Prostate Cancer

What is Prostate Cancer ?

Prostate Cancer is one of the commonest cancers in men. The general statistics imply that this is predominantly a disease that affects the Western world and studies do show a wide difference in clinical incidence between that of the Western and Asian populations. With the expected doubling of the elderly population by the year 2020, it is likely that prostate cancer will be more evident in Malaysia in the coming years.

Prostate Cancer is very rare before the age of 50 years and the risk of developing prostate cancer increases with age. The exact cause is unknown, but basically it begins when a group of cancerous cells (abnormal body cells that grow and spread uncontrollably) forms a tumour in the prostate.


What are the symptoms ?

In its early stages, prostate cancer may not cause any symptoms. But as the cancer progresses, the tumour grows, putting pressure on surrounding parts of the body.

The enlarged tumour may compress the urethra, blocking the flow of urine. When this happens, the patient may urinate more frequently than normal, get up too often at night and also have a reduced force of urination. Sometimes there may even be painful urination. Occasionally, there may be blood in the urine or semen or painful ejaculation.

In the later stages, prostate cancer may spread to nearby organs especially the surrounding lymph nodes and the bones. At this stage, many men may suffer from bony aches and pains as well as becoming increasingly unwell.


What are the stages of the disease ?

Prostate Cancer is best classified into its 4 stages (figure 1). After the diagnosis of the cancer which is established by examining prostatic tissue under the microscope, staging must be done to see how extensively it has or has not spread. The best treatment of the individual case then depends on the stage the disease is at.

Figure 1 Local Staging of Prostate Cancer.
The tumour may advance (left picture to right picture) with or without the development of metastases

Stage 1. (T1NOMO or A)

In stage 1, prostate cancer has no symptoms. It refers to relatively small foci of cancer which is located wholly within the prostate gland. It usually goes undetected and is often diagnosed "by surprise" after examining prostatic tissue following transurethral prostate surgery (done to improve urination). More recently, this can also be diagnosed by needle biopsy (figure 2) of the prostate gland if indications are present for such a biopsy. Stage 1 prostate cancer cannot be detected by digital rectal examination. There is also a very good chance that Stage 1 prostate cancer can be cured.(figure:2- Needle Biopsy)

Figure 2 - Needle Biopsy

Stage 2. (T2NOMO or B)
Stage 2 prostate cancer refers to a more easily detected tumour although still within the prostate. There still may not be any symptoms. The tumour has however grown to the point where it can be detected by a rectal examination. This stage of prostate cancer also has a good chance of being cured.

Stage 3. (T3/T4NOMO or C)
By stage 3, prostate cancer has spread to the area just outside the prostate. Common symptoms at this stage include difficulties with urinating. Stage 3 prostate cancer has less chance of being completely cured, but treatment can effectively slow its spread, and can relieve most symptoms.

Stage 4. (T1-4 N1-3M1 or D)

Stage 4 prostate cancer is an advanced stage of cancer and refers to distant spread beyond the prostate. Commonly, the areas involved are the lymph nodes and the bones (figure 3) but other areas can also be involved. Symptoms at this stage can include difficulty in urinating, bone pain, weight loss and fatigue. At this stage of disease, treatment is targeted to relieve symptoms and hopefully to also slow the cancer’s growth.

Figure 3: X-ray showing cancer spread to skeleton

What treatment is available ?

Early Prostate Cancer.
When the tumour is limited to the prostate gland as in Stages A and B of the cancer, treatment given is to try to remove the tumour from the body and to prevent any possible spread. This can be done through surgery, or with the use of radiation.

1. Surgery.

The surgical removal of the prostate is called a prostatectomy. In this procedure, the entire prostate, and thus the tumor, is removed (figure 4). Pelvic lymph nodes are also removed during this operation to ensure that they are not carrying any cancer. The side effects associated with prostatectomy may include impotence and incontinence, and as with any surgical procedure, there are some risks of other complications. A relatively young, otherwise healthy man is an ideal candidate for surgery.(figure:4)

Figure 4

2. Radiation.

Radiation therapy uses high energy X-rays to kill and eliminate cancerous cells. There are different ways to administer this therapy, either externally or internally. Radiation therapy is a good option for patients who either wish to avoid an operation or may not be suitable for a major operation. Its side effects include fatigue, skin reactions, frequent and painful urination, stomach upsets, diarrhoea and rectal irritation or bleeding. Fortunately, most of these side effects disappear after the end of the treatment. A small percentage of patients may have more long term problems.

Radiation therapy has been used for many years to treat prostate cancer. Although some experts claim that the cure rate is as good as surgery, there are some major disagreements. However there is no doubt that radiation does cure some patients and have fewer risks than surgery. For this reason, it is commonly used in older patients and in patients with other medical problems. It certainly has its role in the treatment of prostate cancer.

3. The No Treatment At All Dilemma. (Watchful Waiting)

Besides surgery and radiation therapy for early prostate cancer, there remains a third option of not treating at all. The rationale behind this is the fact that autopsy studies show a high incidence of prostate cancer and yet only a much lower number of men die or become ill from prostate cancer.

It is therefore not completely clear who will go on to develop serious problems and who will not ? Who shall we treat and who shall we not treat ? This is one of the most difficult questions facing both the physicians and the patients.

Advanced Prostate Cancer.

Both surgery and radiation can be used either alone or together to treat Stage C prostate cancer. However, most Stage C cancer treatment focuses not on achieving a cure, but on slowing the spread of prostate cancer and relieving its symptoms. Often times, the latter treatment would include some form of hormonal treatment.

Hormonal Treatment of Prostate Cancer.

Advanced prostate cancer, especially Stage D disease is generally not amenable to cure. Emphasis is therefore placed on control of the disease and this is most often done by either reducing the production of testosterone, the hormone that fuels the cancer, or blocking the hormones’ action. Depriving prostate cancer of the male hormone (testosterone) usually causes tumour regression (shrinking).

As a simple rule, hormonal therapy is reserved for men with stage D disease or men who have recurrent disease after radiation therapy or surgery. This can be achieved in one of several ways.

1. Orchidectomy.

This is the medical term for surgical removal of the testicles and is a small operation. Because 95% of the body’s testosterone is produced by the testicles, their surgical removal effectively limits the amount of testosterone available to fuel the cancer. The growth of the cancer is therefore slowed, and many of its symptoms alleviated. Side effects of this operation include impotence and hot flushes.

2. Oestrogens.
This was the traditional treatment for advanced prostate cancer and oestrogens are basically female hormones that worked by reducing testosterone levels. This treatment was however complicated by significant complications and now that safer therapy is available, oestrogen is very rarely used.

3. Anti - Androgens.
These drugs block the action of testosterone at the cell level. There are various drugs that act this way and are also used in combination with other therapies. Their side effects vary between the different groups of drugs.

4. LHRH analogues.

This group of drugs is usually given as an injection under the skin either monthly or 3 monthly depending on the depot preparation (figure 5). They act by shutting down testosterone production in the testicles. Its actions are therefore similar to that of orchidectomy. The side effect profile is also rather similar to that of surgical orchidectomy.

Figure 5

Conclusion.
Prostate cancer is proving itself to be a significant issue in terms of the morbidity and the mortality that it brings to elderly men. With proper management, prostate cancer can be cured or survival increased. As a cancer that is likely to affect a significant section of any elderly population, it is hoped that information like that presented here would keep people aware of this disease in its earliest stages and thus be amenable to some form of treatment.