Prostate Cancer:
Screening, diagnosis and treatment options remain controversial, because the disease mostly behaves indolently in the older age group. The value of screening in terms of saving lives has not been fully established. Autopsy series show that 60 % of men will develop prostate cancer over time. Does finding and treating it early come at great cost, without significant benefit? It is still being worked out.
Risk factors: mainly age, race (black Americans are at greatest risk), geography (Scandinavians greater than Asians) and family history in first-degree relatives. Dietary fat, vasectomy and STDs have not been shown to be contributory.
Diagnosis: is difficult in early stages because of the lack of symptoms. By the time it is locally advanced, it can cause obstructive bladder symptoms, blood in the urine and urinary tract infections. When it has spread to the bones, it causes bone pain, and possibly, spinal cord compression.
Digital rectal examination should be done every year. Anything that feels abnormal needs a biopsy. PSA is a blood test that measures a protein enzyme that is produced by the prostate tissue. Any inflammation, infection or trauma will cause a rise in the PSA. It is a sensitive test, but not specific to Prostate Cancer. An abnormal level or an abnormal rate of increase over serial testing will lead to a prostate biopsy.
Pathology: Most Prostate Cancers are adenocarcinomas, or glandular cancers. Rarely, other types of cells cause cancer of the prostate gland, e.g. neuroendocrine cells, which have an aggressive course.
Gleason score: is a way of grading the cancer cell, on its aggressivity. The lower the score, the lesser the likelihood of dying from the disease. It is grouped into a
-Low (2-4), Intermediate (5-7) and High (8-10).
Treatment: is individualized and depends on
-Age, Life Expectancy and other significant medical problems.
-Stage and Gleason Score
-Rate of increase of the PSA level.
Watchful waiting: has been an accepted approach for low-grade disease, and older age group, where the risk of dying from prostate cancer is low. The morbidity caused by treatment outweighs the benefits.
When intervention is recommended the choices depend on the disease volume and age. These include:
Radical Prostatectomy/ Nerve sparing Radical Prostatectomy. : The approaches can be laparoscopic or by open incision. Robotic surgery is being performed, but its benefit in decreasing morbidity is still being established.
Radiation Therapy: can be delivered via
- Radioactive Iodine Seeds Implantation. A trans rectal ultrasound helps guide placement to cover the entire area of the prostate gland accurately.
- External Beam Radiation: can cover the prostate gland and regional lymphatics, as well as areas of painful bony involvement. This is delivered in daily fractions, over the course of several weeks.
- IMRT: Intensity Modulated Radiotherapy is a way of creating a radiation field to conform to the prostate gland.
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Hormonal Therapy: Prostate Cancer cells are stimulated to grow by Testosterone, or the male hormone produced in the Testes. A number of drugs and interventions block this hormone production and activity:
-Chemical Castration with monthly injections of Leuprolide or goserelin
-Surgical Castration: with removal of the testicles. These produce 95 % of the body’s testosterone.
-Total Androgen Blockade, by combining anti-androgen drugs (Flutamide, Nilutamide, Ketoconazole) with castration methods to further decrease androgen effect
-Estrogen used to be used more widely before the advent of modern anti-androgens, and can still be considered an option.
Chemotherapy: is used when disease progresses through hormonal maneuvers, or presents as rapidly progressive disease. These treatments are used till further disease progression occurs, which means that they are no longer beneficial. Inherently, they are not curative treatments, and need to be judiciously used, considering that the population that is being treated: elderly men with other medical conditions.
-Combination of Docetaxel given intravenously once every 3 weeks with daily steroids has shown benefit in slowing disease progression.
- Cabazitaxel is a new drug that has shown responses in previously treated, i.e. resistant cancers
-Mitoxantrone + Prednisone.
Side effects of treatment:
Surgery can cause Incontinence and Impotence.
Radiation can cause diarrhea, impotence, pelvic marrow radiation leading to low blood counts
Hormone therapy causes Impotence, loss of bone mass and anemia
Chemotherapy causes nausea, hair loss, low blood counts and fatigue.
Optimal treatment continues to evolve.