Dieter Bruno, M.D.
Published: April 24, 2009
Prostate cancer has been a significant male health issue for many years, however until recently little has been understood regarding the true nature of prostate cancer. In the broadest sense the most significant problem in understanding prostate cancer development and expression lies in the sheer prevalence of the condition and the variability of its clinical manifestations in different individuals depending on a multitude of factors. This vignette will focus on the contemporary concepts of prostate cancer screening, diagnosis and management, In hopes of enlightening men regarding the most common solid organ malignancy that they are at risk of developing.
Prostate cancer is a heterogeneous disorder characterized by the cancerous transformation of the normal prostate tissue. Although 95% of prostate cancers arise from the prostate glandular tissue, there are other types as well (1). this discussion will focus on the garden variety of prostate cancer called adenocarcinoma of the prostate.
Prostate cancer is the most common solid organ malignancy in men and is second only to skin cancer with respect to incidence. It was reported by the American Cancer Society that 230, 900 new prostate cancer cases were diagnosed in 2007 and that 27,050 men succumbed to the disease. Currently prostate cancer is the second most common cause of cancer related mortality in men, behind only lung cancer. In general prostate cancer occurs in 1 out of 6 men with African American men having the highest incidence, and Asian males reporting one of the lowest incidence (1,2).
Despite all we know regarding prostate cancer, understanding of all of the genetic and environmental risk factors still remains elusive. It is known that the majority of prostate cancers (75%) are detected in individuals over the age of 65, making age a significant risk factor (1). Other risk factors include race, diet, family history, and a genetic predisposition (1). It is known that although African Americans have a higher incidence of prostate cancer compared to other ethnic groups such as Asian Americans, when other groups immigrate to the United States they adopt a higher incidence of prostate cancer compared to the incidence in their native country (2). The reasons for this are assumed to be environmental, however are not fully understood. Similarly diet has remained controversial with respect to prostate cancer development. It has been widely quoted that diets high in saturated fats involve a selection pressure towards prostate cancer development, however the specific factors involved are unclear. Additionally many of the previously thought dietary protective considerations such as selenium, and vitamin E have lost favor (7). Other considerations such as lycopene ingestion remain widely quoted, but unproven. Having a first-degree relative (immediate family) with prostate cancer doubles the risk of prostate cancer, whereas having a second-degree relative confers a less significant, but measurable risk for prostate cancer development (1). Ongoing research is remains to clarify the specific genetic factors behind prostate cancer development and expression.
The majority of prostate cancers begin around the external surface of the prostate gland and are typically asymptomatic, whereas benign prostatic hyperplasia (BPH) originates within the prostate gland and thereby produces symptoms of impaired urination, primarily because of urethral compression by prostate glandular growth (3). A relatively late phenomenon of untreated prostate cancer is the spread to the spine and other bones in the body. Although was common in the past, it is relatively uncommon given how aggressively we treat prostate cancer in this day and age.
Prostate cancer diagnosis requires a prostate biopsy through the rectum with the aid of an ultrasound machine. Currently there are no radiographic studies that are used to diagnose prostate cancer, however there are various radiographic adjuncts that are used to follow previously diagnosed prostate cancer or to document a recurrence of prostate cancer. These studies include abdomen and pelvis computed tomography, endorectal coil magnetic resonance, bone scan, and prostascint scan imaging. Despite the acceptance of prostate biopsy as a definitive diagnostic tool, up to 30% of prostate cancers were previously missed by old fashioned biopsy techniques which have recently been revised to decrease false negative biopsy results (4). Additionally there remains continued controversy regarding prostate cancer screening as the direct improvement in lives saved has been an elusive factor to document. Currently the American Cancer Society and American Urological Association recommend screening for prostate cancer for individuals age 50 or older who have a life expectancy of at least 10 years (5). Screening consists of an annual digital rectal examination (DRE), and a serum prostate specific antigen (PSA) level.
The treatments for prostate cancer are fivefold and include: watchful waiting, hormonal ablation, radical prostatectomy, radiation therapy, and cryotherapy. Selection of a treatment must be individualized based upon biologic factors of the patient’s prostate cancer such as stage, grade and health, as well as personal factors such as patient desire, previous medical conditions, social considerations, and a reasonable understanding and assessment of the potential complications and side effects specific to each treatment option. Curative intent should be offered to appropriate candidates with organ confined prostate cancer and include radical prostatectomy, radiotherapy, or cryotherapy as these are the only proven treatments that can offer a cure in carefully selected patients. The robotic radical prostatectomy is one of the newest techniques for curing organ confined prostate cancer offering a number of advantages over the historical open radical prostatectomy. Recently the robotic radical prostatectomy has become the most common approach to the radical prostatectomy. Treatment for advanced or metastatic disease is palliative and includes hormonally based therapies centered around chemical or surgical castration which temporarily halts prostate cancer growth, site specific radiation therapy, and chemotherapy which is still considered investigational (1,3). There is evidence that prostate cancer prevention is a tenable goal and preliminary data suggests that finasteride (Proscar), a medication approved for the treatment of BPH, has promise in decreasing the incidence of prostate cancer (6).
Prostate cancer is an extremely prevalent condition that has been associated with significant morbidity and mortality, yet a variable expression in that most men will develop the malignancy if they live long enough. The current challenge involves determining which men would succumb to the disease if untreated. This has sparked an ongoing controversy regarding which men should be screened and furthermore treated. Although the complete list of genetic and environmental risk factors in prostate cancer development remain elusive and the screening criteria are currently evolving and need further elucidation, a candid relationship and discussion between patients and their providers is required to minimize the negative health care impacts of this deadly yet common disease. With continued research into prostate cancer prevention, genetic testing and risk factor reduction the prostate cancer issues which plague society today will likely undergo significant change and be more completely understood and addressed in the near future to come.
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