Prostate Cancer
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Aug 3, 2005
Grey Matters
You may be in a prostate of emergency
Prostate cancer has become the fifth most common cancer among men here. But how reliable are the tests for it and will mass screening help? Judith Tan and Elaine Young examine the issues.
This X-ray shows the cross-section of a patient's pelvis. The area marked with a cross indicates the prostate, which is almost three times its regular size.
--ISTOCKPHOTO
Raymond Tan, 80, has prostate cancer but he doesn't know it.
'We didn't actually say the word cancer to him. We told him he had an enlargement of his prostate gland and he needed treatment to control it. Cancer isn't a nice word,' said Charles, his 48-year-old son.
Mr Tan finds it an embarrassing condition - one a son is best placed to handle.
Prostate cancer has increased four times in the past 35 years.
Now it is the fifth most common cancer among men in Singapore.
Professor Christopher Cheng, head of the department of urology at the Singapore General Hospital (SGH), attributed this increase to greater longevity, the popularity of a Western-style diet and increasingly sedentary lifestyles.
According to the Singapore Cancer Registry, there were 1,346 cases of prostate cancer between 1998 and 2002. This translates to about 269 cases a year on average.
'The number of cases among Chinese men in Singapore increased by 120 per cent between 1978 and 1997. This is perhaps due to diagnostic intensity,' Prof Cheng added.
The prostate, or male gland, is about the size of a walnut. Located below the bladder and in front of the rectum, it is 30 per cent muscular tissue and 70 per cent glandular tissue. It makes and secretes prostatic fluid, one of the five fluids that make up semen.
Though it is very small, it can have a large impact on a man's health, says Dr Clarence Yeo, a GP practising at Singapore Men's Health Clinic and Killiney Family and Wellness Clinic.
Prostate cancer occurs when a malignant tumour forms in the tissue of the gland.
In its early stage, prostate cancer needs the male hormone testosterone to grow and survive, though scientists do not know the exact cause of the disease.
One risk factor is age. The disease is extremely rare among men under the age of 40. More than 75 per cent of cases are diagnosed in men over 65. The average age at the time of diagnosis is 70.
The rising numbers here prompted two MPs, Dr Lily Neo and Mr Leong Horn Kee, to ask the Government to conduct mass screening for this cancer.
They made this request of the Senior Minister of State for Health, Dr Balaji Sadasivan, in Parliament early last month.
Dr Balaji said no, not because of costs, he said, but because the prostate-specific antigen (PSA) test in question is highly unreliable. -
DETECTION
One of the problems with prostate cancer diagnosis is detection.
Since the mid-1980s, the PSA test has been used to find out if a patient has a prostate problem. It measures the level of PSA, a protein produced by the prostate that leaks into the blood.
When a person has prostate cancer or some other prostate disease, the amount of PSA in the blood often increases, thus indicating a problem.
However, a higher level of PSA may simply mean an infection, or an enlarged prostate, not necessarily cancer.
According to the United States National Institutes of Health, the PSA test is highly unreliable as a person can have prostate cancer and still have a low level of PSA in their blood.
Only one in three men who tests positive actually has cancer.
A report in The New York Times in June this year quoted Dr Michael Barry, a professor of medicine at Harvard Medical School, who said the PSA test 'is just not as discriminating as we thought it was'. As a result, many experts are suggesting that the PSA test should not be the sole focus of prostate cancer screening.
Some experts are also asking doctors to be more open to the idea that some men may be better off forgoing treatment and instead be monitored regularly for changes in their tumour's growth.
A series of papers published last year sparked this change in thinking.
The first was by Dr Ian Thompson Jr, head of urology at the University of Texas Health Science Centre in San Antonio.
His paper reported that biopsies found prostate cancer in as many as 15 per cent of men with PSA levels normally considered safe.
Then, in October last year, Dr Thomas Stamey, a professor of urology at Stanford University School of Medicine, published a paper arguing that PSA tests are virtually useless.
Finally, in May this year, Dr Peter Albertsen of the University of Connecticut Health Centre published a study arguing that men with prostate cancers that do not look particularly aggressive under a microscope can do perfectly well without treatment for at least 20 years. All they need is to be monitored by a doctor to ensure that their PSA levels do not shoot up.
Prof Cheng said that during the Prostate Awareness Week in April, about 3,000 men between the ages of 50 and 70 were given PSA tests.
'They are the second cohort to be tested and about 6 to 8 per cent were found to have an abnormal PSA reading. A quarter of these were cancerous,' said Prof Cheng.
Prof Cheng said PSA testing is useful to detect an enlarged prostate but it is not the final word.
For this reason, it should not be advocated in community screening.
Dr James Tan, a urologist at Mount Elizabeth Medical Centre, agreed. 'At this point, there is no evidence to suggest that mass screening would be beneficial. Even after biopsy, the PSA could be high and still not indicate cancer. In the West, where incidence rates are 10 times higher than those in Singapore, they do not have conclusive evidence that mass screening is beneficial and they have not found it to be cost- effective either,' he said. -
ANOTHER OPTION
Dr Yeo feels that PSA should not be used in isolation, but together with the digital rectal examination (DRE), which could tell the doctor if there are any suspicious prostatic nodules.
Both Dr Tan and Prof Cheng feel that the side effects of further investigation, such as the bleeding complications of biopsy, may do more harm than good.
'A biopsy is surgery and as long as it is surgery, it is invasive. It can cause bleeding and infection. For those who have a benign growth, then removing it surgically could harm them more than not touching it at all,' Prof Cheng said.
Patients, Dr Tan said, need to be told what a PSA, DRE and biopsy involve, and what the side effects of further investigation could be.
Prof Cheng said: 'PSA testing should be encouraged as a personal choice and with adequate education, older men will make it their priority to be tested.
'Many men will die, however, of competing medical conditions before they die of prostate cancer, because the cancer is a slowly progressive disease.' -
IN A WALNUT SHELL
The prostate is a gland about the size of a walnut.
It is located below the bladder and in front of the rectum. Thirty per cent of it is muscular tissue and the rest, glandular tissue.
The gland makes and secretes prostatic fluid, one of the five fluids that make up semen.
Prostate cancer occurs when a malignant tumour forms in the tissue of the gland. -
be very careful guys.. time to chk chk chk
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Too boring to read, what are the symptoms?
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Signs and Symptoms of Prostate Cancer
What are the symptoms of prostate cancer?
There are usually no specific signs or symptoms of early prostate cancer -- which is why prostate screening is so important. An annual physical examination, prostate-specific antigen (PSA) blood test, and digital rectal exam (DRE) provide the best chance of identifying prostate cancer in its earliest stages.
The following signs and symptoms may be caused by prostate cancer, or by a variety of other conditions. Consult your physician right away if you are experiencing any/all of the following symptoms:
weak or interrupted flow of urine
urinating often (especially at night)
difficulty urinating or holding back urine
inability to urinate
pain or burning when urinating
blood in the urine or semen
nagging pain in the back, hips, or pelvis
As a man gets older, his prostate may grow bigger and block the flow of urine, or interfere with sexual function. Although an enlarged prostate gland -- a condition called benign prostate hyperplasia -- may not be life-threatening, it may require treatment with medicine or surgery to relieve symptoms. This common benign prostate condition, which is not cancer, can cause many of the same symptoms as prostate cancer. -
Staging of Prostate Cancer
What is staging of prostate cancer?
If cancer is found in the prostate, your doctor needs to know the stage, or extent, of the disease. Staging is an attempt to determine whether the cancer has spread and, if so, what areas of the body are affected. Various blood and imaging tests are used to learn the stage of the disease. Treatment decisions depend on these findings.
There are several different systems used by healthcare professionals to describe stages of cancer. The different systems may use a letter of the alphabet, a Roman numeral, a number, or any combination of these, or others, to designate the appropriate stage of the cancer.
In general, the different systems attempt to classify stage of the cancer by evaluating:
the size and location of the tumor
whether the cancer cells have moved beyond the tumor, but are still within a specific area or organ of the body
whether the cancer cells have spread beyond the specific area or organ of the body to other tissues beyond it
whether the cancer cells have spread into the lymph nodes
whether the cancer cells have metastasized into another part of the body
Results from staging and grading the cancer provide information a cancer team can use to define a treatment plan that will be presented to and discussed with the patient and family members.