Thousands of bowel cancer patients could be spared radiotherapy with no impact on their survival

Thousands of patients with colorectal cancer could be spared debilitating radiotherapy without affecting their survival, research shows.

Most people with advanced colon cancer currently undergo radiotherapy, followed by chemotherapy and then surgery.

But one large study found that more than nine in ten patients who skipped radiotherapy were just as likely to be alive five years later as those who had radiotherapy.

Experts said avoiding radiotherapy would be a ‘great step forward’ for patients, who would be spared debilitating side effects such as pelvic fractures, impaired bowel, bladder and sexual function and secondary cancers.

They presented their findings at the world’s largest cancer conference in Chicago and called for clinical practice change.

Dr. Deb Schrag, of the division of medicine at Memorial Sloan Kettering Cancer Center, New York, said: ‘Most patients with intermediate risk rectal cancer can be cured without pelvic radiation.

“It’s a big deal because we’ve been irradiating pelvises for the past 30 years to treat this type of rectal cancer.

“While it works well, pelvic irradiation has real toxicities. It reduced bowel, bladder and sexual function and has an increased risk of pelvic fractures and secondary cancers. It can affect bone marrow function, which can affect chemotherapy in the future.

‘We asked the question, can we use the radiation more selectively and only give it to people who do not respond to chemotherapy instead of giving the radiation to everyone as standard?

“There were no meaningful differences between the two approaches and only 9 percent of patients in the radiation arm required radiation.” Each year around 40,000 people in the UK are diagnosed with bowel cancer, of which around 20 to 30 per cent are diagnosed with rectal cancer.

The study involved 1,194 patients with stage 3 rectal cancer, meaning the cancer has spread to the lymph nodes but not to other organs.

About half did not receive radiation unless they did not respond to chemotherapy followed by surgery to remove the tumor.

Of this group, only nine percent were also found to need radiotherapy, according to findings published in the New England Journal of Medicine.

One study found that more than nine in ten patients who skipped radiotherapy were just as likely to be alive five years later as those who had radiotherapy (File image)

After five years, 80.8 percent of those who had just received chemotherapy and surgery were free of disease, compared with 78.6 percent of those who had received both radiotherapy and chemotherapy before surgery.

Recurrence rates were very low and similar for both groups at two percent, the study found.

While radiotherapy has been part of the standard treatment for this cancer for decades, chemotherapy has improved.

Cancer Research UK’s chief physician, Professor Charles Swanton, said oncologists were increasingly looking for ways to reduce exposure to drugs or radiation to limit long-term side effects for patients.

‘Pelvic radiotherapy is associated with major long-term side effects. I think avoiding radiation is a big step forward. And this non-inferiority study has shown that it seems that for most patients you can avoid radiation.

He added: ‘I think you’re probably talking about thousands of patients a year in the UK [who could be spared radiotherapy].

‘It’s excellent for NHS resources as it can avoid radiation and free up radiotherapy slots for other patients.’ Dr. Pamela Kunz, an ASCO expert, said it was “truly a case of less is more.”

She said: ‘The study shows that we can protect selected patients from radiation without compromising efficacy.

“This leads to improved quality of life and reduced side effects, including things like early menopause and infertility.” This test changes the practice.’