Lymph Node Radiation Reduced Death in Young Patients with Prostate Cancer

Whole-pelvic radiation was found to be more beneficial among patients with prostate cancer who are younger than 65, research showed.

Treatment with whole-pelvic radiation therapy (WPRT) may reduce mortality among younger patients with unfavorable-risk prostate cancer, researchers have found.

Long-term findings of a phase 3 clinical trial, published in the Journal of Clinical Oncology, showed that WPRT, which includes treatment to patients’ pelvic lymph nodes, conferred a 67% lower risk of all-cause mortality among patients younger than 65 when compared to prostate-only radiation therapy (PORT). However, researchers reported that this was not the case among patients 65 and older.

“What we found was the radiation treatment of the of the lymph node that oversees the prostate gland that appears to allow the younger patients with prostate cancer to live longer,” said study co-author Dr. Mutlay Sayan, an assistant professor at Harvard Medical School and radiation oncologist at Brigham and Women’s Hospital and Dana-Farber Cancer Institute in Boston, in an interview with CURE.

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Asked about the age-based difference in patient outcomes, Sayan stated that young patients tend to be healthier and live longer, whereas older patients’ health may be impacted by comorbidities (when a patient has two or more diseases at the same time).

Researchers drew on data from 350 men with localized, unfavorable-risk (at an intermediate risk to grow and spread) prostate cancer who, from 2005 to 2015, received androgen deprivation therapy and radiation therapy plus docetaxel chemotherapy or androgen deprivation therapy and radiation therapy, with the pelvic lymph nodes treated at the discretion of the patient’s treating physician, according to the study. There were 88 patients who received WPRT, and 262 patients underwent PORT.

“The fundamental reason for recommending elective pelvic radiation is that a subgroup of patients with clinically node negative disease might actually have microscopic disease within the pelvic lymph nodes,” Sayan said. “And because of that, the use of [whole] pelvic RT provides oncological benefit.”

Learn more: SBRT and Hormone Therapy May Delay Advanced Prostate Cancer Progression

After a median follow-up of 10.2 years, 89 patients had died, with 42 of them having died of prostate cancer. Among patients younger than 65, four who received WPRT died and 27 who received PORT died. For patients ages 65 and older, those numbers were 17 and 41 patients, respectively.

The adjusted 10-year all-cause mortality rate among patients younger than 65 who were treated with WPRT was 8.42%, versus 30.1% among those who were treated with PORT. The estimated rates were 28.51% and 28.7%, respectively, among patients who were 65 and older, according to the study.

The study, Sayan said, “suggests that we should continue to adopt the elective [whole] pelvic radiation treatment in patients, because our study shows that a benefit exists with [whole] pelvic radiation treatment.”

“Specifically, this benefit was limited to men younger than 65 years, suggesting that competing risks might have prevented the increased regional control provided by WPRT to translate into mortality reduction in older men who are more likely to have comorbid illnesses,” researchers wrote. “The clinical significance of this finding is that, with a median follow-up exceeding 10 years, it appears that a reduction in mortality may be possible as a result of treatment of the pelvic lymph nodes using radiation therapy in otherwise healthy, young men with unfavorable risk [prostate cancer].”

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