PROSTATE CANCER

Prostate cancer is cancer of the prostate. The prostate is a gland in the male reproductive system that surrounds the urethra just below the bladder. Most prostate cancers are slow growing. Cancerous cells may spread to other areas of the body, particularly the bones and lymph nodes. It may initially cause no symptoms. In later stages, symptoms include pain or difficulty urinating, blood in the urine, or pain in the pelvis or back. Benign prostatic hyperplasia may produce similar symptoms. Other late symptoms include fatigue, due to low levels of red blood cells.

Factors that increase the risk of prostate cancer include older age, family history and race. About 99% of cases occur after age 50. A first-degree relative with the disease increases the risk two- to three-fold. Other factors include a diet high in processed meat, red meat, or milk products or low in certain vegetables. An association with gonorrhea has been found, although no reason for this relationship has been identified. An increased risk is associated with the BRCA mutations. Diagnosis is by biopsy. Medical imaging may be done to assess whether metastasis is present.

Prostate cancer screening, including prostate-specific antigen (PSA) testing, increases cancer detection but whether it improves outcomes is controversial. Informed decision making is recommended for those 55 to 69 years old. Testing, if carried out, is more appropriate for those with a longer life expectancy. Although 5α-reductase inhibitors appear to decrease low-grade cancer risk, they do not affect high-grade cancer risk, and are not recommended for prevention. Vitamin or mineral  supplementation.  does not appear to affect risk.  ` 

Many cases are managed with active surveillance or watchful waiting. Other treatments may include a combination of surgery, radiation therapy, hormone therapy, or chemotherapy. Tumors limited to the prostate may be curable. Should the disease spread to the bones, pain medications, bisphosphonates, and targeted therapy, among others, may be useful. Outcomes depend on age, health status and how aggressive and extensive the cancer is. Most men with prostate cancer do not die from it. The United States five-year survival rate is 98%.

Globally, it is the second-most common cancer. It is the fifth-leading cause of cancer-related death in men. In 2018, it was diagnosed in 1.2 million and caused 359,000 deaths. It was the most common cancer in males in 84 countries, occurring more commonly in the developed world. Rates have been increasing in the developing world. Detection increased significantly in the 1980s and 1990s in many areas due to increased PSA testing. One study reported prostate cancer in 30% to 70% of Russian and Japanese men over age 60 who had died of unrelated causes.

Early prostate cancer usually has no clear symptoms. When they do appear, they are often similar to those of benign prostatic hyperplasia. These include frequent urination, nocturia (increased urination at night), difficulty starting and maintaining a steady stream of urine, hematuria (blood in the urine) and dysuria (painful urination). One study found that about a third of diagnosed patients had one or more such symptoms.

Prostate cancer is associated with urinary dysfunction as the prostate gland surrounds the prostatic urethra. Changes within the gland directly affect urinary function. Because the vas deferens deposits seminal fluid into the prostatic urethra, and secretions from the prostate are included in semen content, prostate cancer may also cause problems with sexual function and performance, such as difficulty achieving erection or painful ejaculation.

Metastatic prostate cancer can cause additional symptoms. The most common symptom is bone pain, often in the vertebrae (bones of the spine), pelvis, or ribs. Spread of cancer into other bones such as the femur is usually to the part of the bone nearer to the prostate. Prostate cancer in the spine can compress the spinal cord, causing tingling, leg weakness, and urinary and fecal incontinence.

The primary risk factors are obesity, age, and family history. Obese men have been found to have a 34% greater death rate from prostate cancer than those with normal weight. Prostate cancer is uncommon in men younger than 45, but becomes more common with advancing age. The average age at the time of diagnosis is 70. Autopsy studies of Chinese, German, Israeli, Jamaican, Swedish, and Ugandan men who died of other causes found prostate cancer in 30% of men in their 50s, and in 80% of men in their 70s.

Men with high blood pressure are more likely to develop prostate cancer. A small increase in risk is associated with lack of exercise. Elevated blood testosterone levels may increase risk.

Regards

Amalia Azzariti

Managing Editor

Journal of Clinical Oncology and Cancer Research