Prostate cancer is the most common cancer in men over age 50. Adenocarcinoma is its most common form; sarcoma occurs only rarely. Most prostatic carcinomas originate in the posterior prostate gland; the rest originate near the urethra. Malignant prostatic tumors seldom result from the benign hyperplastic enlargement that commonly develops around the prostatic urethra in elderly men. Prostatic cancer seldom produces symptoms until it's advanced.
Incidence of prostate cancer increases with age more rapidly than that of any other cancer.
Exact cause unknown
Implicated contributing factors
· Familial or ethnic predisposition
· Exposure to environmental toxins (radiation, air pollution: arsenic, benzene, hydrocarbons, polyvinyl chlorides)
· Sexually transmitted diseases
· Endogenous hormonal influence
· Diet containing fat from animal products
Typically, when a primary prostatic lesion spreads beyond the prostate gland, it invades the prostatic capsule and spreads along ejaculatory ducts in the space between the seminal vesicles or perivesicular fascia. Endocrine factors may play a role, leading researchers to suspect that androgens speed tumor growth.
Signs and symptoms
· Nonraised, firm, nodular mass with a sharp cage
· Difficulty initiating a urine stream
· Dribbling, urine retention
· Unexplained cystitis
· Edema of the scrotum or leg
· Hard lump in the prostate region
Diagnostic test results
· Serum prostate-specific antigen test reveals elevated levels indicating cancer with or without metastases.
· Transrectal prostatic ultrasonography shows prostate size and presence of abnormal growths.
· Bone scan and excretory urography determine the extent of disease.
· Magnetic resonance imaging and computed tomography scan define the extent of the tumor.
· Standard screening test, digital rectal examination, is recommended yearly by the American Cancer Society for men over age 40.
· Radiation by external beam radiation or radioactive implants
· Hormonal manipulation
· Luteinizing hormone-releasing hormone agonists, such as Lupron or Zoladex
· Androgen blocking agents
Clinical Tip: Pathway for Metastasis of Prostate Cancer
When primary prostatic lesions metastasize, they typically invade the prostatic capsule, spreading along the ejaculatory ducts in the space between the seminal vesicles or perivesicular fascia.