Although prostate cancer is one of the less
lethal cancers, a wide range of treatments is available, and one patient's
fight has strengthened his belief in a healthy lifestyle.
Screening for prostate cancer, the third most
common cancer here among males, has undergone a change in thinking. Doctors are
likely to recommend it mainly for those who are at higher risk instead of every
male of a certain age, as used to be the case.
This is because the prostate specific antigen
(PSA) test is prone to false positives, so about two-thirds of men who have
raised levels of the protein in their blood actually do not have cancer, said
Dr Ravindran Kanesvaran of the National Cancer Centre Singapore.
They end up undergoing unnecessary biopsies,
which have their own risk, just to rule out cancer.
What is more, most men with prostate cancer
will not die of it, as it tends to be slow-growing in many cases, said Dr
Kanesvaran.
But once diagnosed, men might end up having unnecessary
treatments such as surgery or radiation therapy, he said. Screening is best
done on men who meet certain criteria, such as those between 50 and 75 years
old, with a life expectancy of more than 10 years, and a strong family history
of prostate cancer - first-degree relatives who were diagnosed before they
turned 65.
The prostate gland, about the shape and size
of a walnut, secretes fluids that help in reproduction.
Prostate cancer was the third most common
cancer diagnosed in men between 2010 and 2014, with 3,694 new cases found in
that time period. During that period, 739 men died of prostate cancer, making
it the sixth most common cause of cancer death among men.
In the 1980s, the rate of metatstatic
prostate cancer was 72.4 per cent, said Dr Sim Hong Gee, who is a senior
consultant urologist of the Ravenna Urology Clinic at Gleneagles Medical
Centre. Because of screening, most patients are now diagnosed at Stage 1 or 2,
he said.
According to the National Registry of
Diseases Office, only three in 10 prostate cancer patients were diagnosed at
Stage 4. At the National University Health System, one- quarter are diagnosed
at Stage 4.
In comparison, about 5 per cent of men in the
United States are diagnosed at Stage 4, simply because they screen more, said
Dr Lincoln Tan, consultant at the division of surgical oncology (urology),
National University Cancer Institute, Singapore (NCIS). But, he added: "In
the US, there is a lot of unnecessary treatment going on, it is just
overdone."
A test with better accuracy may put the
screening dilemma to rest. The NCIS is working on a new blood test for
screening called the Prostate Health Index. From a study of 150 men, its
accuracy appears to be three times higher than that of the PSA test, said Dr
Tan. But it is more expensive - about $120 out of pocket, compared to $30 for
the PSA test.
On the treatment front, with prostate cancer
being so slow-growing, the NCIS has embarked on an active surveillance
programme, in which prostate cancer patients are observed instead of treated
right away. They have a PSA test every six months, and a biopsy every one to
three years."The key benefit of being on this programme is that patients
avoid the toxicity of treatments," said Dr Tan.
Nevertheless, some patients request immediate
treatment rather than monitoring. The latest treatments include using radiation
seeds implanted directly onto the prostate gland to target cancer cells more
directly, and robotic surgery, which is highly precise, to remove the tumour.
There is also hormonal therapy to reduce testosterone levels.
As for prevention, a diet
rich in certain nutrients is advised."Males may want to include more
lycopene in their diet, which is present in tomatoes. Also, cruciferous
vegetables and green tea may help. But how far it prevents the cancer, we
aren't really sure," said Dr Sim.
DR SIM HONG GEE, senior consultant urologist
of the Ravenna Urology Clinic at Gleneagles Medical Centre, on preventing
prostate cancer through diet.
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