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Article Excerpt
--Linda H. Yoder, PhD, MBA, RN, A OCN[R], FAAN
Prostate cancer is the most commonly diagnosed cancer and the second leading cause of cancer-related death among American males (Terris & Rhee, 2006). The incidence of this disease is highest among Caucasian and African-American males, with reported incidences of 161/100,000 and 256/100,000, respectively. The estimated overall incidence of prostate cancer in the United States for 2008 is 186,320, with projected mortality of 28,660 (Jemal et al., 2008). Despite the high incidence of the disease, positive outcomes can be achieved through early, effective, and appropriate treatment. Many health professionals will care for individuals with prostate cancer, or know individuals at risk for developing the disease. All nurses should be familiar with the guidelines for screening, treating, and managing early or localized prostate cancer.
Stages of Prostate Cancer
Localized prostate cancer has been defined as a cancer confined to the prostate (Bott, Birtle, Taylor, & Kirby, 2003). Research to date has failed to link prostate cancer to any specific modifiable lifestyle choices, but it has identified non-modifiable risk factors. These include increasing age, a family history of the disease, and ethnicity. Higher incidences of localized prostate cancer are reported among men over age 60, especially in African Americans. Caucasian men have the second highest incidence of prostate cancer, and rates of the disease are lowest among men of Asian-American and Hispanic-American decent (U.S. Department of Health and Human Services, 2006). The American Cancer Society (ACS) (2007) estimates that one in six men will be diagnosed with prostate cancer during their lifetime, but only 1 in 35 will die of this disease.
The identification of family history as a major risk factor for prostate cancer has resulted in a great deal of research to isolate a genetic component (Lessick & Katz, 2006). The first prostate cancer susceptibility gene, HPC1 (Hereditary prostate cancer 1), was discovered in 1996 (Smith et al., 1996) and mapped to the long arm of chromosome 1. Since then, several other prostate cancer susceptibility genes have been linked to various regions on other chromosomes (Ostrander, Markianos, & Stanford, 2004; Verhage & Kiemeney, 2003).
In addition to the discovery of the HPC1 gene, several other theories have been developed in an attempt to explain the genetic basis of prostate cancer. The Mendelian autosomal dominant inheritance theory is thought to best explain familial clustering of prostate cancer among men with early-onset disease. Approximately 43%-65% of prostate cancer cases diagnosed in patients before age 56 have been linked to the presence of a rare autosomal dominant, high-risk susceptibility gene (Verhage & Kiemeney, 2003). A multifactorial model has been developed which describes how prostate cancer may occur when several susceptible genes interact with environmental factors (Gong et al., 2002).
A virus was identified recently which may be an environmental influence on the development of prostate cancer. The HPC1 gene has been implicated in viral defense, and scientists have found that men with mutations in their HPC1 gene harbor this virus 30 times more than men without the genetic mutation. The HPC1 gene encodes an antiviral protein which is activated by viral infection. Any impairment in this gene has been proposed as a susceptibility factor in the development of prostate cancer (Hampton, 2006). There has been speculation that the virus interacts with the prostate and the tissue surrounding it to cause prostate cancer. Further research in this area is targeting development of a vaccine to prevent prostate cancer (Simard et al., 2003).
Prostate cancer frequently offers no specific clinical symptoms. Lower urinary tract symptoms may be present, but these are neither specific nor sensitive enough to diagnose prostate cancer. Lower urinary tract symptoms are more specific to another condition known as benign prostatic hyperplasia (BPH) and should not be correlated directly to the presence of prostate cancer. However, if prostate cancer is present, lower urinary tract symptoms also may be present, especially if the prostate enlarges or intrudes into the urethral space. These symptoms may include urgency, hesitancy, frequency, dysuria, weak stream, and urine leakage. In a review article, Hamilton and Sharp (2004) determined that lower urinary tract symptoms are more prevalent in the presence of prostate cancer, yet the high prevalence of these symptoms among the general population decreases their predictive value. No evidence thus suggests that...
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