According to current estimates, prostate cancer is the second leading cause of cancer deaths among North American men, with more than 33,000 dying from the disease in 2013. For men with androgen-sensitive metastatic disease, continuous androgen-deprivation therapy is considered the current standard of care, but many of these individuals will go on to develop castration-resistant prostate cancer (CRPC). When this occurs, patients will need additional lines of treatments to support their androgen-deprivation therapy. These additional therapies have the potential to improve survival and quality of life (QOL).
A Welcome Guideline
Recently, the American Society of Clinical Oncology (ASCO) and Cancer Care Ontario (CCO) released a joint clinical practice guideline for treating men with metastatic CRPC. Published in the Journal of Clinical Oncology, the guideline builds upon previous ASCO/CCO recommendations based on a systematic review of 28 randomized clinical trials published between 1979 and 2004. Since the previous guideline was released, an additional 28 trials on systemic therapies have been identified for treating metastatic CRPC, including analyses involving targeted therapies and immunotherapies. These additional randomized trials helped inform the current recommendations.
The updated guideline includes recommendations on systemic therapies indicated for use along with androgen deprivation. They address survival and QOL benefits, side effects, and cost considerations for each of these therapies (Table). The expert panel also recommends that palliative care be offered to all patients, particularly for those exhibiting symptoms or QOL decrements.
Recently, there has been significant progress in the care of advanced prostate cancer, with several new treatments gaining FDA approval over the last few years, says Ethan Basch, MD, MSc, who co-chaired the ASCO/CCO expert writing group that developed the guideline. “When selecting treatments for patients,” he says, “there are many nuances to consider, including the stage of disease and therapies that patients have previously received. The guideline is intended to help clinicians and patients make informed treatment decisions.”
Focus on QOL & Costs
The ASCO/CCO guideline paid particular attention to QOL considerations when developing the recommendations. Dr. Basch says that including QOL data in the guideline can help inform discussions with patients about the extent of potential benefits and harms. ASCO and CCO consider it essential to assure that the goals of care are understood by patients. The guideline notes that many patients with metastatic CRCP misunderstand the goals of care to be curative rather than palliative. This may lead patients to be more accepting of greater toxicity or higher costs based on incorrect assumptions about potential benefits of treatment.
The guideline notes that some metastatic CRCP treatments are associated with considerable cost, leading some patients to potentially decide against specific therapies because of finances. “We need to be especially conscious of cost when treating patients with metastatic CRCP because it can affect access to treatment and QOL,” explains Dr. Basch. “This potential barrier or hardship should be openly discussed with patients.”
The ASCO/CCO guideline notes that many patients have limited access to medical care. Awareness of disparities in access to care should be considered in the context of the guideline. Healthcare providers are recommended to make extra efforts to deliver the highest level of cancer care possible to vulnerable populations. They are also encouraged to enroll a wide range of patient populations into clinical trials to better represent diversity within the community. In addition, the guideline recommends that clinicians be conscious of the role of multiple chronic conditions among patients with metastatic CRCP. A review of all other chronic conditions should be conducted and taken into account when formulating treatment and follow-up plans.
Dr. Basch says that more research is needed to determine the optimal sequencing of available therapies for managing metastatic CRCP. “Ongoing clinical trials are exploring this issue as well as the potential benefits and harms of combining various treatments,” he says. “We also need data on the efficacy of drugs in treatment sequences other than those tested in clinical trials.”
Few cost-benefit analyses have been conducted on the management of patients with metastatic CRCP. There is also limited evidence available on the effectiveness of therapies being used in real-world populations and the clinical benefits of lower-cost treatments in low resource contexts. Comparative data are needed regarding QOL and the symptomatic benefits of currently available therapeutic options. The ASCO/CCO panel recommends that efforts be made to develop more rigorously designed symptom and QOL outcome measures in all late-phase clinical trials in metastatic CRPC. “Clinical trials are vital to informing medical decisions and improving cancer care,” Dr. Basch says. “As we learn more about advances in care for metastatic CRPC in the coming years, we will revisit these recommendations and amend them accordingly.”
Readings & Resources (click to view)
Basch E, Loblaw DA, Oliver TK, et al. Systemic therapy in men with metastatic castration-resistant prostate cancer: American Society of Clinical Oncology and Cancer Care Ontario clinical practice guideline. J Clin Oncol. 2014 Sep 8 [Epub ahead of print]. Available at: http://jco.ascopubs.org/content/early/2014/09/03/JCO.2013.54.8404.full.pdf+html.
Basch EM, Somerfield MR, Beer TM, et al. American Society of Clinical Oncology endorsement of the Cancer Care Ontario Practice guideline on nonhormonal therapy for men with metastatic hormone-refractory (castration-resistant) prostate cancer. J Clin Oncol. 2007;25:5313-5318.
Loblaw DA, Virgo KS, Nam R, et al. Initial hormonal management of androgen-sensitive metastatic, recurrent, or progressive prostate cancer: 2007 update of an American Society of Clinical Oncology practice guideline. J Clin Oncol. 2007;25:1596-1605.
Loblaw DA, Walker-Dilks C, Winquist E, et al. Systemic therapy in men with metastatic castration-resistant prostate cancer: a systematic review. Clin Oncol (R Coll Radiol). 2013;25:406-430.