Prostate matters

FOR a cancer that is the most common non-skin cancer in men worldwide, prostate cancer remains a disease that is filled with scientific uncertainties.

Besides the area it affects - the prostate - there is a lot researchers and doctors are not certain about.

They know for certain that after 40 years of age, the risk of developing prostate cancer increases with every passing year, but unlike some cancers (such as cervical cancer and liver cancer), they are still unsure what the exact causes are.

And although there are treatments available to treat and even cure some prostate cancers, doctors are divided in determining when to start treatment and whether or not they should treat mild forms of the cancer at an early stage.

Recognising the controversies surrounding the disease, a prostate cancer symposium was organised by Pantai Hospital Kuala Lumpur to address some of the issues surrounding prostate cancer diagnosis and treatment.

While decades ago, prostate cancer was more common in the West, it is now increasing in Asian countries. If you go by the National Cancer Registry statistics, since year 2003, prostate cancer was ranked the fourth most common cancer among males in Malaysia.

"The reasons for the increase of incidence could be due to the ageing population, and a change of lifestyle and diet habits," says organising chairman, consultant oncologist Dr John Low.

But with our ageing population, and age being so closely related to the risk of developing prostate cancer, the incidence of prostate cancer is bound to increase.

Detection

Detecting it early

As symptoms of prostate cancer may not appear in every patient, very often, the discovery of prostate cancer is incidental.

"People find out they have prostate cancer through various ways. Sometimes they go for surgery for other conditions, or they have urinary retention and find out they have cancer," says Singapore General Hospital urology department senior consultant and director of uro-oncology Dr Weber Lau, one of the speakers at the symposium.

But when symptoms do appear, they include problems in passing urine, difficulty in having erections, having blood or semen in the urine and frequent pain in the lower back, hips, or upper thighs.

All of these symptoms can be caused by other conditions. Problems in urinating and the presence of blood in urine can be caused by infections. Difficulty in having erections can be due to erectile dysfunction or chronic conditions such as diabetes.

So, to detect whether it is likely someone has prostate cancer, doctors use screening tests: a blood test to test for the Prostate Specific Antigen (PSA), a protein produced by cells of the prostate gland, and a Digital Rectal Examination (DRE), a test where the doctor inserts a gloved finger into the rectum and feels the prostate to check if there are any out-of-the-ordinary bumps.

However, these screening tests need to be evaluated together with other information: things like family history and the presence of other factors that may have contributed to the elevated level of PSA.

After that, if the doctor feels that there is a high likelihood a man has prostate cancer, he may suggest a prostate biopsy (a procedure to remove samples of prostate tissue with a needle) because the only way to be sure that a man has prostate cancer is to examine these tissues under a microscope.

In the past, most doctors consider PSA levels below four nanograms/milliliter (4ng/ml) as normal. However, a large Texas (US) study found that 15% of the men in the study with PSA levels below that were diagnosed with prostate cancer.

Conversely, another US study showed that only 25% to 35% of a group of men with elevated PSA levels of 4.1 to 9.9ng/ml were diagnosed with prostate cancer after a biopsy.

In Asia, the statistics are similar. "PSA does not equal cancer," says Dr Lau. Even with a PSA level of four to 10ng/ml, the pickup rate in the Asian context is only about a quarter, or 24% to 25%. The majority of patients do not have prostate cancer.

"The thing is that you don't know who has it," he notes.

As many laboratories worldwide offers the PSA test as part of routine blood tests, doctors are urging people to talk to them and understand more about the test before undergoing it.

In his talk about the role of PSA screening and early detection of prostate cancer, consultant urologist Dr Azad Hassan Abdul Razak says, "We hear stories about patients who have their PSA done and had multiple biopsies done. Although it is negative (for prostate cancer), they still become very anxious and we can't explain why the PSA level is high. We can create a lot of anxiety as well."

This "patient stimulated anxiety", as Dr Lau calls it, calls for the need for patients to be counselled properly before the test.

"If you have a high PSA level but you have other ways to explain that, for instance, a recent urinary tract infection, urinary retention, or even if you just had sex - which can elevate your PSA up to 20%, we can watch the levels for a while first," he says.

So, unless you can benefit from early detection (you are young and have a strong family history of prostate cancer), even with high PSA levels you don't always have to do a biopsy.

To treat, or not to treat?

To treat, or not to treat?

Currently, treatment options for prostate cancer include watchful waiting, surgery, radiation therapy, and hormone therapy. If a patient's condition does not improve, and if the cancer has spread to other parts of the body, chemotherapy is used.

This is because while high-grade cancers of the prostate progress quickly, low-grade cancers take an average of five to 10 years to progress to become a clinically significant one which needs treatment.

That is why in low-grade prostate cancers, doctors may adopt the watchful waiting approach - they monitor the disease closely without putting the patient on treatment.

As all treatments targeted at the prostate may affect its functions and the functions of surrounding organs and structures (like the bladder, rectum and nerves controlling bladder and bowel function), they may cause problems like incontinence and impotence.

Improvements in techniques may minimise these complications, but doctors still have to weigh the potential benefit a patient will have after treatment against the side effects the treatment may cause.

"It's like running a race," says Dr Lau.

So, if you have a 30-year-old and a 70-year-old man diagnosed with the same stage of prostate cancer, chances are, doctors will treat the 30-year-old more aggressively than the 70-year-old.

To Dr Lau, the important message people should be aware of when it comes to prostate cancer is that it is getting more common. But with more screening methods and better healthcare, if men are diagnosed with it these days, such cancers are more readily treatable.

However, it is important for patients to consult a doctor if they are concerned about abnormal laboratory tests that indicate cancer.

Tests for biological markers (or what laboratories call the "tumour markers") like the PSA are useful to determine whether treatments are working for cancer patients, but they are usually not enough to determine whether one has cancer.

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