Prostate cancer is the fourth most common cancer affecting Malaysian men, with rates expected to escalate in the coming years. It is a slow growing cancer and mostly affects men > 50 year old. Prostate gland is a walnut-sized gland found only in male located below the bladder in front of the rectum, which is responsible to make fluid that forms part of semen. The causes of prostate cancer are not understood and there is currently no clear prevention strategy. Men who have first degree male relatives affected by prostate cancer has increased risk of getting prostate cancer.
Prostate cancer often has no early symptoms. Symptoms become apparent when the prostate has enlarged affecting the urethra. Symptoms of advanced prostate cancer include difficulty in urinating, blood in the urine and the urge for more frequent urination. A small number of individuals may experience pain in the bones due to cancer metastasis to the bone.
Diagnosis of prostate cancer
The diagnosis of prostate cancer can be pursued through symptoms, blood test, digital rectal examination (DRE) of prostate and a biopsy. DRE involves inserting a lubricated and gloved finger into the rectum to feel for the consistency and size of the prostate gland.
Measurement of prostate-specific antigen (PSA) may help to detect early prostate cancer. However, PSA is non specific to prostate cancer as it can cause false positive result in non cancerous conditions such as benign prostatic hypertrophy, urinary tract infection, or prostatic inflammation.
A biopsy is a procedure in which small samples of the prostate are removed and then looked at under a microscope. A core needle biopsy is the main method used to diagnose prostate cancer. It is usually done by a urologist, a surgeon who treats cancers of the genital and urinary tract, which includes the prostate gland.
The diagnosis is established by a transrectal ultra-sound guided needle biopsy, a procedure done by the urologist. Upon diagnosis of prostate cancer, CT scan and / or MRI and bone scans are used to stage the disease.
Staging of prostate cancer is important in deciding the treatment options and predicting the prognosis. The staging of prostate cancer is based on the extent of primary tumor, involvement of lymph node, whether the cancer has metastasized, blood PSA level, and the result of biopsy (Gleason score).
The 10-year survival rate of prostate cancer following treatment is good, usually up to 90%.
The treatment options for early stages of Prostate Cancer include prostatectomy and/or radiotherapy. There is as yet no consensus as to which yields better results.
Men with low risk prostate cancer are eligible for active surveillance that provides a period of observation to see whether the disease is changing. This involves careful observation of tumor symptoms, repeated biopsies or serial PSA level to ensure signs of progression are found as early as possible.
Treatment of fast-growing prostate cancer involves surgery, radiotherapy, high-intensity focused ultrasound (HIFU), chemotherapy, cyrosurgeyrm hormone therapy or some combinations. Radical prostatectomy is the removal of prostate gland and us an option for localised lesion and locally advanced prostate cancer. Studies have shown that radiotherapy after prostatectomy may increase the chances of cure, although research is still on-going on when it should be used after the surgery.
Surgery for prostate cancer (called a radical prostatectomy) aims to remove the whole prostate and the prostate cancer cells inside it.
You might be offered surgery if your cancer hasn’t spread outside your prostate (localised prostate cancer) and you are generally fit and healthy. Research involving men with localised prostate cancer that is low risk (likely to grow slowly) has shown that men who go on active surveillance, surgery or external beam radiotherapy all have the same chances of living for 10 years or more.
Surgery may also be an option for some men whose cancer has spread to the area just outside the prostate (locally advanced prostate cancer). This will depend on how far the cancer has spread.
A radical prostatectomy is a major operation. It may not be suitable if you have other health problems, such as heart disease, that would increase the risks involved.
Chemotherapy uses anti-cancer drugs to kill cancer cells, wherever they are in the body. Chemotherapy won’t get rid of your prostate cancer, but it aims to shrink it and slow down its growth. This can help men to live longer, and can help to control or delay symptoms such as pain.
Androgens stimulate prostate cancer cells to grow. Most of the androgens are made by the testicles, but the adrenal glands (glands that sit above your kidneys) also make a small amount. Lowering androgen levels or stopping them from getting into prostate cancer cells often makes prostate cancers shrink or grow more slowly for a time. But hormone therapy alone does not cure prostate cancer.
Hormone therapy may be used:
- If the cancer has spread too far to be cured by surgery or radiation, or if you can’t have these treatments for some other reason
- If the cancer remains or comes back after treatment with surgery or radiation therapy
- Along with radiation therapy as initial treatment if you are at higher risk of the cancer coming back after treatment (based on a high Gleason score, high PSA level, and/or growth of the cancer outside the prostate)
- Before radiation to try to shrink the cancer to make treatment more effective
Radiosurgery is a form of radiation therapy that uses precisely targeted radiation to destroy tumors. Radiosurgery is non-invasive – there is no cutting involved. The term “surgery” refers to the high level of precision of the energy beams. Radiosurgery is commonly used by neurosurgeons to treat conditions within the brain and spine. Stereotactic body radiation therapy (SBRT) is a treatment that uses precisely targeted radiation to destroy tumors located outside the brain and spine. The CyberKnife System is a unique, robotic system designed to deliver high-precision radiosurgical and SBRT procedures.
With regular radiation therapy treatment, healthy tissue also receives radiation. With stereotactic radiosurgery, our cancer doctors can better focus the radiation on a tumor, so nearby healthy tissue is protected.
Using this technology, our doctors are able to reach tumors deep inside the body without the risks of surgery. There is no incision, minimal discomfort, and few of the risks typically associated with surgery, such as infection.
Our doctors also deliver fractionated stereotactic radiosurgery. In this treatment, the total dose of radiation is divided into several smaller doses of radiation, delivered over several days.
The aim of all types of radiotherapy is to destroy cancer cells.
Radiotherapy damages cells and stops them from dividing and growing. Cancer cells can’t recover from this damage so they die, but healthy cells can repair themselves more easily.
For advanced prostate cancer, the main aims of radiotherapy are:
- to shrink the cancer in the part of the body being treated – to stop it pressing on the nerves and causing pain
- to slow the growth of the cancer, giving your bones time to repair and strengthen.
Targeted Drug Therapy
Targeted therapies are newer cancer treatments that work by targeting specific abnormalities in cancer cells. Targeted therapy drugs are often used in combination with chemotherapy drugs.
Some targeted therapies only work in people whose cancer cells have certain genetic mutations. Your cancer cells will be tested in a laboratory to see if these drugs might help you.
Targeted therapy for advanced prostate cancer has, to date, predominantly used Lutetium-177 (177-Lu) labeled PSMA peptides. Early clinical studies evaluating the safety and efficacy of 177Lu-PSMA therapy have demonstrated promising results with a significant proportion of men with advanced metastatic castrate resistant prostate cancer, who have already failed other therapies, responding clinically to 177Lu-PSMA.
Prostate cancer is treatable but its management can be complex. Individuals diagnosed with prostate cancer should consult both the urologist and the oncologist for various treatment options.