What is prostate cancer?
The prostate is a walnut shape and size gland found in men and its main function is to produce the fluid in semen. It sits in front of the rectum and underneath the bladder. Prostate cancer develops when gland cells turn malignant and become a tumour. It tends to occur at age 50 and above, which is when men can opt to start screening for prostate cancer using a blood test known as PSA (prostate specific antigen).
My PSA is abnormally high – what should I do?
It is important to recognise that high PSA may not be just due to cancer, but other causes like infection and benign enlargement of the prostate. However, further checks have to be done to exclude cancer as early diagnosis and treatment has a good chance of success. These checks involve further blood tests, prostate MRI scans and ultimately a biopsy of the prostate to confirm the presence of cancer.
What are the different treatment options for prostate cancer, and what should be considered for each?
The main curative treatment options for prostate cancer include:
- Radical Prostatectomy
- Radiation Therapy (RT)
- Active Surveillance
Radical prostatectomy is a surgery done to remove the entire prostate gland. Increasingly, the robotic technique is used. Several small incisions are made with small instruments and a camera placed through them. The surgeon operates by looking at a monitor and controls the instruments with fine movements via the robot.
Radiation Therapy comes in two forms – external beam or internal (brachytherapy). External beam radiotherapy is non-invasive and involves using a machine to direct x-rays focused on the prostate that kill the cancer cells within. Each daily treatment takes a few minutes and most patients can continue their daily activities. Advances in radiotherapy have allowed external beam courses to be shortened from 8 weeks to 4 weeks in 20 treatments and most recently, 1.5 weeks in just 5 treatments.
Brachytherapy is the use of radioactive sources placed within the prostate via needles, under general anesthesia. In one form, tiny rice-grain-sized seeds placed permanently within the prostate release radiation slowly and kill the cancer. Another form involves temporarily implanting radioactive sources into the prostate that are removed after one or two days.
Active surveillance is used for small tumours with a low risk of growth and spread. The tumour will be monitored closely using the PSA blood test every few months, and periodic MRI scans of the prostate. The rationale is to postpone aggressive treatment and its side effects, and only have surgery or RT when the cancer begins to grow.
Are there any side effects from these treatments?
The most common side effects of prostatectomy are urinary incontinence and erectile dysfunction. The incontinence is usually temporary but there may still be occasional leakage in the long term for some patients. As for radiation therapy, there may be increased urinary and bowel frequency, mainly in the first six months after treatment, with subsequent recovery. While in the past having blood in the stool was a potential long term side effect post-radiation, this has become quite rare due to advances in targeting and delivery that minimize exposure of the rectum to high dose radiation. The placement of biodegradable hydrogel spacers in between the prostate and rectum prior to radiation is now available to further protect the rectum.
Which is more effective – surgery or radiation therapy?
In early-stage cancers, both are equally effective when used alone. For more advanced or aggressive tumours, a combined approach may be required. Surgery might need to be followed by radiotherapy, while radiotherapy would need to be combined with hormonal therapy. These two approaches again afford equivalent cure rates.
What advice do you have for men newly diagnosed with localised prostate cancer?
A proportion of men with prostate cancer experience ‘treatment decision regret’. It has been found that those who were well informed of the pros and cons of the options and kept involved in decision-making experienced the least regret about their treatment choice. Therefore, men should have an in-depth discussion with both a urologist as well as a radiation oncologist to get a full picture, before making their decision.
If the prostate cancer has spread (stage IV), what are the treatment options?
The vast majority of prostate cancers that have spread can be well controlled by hormone therapy which reduces testosterone levels in men or blocks the action of testosterone. More aggressive stage IV cancers may benefit from the addition of chemotherapy as well. Newer targeted therapy against certain genetic mutations is an option for a small proportion of men with prostate cancer.
This article is contributed by Dr Jonathan Teh Yi Hui, Medical Director (Centre for Stereotactic Radiosurgery) & Senior Consultant Radiation Oncologist at Asian Alliance Radiation & Oncology (AARO).
