Prostate Cancer is a disease of men, particularly older men. It is uncommon in men in their forties, and very common in men in their seventies and eighties. One in six men in North America will be diagnosed with the disease in their lifetime. However, not all men die because of the cancer. In fact, the majority die with the cancer, rather than from it. Between 1 in 4 to 1 in 7 men die from the cancer. The younger the man, the greater the risk of dying from the disease. On the good news side, the mortality rate from prostate cancer is falling in recent years in North America. These facts dictate how doctors approach the diagnosis and treatment of prostate cancer.
Prostate cancer in its early stages has no symptoms. This is why it is important for men to see their doctor for annual check-ups. The most important tools in diagnosing the disease are: digital rectal exam (DRE), and prostate specific antigen (PSA), a blood test. Early detection is very important, as the earlier the diagnosis, the greater the chances of cure.
There are some factors that increase the risk. A family history of prostate cancer increases the risk from 100% to 1000%, depending on the relationship to a relative with the disease. Also, a family history of breast or colon (bowel) cancer increases the risk. The risk is higher in African-Americans than Caucasians, and lower in Oriental races.
High fat diet, a diet high in calcium and red meat has also been shown to increase the risk.
Many men who develop prostate cancer have none of these risk factors. Many older men will gradually develop difficulty passing urine. This is because the prostate enlarges as men age, and restricts the water passage. It is very rare that these symptoms are from cancer.
You can assess your risk of developing prostate cancer by using the program linked below.
What is Cancer?
Cancer is uncontrolled growth of abnormal cells. The body is made of billions of cells (like building blocks). The cells are replaced over time by dividing and forming new healthy cells. This is done in an organized and controlled fashion. If a cell changes and becomes abnormal (mutates), the control and organization is lost, and the cells grow rapidly, forming a growth (tumor). These growths may be benign (not cancers), or malignant (cancer).
Benign growths in the prostate (BPH) cause the gland to swell, which compresses the water passage (urethra), making it difficult to urinate. These changes are common in older men, but are not life threatening.
A malignant tumor (cancer) invades and destroys surrounding tissue. These cancer cells can also spread to other parts of the body (metastasize), where they grow and form new tumors.
What is Prostate Cancer?
Prostate cancer is the most common cancer in Canadian men. One out of six men will develop it in their lifetime. One in four will die from it. Almost four and four and a half thousand men die in Canada each year from prostate cancer. If diagnosed early, prostate cancer may be curable. Even when the disease is advanced, treatment can eradicate symptoms, and prolong survival.
Survival rates for prostate cancer have been improving for the last four years.
Where is the prostate and what does it do?
The prostate is a small gland about the size and shape of a chestnut. It is situated just below the bladder and surrounds
the urethra, the passage that carries urine from the bladder through the penis during urination. Women do not have a prostate.
The prostate secretes fluid, which forms part of the semen in which sperm are transported. During sexual activity and
orgasm, the semen enters the urethra and passes along it through the penis to the outside. This is called ejaculation.
What are the symptoms of Prostate cancer?
Most men with prostate cancer have no symptoms.
More advanced cancers may cause symptoms. These symptoms may be due to invasion in the prostate area, causing problems with urination, bleeding, or inability to urinate. These symptoms are most common with BENIGN enlargment of the prostate, and should not be confused with cancer.
If the cancer spreads, it most commonly invades bone. This may cause bone pain, most commonly in the lower back and pelvis.
What causes prostate cancer?
We do not know the cause of prostate cancer. Some factors may increase the risk:
Older age
Family history of prostate cancer
Family history of Breast or Bowel cancer
African race
High fat diet
Many men with none of these risk factors develop prostate cancer.
How is prostate cancer detected?
1. Digital Rectal Exam (DRE): As the prostate is located just in front of the rectum, it can be felt by inserting a lubricated gloved finger into the rectum. A lump, or hard area will suggest cancer. Not all lumps are cancerous, and a biopsy (tissue sample) will confirm or exclude cancer. A DRE should be performed in men with urinary symptoms, and at an annual physical exam.
2. PSA: Another way of detecting prostate cancer is by means of a blood test for prostate specific antigen (PSA). Only the prostate produces PSA. It can be detected in the blood and is normally present in small amounts. In most, but not all men with prostate cancer, blood levels of PSA are increased. Abnormal levels of PSA may indicate the need for a prostate biopsy even when the DRE is normal. However, an elevated PSA does not necessarily mean that prostate cancer is present as this can also occur in some patients with benign prostatic hyperplasia (BPH) or prostate infection (prostatitis). On the other hand, cancer may be present even with normal PSA levels. DRE is therefore important to detect these cancers. Approximately 70% of prostate cancers are detected because of an elevated PSA.Having an annual PSA test and DRE have been shown to increase the early detection of prostate cancer. The chance of curing prostate cancer may be increased if it is detected early. Because there is no definite proof that early detection is beneficial and because these tests may be abnormal in men who do not have prostate cancer, the decision as to whether men over 50 years old should have these tests performed annually is controversial. If you are in this age group, you should read the Canadian Prostate Health Council @ http://www.canadian-prostate.com/ booklet on Prostate Specific Antigen and discuss the matter further with your physician.
3. Prostate Biopsy: A biopsy is a tissue sample taken to examine under the microscope. When there is a suspicion of prostate cancer, a biopsy is required to make the diagnosis. This is done by passing a small needle through the rectal wall, into the prostate. This is the only way to make a definitive diagnosis of cancer. This procedure is usually done with the guidance of transrectal ultrasound (TRUS). It is done using local anesthesia, as an outpatient.
TRUS is only a guide for where to place the biopsy needle. It is not a test to screen for prostate cancer.
4. Other tests
A bone scan may be done if cancer is diagnosed, to check if the cancer has spread to bones. It is only of value if the PSA level is high (>20).
Other X-rays are of limited value, unless individually indicated.
CT scanning is used in the planning of Radiation treatment.
What is cancer "staging and grading"?
Staging refers to the extent of the cancer. It is based on 3 bits of information:
T (tumor); N (nodes); M (metastases). The TNM classification is applied to all cancers.
N refers to lymph nodes. N0 means no lymph node invasion. N1, N2 etc means the number of nodes involved. Nx means the nodes have not been tested. M refers to metastases (spread to other parts of the body, usually bone): M0 means no metastases, M+ means bony invasion. Mx means the bones have not been scanned (most cases)
Grading refers to the aggressiveness of the cancer cells. The Pathologist can tell how aggressive the cells are when examining the biopsy sample. The cells are given a score (Gleason) from 1 to 5, with the lower number indicating least aggressive. The most common and second commonest appearing cells are scored, and the numbers added together.
This sum is the Gleason score: e.g. one are of 3, the other area 4; 3 + 4 = Gleason 7.
The higher the Gleason score, the more aggressive the cancer. Gleason 6 and 7 are the most common grades seen in practice.
How is prostate cancer treated?
The treatment of prostate cancer depends upon many factors. These include the stage, tumor grade and serum PSA and the patient's general health status.
Watchful waiting
It might seem strange that you have been diagnosed as having prostate cancer and your urologist has recommended that no treatment be given. The reason is that while some prostate cancers grow rapidly and metastasize, others grow very slowly and are unlikely to metastasize. In older men, slow growing prostate cancer may not have time to cause significant problems. Complications of treatment may outweigh the advantages of treatment. Depending upon the size of your cancer, tumor grade, your age and general health, your urologist will discuss with you whether treatment should be postponed. If treatment is not given, you will have regular
check-ups so that treatment can be given if you develop symptoms or the cancer is progressing.
Surgery-Radical Prostatectomy
Radical prostatectomy involves removal of the entire prostate unlike the type of prostatectomy performed for benign prostatic hyperplasia (BPH) where only the inner obstructing part of the prostate is removed. It is therefore a bigger operation and has more potential complications. However, if the cancer is confined to the prostate it offers an excellent chance for cure. It is usually performed through an incision in the lower abdomen. Pelvic lymph nodes may be removed to check for metastases. Radical prostatectomy will usually only be done if there are no metastases. Potential complications include impotence and incontinence. In the past, impotence almost always occurred due to damage to nerves, which lie very close to the prostate. With improved surgical techniques these nerves may be spared, preserving sexual potency. The likelihood of preserving potency will depend on a number of factors. If you are potent, you should discuss this with your urologist.
Incontinence is common immediately after surgery. However, control is usually regained over the first few months. Persistent, severe incontinence should occur in
less than 5 percent of patients. Mild stress incontinence (e.g., with coughing or lifting) may persist in 10 to 15 percent of patients. Other complications include narrowing at the junction of bladder and urethra and, very rarely, injury to the rectum.
Radical prostatectomy may also be done through an incision in the perineum i.e. behind the scrotum and
in front of the anus. While this is less common, some surgeons prefer it. Radical prostatectomy may also be performed using laparoscopy. The benefits of this approach are being assessed.
Radiation Therapy
Cancer cells can be killed using radiation. Radiation may be given using external beam radiation or, in some centers, by the use of radioactive implants inserted into the prostate (brachytherapy). Radiation treatment may also cause impotence but incontinence is uncommon. Some patients have problems with bowel and/or bladder function. External beam radiation is generally given 5 days per week for about 6 weeks. Brachytherapy is performed using general, spinal or local anesthesia. Whether external beam radiation or brachytherapy is the appropriate treatment depends upon the tumor stage, grade and PSA level. You should discuss which form of radiation is best for you with your urologist and radiation oncologist.
Patients who have cancer confined to the prostate have the choice of radical prostatectomy or radiation therapy. Which is more suitable will depend upon factors such as the size of your tumor, your age and general health. These options should be discussed with your urologist. Radiation therapy is also useful for palliation (e.g., relief of pain due to metastases in the bone).
Cryotherapy
Cryotherapy uses extreme cold to destroy cancer cells. It is
relatively new and only available in a few centers in Canada. It is performed under spinal anesthesia and requires one night in hospital. Early results are comparable to surgery and radiation. Impotence is common. It is well tolerated and safe in older men. It is an alternative for those men who cannot or wish not to have radical prostatectomy or radiation. Cryotherapy is or particular value in men whose cancer has recurred following radiation therapy. The risks of side effects are slightly higher in this group rather than when used as a primary treatment.
Hormonal Therapy
Most prostate cancers depend on the male hormone testosterone for their growth. Removing testosterone or blocking its action causes prostate cancer cells to regress. This is generally referred to as hormonal therapy. Unfortunately, resistant cells eventually develop which
can survive and grow in the absence of testosterone.
Hormonal therapy, therefore, does not cure prostate cancer but can very effectively improve symptoms and quality of life. As well, hormonal therapy may also prolong life. Hormonal therapy is generally used in the treatment of more advanced prostate cancer, but may be useful in combination with surgery or radiation.
Hormonal therapy can be achieved in a variety of ways:
§ Surgical removal of the testes
This is called orchiectomy and is a relatively simple and effective way to remove testosterone. If you are potent and sexually active you will likely notice decreased sexual desire and difficulty achieving erections. You may also notice hot flashes.
§ LH RH (Luteinizing Hormone Releasing Hormone)analogs
These drugs are given by injection, usually every 3 or 4 months. They prevent the release of testosterone from the testes and have similar benefits as orchiectomy. Side effects are the same.
§ Antiadrogens
These are pills, which block the stimulating effect of
testosterone on prostate cancer. There are a number of these drugs with similar methods of action. Some
permit preservation of sexual activity but have other side effects and may be less effective in controlling the cancer when taken alone. Most antiandrogens are used in combination with either orchiectomy or LHRL analogs.
Unlike orchiectomy which is a one-time treatment, if drug therapy is used you will generally be required to continue with it indefinitely. In some patients, intermittent (off and on) hormone therapy may be an option. This alternative may reduce side effects but is still under investigation. Should you require hormonal therapy, your urologist will discuss the advantages and disadvantages of the different options.
You should also read the CPHC booklet on Hormonal Therapy for Prostate Cancer.§ Chemotherapy
Chemotherapy is the use of anticancer drugs, other than hormones. Chemotherapy is very effective against some cancers. Unfortunately, at present, we do not have very
effective chemotherapy for prostate cancer but new drugs continue to undergo investigation. Chemotherapy may aid in controlling symptoms and is sometimes used for patients whose disease is progressing despite hormonal therapy. A great deal of research is ongoing to find effective therapy when hormonal therapy is no longer sufficient to control the cancer.
§ Chemotherapy
Chemotherapy is the use of anticancer drugs, other than hormones. Chemotherapy is very effective against some cancers. Unfortunately, at present, we do not have very
effective chemotherapy for prostate cancer but new drugs continue to undergo investigation. Chemotherapy may aid in controlling symptoms and is sometimes used for patients whose disease is progressing despite hormonal therapy. A great deal of research is ongoing to find effective therapy when hormonal therapy is no longer sufficient to control the cancer.
