Prostate cancer is tumor growth within the prostate gland, a structure that rests below the bladder in the male urinary tract. Patients are often asymptomatic early in the disease but may eventually develop urinary symptoms such as urinary frequency, trouble passing urine, and blood urine the urine. Prostate cancer often spreads to the spine; therefore, patients can develop back pain as well. Risk factors for prostate cancer include advanced age, a family history of prostate cancer, and African ancestry.
Prostate cancer tends to occur later in life and progresses slowly. Most individuals with prostate cancer do not die from cancer itself, but from other medical conditions or natural causes. The United States Preventative Task Force does not recommend for or against prostate cancer screening and suggests that the decision be based on a discussion between the doctor and patient.
Prostate cancer is a malignancy of the prostate gland. In general, cancer is considered a problem with uncontrolled cell division. Cancer cells do not respond to normal regulatory signals that slow or stop cellular division in healthy cells and tissues. Uncontrolled cellular expansion can eventually result in metastatic disease – spread of the cancerous cells to other tissues and organs. Prostate cancer tends to initially spread to regional lymph nodes followed by the spine.
The risk factors for developing prostate cancer are mainly related to age and genetics. Almost all cases are in men over the age of 40, with the majority of cases occurring in men approaching the age of 60. The most common risk factor is African descent. African American men tend to develop prostate cancer at a younger age and usually have a more aggressive form of the disease.
Prostate cancer is relatively common in the United States. Around 1 in 9 men will be diagnosed with prostate cancer at some point in their lifetime. The average age of diagnosis is 66 years of age with 6 out of 10 cases occurring in men over 65. Due to the incredible number of prostate cancer cases, it is a relatively common cause of death. According to the American Cancer Society, it is the second leading cause of cancer death with around 30,000 deaths annually.
Prostate cancer may remain asymptomatic for years, and even decades in some men. 80% of cases are detected incidentally during routine physical exams and with prostate cancer screening tests such as the PSA (prostate-specific antigen) blood test.
In those that do present with symptoms, urinary symptoms are almost always seen. The Prostate surrounds the urethra, the structure that allows urine to exit the bladder. Compression of this structure most commonly leads to the following symptoms:
- Urinary frequency (polyuria)
- Burning on urination (dysuria)
- Blood in the urine (hematuria)
- Urinating frequently at night (nocturia)
- Incomplete bladder emptying
Urinary symptoms are often related to coexisting benign prostatic hyperplasia (BPH) and do not always indicate prostate cancer. Those that have metastatic disease to the bones may complain of bone pain – particularly involving the back.
Patients may have a palpable mass or induration during the examination of the prostate. This is the only common sign of prostate cancer.
The diagnosis of prostate cancer is generally suspected only when a screening blood test called prostate-specific antigen (PSA) is elevated. If this test is elevated, your doctor will likely repeat the study. They will also usually obtain a urine analysis to evaluate for blood in the urine. Often times, your doctor will also perform a rectal examination to evaluate for any masses or irregularities of the prostate.
Screening is a controversial topic as it has not been shown to lead to a significant benefit in terms of morbidity and mortality. Screening may also result in unnecessary procedures or tests that are costly and potentially harmful. The US Preventative Task Force recommends that the decision to perform prostate cancer screening be a discussion between the doctor and patient and does not make a universal recommendation.
If your PSA is elevated and you are interested in further workup of prostate cancer, your doctor will typically refer you to a urologist. They will discuss the risks and benefits of prostate biopsy – this procedure is typically guided with a rectal ultrasound and involves taking a small sample of the prostate tissue for analysis.
Prostate cancer treatment depends on whether the cancer is localized or has spread (metastasized) to other tissues. Men with localized cancer and a life expectancy greater than 10 years typically benefit from either radiation therapy or radical prostatectomy (surgical prostate removal).
Patients with high-risk features such as advanced age or multiple chronic conditions or those with metastatic spread of disease typically benefit from antiandrogen therapy – this treatment involves reducing testosterone levels either medically or surgically. Testosterone reduction is an important aspect of treatment as testosterone often fuels the growth of prostate cancer.
Medical options for antiandrogen therapy, which is used to lower testosterone levels typically include:
- GnRH agonists – Zoladex (Goserelin), Vantas (histrelin), Lupron (Leuprolide), and Trelstar (triptorelin)
- Pure GnRH antagonists – Firmagon (degarelix)
- Antiandrogens – Casodex (Bicalutamide), Eulexin (flutamide), and Nilandron (nilutamide).
- Androgen inhibitors – Xtandi (Enzalutamide) and Zytiga (Abiraterone)
Some patients prefer surgical androgen deprivation – this cost-effective strategy involves bilateral removal of the testes (orchiectomy). This is less commonly performed in North America.
- National Comprehensive Cancer Network (NCCN). NCCN Clinical practice guidelines in oncology. http://www.nccn.org/professionals/physician_gls/f_guidelines.asp (Accessed on May 2, 2017). – https://www.nccn.org/professionals/physician_gls/default.aspx
- Barry MJ, Nelson JB. Patients Present with More Advanced Prostate Cancer since the USPSTF Screening Recommendations. J Urol 2015; 194:1534. Pokhrel PK, Loftus SA. Ocular emergencies. Am Fam Physician 2007; 76:829.
- Winters BR, Wright JL, Holt SK, et al. Extreme Gleason Upgrading From Biopsy to Radical Prostatectomy: A Population-based Analysis. Urology 2016; 96:148. – https://www.ncbi.nlm.nih.gov/pubmed/27313123