Thousands of bowel cancer patients could be spared radiotherapy, a study suggests, after doctors discovered they could rely on chemotherapy and surgery alone to treat their disease. Radiotherapy has been used to treat bowel cancer patients for decades, but the side-effects can be brutal. It can cause problems that negatively affect quality of life, including infertility, the need for a temporary colostomy, diarrhoea, cramping and bladder problems. Now a clinical trial has found patients do just as well without radiotherapy as with it. The research was presented on Sunday at the annual meeting of the American Society of Clinical Oncology (Asco), the world’s largest cancer conference, in Chicago. The results were also simultaneously published in the New England Journal of Medicine and the Journal of Clinical Oncology. “Omitting radiation therapy can reduce short- and long-term side-effects that impact quality of life while providing similar outcomes in disease-free survival and overall survival,” Asco announced in a briefing paper. In the study led by doctors at Memorial Sloan Kettering Cancer Center in New York, 1,194 patients with rectal cancer were randomly assigned to one of two groups. One group received the standard treatment, radiation followed by surgery, and then, after the patients recovered from surgery, chemotherapy at their doctor’s discretion. The other group received the experimental treatment, which consisted of chemotherapy first, followed by surgery. At their doctor’s discretion, another round of chemotherapy could be given. Radiotherapy did not improve outcomes, the study found. After 18 months, there was no difference between the two groups in quality of life, and after five years, there was no difference in survival between them. The study represents an exciting emerging area of cancer research. Experts are increasingly starting to focus efforts on trying to find elements of treatments that can be eliminated to provide patients with a better quality of life. “We’ve reached a tipping point,” said Dr Pamela Kunz, an Asco expert who was not involved with the study. “As we develop new therapies, we are also exploring where we can eliminate toxic therapies for our patients’ wellbeing. “The findings of this study allow us to do just that, showing we can omit radiation therapy for some patients, improving quality of life without compromising efficacy.” The trial will continue to follow the participants and collect additional data on disease-free survival, overall survival, local recurrence-free survival and other secondary endpoints for eight years. “This is really a case of less is more,” said Kunz. “The study shows that we can spare select patients from receiving radiation. This leads to improved quality of life and reduced side-effects including things like early menopause and infertility. This trial is practice-changing.” Prof Charles Swanton, Cancer Research UK’s chief clinician, said doctors around the world were increasingly trying to find ways to reduce drug or radiation exposure to limit the long-term side-effects for patients. “Pelvic radiotherapy is associated with major long-term side-effects,” he told reporters in Chicago. “I think avoiding radiation is a major step forward.” Swanton said the research was “pretty solid”, adding: “On the basis of this, I think you can say you can safely avoid radiotherapy for many patients with this disease. I think it’s definitely an advance.”