Lessons from recent trials of localized prostate cancer treatments

- Kenny Lin, MD, MPH

From 2012 to 2018, the U.S. Preventive Services Task Force and the American Academy of Family Physicians recommended against screening for prostate cancer, based on evidence that the then-widespread practice produced no net benefit. As a result, fewer family physicians subsequently screened their patients with the PSA test, and fewer men were diagnosed (or overdiagnosed) with localized prostate cancer. However, the USPSTF's recent change to a more permissive approach to PSA-based screening has increased the likelihood that more men will need to make difficult decisions regarding what to do about a prostate cancer diagnosis.

As discussed in a previous AFP Community Blog post, surveyed men with newly diagnosed localized prostate cancer expected to gain an average of 12 years of life expectancy by undergoing surgery or radiation. In fact, two randomized, controlled trials found no gains in prostate cancer-specific or all-cause mortality. After nearly 20 years of follow-up, the U.S. Prostate Cancer Intervention versus Observation Trial (PIVOT) reported in 2017 that radical prostatectomy reduced the likelihood of treatment for asymptomatic, local, or biochemical (PSA) disease progression compared to observation, but caused more urinary incontinence, erectile dysfunction, and limitations in activities of daily living. Similarly, the U.K. Prostate Cancer for Testing and Treatment (ProtecT) trial found that active surveillance was comparable to radiotherapy or prostatectomy, with a slightly greater likelihood of clinical progression and metastatic disease in the active surveillance group.

An older Swedish randomized trial comparing radical prostatectomy to watchful waiting in men with predominantly clinically-detected (rather than PSA-detected) localized prostate cancer found that radical prostatectomy was associated with less than 3 years of life gained after 23 years of follow-up. Altogether, the evidence suggests that curative treatments may be worthwhile for selected men with symptoms, but that there is little or no benefit to looking for prostate cancer in men who feel well.

A 2018 AFP article reviewed the evolving National Comprehensive Cancer Network guidelines for treatment of localized prostate cancer, which recommend incorporating comorbidity-adjusted life expectancy into screening and treatment decisions:

The comorbidity-adjusted life expectancy is particularly important because the number of comorbid diseases is among the most significant predictors of survival after prostate cancer treatment. Prostate cancer is usually slow growing, and the survival benefit of treatment may present only after 10 years. Therefore, patients with low-risk or very low-risk prostate cancer should be treated only if the patient has a comorbidity-adjusted life expectancy of at least 10 years.