Thousands of bowel cancer patients could be spared radiotherapy

Thousands of people with bowel cancer could be spared radiotherapy on top of chemotherapy after a study found it did not affect their survival chances.

Patients often undergo chemotherapy and radiotherapy before surgery to shrink tumours, making them easier to remove and reducing the risk of recurrence.

But researchers discovered rectal cancer patients could skip radiotherapy – which can cause nasty long-term side effects – if they responded well to chemo.

Study leader Dr Deb Schrag, of Memorial Sloan Kettering Cancer Center in New York, said the findings were “a big deal because we have been radiating pelvises to treat this type of rectal cancer for the past 30 years”.

She said most “intermediate risk” rectal cancer patients can be treated without pelvic radiation, adding: “[It] has real toxicities. It impairs bowel, bladder and sexual function and has increased risk of pelvic fractures and secondary cancers.”

Around 43,000 people are diagnosed with bowel cancer each year in the UK. Rectal cancer is the most common subtype, accounting for 20-30 percent of cases.

The study involved 1,194 patients with advanced rectal cancer. Half received the standard treatment of chemoradiation followed by surgery.

The rest started with just chemo. If tumours shrank by at least a fifth, they went on to surgery. If not, they had chemoradiation as usual, then an op.

Five years later, 79 percent of patients in the conventional care group were disease-free, compared with 81 percent in the other group.

Only nine percent of those in the second treatment group did not see their tumours shrink enough after chemo and needed radiotherapy.

Common side effects of radiotherapy also include sore skin, bladder problems, tiredness and infertility.

Dr Pamela Kunz, of the American Society of Clinical Oncology which hosted the Chicago conference where the research was presented, said it should change the way doctors treat this cancer.

She explained: “As we develop new therapies, we are exploring where we can eliminate toxic therapies for our patients. The findings of this study allow us to do just that.”

Prof Charles Swanton, Cancer Research UK’s chief clinician, said medics were keen to reduce drug or radiation exposure to cut side effects. He explained: “Pelvic radiotherapy is associated with major long-term side effects. Avoiding radiation is a major step forward.”

He added: “It’s also excellent for NHS resources, being able to avoid radiation and free up radiotherapy slots for other patients.”