Bowel cancer is a major killer
Scientists have found a way to cut the risk of recurrence of a form of bowel cancer to as little as 1%.
They found giving patients radiotherapy before having surgery to remove their tumour significantly improved their survival chances.
The Medical Research Council (MRC) trial looked at data from 1,350 patients in the UK, Canada, South Africa and New Zealand.
The results were presented to the National Cancer Research Institute.
The trial focused on patients with tumours in their rectum. About 13,000 new cases of this form of bowel cancer - more than a third of all bowel cancers - are diagnosed in the UK each year.
Traditionally, cancer found in the lower 15cm of the bowel is removed through surgery.
But surgeons cannot guarantee that all cancer cells will be removed, and there is a chance that the disease will return - often in an incurable form.
The latest trial, called CR07, compared people given radiotherapy before surgery and those given radiotherapy in a selective way after surgery.
The first group were given five daily treatments of radiotherapy followed by surgical removal of the tumour within two weeks.
The second group had surgery first, and those who still had cancer cells were then given follow up radiotherapy combined with drugs over a five week period.
Bowel cancer only came back within five years in one out of 20 people in the first group, which overall had a 75% chance of being alive after five years.
In the second group 17% had a recurrence of their cancer, and overall the five year survival rate was 67%.
Combining radiotherapy before the best possible surgery cut the risk of recurrence in the bowel to just 1%.
Lead researcher Dr David Sebag-Montefiore, a consultant clinical oncologist from Leeds, said: "There are approximately 35,000 cases of bowel cancer diagnosed every year in the UK alone.
"The results of the CR07 trial show that giving a patient radiotherapy before rectal cancer surgery gives them the best chance of avoiding re-growth of the cancer and of survival in the longer term."
Scans a factor
Dr Sebag-Montefiore said the results could lead to an increase in the use of pre-operative radiotherapy in the UK.
He said: "The trial results show that patients should have the opportunity to discuss the benefit of radiotherapy before rectal cancer surgery."
Dr Rob Glynne-Jones, chief medical advisor to the charity Bowel Cancer UK and a clinical oncologist at Mount Vernon Hospital, said: "The CR07 trial is a really important study, as it shows the considerable benefits of radiotherapy before surgery in the treatment of colorectal cancer.
"We need to remain aware, however, of the not insignificant side effects involved in treating large numbers of patients with radiotherapy.
"Our real problem, currently in the UK, is how to integrate the results of this trial into everyday practice, now that virtually all patients in the UK have an MRI scan.
"The MRI scan can tell you which patients are at a high risk of recurrence of the disease and the CR07 trial predates the routine use of MRI."