According to a new study from researchers from Dana-Farber/Brigham and Women’s Cancer Center (DF/BWCC), a small percentage of men treated for prostate cancer complained that their penis seemed shorter after treatment. Some of the men even complained that the predicament interfered with their intimate relationships and regretted their treatment option.

The complaints were more common in men treated with radical prostatectomy (the surgical removal of the prostate) or hormone-blocking drugs combined with radiation therapy. No men who received radiation therapy alone complained of a shortened penis.

The study, soon to be published in the journal Urology, is the first to link perceptions of a shorter penis to lowered life satisfaction, relationship problems, and regret about certain prostate cancer treatments. Researchers surveyed 948 doctors who had treated men for prostate cancer that had seen a recurrance. Overall, 2.63% of the men complained of smaller penises, while 3.73% of those who received surgery complained of a shortened penis.

It seems that the men might not just be imagining things, either. Dr. Paul Nguyen, a radiation oncologist who led the study, stated that a smaller penis is a “well-known” side effect among doctors, but that “it’s almost never discussed with patients, so it can be very upsetting to some men when it occurs.”

There were no direct measurements of penis size in the study, and the surveyed doctors did not ask patients about their penis size. The complaints were brought up by the patients themselves during conversations with their doctors. For this reason, the study’s authors suggest that the problem could be more widespread than the survey found. The study recommends that doctors discuss the possibility of a shortened penis with patients before treatment.

“Patients can deal with almost any side effect if they have some inkling ahead of time that they may happen,” said Nguyen. “Prostate cancer is one of the few cancers where patients have a choice of therapies, and because of the range of possible side effects, it can be a tough choice. This study says that when penile shortening does occur, it really does affect patients and their quality of life. It’s something we should be discussing up front so that it will help reduce treatment regrets.”