Prostate cancer, also known as carcinoma of the prostate, is a disease in which malignant (cancer) cells form in the tissues of the prostate.
The prostate is a gland in the male reproductive system. It lies just below the bladder and in front of the rectum.
The word "prostate" comes from Medieval Latin prostate and Medieval French prostate. The ancient Greek word prostates means "one standing in front", from proistanai meaning "set before". The prostate is so called because of its position.
Prostate cancer is one of the most common types of cancer in men and the most common in older men, but it can often be treated successfully.
Prostate cancer usually grows slowly and initially remains confined to the prostate gland, where it may not cause serious harm. While some types of prostate cancer grow slowly and may need minimal or no treatment, other types are aggressive and can spread quickly.
Prostate cancer that is detected early, when it's still confined to the prostate gland, has a better chance of successful treatment.
The prostate is a small, squishy gland about the size of a walnut. It sits under the bladder and in front of the rectum.
The bladder holds your urine until you are ready to void, and is like a balloon that gets larger as it fills with urine.
The urethra is a narrow tube that connects to the bladder, runs right through the middle of the prostate, and runs through the length of the penis and carries both urine and semen out of the body. It is the hose that drains the bladder.
The rectum is the lower end of your intestines and it sits right behind the prostate.
The seminal vesicles are rabbit eared structures that store and secrete a large portion of your ejaculate. These structures sit on top of the prostate.
The neurovascular bundle is a bundle of nerves and vessels that run along each side of the prostate. These nerves and vessels help control erectile function. They sometimes are a short distance away from the prostate, but sometimes they are adherent to the prostate itself.
The prostate is important for reproduction. It supplies substances that facilitate fertilization and sperm transit and survival. The prostate gland makes fluid that forms part of semen that carries sperm. Sperm is not made in the prostate, but rather the testes.
What are the Early Warning Symptoms of Prostate Cancer?
Usually there aren’t any. However, in rare cases prostate cancer can cause symptoms and you need to be aware of what they are.
Symptoms can include:
A need to urinate frequently, especially at night; sometimes urgently
Difficulty starting or holding back urination
Weak, dribbling, or interrupted flow of urine
Painful or burning urination
Difficulty in having an erection
A decrease in the amount of fluid ejaculated
Blood in the urine or semen
Pain or stiffness in the lower back, hips, pelvis, or thighs
However, urinary symptoms don’t mean you have cancer. Prostatitis or Benign Prostatic Hyperplasia (BPH), also known as enlargement of the prostate, can cause similar symptoms and are very common.
Again, difficulty in having an erection is most likely not caused by cancer, but by something else, such as diabetes, smoking, cardiovascular disease, or just plain getting older.
Mostly, there are no early warning symptoms for prostate cancer. That’s why periodic screening is important from the age of 40.
What Causes Prostate Cancer?
It's not clear what causes prostate cancer.
Doctors know that prostate cancer begins when some cells in your prostate become abnormal. Mutations in the abnormal cells' DNA cause the cells to grow and divide more rapidly than normal cells do. The abnormal cells continue living, when other cells would die. The accumulating abnormal cells form a tumour that can grow to invade nearby tissue.
Some abnormal cells can break off and spread (metastasize) to other parts of the body.
Factors that can increase your risk of prostate cancer include:
Older age. Your risk of prostate cancer increases as you age.
Being black. Black men have a greater risk of prostate cancer than do men of other races. In black men, prostate cancer is also more likely to be aggressive or advanced. It's not clear why this is.
Family history of prostate or breast cancer. If men in your family have had prostate cancer, your risk may be increased. Also, if you have a family history of genes that increase the risk of breast cancer (BRCA1 or BRCA2) or a very strong family history of breast cancer, your risk of prostate cancer may be higher.
Obesity. Obese men diagnosed with prostate cancer may be more likely to have advanced disease that's more difficult to treat.
Other risk factors for aggressive prostate cancer include:
Lack of exercise and a sedentary lifestyle
High calcium intake
Research in the past few years has shown that diet modification might decrease the chances of developing prostate cancer, reduce the likelihood of having a prostate cancer recurrence, or help slow the Progression of the disease.
Myths and Non-Risks of Prostate Cancer
Sexual Activity – High levels of sexual activity or frequent ejaculation have been rumoured to increase prostate cancer risk. This is untrue. In fact, studies show that men who report more frequent ejaculations may have a lower risk of developing prostate cancer. Several case-control studies have shown that having many lifetime sexual partners or starting sexual activity early in life substantially increases the risk of prostate cancer.
While the available evidence is weak, tentative results suggest that frequent ejaculation may decrease the risk of prostate cancer. A study, over eight years, showed that those that ejaculated most frequently (over 21 times per month on average) were less likely to get prostate cancer (however, the researchers asserted ejaculation frequency was not statistically significantly associated with risk of advanced prostate cancer and concluded our results suggest that ejaculation frequency is not related to increased risk of prostate cancer). The results were broadly similar to the findings of a smaller Australian study.
Having a vasectomy was originally thought to increase a man’s risk, but this has since been disproven.
Medications – Several recent studies have shown a link between aspirin intake and a reduced risk of prostate cancer by 10-15%. This may result from different Screening practices, through a reduction of inflammation, or other unknown factors.
Alcohol – There is no link between alcohol and prostate cancer risk.
Vitamin E – Recent studies have not shown a benefit to the consumption of vitamin E or selenium in the prevention of prostate cancer.
How to Diagnosis Prostate Cancer
Whether to screen healthy men with no symptoms for prostate cancer is controversial. Medical organizations don't agree on the issue of screening and whether it has benefits.
Some medical organizations recommend men consider prostate cancer screening in their 50s, or sooner (40s) for men who have risk factors for prostate cancer. Other organizations advise against screening.
Discuss your particular situation and the benefits and risks of screening with your doctor. Together, you can decide whether prostate cancer screening is right for you.
Tests that examine the prostate and blood are used to detect and diagnose prostate cancer.
The following tests and procedures may be used:
Physical exam and history: An exam of the body to check general signs of health, including checking for signs of disease, such as lumps or anything else that seems unusual. A history of the patient’s health habits and past illnesses and treatments will also be taken.
Digital rectal exam (DRE): An exam of the rectum. The doctor or nurse inserts a lubricated, gloved finger into the rectum and feels the prostate through the rectal wall for lumps or abnormal areas.
Prostate-specific antigen (PSA) test: A test that measures the level of PSA in the blood. PSA is a substance made by the prostate that may be found in an increased amount in the blood of men who have prostate cancer. PSA levels may also be high in men who have an infection or inflammation of the prostate or BPH (an enlarged, but noncancerous, prostate).
Transrectal ultrasound: A procedure in which a probe that is about the size of a finger is inserted into the rectum to check the prostate. The probe is used to bounce high-energy sound waves (ultrasound) off internal tissues or organs and make echoes. The echoes form a picture of body tissues called a sonogram. Transrectal ultrasound may be used during a biopsy procedure.
Transrectal magnetic resonance imaging (MRI): A procedure that uses a strong magnet, radio waves, and a computer to make a series of detailed pictures of areas inside the body. A probe that gives off radio waves is inserted into the rectum near the prostate. This helps the MRI machine make clearer pictures of the prostate and nearby tissue. A transrectal MRI is done to find out if the cancer has spread outside the prostate into nearby tissues. This procedure is also called nuclear magnetic resonance imaging (NMRI).
Biopsy: The removal of cells or tissues so they can be viewed under a microscope by a pathologist. The pathologist will check the tissue sample to see if there are cancer cells and find out the Gleason score. The Gleason score ranges from 2-10 and describes how likely it is that a tumour will spread. The lower the number, the less likely the tumour is to spread.
A transrectal biopsy is used to diagnose prostate cancer. A transrectal biopsy is the removal of tissue from the prostate by inserting a thin needle through the rectum and into the prostate. This procedure is usually done using transrectal ultrasound to help guide where samples of tissue are taken from. A pathologist views the tissue under a microscope to look for cancer cells.
Determining how far the cancer has spread
Once a prostate cancer diagnosis has been made, your doctor works to determine the extent (stage) of the cancer. If your doctor suspects your cancer may have spread beyond your prostate, imaging tests such as these may be recommended:
Computerized tomography (CT) scan
Magnetic resonance imaging (MRI)
Positron emission tomography (PET) scan
Not every person should have every test. Your doctor will help determine which tests are best for your individual case.
Once testing is complete, your doctor assigns your cancer a stage. This helps determine your treatment options. The prostate cancer stages are:
Stage I. This stage signifies very early cancer that's confined to a small area of the prostate. When viewed under a microscope, the cancer cells aren't considered aggressive.
Stage II. Cancer at this stage may still be small but may be considered aggressive when cancer cells are viewed under the microscope. Or cancer that is stage II may be larger and may have grown to involve both sides of the prostate gland.
Stage III. The cancer has spread beyond the prostate to the seminal vesicles or other nearby tissues.
Stage IV. The cancer has grown to invade nearby organs, such as the bladder, or spread to lymph nodes, bones, lungs or other organs.
Prostate Cancer Treatment
There is no “one size fits all” treatment for prostate cancer. You should learn as much as possible about the many treatment options available and, in conjunction with your physicians, make a decision about what’s best for you.
Certain factors affect prognosis and treatment options.
The prognosis (chance of recovery) and treatment options depend on the following:
The stage of the cancer (level of PSA, Gleason score, grade of the tumour, how much of the prostate is affected by the cancer, and whether the cancer has spread to other places in the body).
The patient’s age.
Whether the cancer has just been diagnosed or has recurred (come back).
Treatment options also may depend on the following:
Whether the patient has other health problems.
The expected side effects of treatment.
Past treatment for prostate cancer.
The wishes of the patient.
Most men diagnosed with prostate cancer do not die of it.
Immediate treatment may not be necessary
For men diagnosed with very early-stage prostate cancer, treatment may not be necessary right away. Some men may never need treatment. Instead, doctors sometimes recommend active surveillance.
In active surveillance, regular follow-up blood tests, rectal exams and possibly biopsies may be performed to monitor progression of your cancer. If tests show your cancer is progressing, you may opt for a prostate cancer treatment such as surgery or radiation.
Active surveillance may be an option for cancer that isn't causing symptoms, is expected to grow very slowly and is confined to a small area of the prostate. Active surveillance may also be considered for a man who has another serious health condition or an advanced age that makes cancer treatment more difficult.
Active surveillance carries a risk that the cancer may grow and spread between checkups, making it less likely to be cured.
Radiation therapy uses high-powered energy to kill cancer cells. Prostate cancer radiation therapy can be delivered in two ways:
Radiation that comes from outside of your body (external beam radiation). During external beam radiation therapy, you lie on a table while a machine moves around your body, directing high-powered energy beams, such as X-rays or protons, to your prostate cancer. You typically undergo external beam radiation treatments five days a week for several weeks.
Radiation placed inside your body (brachytherapy). Brachytherapy involves placing many rice-sized radioactive seeds in your prostate tissue. The radioactive seeds deliver a low dose of radiation over a long period of time. Your doctor implants the radioactive seeds in your prostate using a needle guided by ultrasound images. The implanted seeds eventually stop giving off radiation and don't need to be removed.
Side effects of radiation therapy can include painful urination, frequent urination and urgent urination, as well as rectal symptoms, such as loose stools or pain when passing stools. Erectile dysfunction can also occur.
Hormone therapy is treatment to stop your body from producing the male hormone testosterone. Prostate cancer cells rely on testosterone to help them grow. Cutting off the supply of hormones may cause cancer cells to die or to grow more slowly.
Hormone therapy options include:
Medications that stop your body from producing testosterone. Medications known as luteinizing hormone-releasing hormone (LH-RH) agonists prevent the testicles from receiving messages to make testosterone. Drugs typically used in this type of hormone therapy include leuprolide (Lupron, Eligard), goserelin (Zoladex), triptorelin (Trelstar) and histrelin (Vantas). Other drugs sometimes used include ketoconazole and abiraterone (Zytiga).
Medications that block testosterone from reaching cancer cells. Medications known as anti-androgens prevent testosterone from reaching your cancer cells. Examples include bicalutamide (Casodex), flutamide, and nilutamide (Nilandron). The drug enzalutamide (Xtandi) may be an option when other hormone therapies are no longer effective.
Surgery to remove the testicles (orchiectomy). Removing your testicles reduces testosterone levels in your body.
Hormone therapy is used in men with advanced prostate cancer to shrink the cancer and slow the growth of tumors. In men with early-stage prostate cancer, hormone therapy may be used to shrink tumors before radiation therapy. This can make it more likely that radiation therapy will be successful.
Side effects of hormone therapy may include erectile dysfunction, hot flashes, loss of bone mass, reduced sex drive and weight gain.
Surgery to remove the prostate
Surgery for prostate cancer involves removing the prostate gland (radical prostatectomy), some surrounding tissue and a few lymph nodes. Ways the radical prostatectomy procedure can be performed include:
Using a robot to assist with surgery. During robot-assisted surgery, the instruments are attached to a mechanical device (robot) and inserted into your abdomen through several small incisions. The surgeon sits at a console and uses hand controls to guide the robot to move the instruments. Robotic prostatectomy may allow the surgeon to make more-precise movements with surgical tools than is possible with traditional minimally invasive surgery.
Making an incision in your abdomen. During retropubic surgery, the prostate gland is taken out through an incision in your lower abdomen. Compared with other types of prostate surgery, retropubic prostate surgery may carry a lower risk of nerve damage, which can lead to problems with bladder control and erections.
Making an incision between your anus and scrotum. Perineal surgery involves making an incision between your anus and scrotum in order to access your prostate. The perineal approach to surgery may allow for quicker recovery times, but this technique makes removing the nearby lymph nodes and avoiding nerve damage more difficult.
Laparoscopic prostatectomy. During a laparoscopic radical prostatectomy, the doctor performs surgery through small incisions in the abdomen with the assistance of a tiny camera (laparoscope). This procedure requires great skill on the part of the surgeon, and it carries an increased risk that nearby structures may be accidentally cut.
Discuss with your doctor which type of surgery is best for your specific situation.
Radical prostatectomy carries a risk of urinary incontinence and erectile dysfunction. Ask your doctor to explain the risks you may face based on your situation, the type of procedure you select, your age, your body type and your overall health.
Freezing prostate tissue
Cryosurgery or cryoablation involves freezing tissue to kill cancer cells.
During cryosurgery for prostate cancer, small needles are inserted in the prostate using ultrasound images as guidance. A very cold gas is placed in the needles, which causes the surrounding tissue to freeze. A second gas is then placed in the needles to reheat the tissue. The cycles of freezing and thawing kill the cancer cells and some surrounding healthy tissue.
Initial attempts to use cryosurgery for prostate cancer resulted in high complication rates and unacceptable side effects. However, newer technologies have lowered complication rates, improved cancer control and made the procedure easier to tolerate. Cryosurgery may be an option for men who haven't been helped by radiation therapy.
Chemotherapy uses drugs to kill rapidly growing cells, including cancer cells. Chemotherapy can be administered through a vein in your arm, in pill form or both.
Chemotherapy may be a treatment option for men with prostate cancer that has spread to distant areas of their bodies. Chemotherapy may also be an option for cancers that don't respond to hormone therapy.
Biological therapy (immunotherapy) uses your body's immune system to fight cancer cells. One type of biological therapy called sipuleucel-T (Provenge) has been developed to treat advanced, recurrent prostate cancer.
This treatment takes some of your own immune cells, genetically engineers them in a laboratory to fight prostate cancer, then injects the cells back into your body through a vein. Some men do respond to this therapy with some improvement in their cancer, but the treatment is very expensive and requires multiple treatments.
Complications of prostate cancer and its treatments include:
Cancer that spreads (metastasizes). Prostate cancer can spread to nearby organs, such as your bladder, or travel through your bloodstream or lymphatic system to your bones or other organs. Prostate cancer that spreads to the bones can cause pain and broken bones. Once prostate cancer has spread to other areas of the body, it may still respond to treatment and may be controlled, but it's unlikely to be cured.
Incontinence. Both prostate cancer and its treatment can cause urinary incontinence. Treatment for incontinence depends on the type you have, how severe it is and the likelihood it will improve over time. Treatment options may include medications, catheters and surgery.
Erectile dysfunction. Erectile dysfunction can be a result of prostate cancer or its treatment, including surgery, radiation or hormone treatments. Medications, vacuum devices that assist in achieving erection and surgery are available to treat erectile dysfunction.
Preventing Prostate Cancer
The ultimate goal is to prevent men from developing prostate cancer. Although significant progress has been made and genetic and environmental risk factors for prostate cancer have been identified, the evidence is not strong enough for conclusive recommendations on how to prevent prostate cancer.
Given that prostate cancer feeds on Testosterone and DHT (dihydrotestosterone), there have been multiple large studies trying to lower DHT in men to prevent prostate cancer.
Diet and lifestyle modifications have also been shown to reduce the risk of prostate cancer development and Progression, and can help men with prostate cancer live longer and better lives.
1. Eat fewer calories or exercise more so that you maintain a healthy weight.
2. Try to keep the amount of fat you get from red meat and dairy products to a minimum.
3. Watch your calcium intake. Do not take supplemental doses far above the recommended daily allowance. Some calcium is okay, but avoid taking more than 1,500 mg of calcium a day.
4. Eat more fish – evidence from several studies suggest that fish can help protect against prostate cancer because they have “good fat” particularly omega-3 fatty acids. Avoid trans fatty acids (found in margarine).
5. Try to incorporate cooked tomatoes that are cooked with olive oil, which has also been shown to be beneficial, and cruciferous vegetables (like broccoli and cauliflower) into many of your weekly meals. Soy and green tea are also potential dietary components that may be helpful.
6. Avoid smoking for many reasons. Drink alcohol in moderation, if at all.
7. Seek medical treatment for stress, high blood pressure, diabetes, high cholesterol, and depression. Treating these conditions may save your life and will improve your survivorship with prostate cancer.
8. Avoid over-supplementation with megavitamins. Too many vitamins, especially folate, may “fuel the cancer”, and while a multivitamin is not likely to be harmful, if you follow a healthy diet with lots of fruits, vegetables, whole grains, fish, and healthy oils you likely do not even need a multivitamin. Ask your doctor about herbal supplements as some may harm you.
9. Relax and enjoy life. Reducing stress in the workplace and home will improve your survivorship and lead to a longer, happier life.
10. Finally, although living a healthy lifestyle and eating right are good for you, they will not eliminate your risk of prostate cancer, nor will they cure you by themselves if you are diagnosed with prostate cancer. If you are age 50 or over, if you are age 40 or over and African-American or have a family history of prostate cancer, you need more than a good diet.
When to see a Doctor
Make an appointment with your doctor if you have any signs or symptoms that worry you.
There is debate regarding the risks and benefits of screening for prostate cancer, and medical organizations differ on their recommendations. Discuss prostate cancer screening with your doctor. Together, you can decide what's best for you.
It is always best to find and diagnose prostate cancer at an early stage and hopefully still confined to its site of origin. At that point treatments can cure it. When prostate cancer is widespread or metastatic it can be treated, but it cannot be cured.