Radiation therapy might not be necessary for treating some forms of rectal cancer and lymphoma, sparing patients from the toxic treatment, a pair of new clinical trials show.
One trial found that rectal cancer patients whose tumors shrink in response to chemotherapy can safely skip the radiation therapy that’s normally provided prior to surgery, researchers reported at the American Society of Clinical Oncology (ASCO) annual meeting, in Chicago.
“We can successfully de-escalate treatment of rectal cancer and achieve the same high cure rates — keep patients disease-free with less long-term toxicity,” said lead researcher Dr. Deb Schrag, chair of medicine at Memorial Sloan Kettering Cancer Center in New York City.
In the second trial, the researchers determined that some people with lymphoma whose cancers respond to chemotherapy and immunotherapy don’t necessarily need radiation treatment.
Radiation therapy is often used to kill cancer cells or slow their growth, but it also damages lots of healthy cells. As a result, it can have dire long-term health consequences for patients.
For example, radiation treatment can lead to a variety of heart problems later in life, said Dr. Julie Gralow, ASCO’s chief medical officer.
“We cure these patients, they are radiated in their mid-30s, and then when they’re 50 they start having substantial cardiac problems from that radiation,” Gralow said.
“So they’re looking at, can we omit the radiation and keep the same excellent long-term survival?” Gralow continued. “In these cancers where we’re doing well with other treatments, the question is can we back off on radiation and improve the side effects for the patients? Can we treat with less?”
In the case of rectal cancer, radiation delivered to the pelvis can damage bowel, bladder and sexual function, and increase a patient’s future risk of pelvic fracture, Schrag said at an ASCO media briefing on Saturday.
Additionally, “it can cause infertility and premature menopause, which is a big deal because we are seeing increasing diagnoses of rectal cancer in people before the age of 50,” Schrag explained.
Globally, there are about 800,000 new rectal cancer diagnoses expected in 2023, with about