Prostate cancer is the most common cancer among men (after skin cancer). Prostate cancer is cancer that occurs in the prostate — a small walnut-shaped gland in men that produces the seminal fluid that nourishes and transports sperm. Usually prostate cancer grows slowly and is initially confined to the prostate gland, where it may not cause serious harm. However, while some types of prostate cancer grow slowly and may need minimal or even no treatment, other types are aggressive and can spread quickly.
Prostate cancer that's detected early — when it's still confined to the prostate gland— has a better chance of successful treatment.
Types of prostate cancer
Almost all prostate cancers are adenocarcinomas. These cancers develop from the gland cells (the cells that make the prostate fluid that is added to the semen).
Other types of prostate cancer include:
• Small cell carcinomas
• Neuroendocrine tumors (other than small cell carcinomas)
• Transitional cell carcinomas.
These other types of prostate cancer are rare. If you have prostate cancer it is almost certain to be an adenocarcinoma.
Some prostate cancers can grow and spread quickly, but most grow slowly. In fact, autopsy studies show that many older men (and even some younger men) who died of other causes also had prostate cancer that never affected them during their lives. In many cases neither they nor their doctors even knew they had it.
What causes prostate cancer?
The exact causes of prostate cancer are not known. Several risk factors for developing prostate cancer have been identified, but which of these risk factors cause a prostate cell to become cancerous is not fully known. For a cancer to develop, changes must occur in the chemicals that make up the DNA, which makes up the genes in the cell. The genes control how the cell works, for example, how quickly the cell grows, divides into new cells, and dies, as well as correcting any mistakes that occur in the DNA of the cell to keep the cell working normally.
Cancer occurs when certain genes that either control the growth or death of the cell are affected, which results in abnormal cell growth and/or death. Genes are inherited (passed on from parents to their children) and thus some changes in the genes (gene mutations) that increase the risk of developing cancer may be inherited. For prostate cancer, approximately 5%-10% of prostate cancers are due to inherited gene changes. Several inherited genes have been identified that increase the risk of prostate cancer, including RNASEL, BRCA 1, and BRCA 2, DNA mismatch genes, HPC1, and HoxB13.
Gene changes may also be acquired (develop during the course of your life). These changes are not passed on to children. Such changes may occur when a cell is normally undergoing growth and division. It is thought that at times during normal cell growth, risk factors may affect the DNA of the cell.
What are the symptoms of prostate cancer?
Most men with early prostate cancer don’t have any signs or symptoms.
One reason for this is the way the cancer grows. You’ll usually only get early symptoms if the cancer grows near the tube you urinate through (the urethra) and presses against it, changing the way you urinate (pee). But because prostate cancer usually starts to grow in a different part of the prostate, early prostate cancer doesn’t often press on the urethra and cause symptoms.
If you do notice changes in the way you urinate, this is more likely to be a sign of a very common non-cancerous problem called an enlarged prostate, or another health problem. But it’s still a good idea to get it checked out.
• difficulty starting to urinate or emptying your bladder
• a weak flow when you urinate
• a feeling that your bladder hasn’t emptied properly
• dribbling urine after you finish urinating
• needing to urinate more often, especially at night
• a sudden urge to urinate – you may sometimes leak before you get to the toilet.
If prostate cancer breaks out of the prostate (locally advanced prostate cancer) or spreads to other parts of the body (advanced prostate cancer), it can cause other symptoms, including:
• back pain, hip pain or pelvis pain
• problems getting or keeping an erection
• blood in the urine or semen
• unexplained weight loss.
These symptoms can also be caused by other things that aren’t prostate cancer, like prostatitis (infection and swelling of the prostate), diabetes, or some medicines. But it’s still a good idea to get any symptoms checked out by your GP so they can find out what’s causing them and make sure you get the right treatment if you need it.
What are the risk factors for prostate cancer?
Certain risk factors may predispose a person to prostate cancer. These include the following:
Sixty percent of cases of prostate cancer arise in men over 65 years of age. The disease is rare in men under 40.
• Race or ethnicity:
African-American men and Jamaican men of African ancestry are diagnosed with prostate cancer more often than are men of other races and ethnicities. Asian and Hispanic men are less likely to develop prostate cancer than are non-Hispanic white males.
• Family history:
Prostate cancer can run in families. A man whose father or brother has or had prostate cancer is twice as likely to develop the disease. The younger the family member is when he is diagnosed with prostate cancer, the higher the risk is for male relatives to develop prostate cancer. The risk of developing prostate cancer also increases with the number of relatives affected.
Prostate cancer is more common in North America, Europe (especially northwestern countries in Europe), the Caribbean, and Australia. It is less common in Asia, Africa, and South and Central America. Multiple factors, such as diet and lifestyle, may account for this.
• Genetic factors:
Mutations in a portion of the DNA called the BRCA2 gene can increase a man's risk of getting prostate cancer, as well as other cancers. This same mutation in female family members may increase their risk of developing breast or ovarian cancer. However, very few cases of prostate cancer can be directly attributed to presently identifiable genetic changes. Other inherited genes associated with an increased risk of prostate cancer include RNASEL, BRCA 1, DNA mismatch genes, HPC1, and HoxB13.
• Other factors:
Diets high in red meats and fatty foods and low in fruits and vegetables appear to be associated with a higher risk of developing prostate cancer. Obesity is also linked to a higher risk of the disease. Increased calcium intake and dairy foods may increase the risk of prostate cancer.
Smoking, a history of sexually transmitted diseases, a history of prostatitis (inflammation of the prostate), and a history of vasectomy have not been proven to play a role in causing prostate cancer.
You can reduce your risk of prostate cancer if you:
• Choose a healthy diet full of fruits and vegetables. Avoid high-fat foods and instead focus on choosing a variety of fruits, vegetables and whole grains. Fruits and vegetables contain many vitamins and nutrients that can contribute to your health.
Whether you can prevent prostate cancer through diet has yet to be conclusively proved. But eating a healthy diet with a variety of fruits and vegetables can improve your overall health.
• Choose healthy foods over supplements. No studies have shown that supplements play a role in reducing your risk of prostate cancer. Instead, choose foods that are rich in vitamins and minerals so that you can maintain healthy levels of vitamins in your body.
• Exercise most days of the week. Exercise improves your overall health, helps you maintain your weight and improves your mood. There is some evidence that men who don't exercise have higher PSA levels, while men who exercise may have a lower risk of prostate cancer.
Try to exercise most days of the week. If you're new to exercise, start slow and work your way up to more exercise time each day.
• Maintain a healthy weight. If your current weight is healthy, work to maintain it by exercising most days of the week. If you need to lose weight, add more exercise and reduce the number of calories you eat each day. Ask your doctor for help creating a plan for healthy weight loss.
• Talk to your doctor about increased risk of prostate cancer. Men with a high risk of prostate cancer may consider medications or other treatments to reduce their risk. Some studies suggest that taking 5-alpha reductase inhibitors, including finasteride (Propecia, Proscar) and dutasteride (Avodart), may reduce the overall risk of developing prostate cancer. These drugs are used to control prostate gland enlargement and hair loss in men.
However, some evidence indicates that men taking these medications may have an increased risk of getting a more serious form of prostate cancer (high-grade prostate cancer). If you're concerned about your risk of developing prostate cancer, talk with your doctor.
Doctors agree that the prostate-specific antigen (PSA) blood test is not a perfect test for finding prostate cancer early. It misses some cancers, and in other cases the PSA level is high even when prostate cancer can’t be found. Researchers are working on strategies to address this problem.
One approach is to try to improve on the test that measures the total PSA level, as described in Prostate Cancer Prevention and Early Detection.
Another approach is to develop new tests based on other forms of PSA, or other tumor markers. Several newer tests seem to be more accurate than the PSA test, including:
• The phi, which combines the results of total PSA, free PSA, and proPSA to help determine how likely it is that a man has prostate cancer that might need treatment
• The 4Kscore test, which combines the results of total PSA, free PSA, intact PSA, and human kallikrein 2 (hK2), along with some other factors, to help determine how likely a man is to have prostate cancer that might need treatment
• Tests such as Progensa that look at the level of prostate cancer antigen 3 (PCA3) in the urine after a digital rectal exam (DRE). (The DRE pushes some of the prostate cells into the urine.) The higher the level, the more likely that prostate cancer is present.
• Tests that look for an abnormal gene change called TMPRSS2:ERG in prostate cells in urine collected after a DRE. This gene change is found in some prostate cancers, but it is rarely found in the cells of men without prostate cancer.
• ConfirmMDx, which is a test that looks at certain genes in the cells from a prostate biopsy sample
These tests aren’t likely to replace the PSA test any time soon, but they might be helpful in certain situations. For example, some of these tests might be useful in men with a slightly elevated PSA, to help determine whether they should have a prostate biopsy. Some of these tests might be more helpful in determining if men who have already had a prostate biopsy that didn’t find cancer should have another biopsy. Doctors and researchers are trying to determine the best way to use each of these tests.
A doctor will carry out a physical examination and enquire about any ongoing medical history. If the patient has symptoms, or if a routine blood test shows abnormally high PSA levels, further examinations may be requested.
Tests may include:
• a digital rectal examination (DRE), in which a doctor will manually check for any abnormalities of the prostate with their finger
• a biomarker test checking the blood, urine, or body tissues of a person with cancer for chemicals unique to individuals with cancer
If these tests show abnormal results, further tests will include:
• a PCA3 test examining the urine for the PCA3 gene only found in prostate cancer cells
• a transrectal ultrasound scan providing imaging of the affected region using a probe that emits sounds
• a biopsy, or the removal of 12 to 14 small pieces of tissue from several areas of the prostate for examination under a microscope.
These will help confirm the stage of the cancer, whether it has spread, and what treatment is appropriate.
To track any spread, or metastasis, doctors may use a bone, CT scan, or MRI scan.
Treatment is different for early and advanced prostate cancers.
Early stage prostate cancer
If the cancer is small and localized, it is usually managed by one of the following treatments:
Watchful waiting or monitoring: PSA blood levels are regularly checked, but there is no immediate action. The risk of side-effects sometimes outweighs the need for immediate treatment for this slow-developing cancer.
Radical prostatectomy: The prostate is surgically removed. Traditional surgery requires a hospital stay of up to 10 days, with a recovery time of up to 3 months. Robotic keyhole surgery involves a shorter hospitalization and recovery period, but it can be more expensive. Patients should speak to their insurer about coverage.
Brachytherapy: Radioactive seeds are implanted into the prostate to deliver targeted radiation treatment.
Conformal radiation therapy: Radiation beams are shaped so that the region where they overlap is as close to the same shape as the organ or region that requires treatment. This minimizes healthy tissue exposure to radiation.
Intensity modulated radiation therapy: Beams with variable intensity are used. This is an advanced form of conformal radiation therapy.
In the early stages, patients may receive radiation therapy combined with hormone therapy for 4 to 6 months.
Treatment recommendations depend on individual cases. The patient should discuss all available options with their urologist or oncologist.
Advanced prostate cancer
Advanced cancer is more aggressive and will have spread further throughout the body.
Chemotherapy may be recommended, as it can kill cancer cells around the body.
Androgen deprivation therapy (ADT), or androgen suppression therapy, is a hormone treatment that reduces the effect of androgen. Androgens are male hormones that can stimulate cancer growth. ADT can slow down and even stop cancer growth by reducing androgen levels.
The patient will likely need long-term hormone therapy.
Even if the hormone therapy stops working after a while, there may be other options. Participation in clinical trials is one option that a patient may wish to discuss with the doctor.
Radical prostatectomy is not currently an option for advanced cases, as it does not treat the cancer that has spread to other parts of the body.
As the prostate is directly involved with sexual reproduction, removing it affects semen production and fertility.
Radiation therapy affects the prostate tissue and often reduces the ability to father children. The sperm can be damaged and the semen insufficient for transporting sperm.
Non-surgical options, too, can severely inhibit a man's reproductive capacity.
Options for preserving these functions can include donating to a sperm bank before surgery, or having sperm extracted directly from the testicles for artificial insemination into an egg. However, the success of these options is never guaranteed.
Patients with prostate cancer can speak to a fertility doctor if they still intend to father children.
Coping and support
When you receive a diagnosis of prostate cancer, you may experience a range of feelings — including disbelief, fear, anger, anxiety and depression. With time, each person finds his own way of coping with a prostate cancer diagnosis.
Until you find what works for you, try to:
• Learn enough about prostate cancer to feel comfortable making treatment decisions. Learn as much as you need to know about your cancer and its treatment in order to understand what to expect from treatment and life after treatment. Ask your doctor, nurse or other health care professional to recommend some reliable sources of information to get you started.
• Keep your friends and family close. Your friends and family can provide support during and after your treatment. They may be eager to help with the small tasks you won't have energy for during treatment. And having a close friend or family member to talk to can be helpful when you're feeling stressed or overwhelmed.
• Connect with other cancer survivors. Friends and family can't always understand what it's like to face cancer. Other cancer survivors can provide a unique network of support. Ask your health care providers about support groups or community organizations that can connect you with other cancer survivors. Organizations such as the American Cancer Society offer online chat rooms and discussion forums.
• Take care of yourself. Take care of yourself during cancer treatment by eating a diet full of fruits and vegetables. Try to exercise most days of the week. Get enough sleep each night so that you wake feeling rested.
• Continue sexual expression. If you experience erectile dysfunction, your natural reaction may be to avoid all sexual contact. But consider touching, holding, hugging and caressing as ways to continue sharing sexuality with your partner.