to do something to correct it," News.com.au quoted Pangon as saying.
"If you lose MCC therefore you lose the ability of the cell to repair DNA damage ... and cancer would probably develop," Pangon said.
Pangon and colleagues studied 200 colorectal cancer patients and found that those with the defective MCC gene had an improved response to radiotherapy, and some types of chemotherapy, as their tumours were much less resistant to treatment.
"That is because those therapies kill cancer cells through inducing DNA damage and if the DNA damage response of the tumour is already defective, the therapies work better," he said.
The study can point doctors to the anti-cancer treatment most likely to work.
The research is published online by the journal Genes and Cancer.