ASTRO: Upped-dose radiation regimen maintains high quality of life for busy prostate cancer patients

BOSTON—Compared with conventional radiation therapy (RT), larger-dose RT delivered over a shorter period—called hypofractionated RT—has previously proven just as efficacious for treating low-risk, early-stage prostate cancer. Now researchers have further shown that, despite the increased doses, hypofractionated treatments do no clinically significant harm to these patients’ quality of life (QOL).

The new finding is a potential game-changer, suggests the lead author of the QOL study, Deborah Watkins Bruner, RN, PhD, a professor of nursing and radiation oncology at Emory University in Atlanta.

“There is now a significant body of evidence showing that men can safely be treated with shorter-course radiation,” Bruner reported Sept. 27 at the annual meeting of the American Society for Radiation Oncology (ASTRO).

Hypofractionated RT “saves men two and a half weeks of treatment,” she added. “It saves them two and a half weeks of having to take time off work, having to get a ride in, having to pay parking fees, having to get childcare, having to get someone to take care of mom and dad if you have elder care.

“And it also probably cuts co-pays, which is another end point we will be looking at in the future.”

For their analysis, Bruner and colleagues reviewed health-related QOL data as self-reported by 962 patients who participated in a 2015 study that established the efficacy of the hypofractionated approach.

The patients had randomly received either conventional RT, consisting of 73.8 Gy in 41 daily treatments delivered over 8.2 weeks, or hypofractionated RT, consisting of 70 Gy in 28 daily treatments delivered over 5.6 weeks.

Negligible side effects

The team looked at the two groups’ respective side effects in the health-related QOL domains of hormonal changes, sexual function, and urinary and bowel function.

They found no difference in hormonal scores at any of the reporting time points—baseline, six months and 12 months—and very little change across time points.

Consistent with previous studies, the accelerated regimen negatively impacted sexual function to a slightly greater degree than the conventional regimen.

“However, between the conventional fractionation and hypofractionation arms, there was no difference statistically at all,” Bruner said. “That means patients could not tell the difference.”

Urinary scores exhibited almost no decline from baseline, and there was no difference between the two arms.

Finally, the bowel score exhibited a small decline from baseline, but there was no clinically significant difference.

“It’s sort of like saying, can a patient tell a difference in quality of life between having three bouts of diarrhea a day versus four bouts of diarrhea a day?” Bruner explained. “In the end, it really doesn’t matter if you have diarrhea four times a day rather than three.”

Hence the designation of clinical insignificance.

Time for guideline change?  

Further comparing their health-related QOL data of the hypofractionation group to that of normal men with no prostate cancer, the team even found very little difference there.

Bruner then asked the natural next question: Will the insights on QOL change practice in the field?

“Well, the International Atomic Energy Agency, in their 2014 prostate cancer guidelines, still lists hypofractionated radiation therapy as investigational,” she said. “We are not in any way going out on a limb to say that it is no longer investigational. It should be a standard option, remembering that men with low-risk prostate cancer have many options, including watchful waiting.”

When watchful waiting is one of the options and treatment is chosen, “it should be the shortest amount of treatment with the least amount of side effects and absolutely at the lowest cost,” Bruner concluded, adding that enhancing value and improving outcomes “has been ASTRO’s whole theme for this conference. So I think this study exemplifies exactly what ASTRO is trying to do. And hopefully this will change ASTRO guidelines.”

A call for doing more by radiating less

Following the session on advances in prostate cancer care, in which Bruner was one of four researchers presenting new study results, session moderator Colleen Lawton, MD, vice chair of radiation oncology at the Medical College of Wisconsin and a former chair of ASTRO’s board of directors, underscored Bruner’s conclusion.

“We really do understand now, based on this data, that if you utilize hypofractionation, the shorter course of radiation to treat our prostate cancer patients with low-risk disease, it does not affect their quality of life,” Lawton said. “It’s cheaper for the healthcare system, it’s cheaper for the patient and it’s easier for the patient.”

Lawton further noted that around half of low-risk patients do get treated, if not more than that, but suggested this may be a paradigm ripe for the tilting toward watchful waiting.

“Part of the problem is that, when patients in the U.S. get a diagnosis of cancer, their [immediate response] is, ‘Cut it out of me! Get rid of it!’” Lawton said. “And that’s because we haven’t done a good job of explaining to them that, if you have low-risk disease, there are decades’ worth of data that show you really can monitor that. You [often] don’t have to have treatment, which is really wonderful.

“That’s a message that we have to get into our patients’ heads,” Lawton added, “so that they don’t freak out when they get this diagnosis—especially if it’s low-risk disease.”