Pelvic Radiotherapy May Cause Chronic Inflammation in Some Cancer Survivors

Survivors of cancer who underwent pelvic radiotherapy may cause them to live with low-grade chronic inflammation within the lower intestine about 20 years after treatment. A recent study has been published by researchers at the University of Gothenburg.

According to the National Cancer Institute, radiotherapy is a high energy radiation that can shrink cancer cells and shrink tumors. This is possible due to x rays, gamma rays, neutrons and protons. Radiation that is used to kill cancer cells and shrink tumors can be outside of the body, or from a device placed near the body.

In order to slow down or get rid of cancer, radiotherapy is necessary. Although it has advanced immensely within the past few years, radiotherapy can still negatively affect healthy tissue where the radiation is taking place. The study noted that cancer survivors involved may have had cervical, prostate or rectum cancers.

The study focused on the side effects of radiotherapy within the lower abdomen in cancer survivors. Radiotherapy within the pelvic area can negatively affect the thin line of mucus that protects the mucous membrane from bacteria. Radiotherapy removes this thin layer, causing bacteria to spread within the body and to the intestine. This may also have an effect on low-grade inflammation that was found within the intestine in patients that had been exposed to radiotherapy years prior.

There were 28 individuals who were analyzed within the study, 24 being cancer survivors. The control group consisted of four patients who did not previously receive radiotherapy. Patients ranged from two years since radiotherapy to 20 years since radiotherapy. The study authors determined that median time between the end of radiotherapy to an intestinal biopsy was five years.

“It can be hard to detect low-grade inflammation,” said Sravani Devarakonda, a researcher at the University of Gothenburg’s Sahlgrenska Academy and lead author of the study. “This is the first time researchers have been able to show with certainty that this is happening in cancer survivors, a long time after pelvic radiotherapy has ended. We saw signs of low-grade inflammation as late as twenty years after radiotherapy.”

Although symptoms were common for survivors who previously underwent radiotherapy, the severity of symptoms ranged from tenesmus (constantly using the bathroom after feeling like the bowels weren’t fully released) to continuous diarrhea, the study established.

Researchers will continue to determine whether low-grade inflammation after radiotherapy causes these symptoms and which symptoms correlate to inflammation. The researchers are also investigating the intestines resistance to radiotherapy to depict long term symptoms for patients.

“Our study subjects included both patients who had received traditional radiotherapy and those who had the more targeted form, IMRT,” Devarakonda said. “We saw low-grade inflammation in both groups. The damage to the surrounding tissue can be limited by IMRT, but there are still long-term inflammatory changes.”

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