Know someone with prostate cancer? What a new study tells us about treatment options.

A longitudinal study that tracked men over 10 years aims to provide patients with more information about their options following a diagnosis of prostate cancer.

The study published Tuesday in the Journal of the American Medical Association followed a large cohort of American men and used the data on their outcomes to provide guidance to patients and health care providers. For example, radical prostatectomy, a common procedure that removes the entire gland along with surrounding nodes, sometimes leads to decreased bladder control but it had similar outcomes as other treatments studied in terms of sexual function. Both are concerns men raise when choosing a treatment for prostate cancer.

Prior to this study, there was a dearth of information about the "side effects of contemporary treatments," according to senior author Dr. Daniel Barocas, a professor and vice-chair of Vanderbilt University Medical Center’s urology department.

“This really fills a knowledge gap," Barocas said. "And we’re hoping that people with prostate cancer and their health care providers can use this information to help make better decisions about their treatment, and potentially reduce treatment regret, by letting people know what to expect.”

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The study followed nearly 2,500 American men 80 and younger who were diagnosed with prostate cancer of varying levels of severity from 2011 through early 2022. It built on prior observational studies looking at three- and five-year results. In the new study, researchers used questionnaires to ask men about the side effects of treatment for their urinary, bowel and sexual function.

Researchers drew from a cohort they say is representative of the U.S. population using National Cancer Institute registries in New Jersey, Louisiana, Utah as well as the Atlanta and Los Angeles areas. About 72% were non-Hispanic white, slightly higher than the overall U.S. population, while the study was about 14% Black. Hispanic and Asian men respectively accounted for about 8% and 3% of the study, both lower than the respective percentages who get prostate cancer nationally. Nonetheless, study authors said, using a relatively diverse cohort provided meaningful insight into the disease and treatments. This was a goal for the group going in since Black men have the highest incidence of prostate cancer.

Researchers classified patients according to two categories: favorable prognosis, which accounted for more than three-quarters of the cohort, and unfavorable prognosis, which included patients who needed more intensive treatment.

Those with favorable prospects chose treatments that ranged from surveilling the cancer to see if it worsened, to nerve-sparing prostatectomy or surgical removal of the prostate, which included trying to protect nerves near the gland to minimize effects on erectile function. This group also pursued external radiation and a type of radiation that implants radioactive “seeds” to kill cancer cells.

People with unfavorable prognoses chose radical prostatectomies or external radiation with androgen deprivation therapy, or ADT, a combined procedure that uses radiation alongside therapies to target male sex hormones like testosterone.

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Surgery with radical prostatectomy was associated with an increased risk, over a decade, of lost bladder control, compared with other treatments, regardless of the cancer risk. As much as a quarter of men who underwent surgery to remove the prostate reported bothersome leakage 10 years post-treatment, compared with up to 11% who underwent external beam radiation therapy to destroy cancer cells.

Meanwhile, a primary concern among prostate cancer patients has been impairment of sexual function. The study found no significant differences in erectile function between patients who underwent radical prostatectomy and radiation with ADT. However, researchers found ADT was associated with slightly worse bowel and hormone functions a decade later for patients with an unfavorable prognosis.

The study has limits as it was merely observational: it simply followed patients and attempted to understand outcomes, which could be influenced by their expectations and preferences, researchers said. It’s unclear if the study can be generalized to men with locally advanced cancer or to men older than 80, who were excluded from the study.

The study was funded by the National Institutes of Health, the U.S. Agency for Healthcare Research and Quality, and the Patient-Centered Outcomes Research Institute.

Researchers are developing a patient tool using study data to estimate functions for 10 years after various treatments. The group also has forthcoming findings on cancer outcomes among the cohort.

This article originally appeared on USA TODAY: Prostate cancer options weighed in study on treatment, side effects