Radiation Dose May Increase Risk of Colorectal Cancer in Hodgkin Lymphoma Survivors

A high dose of radiation therapy and increased dose of procarbazine increased the incidence of colorectal cancer among Hodgkin lymphoma survivors, according to recent study results.

“These findings may enable individualized colorectal cancer risk estimations, identification of high-risk survivors for subsequent screening and optimization of treatment strategies,” the study authors wrote.

It is known that Hodgkin lymphoma survivors have a 2.8 higher fold rate of colorectal cancer development compared to those in the general population, which could be associated with radiation therapy or chemotherapy. It has been previously reported that there is an association between radiation dose with breast, lung, stomach, pancreatic and esophageal cancer after Hodgkin lymphoma. However, the association of radiation therapy with colorectal cancer was unclear.

So, researchers sought to determine the rate of colorectal cancer according to radiation dose among Hodgkin lymphoma survivors. The study, which was published in the journal Cancer, included 316 Hodgkin lymphoma survivors, 78 who developed colorectal cases and 238 who did not. The median time between Hodgkin lymphoma and colorectal cancer was 25.7 years.

There was an increase in colorectal cancer rates observed in patients who received subdiaphragmatic radiation therapy and those who received more than 8.4 g/m procarbazine. Additionally, colorectal cancer rate increased when radiation dose was given to the whole large bowel, and it affected the bowel segment.

The association became stronger when the dose of procarbazine was increased, with higher rates specifically in patients who received both a high radiation dose to the large bowel and a higher dose of procarbazine.

Patients and survivors should be aware of their risk of developing colorectal cancer due to radiation therapy and take precautions to modify that risk, the authors noted.

“Also, given their elevated risk of colorectal cancer, these patients should receive guidance on minimizing risk by avoiding associated risk factors, such as smoking, alcohol use and being overweight,” the authors wrote. “These findings have an important role in the addressing the association of the late effects of Hodgkin lymphoma treatment on the health life expectancy for Hodgkin lymphoma survivors.”

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