Prostate Cancer Summary
In the United States, prostate cancer is the most frequently diagnosed malignancy in men. In 2010, an estimated 215,000 new cases were diagnosed. Prostate cancer is also the second leading cause of deaths related to cancer in men accounting for an estimated 30,000 deaths per year. Nearly all of the deaths associated with this malignancy occur in those patients with advanced cases of disease. The risk of obtaining prostate cancer increases with advancing age. In many patients, it can be a very slow growing, minimally symptomatic problem. In others, it can be a much more devastating illness. Though these numbers may be somewhat sobering, over the past 10 years, there have been some major advancements in the treatment of this illness.
In individuals with localized prostate cancer, or earlier stages of disease, treatment can result in either cure or a prolonged disease free survival. As a means of detection, various cancer associations recommend the initiation of screening men at the age of 50 with digital rectal examinations and annual prostate specific antigen (PSA) laboratory testing, as a means to identify these patients.
Standard treatment options to eradicate localized prostate cancer have historically included surgical removal by a radical prostatectomy or radiation therapy techniques. Recent surgical advancements have included the innovative use of a robotic arm to assist the surgeon which has been associated with fewer complications, such as incontinence and impotence, and thus far, excellent outcomes. Standard forms of radiation include external beam x-ray treatment, and the use of a more localized process of implanted radiation seeds into the prostate itself. Improved utilization of computerized analysis to focus radiation waves has allowed physicians to increase the intensity of the treatment on the cancer and minimize toxicities to the normal body organs. More recent developments include stereotactic techniques, such as the CyberKnife, which furthers the physician’s ability to deliver a very high dose of radiation to a well defined area. Another is the use of a new form of radiation, a proton, which can be focused in a beam to accomplish similar goals. Cryotherapy is another newer localized treatment technique that freezes the cancer cells resulting in their elimination. The preliminary analysis of some of these newer techniques is quite promising and suggests the possibility of improved survival results, though long-term studies are currently pending.
Despite these advancements, one out of three patients will subsequently develop a recurrence of their disease. Unfortunately, though a variety of treatments are available to control this illness, the advanced stage of prostate cancer is one that science has yet to learn how to eliminate. The good news is that it is very treatable and that newer insights regarding the mechanism of this disease have led to the development of a variety of new treatments available for these patients. The standard approach, which is effective, in over 90% of men, is the use of antiandrogen hormonal therapy. The duration of response to treatment in many patients can be measured in years. Eventually, patients become resistant to this form of hormonal therpay. Current available options for these patients include chemotherapy and the recently approved immune therapy, Sipuleucel-T. This immune-based treatment utilizes one’s own immune system to help fight and slow the growth of prostate cancer and improve the duration of survival.
Regarding chemotherapy, the developments have been slow. Starting in 1996, a combination of the agent Mitoxantrone with prednisone was the first regimen approved, but was only able to demonstrate an improvement in pain control and quality of life, not survival. Then in 2004, the combination of Docetaxel with prednisone became available to patients, being the first regimen to provide a significant survival for patients who had failed standard hormonal treatment. Last year, the new agent Cabazitaxel, when combined with prednisone was appoved for use when it demonstrated a survival benefit after those patients who had failed prior chemotherapy, thus further extending the lifespan of these patients. This year, a new antiandrogen hormonal agent with a different mechanism of action, Abiraterone, became available after it confirmed a survival benefit in patients who have previously failed both hormonal therapy and chemotherapy. There are ongoing trials involving these agents, as well as a host of others either by themselves or in combinations, utilized at various stages of this disease, in attempts to further improve the management of this illness.
So though it has taken some time, and at times seemed to be a daunting task, the likelihood of eliminating and treating prostate cancer has enjoyed some recent major successes, and the future of its management appears much more promising.