Understanding Prostate Cancer in Singapore

Most prostate cancers are adenocarcinomas. These cancers develop from glandular cells that produce prostatic fluid, the liquid component of semen. Adenocarcinomas vary in their growth rates. Doctors assess this using the Gleason grading system, which evaluates how abnormal the cancer cells appear under a microscope and helps predict how the cancer might behave.

Small cell carcinoma of the prostate is rare but tends to be more aggressive than adenocarcinoma. This type often doesn’t produce PSA (prostate-specific antigen, a protein made by prostate cells). This can make detection through routine screening more challenging. It typically requires different treatment approaches than adenocarcinoma.

This type of cancer usually starts in the cells lining the urethra (the tube that carries urine out of the body) and can extend into the prostate. Transitional cell carcinomas are uncommon and are managed differently from typical prostate adenocarcinoma.

Neuroendocrine prostate cancers are rare. They can develop on their own or evolve from existing adenocarcinoma, particularly after long-term hormone therapy. These tumours tend to grow quickly and may require tailored treatment protocols.

In the early stages, prostate cancer frequently causes no symptoms. When symptoms do appear, they may include:

• Increased frequency of urination, especially at night
• Difficulty starting or stopping urine flow
• Weak or interrupted urine stream
• Sensation of incomplete bladder emptying

These symptoms overlap significantly with benign prostatic hyperplasia (BPH, a non-cancerous enlargement of the prostate), which is common in older men. Only a proper medical evaluation can determine the cause.

As prostate cancer progresses, symptoms may become more pronounced:

• Blood in the urine or semen
• Painful urination or burning sensation
• Difficulty achieving or maintaining an erection
• Pain or discomfort in the pelvic area
• Decreased force in the urine stream
• Frequent urinary tract infections

When prostate cancer spreads beyond the prostate gland, additional symptoms may develop:

• Persistent bone pain, particularly in the spine, hips, or ribs
• Unexplained weight loss
• Fatigue and general weakness
• Swelling in the legs if cancer blocks lymph drainage
• Loss of bladder or bowel control in advanced cases

For men with low-risk, slow-growing prostate cancer, active surveillance may be recommended. This approach involves closely monitoring the cancer rather than immediate treatment. The goal is to avoid or delay treatment and its potential side effects whilst ensuring the cancer doesn’t progress.

Monitoring includes:

• Regular PSA tests
• Digital rectal examinations
• Periodic MRIs and biopsies

Active surveillance is appropriate for older men or those with other significant health conditions when the cancer is unlikely to cause problems during their lifetime. If monitoring shows signs of progression, treatment can begin promptly.

Watchful waiting is similar to active surveillance but involves less intensive monitoring. It’s typically offered to men who may not benefit from curative treatment due to age or other health conditions. Treatment is initiated only if symptoms develop, focusing on maintaining quality of life rather than curing the cancer.

Symptoms that may trigger treatment include:

• Difficulty urinating
• Blood in urine
• Bone pain

Radical prostatectomy involves surgically removing the entire prostate gland, some surrounding tissue, and seminal vesicles. This procedure can be performed through:

• Open surgery
• Laparoscopic surgery
• Robot-assisted laparoscopic surgery

Robot-assisted surgery is available at major hospitals in Singapore. It offers enhanced precision and may result in shorter hospital stays and faster recovery. Surgery can be a way to achieve long-term cancer control when cancer is confined to the prostate.

Radiation therapy uses high-energy beams to destroy cancer cells. External beam radiation therapy (EBRT) delivers radiation from outside the body. Treatment typically lasts several weeks, with daily sessions. Techniques like intensity-modulated radiation therapy (IMRT) target the prostate whilst minimising exposure to surrounding tissues. Radiation therapy can be used as primary treatment or after surgery if cancer cells remain. It’s suitable for men who may not be good surgical candidates.

Brachytherapy involves placing radioactive seeds directly into the prostate gland. This internal radiation treatment delivers high doses to the cancer whilst limiting exposure to nearby organs.

Two main approaches exist:

• Low-dose-rate (LDR) brachytherapy uses permanent seeds that gradually release radiation over months
• High-dose-rate (HDR) brachytherapy involves the temporary placement of stronger radioactive sources

Brachytherapy may be used alone for early-stage cancer or combined with external radiation for more advanced disease.

Hormone therapy, also called androgen deprivation therapy (ADT), reduces levels of male hormones that fuel prostate cancer growth. This can be achieved through medications that stop testosterone production or block its effects, or through surgery to remove the testicles through orchiectomy. Hormone therapy is often used alongside radiation therapy. It’s also used as a primary treatment for advanced or recurrent cancer. Whilst it doesn’t cure prostate cancer, it can help control growth for extended periods.

Chemotherapy uses drugs to destroy cancer cells throughout the body. It’s typically reserved for prostate cancers that no longer respond to hormone therapy or for aggressive cancers at diagnosis.

Castration-resistant prostate cancer means the cancer continues to grow despite very low testosterone levels. Docetaxel and cabazitaxel are commonly used chemotherapy drugs for prostate cancer. Treatment is usually given in cycles with rest periods between treatments to allow your body to recover.

Newer targeted therapies work by identifying specific characteristics of cancer cells. PARP inhibitors, for example, can be used in men whose prostate cancers have BRCA gene mutations (inherited genetic changes that affect how cells repair damaged DNA). These medications block certain enzymes that cancer cells need to repair their DNA, leading to cancer cell death. Genetic testing can help determine if targeted therapies might be beneficial for your specific cancer.

Immunotherapy helps your immune system recognise and attack cancer cells. Sipuleucel-T is an immunotherapy for advanced prostate cancer when the cancer has spread and is resistant to hormone therapy. This treatment involves collecting your immune cells, modifying them to target prostate cancer, and returning them to your body. Research continues into other immunotherapy approaches for prostate cancer.

Focal therapy aims to treat only the cancerous portion of the prostate rather than the entire gland.

Techniques include:

• High-intensity focused ultrasound (HIFU)
• Cryotherapy
• Laser ablation

These approaches may preserve more normal prostate tissue and reduce side effects compared to whole-gland treatments. Focal therapy is generally considered for carefully selected patients with localised cancer.