Men undergoing treatment for prostate cancer often experience debilitating hot flashes as a side effect of androgen-deprivation therapy (ADT). Now, a new study offers a promising solution: oxybutynin, a medication commonly used to treat overactive bladder, significantly reduces the frequency and severity of these hot flashes. The findings, published in the journal JCO Oncology on January 26, 2026, suggest a readily available and affordable option for improving the quality of life for many cancer patients. This research addresses a significant unmet need in prostate cancer care, as hot flashes can profoundly impact daily activities and overall well-being.
The study, known as Alliance A222001, involved 88 patients with prostate cancer receiving ADT who reported experiencing at least 28 hot flashes per week. Participants were randomly assigned to receive either oxybutynin at a dosage of 2.5 mg twice daily, 5 mg twice daily, or a placebo for six weeks. Researchers focused on changes in patient-reported hot flash scores as the primary measure of effectiveness, alongside assessments of adverse events and interference with daily life. The results demonstrate a clear benefit from oxybutynin treatment, offering a new avenue for managing this challenging side effect.
Oxybutynin Demonstrates Significant Reduction in Hot Flash Frequency
The research revealed that patients taking oxybutynin experienced a notable decrease in the number of hot flashes per day compared to those receiving a placebo. On average, the placebo group saw a reduction of 2.15 hot flashes per day, while those on 2.5 mg of oxybutynin experienced a reduction of 4.77 (p = .02), and those on 5 mg experienced a reduction of 6.89 (p < .001). This translates to a substantial improvement in symptom control for many patients. The study also measured daily hot flash scores, with the placebo group showing a reduction of 4.85 points, 2.5 mg oxybutynin reducing scores by 9.94 points (p = .07), and 5 mg oxybutynin reducing scores by 13.95 points (p = .002).
Beyond simply reducing the number of hot flashes, oxybutynin also lessened their impact on daily life. Using the Hot Flash-Related Daily Interference Scale (HFRDIS), researchers found improvements of 14.2 and 20.7 points in the 2.5 mg and 5 mg oxybutynin arms, respectively, compared to just a 3.1-point improvement in the placebo group. This suggests that oxybutynin doesn’t just create hot flashes less frequent, but also less disruptive to a patient’s routine and quality of life.
Safety and Tolerability Profile
Importantly, the study found that oxybutynin was well-tolerated by patients. No treatment-related grade 3 or higher adverse events were reported. This is encouraging, as many medications used to manage cancer treatment side effects can arrive with their own set of potentially serious complications. The favorable safety profile of oxybutynin makes it an attractive option for men already facing the challenges of prostate cancer and its treatment.
Understanding Androgen-Deprivation Therapy and Hot Flashes
Androgen-deprivation therapy is a common treatment for prostate cancer, working by reducing the levels of male hormones (androgens) that fuel the growth of cancer cells. Yet, this therapy can also lead to a range of side effects, including hot flashes, fatigue, sexual dysfunction, and bone loss. Hot flashes, in particular, are a frequent complaint, affecting a significant proportion of men undergoing ADT. The mechanism behind these hot flashes isn’t fully understood, but it’s believed to involve changes in the brain’s temperature regulation system due to the hormonal shifts caused by ADT.
Implications for Prostate Cancer Care
The findings from the Alliance A222001 study have significant implications for how hot flashes are managed in men with prostate cancer. Previously, options were limited, often involving off-label use of medications or lifestyle modifications. Oxybutynin offers a targeted and effective treatment option with a favorable safety profile. The study’s authors conclude that oxybutynin is superior to placebo for managing ADT-associated hot flashes.
Figure 1- Consolidated Standards of Reporting Trials (CONSORT) diagram. Source: JCO Oncology
While the study provides strong evidence for the effectiveness of oxybutynin, further research may be warranted to determine the optimal dosage and duration of treatment for individual patients. Exploring the potential benefits of oxybutynin in combination with other therapies could further enhance symptom management. The availability of a well-tolerated and effective treatment like oxybutynin represents a significant step forward in improving the quality of life for men battling prostate cancer.
Disclaimer: This article is for informational purposes only and should not be considered medical advice. Please consult with a qualified healthcare professional for any health concerns or before making any decisions related to your health or treatment.
The next step in disseminating these findings will be incorporating the results into clinical practice guidelines and educating healthcare providers about the benefits of oxybutynin for managing ADT-associated hot flashes. Patients experiencing hot flashes during prostate cancer treatment are encouraged to discuss this option with their oncologist.
Have you or a loved one experienced hot flashes during prostate cancer treatment? Share your experiences and thoughts in the comments below, and please share this article with anyone who might uncover it helpful.
