TESTOSTERONE FUELS prostate cancer growth. Men with prostate cancer are often treated with androgen deprivation therapy (ADT), a type of hormone therapy that blocks the production of testosterone or stops the hormone from acting on prostate cancer cells.

A study published March 2024 in Psycho-Oncology, however, found that long-term ADT use may contribute to cognitive decline in older prostate cancer patients. The study compared verbal learning, verbal recall and visuospatial abilities in 67 patients who had undergone ADT with those in 66 men who had undergone treatment without ADT.

All the study participants were 65 or older, with an average age of 72. The ADT group consisted of men with early-stage prostate cancer undergoing radiation therapy and men with later-stage prostate cancer. These men were currently on continuous androgen deprivation therapy for one to three years. The non-ADT group included early-stage prostate cancer patients who had not been treated for at least a year.

In the verbal tests, participants were read a list of 12 words and asked to recite back as many as they could immediately afterward. This learning cycle was repeated three times. Following a 10-minute interval, they were asked to recall as many words as they could, says clinical psychologist Christian Nelson of Memorial Sloan Kettering Cancer Center in New York City, a study co-author.

Visuospatial function refers to the ability to understand what we see and to interpret spatial relationships. In these tests, participants were shown a picture of a house and asked to draw it on a piece of paper. They were then asked to draw it again from memory 20 to 30 minutes later. They were also shown images of increasingly complex geometric shapes of different color combinations and asked to re-create them with colored blocks.

“Maybe it’s a square where half of it is white and half of it is red, so then you have to re-create that with your blocks, a square half white and half red,” Nelson explains.

Overall, the ADT-treated patients performed worse on verbal learning and recall than those not on ADT. The researchers found potential adverse effects on visuospatial ability, but the evidence there was less conclusive.

Although Nelson says the ADT-treated patients performed “moderately worse” on all the tests than the non-ADT treated patients, patients on ADT should not be overly worried about the results.

“You don’t need to be concerned in terms of, ‘Boy, this is going to trigger dementia or Alzheimer’s,’” says Nelson, who specializes in short-term counseling of men with genitourinary cancers. “What we’re finding is basically subtle impacts. It’s very similar to [the effects of] chemotherapy.”

Patients on ADT should remain watchful but active, says Nelson. Most people occasionally forget where they left their keys or why they walked into a room, but frequently experiencing events like these should spark a conversation with your oncologist.

“It is something you should watch out for, like side effects from any other treatment, and discuss them with your doctor,” Nelson says.

Andrew Iskandar, a hematologist-oncologist at Sidney Kimmel Comprehensive Cancer Center at Jefferson Health in Cherry Hill, New Jersey, who was not part of the study, advises family members and others close to the patient to be vigilant for symptoms of declining cognition.

“A lot of times, our loved ones notice these things more than we do,” Iskandar says. “Maybe you don’t see it, but your loved one is like, ‘You always do things in order of A, B, C, and you’re not doing that anymore.’”

Strategies to manage the cognitive side effects of ADT include simple measures such as keeping lists and writing important things down. Maintaining a healthy diet, getting regular exercise and engaging in activities that stimulate your mind are also good ideas, Iskandar says.

“I’ve had patients that have always wanted to learn some new skill, whether it be dancing or [playing] a musical instrument or [learning] a new language,” he notes.

Most importantly, patients should not let the study findings prevent them from undergoing ADT.

“I think it’s something that they should be aware of and should monitor,” Nelson says. “It’s not anything that I would say should prevent them from using [this] treatment.”