Although radiation can be an effective therapy for prostate cancer, about one in six men will experience more frequent or painful urination as a lingering side effect. These disruptive genitourinary toxicities can occur whether the patient receives conventionally fractionated radiotherapy or stereotactic body radiotherapy. A new study published by Amar U. Kishan, MD, and colleagues in Radiotherapy and Oncology sought to determine if differences in a patient’s DNA could predict whether he would have genitourinary toxicity after receiving either type of radiation.
“One of the biggest goals of our research program is to try to minimize toxicity and improve quality of life after treatment,” Dr. Kishan said.
Amar U. Kishan, MD
The research team analyzed DNA collected from 201 men who received either conventionally fractionated radiotherapy or stereotactic body radiotherapy. Using unique differences in the patients’ DNA, the researchers then developed a model involving single nucleotide polymorphisms disrupting microRNA targets for both forms of radiation therapy to see if they could predict which patients would develop side effects.
The study found that the models were highly predictive in differentiating between those who would experience toxic side effects after radiation therapy and those who would not. Furthermore, the models were able to predict toxicity depending on which type of radiation the patient received (long-course or short-course), indicating they could potentially help with decision-making in choosing one treatment course over the other.
In an ongoing clinical trial, Dr. Kishan is testing this model on a new set of patients to further confirm the study’s findings. In the trial, the results from the DNA analysis are shared with each patient, and the impact of the information on shared decision-making, as well as decreasing toxicity in the group as a whole, is being evaluated.
“This research may ultimately guide a … patient’s treatment plan,” said Dr. Kishan. "If we can know ahead of time who will tolerate radiation treatment and who may suffer these side effects, we can do a better job of assuring not only the best treatment but the one with the least impact on quality of life."
Disclosure: For full disclosures of the study authors, visit thegreenjournal.com.The content in this post has not been reviewed by the American Society of Clinical Oncology, Inc. (ASCO®) and does not necessarily reflect the ideas and opinions of ASCO®.