Dr Zee Ying Kiat, a Senior Consultant and Medical Oncologist at Parkway Cancer Centre, talks about the third most common cancer among Singapore men.
What is prostate cancer?
To answer this question, we first need to know what the prostate is.
The prostate is a gland located below the bladder and in front of the rectum. The prostate’s job is to make some of the fluid that protects and nourishes sperm cells in semen. The prostate is the size of a walnut and may grow in size as we grow older.
The stimulus behind this is the male hormones (also known as androgens) in the body, such as testosterone and dihydrotestosterone.
Prostate cancer is a disease in which cancer or malignant cells form in the tissues of the prostate. In the vast majority of cases, prostate cancer starts off within the glandular cells and this is also known as adenocarcinoma.
Is it fairly common?
Prostate cancer is a very important health issue. Worldwide, it is the second most common cancer in men, behind lung cancer. One in seven men will be diagnosed with prostate cancer during their lifetime.
Closer to home, prostate cancer is the third most common cancer in Singaporean men, behind colorectal and lung cancer. About 3,500 Singaporean men were diagnosed with prostate cancer in the five years from 2009 to 2013.
Are there warning symptoms or signs to look out for?
Early prostate cancer often does not cause any symptoms. But more advanced prostate cancers can sometimes cause symptoms, such as:
> Problems passing urine (frequent urination, especially at night; painful urination, and difficulty starting and maintaining a steady flow of urine)
> Blood in the urine
> Pain in the hips, spine, ribs, or other areas, from the cancer that has spread to the bones
> Weakness or numbness in the legs or feet, or even loss of bladder or bowel control from the cancer pressing on the spinal cord.
Other conditions can also cause similar symptoms. For example, trouble passing urine is much more often caused by benign prostatic hyperplasia (BPH) than by cancer. Still, it is important to tell your doctor if you have any of these problems so that the cause can be found and treated, if needed.
What are some of the screening modalities that doctors employ?
Screening tests for prostate cancer include a tumour marker blood test (for prostate- specific antigen, or PSA) and digital rectal examination.
During a digital rectal examination, the doctor would insert a gloved lubricated finger into the rectum.
Prostate cancer on its own is a heterogeneous disease which means that it can exhibit a spectrum of behaviours, ranging from the slowest growing, most indolent type of prostate cancer that is unlikely to cause any problems for that man with that cancer for the rest of his life, to some other prostate cancers at the opposite end of the spectrum where the disease is actually far more aggressive and more likely to have spread to different parts of the body leading to its incurability.
So, a big challenge for doctors screening patients for prostate cancer is to identify which patients are likely to fare better than others and therefore, to spare patients from issues related to over-diagnosis and even over-treatment.
What are the types of treatment options?
The management of prostate cancer can be quite varied.
Depending on the situation, management of men with prostate cancer might include observation, which in medical terms is called expectant management or active surveillance.
Active forms of treatment include surgery, radiation therapy, hormonal manipulation and chemotherapy. More recently, researchers have developed vaccine therapy as well as various bone-directed therapies for patients with prostate cancer. These treatments are generally used one at a time, although in some cases doctors may combine them for better effect.
The treatment choices for prostate cancer should take into account a person’s age, life expectancy, other medical conditions that he may have, the stage and grade of the cancer, and the patient’s feelings about the possible side effects from each treatment.
What is a keyhole prostatectomy?
Surgery is a common choice of treatment in trying to cure patients of prostate cancer if it is thought not to have spread outside of the gland.
The main type of surgery for prostate cancer is a radical prostatectomy. The aim of the operation is for the surgeon, typically the urologist, to remove the entire prostate gland plus some of the tissues around it.
A radical prostatectomy can be done in several ways.
The traditional and conventional approach is by the surgeon operating through a long and single incision to remove the prostate and nearby tissues. This type of surgery, sometimes referred to as an open approach, is now being done less often than in the past.
The newer method of surgery is the keyhole approach, also known as laparoscopic surgery. Smaller incisions with the use of special surgical tools are used to remove the prostate. This can be done with the surgeon, either using the tools directly, or using a control panel to move robotic arms that hold the tools. The latter is known as robotic assisted laparoscopic radical prostatectomy, where the surgeon sits at a panel near the operating table and controls robotic arms to do the operation through several small incisions in the patient’s abdomen.
The key advantages of laparoscopic surgery are less pain and blood loss, shorter hospital stays, and faster recovery as compared to open surgery.
What is the long-term effect of removing one’s prostate?
The major possible side effects of radical prostatectomy are urinary incontinence (being unable to control urine) and impotence (being unable to have erections).
It should be noted that these side effects can also occur with other forms of treatment for prostate cancer.
Is there a risk in active surveillance?
It may, at first, sound incongruous to just watch a cancer after diagnosis, but such an option is possible because prostate cancer often grows very slowly, so some men (especially those who are older or have other serious health problems) might never need treatment for their prostate cancer. This can have the advantage of sparing them from potential treatment-related effects (e.g. urinary incontinence, impotence).
Not everyone is suitable for this approach.
Men who may be suitable for this approach include those whose cancer is not causing any symptoms, is expected to grow slowly, and is small and contained within the prostate. Patients are monitored through regular visits for a PSA blood test and physical examination. If there is a change in the patient’s clinical condition, be it a noticeable increase in size of the prostate lump, or a rise in the PSA blood test, then a change in the management approach would be taken.
Are there preventive measures?
There is no sure way of preventing prostate cancer. The reason is that we do not know exactly what causes prostate cancer.
We do know, however, some factors that may increase a person’s risk of getting prostate cancer.
These so called risk factors are not always modifiable, meaning we cannot control them. These include age, ethnicity and a strong family history of prostate cancer.
Some other risk factors are modifiable, including one’s diet and lifestyle. A high fat diet may increase a person’s risk of developing prostate cancer.
There are, therefore, some things that we can do to lessen our risk of developing prostate cancer, like taking a healthy diet, exercising regularly, and maintaining a healthy weight.
When should men start screening regularly if there are no presence of signs and symptoms?
There are different camps for and against prostate cancer screening.
According to Singapore’s Ministry of Health cancer screening guidelines, there is insufficient data to support prostate cancer screening in our local population. Instead, doctors may adopt a shared approach to decision-making for men who express an interest in prostate cancer screening.
Men who are between 50 and 75 years of age will discuss with them the option of prostate cancer screening after a discussion of both the potential benefits and risks associated with prostate cancer screening.
On the other hand, men who may be at higher risk, such as African-American men and men with a strong family history of prostate cancer, may be offered screening at an earlier age.
Tags: cancer laparoscopic (minimally invasive) surgery, common cancer, common side effects of cancer treatment, history of cancer, men's cancer, prostatectomy