Anatomy
In order to understand the causes of prostate cancer, it is important to appreciate the gland itself. The prostate gland is the size of a walnut, situated between the bladder and the penis, in front of the rectum. The urethra is the tube which lets urine run through the center of the prostate, from the bladder to the penis, and out of the body. The function of the prostate is to secrete fluid – semen – in order to nourish and protect sperm.
Image: Courtesy of www.healthed.govt.nz
Causes
Approximately 1 in 10 New Zealand men develop prostate cancer and the incidence seems to be increasing. Among New Zealand men, it is one of the most commonly diagnosed cancers, and the third most common cause of death from cancer – with approximately 600 deaths per year.
As men age, generally over the age of 50, the prostate naturally enlarges – this enlargement is called Benign Prostatic Hypertrophy (BPH). The most apparent symptom of BPH is difficulty in urination – if you are over the age of 50 and experiencing difficulty peeing then consult your doctor. BPH is not cancerous and can be treated with medication or surgery.
On the other hand, when the cells within the prostate gland become cancerous, this is called Prostate cancer. The causes of prostate cancer are not fully understood however there are predisposing factors which increase the chances of developing prostate cancer. These include increasing age and familial history of prostate cancer, and other factors such as smoking and dietary, hormonal and environmental influences such as exposure to certain chemicals. Prostate cancer can affect multiple areas as explained below:
- Localised prostate cancer: Cancer is localized within the prostate gland only.
- Extracapsular prostate cancer: The cancer has spread to the tissues surrounding the prostate gland.
- Metastatic prostate cancer: The cancer has spread to other parts of the body.
Symptoms
Symptoms of prostate cancer may not be apparent at an early stage which is why it is important to do regular screenings. The most visible symptoms are generally associated with difficulty in urination, therefore it is important for men over the age of 50 to give immediate attention to changes in urinary function. Symptoms of prostate cancer and BPH can be quite similar.
Common symptoms include:
- Reduced urge to push or force urine out
- Experiencing pain or having difficulty urinating
- Frequent urination especially at night
- Blood in the urine
- As the cancer enlarges, it pushes on the urethra and blocks the flow of urine – this can cause inability to pass urine
- In metastatic prostate cancer, cancer cells most commonly spread to the lymph nodes of the pelvis and the bones of the spine – this can cause lower back pain
Tests
Common tests for prostate cancer include:
- Prostate specific antigen (PSA): The prostate gland produces a protein called PSA which is released into the bloodstream and detected via blood tests. PSA levels rise with age as well as the enlargement of the prostate gland. PSA levels do not confirm cancer itself, however significantly elevated levels call for investigation and require further assessment such as a digital rectal examination.
- Digital Rectal Examination (DRE): If PSA levels are elevated, then the doctor will perform a digital rectal examination. During this examination the doctor is checking for enlargement or irregularity of the prostate gland. In order to reach the prostate gland, the doctor places a gloved finger into the rectum (anus) and through the wall of the rectum the doctor can feel the prostate gland. If any irregularity is found the doctor may recommend a biopsy.
- Transrectal ultrasound biopsy (TRUS): During a biopsy, a needle is inserted through the rectum (anus) and the ultrasound guides the needle to the correct biopsy location in the prostate gland. Using the needle, a small sample of tissue is taken for further assessment under a microscope. Antibiotics are given prior to the procedure in case there is an infection following this procedure.
- X-rays, CT/MRI and Bone Scans: If prostate cancer is confirmed, X-rays, a CT, MRI or bone scans are performed to assess whether the cancer has spread to other areas of the body.
Treatment
Treatment options differ from one individual to another depending on the person’s age, health status, and stage of the cancer as well as their symptoms and lifestyle. It is important to take your time to consider the treatment options available. Treatment choices are:
- Watchful waiting: If there are no symptoms, then you might be recommended to take regular PSA blood tests and the doctor will monitor you closely as prostate cancer is usually slow growing.
- Surgery: If the cancer is affecting your urine flow or causing complete blockage then surgery may be required to relieve this, before other treatment options are sought. If the cancer is localized to the prostate gland, then surgical removal of the gland, called radical prostatectomy, may be recommended.
- Radiotherapy: Radiotherapy is the controlled use of radiation to stop the growth of cancer cells.
- Hormonal treatment: When the cancer has spread beyond the prostate gland, hormone treatment may be recommended.
- Chemotherapy: In cases of advanced metastatic prostate cancers, chemotherapy is used only if the patient has failed to respond to other treatments.
Screening for prostate cancer
There is debate as to the benefits of screening (regularly testing) men who do not have symptoms of prostate cancer. While further studies are being completed as to the advantages/disadvantages of screening, patients should discuss the implications of being screened for prostate cancer with their doctor.
Prostate checklist for men
Choosing whether to have a prostate check is an important decision. You need to have enough information to make the decision that is right for you and your loved ones. If you answer ‘Yes’ to any of the following, talk to your doctor, nurse or health professional (www.healthed.govt.nz).
| Yes/No | |
| I am peeing more often.* | |
| When I pee, I have trouble getting started or stopping.* | |
| I have poor urine flow or dribbling.* | |
| I often get up at night to pee.* | |
| I have blood in my urine.* | |
| I have pain in my lower back, hips or ribs.* | |
| I have a family history of prostate cancer and I’m 40 years old or more. | |
| I am 50 to 70 years old. | |
| I am concerned or want to know more. |
*Answering yes to any of these points may not mean you have cancer but you should get them checked by your doctor, nurse or health professional straight away.
Support and information
The Prostate Cancer Foundation of New Zealand can provide patients, their families and friends with information and discuss options concerning prostate problems.
Phone: 0800 PROSTATE (477 678)
Website: www.prostate.org.nz
Dr Sarkaw Mohammad
