What is prostate cancer?

Prostate cancer is cancer that develops in the cells of the prostate, a gland in the male reproductive tract located below the bladder and in front of the rectum. Prostate cancer occurs when cells in the prostate develop abnormally and become cancerous. 

Prostate cancer is common, and usually occurs in men over the age of 50, although it can sometimes occur in younger patients. It is often diagnosed in the early-stage where it is confined to the prostate gland, although more aggressive forms of the disease are sometimes diagnosed in later stages. 

Types of Prostate Cancer 

The most common type of prostate cancer is Adenocarcinoma, less common subtypes include neuroendocrine carcinomas, transitional cell carcinomas and sarcomas.

What are the symptoms of prostate cancer?

There are usually no symptoms in the early stages of prostate cancer. As most prostate cancers are slow growing, many men reach old age or pass away without knowing that they have prostate cancer. Most men discover they have prostate cancer during routine medical check-ups or through blood tests.

• Difficulty passing urine
• Increased urinary frequency, especially at night (nocturia)
  
• Weak, interrupted urinary stream
• Burning or pain during urination
  
• Haematuria - blood in urine
• Blood in semen
• Weight loss
• Loss of appetite
  
• Pain in the back (spine), hips, chest (ribs), pelvis or other bony areas
• Weakness or numbness in the legs and difficulty walking
• Difficulty controlling the bladder or bowels
  

When should you see a doctor?

The symptoms mentioned above should not be ignored, although they can be caused by a number of other reasons. There are several conditions that can present with symptoms similar to prostate cancer such as benign prostatic hyperplasia, urinary tract infections (UTIs) or kidney stones. You should make an appointment with your doctor if you experience any signs or symptoms that worry you.

How can prostate cancer be prevented?

There are no proven preventive strategies for prostate cancer. And at present, there is a lack of evidence to support population-based screening for prostate cancer in Singapore. However, adopting a healthy lifestyle can help prevent the risk of prostate cancer. This includes: 

• Eating a diet rich in fruit, vegetables and whole grains, while limiting the consumption of fat 
• Quitting or not starting smoking 
  
• Limiting alcohol consumption 
  
• Keeping fit and doing regular exercise
  
  

What causes prostate cancer?

While it is not clear what causes prostate cancer, there are certain risk factors including age, family history of prostate cancer, obesity and ethnicity. In Singapore, Chinese men have double the risk of getting prostate cancer compared to Malay or Indian men.

What are the risk factors for prostate cancer?

Some of the risk factors that are known to increase the risk of developing prostate cancer are:

• Age - This is the strongest risk factor. Men above the age of 50 are at risk and the risk increases with age. 
• Ethnicity - In Singapore, Chinese men have double the risk of getting prostate cancer compared to Malay or Indian men.
• Family history - Men with a father or brother with prostate cancer are more likely to get the disease. The risk is higher for men who have a brother with prostate cancer than for those with an affected father. Risk is also much higher for men with several affected family members, especially if they were young when the prostate cancer was detected.
• Diet - Men who consume large amounts of fat, particularly from red meat and other sources of animal fat, including dairy products.

How is prostate cancer diagnosed?

Several different tests can be used to diagnose prostate cancer, including:

• Digital rectal examination

  • Often part of a routine physical examination, during a digital rectal examination the doctor inserts a lubricated gloved finger into the rectum to examine the prostate which is located next to the rectum. This may be uncomfortable but should not be painful. If any abnormalities are found, you may be referred for further tests.
    
    

• Prostate-specific antigen (PSA) blood test

  • The Prostate-Specific Antigen (PSA) is a substance produced by the prostate and a small amount of it is normal, however men with prostate cancer tend to have higher levels of PSA in their blood. If higher than usual levels of PSA are found in a blood test that measures PSA levels, additional tests will be needed.
    
    

• Transrectal Ultrasound Scan (TRUS)

  • This test uses high-frequency sound waves to produce images of the prostate. It is done by inserting a small probe into the rectum which is located next to the prostate. TRUS is often recommended if a man has an abnormal digital rectum exam, or a high level of prostate-specific antigen (PSA) is found during the blood test. It is also commonly used during a prostate biopsy for the doctor to determine where to extract the sample tissue from.
    
    

• Biopsy

• During a prostate biopsy, small samples of prostate tissue are taken for further examination in the lab to determine the presence of cancer cells. Prostate biopsy samples can be collected by inserting a thin needle either through the rectum (transrectal biopsy) or through the area between the anus and scrotum (transperineal biopsy).
  

What tests are used to determine the spread of prostate cancer?

• Computer tomography (CT) scan

  • A CT scan takes X-ray images from different angles to build a 3D picture. This can identify the area where the cancer occurs in the prostate and show any spread to nearby structures or body parts.
    
    

• Magnetic Resonance Imaging (MRI) scan

  • An MRI scan uses magnetic fields to give detailed pictures of the pelvic area to detect prostate cancer and look for any spread to the lymph nodes.
    
    

• Bone scan
  

  • A bone scan can detect if the cancer has spread from the prostate to the bones. A small amount of radioactive material called a tracer is injected and a scan is done to see how the tracer is absorbed, to indicate the presence of cancer.
    
    

• Positron Emission Tomography - Computed Tomography (PET-CT) scan

• A PET-CT scan combines both a CT scan and a PET scan to provide more detailed 3D images that enable more accurate diagnosis. The scan uses X-rays to take images to check for any areas with abnormalities, while a radioactive glucose solution which is injected into the body and absorbed by cells that are growing quickly, can indicate the presence of cancer.
  

How is prostate cancer treated? 

Treatment for prostate cancer depends on several factors including the patient’s age, medical conditions, significant illnesses, prostate-specific antigen level, digital rectal examination results, aggressiveness of the cancer and spread of disease. 

An individual with prostate cancer should be assessed by a multi-disciplinary team of specialists to determine which modality of treatment is best for them. Prostate cancer treatment requires the involvement of different specialists – urologists, interventional radiologists, nuclear medicine physicians, medical oncologists, radiation oncologists and palliative medicine specialists. Such multi-disciplinary care is available at SingHealth healthcare institutions. It is important to discuss all the possible treatment choices, including what to expect and possible side effects, to help you make an informed decision.

Types of treatment

• Active surveillance
  

• Men with early-stage prostate cancer, that is slow-growing and causing little or no symptoms, may not need immediate treatment. In such cases, doctors may advise waiting and observing to see if the cancer progresses before starting any treatment. Active surveillance may include regular bloods tests for prostate-specific antigen (PSA), digital rectal examination, imaging investigations and repeat biopsies if required.
  

• Surgery
  

• Surgery to treat prostate cancer is known as prostatectomy. It involves removing all or part of the prostate gland. Surgery is usually offered to men with early-stage disease or cancer that is confined to the prostate, who do not have other serious health problems.
  
  In radical prostatectomy, the entire prostate gland and other nearby tissues (e.g. surrounding structures and lymph nodes) are surgically removed.
  
  Another approach is the robotic-assisted laparoscopic radical prostatectomy. This is a minimally invasive surgical technique, where the surgeon makes several small incisions in the lower abdomen and uses instruments attached to a mechanical device, known as “robotic arms”, to perform the surgery.
  
  Tissues that have been surgically removed are sent to the pathology lab to be examined to determine how advanced the prostate cancer is, the risk of cancer recurrence and if additional treatment is necessary.
  

What can you expect after prostate cancer surgery?

After recovering from surgery, you will be given regular outpatient appointments to see your team of doctors. These visits may include blood tests and scans to monitor and check if prostate cancer recurs. 

It is important to follow your doctor's advice, keep to scheduled clinic visits and do the prescribed tests so that timely treatment can be administered if prostate cancer or other problems arise. 

• Hormone therapy
  

• Hormone therapy, known as androgen deprivation therapy, works by preventing prostate cancer cells from receiving testosterone, this causes the prostate cancer cells to die or grow more slowly. Hormone therapy for prostate cancer usually involves the use of drugs, given as injections or tablets. Another less common form of hormone therapy is the surgical removal of the testes which produce testosterone. 
  
  

• Radiotherapy
  

• Radiotherapy, also known as radiation therapy, is the use of high-energy radiation (rays or particles) to kill or damage the prostate cancer cells. Radiation affects both normal and prostate cancer cells. Generally, more cancer cells are killed compared to normal cells, which are able to repair themselves after radiotherapy.
  
  Radiotherapy can be delivered in two main ways: external beam radiotherapy (EBRT) or internal radiotherapy. During EBRT, radiation beams are generated from a machine and directed at the prostate. For Internal Radiation Therapy, also known as Brachytherapy, radiation is delivered to the prostate by placing radioactive materials in the prostate to kill the cancer cells.
  
  The type of radiation therapy the doctor recommends depends on the stage of the prostate cancer and the patient’s underlying health condition. Click here for instructions on preparations prior to Prostate Cancer Radiotherapy. 
  
  

• Proton Therapy
  

• Proton therapy is an advanced type of radiation treatment that targets cancer cells using positively charged subatomic particles called protons. The unique physical properties of protons enable tumours to be more precisely targeted compared to the x-rays used in conventional radiotherapy. This minimises damage to nearby healthy tissues and organs and therefore results in fewer radiation-related side effects. 
  
  

• Chemotherapy
  

• Chemotherapy is the use of anti-cancer drugs to eradicate prostate cancer cells or prevent their growth. Chemotherapy can also help to relieve or delay symptoms like pain. Chemotherapy is usually offered to men with advanced or metastatic prostate cancer, which has spread beyond the prostate to other parts of the body.
  

What are the side effects of prostate cancer treatment?