Competing Risks for Patients With Localized Prostate Cancer

Abstract

In health care, as in the rest of life, decisions have consequences. A chosen treatment for prostate cancer can yield benefits, but it can also cause harm. In localized prostate cancer, as in most diseases, baseline characteristics influence the natural history of the disease and thus a treatment’s potential for benefit. The most relevant estimates for an individual come from studies involving patients who are similar to the individual selecting treatment. The recently updated guideline from the American Urological Association lists the following primary treatments for localized prostate cancer: watchful waiting, active surveillance, interstitial brachytherapy, external beam radiotherapy, radical prostatectomy, primary hormonal therapy, and others (e.g., cryotherapy) ( 1 ). To choose from this menu, patients must fi rst weigh their individualized risk of death from prostate cancer in the absence of treatment and then each treatment’s likely effect on that risk, along with associated specifi c types and risks of complications. These guidelines caution patients that there are important limitations to the available studies because follow-up is often insuffi cient for most treatment options, researchers use inconsistent defi nitions for the most commonly reported complications, and authors often fail to adequately detail baseline patient characteristics. Finally, because most evidence is derived from case series and small randomized trials that frequently pool data from patients with various levels of disease burden, the evidence base is subject to selection and other biases. Selecting a primary therapy is not the only choice facing patients with localized prostate cancer. Some patients are offered androgen deprivation therapy (ADT) after prostatectomy or radiation therapy (adjuvant ADT) that can continue for years. Others are offered several months of ADT (neoadjuvant ADT) before defi nitive primary therapy. Many trials on adjuvant or neoadjuvant ADT for localized or locally advanced prostate cancer fail to report the key outcome of interest, and most do not report outcomes stratifi ed by risk groups. Some reviews address side effects of ADT ( 2 , 3 ) but focus primarily on morbidity and quality of life. A recently published Cochrane systematic review ( 4 ) reported estimates for outcomes of treatment effi cacy by primary therapy (prostatectomy or radiation therapy) and by type of hormonal deprivation (adjuvant or neoadjuvant). ADT use for patients with localized prostate cancer has increased substantially over time ( 5 ), and recent evidence suggests that ADT may be associated with increased risk for diabetes and cardiovascular disease ( 6 ). In this issue of the Journal, Tsai et al. ( 7 ) use registry data from the Cancer of the Prostate