(Reuters Health) - Elderly men with prostate cancer are more likely to be treated with radiation when their doctors own radiation machines - even patients who may be too old to benefit from the treatment, a U.S. study suggests.

Prostate cancers may grow too slowly to cause symptoms before an elderly man dies from other causes. Doctors can therefore opt to forego screening or treating some older men to spare them unnecessary procedures with side effects like impotence and incontinence.

For the current study, researchers examined data on more than 31,000 men aged 65 and older who were newly diagnosed with prostate cancer. The researchers were looking to see how often patients received radiation even when they had little risk of dying from tumors over the next decade, and high odds of dying from some other cause.

They looked, for example, at men with prostate cancer who had at least a 75 percent chance of dying from something other than cancer within 10 years. Doctors in practices that owned radiation equipment treated 53 percent of these men, whereas physicians without the financial incentive of owning the equipment treated 44 percent of these cases.

Researchers also looked at what’s known as intensity-modulated radiation therapy (IMRT), a newer computer-guided form of radiation that’s designed to target tumors while sparing surrounding tissue.

When doctors had an ownership stake in IMRT, 42 percent of men with a high chance of dying from something other than cancer received this treatment, compared to 26 percent of men when physicians didn’t own IMRT machines.

“Patients should be aware that financial incentives of their provider can influence how they are treated for their prostate cancer,” said lead study author Dr. Brent Hollenbeck of the University of Michigan in Ann Arbor.

“Urologists in some single-specialty groups with an ownership interest in IMRT were more likely to treat, and even overtreat, patients with IMRT than urologists affiliated with a multispecialty practice or a group without an ownership stake,” Hollenbeck said by email.

Among men with newly diagnosed prostate cancer, use of IMRT ranged from 24 percent in multispecialty groups to 37 percent in large urology groups, the study team reports in European Urology.

Patients managed in groups with IMRT ownership were more likely to receive IMRT than those managed by single-specialty groups without ownership regardless of the size of the group practice, the researchers also found.

The study wasn’t a controlled experiment designed to prove that financial incentives influence treatment decisions, the authors note.

Even so, the findings suggest it may make sense for men to seek a second opinion, doctors say.

“For men diagnosed with prostate cancer, if doctors are not spending the time to understand your individual hopes and concerns about rates of cure, toxicity and impact on quality of life and tailor their recommendations based on those discussions, then you should seek the counsel and care of another doctor,” Dr. Justin Bekelman, a prostate cancer specialist at University of Pennsylvania Perelman School of Medicine in Philadelphia, who wasn’t involved in the study, sad by email.

To get the care that’s right for their specific circumstances and preferences, patients need to think about more than just whether doctors have financial ties to radiation equipment, said Dr. Lih-Ming Wong of St Vincent’s Hospital and the University of Melbourne in Australia.

“It is not unreasonable to ask about any financial conflict of interest,” Wong, who wasn’t involved in the study, said by email.

But patients should also ask what would happen if they opted for observation instead of treatment and what treatment alternatives they can consider if they don’t do IMRT, Wong added.

“Like all professions there will be a range in the way individuals within it practice,” he said. “It is not as simple as avoiding a group practice that owns their IMRT equipment.”

SOURCE: bit.ly/2xAUppO European Urology, online August 17, 2017.