Monday, December 08, 2014

Four reasons I won’t have a prostate cancer blood test - Prof Ian Haines



5 December 2014
Four reasons I won’t have a prostate cancer blood test
Adjunct Clinical Associate Professor & Senior Medical Oncologist and Palliative Care Physician at Monash University

For many men, the down sides of PSA testing outweigh the benefits.

Cancer Council Australia and the Prostate Cancer Foundation of Australia yesterday released new draft guidelines to help GPs counsel men who ask about prostate cancer tests. They advise GPs to explain the pros and cons of testing and, if the man wants to proceed, to give him a prostate specific antigen (PSA) blood test every two years between the ages of 50 to 69.

Over the past few decades public health messages have drummed into us that early detection and treatment of diseases are key to good outcomes. Add to this the celebrity testimonials for prostate tests and non-celebrities who tell us their PSA test “saved their life” and it’s easy to see why men think the tests are beneficial.

While some prostate cancers are harmful and require treatment, many are not. So the prevailing wisdom – that early detection and treatment is best – doesn’t necessarily apply. At least 70% of men over 70 have prostate cancer detected in autopsies, and only 3% of men die because of prostate cancer.
I’m a 60-year-old male oncologist who has practised full-time for 36 years. Having “skin in the game” I’ve followed the testing debate closely since PSA was first used for screening in the early 1990s. Based on the evidence, if I was asymptomatic, I would not choose to have PSA test. Here’s why.

1. PSA is a poor testing tool
Prostate specific antigen (PSA) is an enzyme secreted in large amounts by normal as well as cancerous prostate cells. Only small amounts of PSA leak into circulation from a normal prostate, but this increases with any prostatic disease, benign or malignant.

An elevated PSA very often does not indicate cancer. Just one in four men with a positive PSA test will have prostate cancer.

PSA tests also miss many cancers. A 2003 study found that 21% of men who had a “normal” PSA of 2.6 to 3.9 at the end of a seven-year study did, in fact, have prostate cancer. Of the men with a PSA of 2.5 or less, 15% had cancer.

2. Prostate cancer isn’t like other cancers
The point of a cancer screening test is that it can reliably detect lesions that, if removed, will reduce the chances of that patient later developing a life-threatening cancer.

This is certainly true for polyps and bowel cancer screening. It is also powerfully true for precancerous lesions of the cervix and cervical cancer. It is somewhat true for mammography and precancerous or early invasive breast lesions.

It is not at all true for prostate cancer screening. In the majority of cases, prostate cancer behaves more like an indolent condition and does not pose any threat to the patient’s natural life span. This proportion of men dying of other causes continues to increase in the PSA era.

The only prostate screening study showing an advantage for screening has very serious flaws, which have also been noted by the head of the American Cancer Society Professor Otis Brawley and Professor Richard Ablin, who discovered the prostate specific antigen in the 1970s.

3. Surgery won’t always cure you
The only study comparing radical surgery with no treatment found equivalent outcomes. It concluded:
Among men with localized prostate cancer detected during the early era of PSA testing, radical prostatectomy did not significantly reduce all-cause or prostate-cancer mortality, as compared with observation, through at least 12 years of follow-up. Absolute differences were less than three percentage points.

Radical surgery “cures” six in seven cases of prostate cancer. But this does not remove the uncertainty and doubt for men with prostate cancer, as most of the six in seven who are “cured” did not require treatment and most of the one in seven with dangerous cancers requiring cure will not be helped by the treatment.

4. Detection and treatment comes with side effects
One in six men will be diagnosed with prostate cancer during his lifetime. Their lives will be profoundly changed by this cancer diagnosis, whether or not they proceed with treatment.

I do not want the anxiety, depression and relationship changes that follow diagnosis, radical surgery, active surveillance or any regular monitoring. I do not want to be impotent, which is very likely after radical treatment, or have urinary incontinence.

Even before treatment commences, after an abnormal PSA result, men are referred for a prostate biopsy: a surgical procedure that, even though it can indicate cancer, cannot give reliable information about how that cancer will behave.

I do not want the 1-2% risk of life-threatening infections caused by prostate biopsies.

Bottom line
I’m happy to take active positive steps to improve my health where it is proven that the benefits of the intervention outweigh the costs. But I’m not prepared to have my life ruled by a regular blood test like PSA that has no advantage.

First published in The Conversation

Thursday, December 04, 2014

What do the Greens support as alternatives to the burning of fossil fuels?

The recent China/US agreement to reduce CO2 emissions prompted Martin Ferguson, former Labor Minister for Resources and Energy, to publicize a few "energy" facts which raise the question of whether emissions reduction is the real objective for "The Greens". Here is the reaction from my retired financial advisor friend AP to the former Minister's criticism:

"China and US have shown they will act," cheered The Greens' leader, Christine Milne. "The Australian Greens are congratulating the US and China on their agreement to act on global warming and say it's not too late for Australia to get on board."

It's fair to say the Greens and their boosters have used the USA-China accord as a stick with which to beat pretty much anyone outside of the renewable energy sector.

Their rhetoric is symptomatic of a broader malaise; our increasing inability to listen to, analyse, and properly understand the words and numbers underpinning complex policy.

Slogans should not be a substitute for serious discussion or critical thinking.

The question I would like answered is whether the Greens and the wide array of energy dogmatists who cheer them on actually understand - let alone support - any of the energy technologies that underpin the capacity of the two global superpowers to enter into the "Climate Pact" in the first place?

The People's Republic of China has 22 nuclear power reactors operating and a further 26 under construction.

Additional reactors - enough to triple nuclear capacity to at least 58 gigawatts by 2020 - are planned. As a rule of thumb, a typical new-build reactor will generate about 1 gigawatt a year, so it appears there are quite a few new Chinese nuclear power plants on the drawing board.

This will raise the percentage of China's electricity produced by nuclear power from the current 2 per cent, to more than 7 per cent, by 2020. Thereafter, another threefold increase in nuclear capacity (to about 150 gigawatts) is planned by 2030; and then more again by 2040.

Not only does nuclear power offer an enormous opportunity to Australia's uranium exporters, it clearly has a central role to play in China's decarbonisation. Yet the last time I checked, the Australian Greens were trenchantly opposed to the use of - let alone the further development of - this major energy source. Of course, they are not the only people in Canberra to hold such a view.

Hydroelectricity is also incredibly important to any future reduction in China's emissions.

Hydro is the world's leading source of renewables-based electricity and in
2012, it produced more than twice as much power as all other forms of renewables combined. In China, hydropower has long been the single most important source of renewable energy and it will remain so in 2040. China last year brought online a record 31 gigawatt of hydropower.

And while the country's investment in hydro will fall after 2020, this is simply because most of the suitable hydro sites will have been by then developed, not because better or cheaper renewable technologies will have become available. Hydro will still account for about 40 per cent of total energy produced by renewables in China in 2040.

As a party who owes its parliamentary advent to an anti-dam campaign, it is hard to see how the Australian Greens could change the party's opposition to China's - or anyone else's - dam-building.

Now let's look at the USA; a country that is already leading the world in the field of carbon reductions; with emissions today back to levels last seen in the mid-1990s. It is an astounding achievement, but not one born of a carbon price or a Renewable Energy Target. Rather, it has been the rapid and dramatic discovery and use of cleaner burning indigenous natural gas supplies that has cleaned up the American power system.

The scale of the USA shale gas expansion is immense. In the few years immediately following the technological advancements in hydraulic fracturing and horizontal drilling that made vastly more resources commercially available, the price of gas fell from more than $13 per gigajoule in 2006, to less than $4 today.

Gas use has soared and gas has displaced coal as the country's leading energy source.

The United States today has 487,286 gas wells in production; a staggering number. And throughout 2014, more than 300 drill rigs have been drilling for gas across the US. The International Energy Agency (IEA) says that in 2040, gas will provide more energy to the USA than coal, wind and solar combined.

And what do The Australian Greens say on natural gas development? They oppose it.

Lastly, the IEA forecasts China will remain the world's largest coal user in
2040 - with consumption three times that of India, the world's second-largest user. Not surprisingly, the IEA says carbon capture and storage (CCS) is an essential mitigation technology.

As part of their "Climate Pact" the US and China aim to use advanced coal technologies, including a major CCS project in China.

The Australian Greens? In 2011, they insisted CCS be excluded from the $10 billion Clean Energy Finance Corporation, set up with the Gillard Government.

Frankly, it is hard to see what Senator Milne was referring to last week when she said: "The Greens will continue to push for true leadership and real action to address the greatest challenge of this century - global warming."

Energy security and climate policy are areas of complex policy. "True leadership and real action" is indeed required.

But it actually consists of sophisticated thinking and rigorous debate; not opportunism"