I would agree with a number of his points. Yes, some men having a PSA test will ultimately be diagnosed with a cancer that does not need to be treated. Yes, some of those men will ultimately have treatment, which is therefore unnecessary, and, yes, some of those men will suffer significant adverse effect as a result of those treatments.

However, I would disagree with Professor Glasziou's conclusion that these problems are the fault of the PSA test. Based on the figures quoted by Professor Glasziou, the actual risk of these outcomes from having the blood test are 2.8 per cent, 0.07 per cent and 0.028 per cent. Even allowing for the obvious typographical error quoting uncertainty in treatment per 1000 instead of 100, the risk of adverse effects from unnecessary treatment is 0.28 per cent, and that is assuming that all, not just many, of the cancers diagnosed are insignificant.

The likelihood of benefit, ie saving a life, is 0.2 per cent, close enough to a 50:50 call. The most sensible advice is surely to see your GP to discuss having the test, not tell men not to have the test.

In fact, the risk from the PSA test itself is a tiny risk of infection and a bruise. The risk of overdiagnosis, overtreatment and adverse effects from that treatment, arise from the advice given to those men. Men need to be aware of these issues, so an informed decision regarding the risks and benefits of diagnostic testing and treatment can be made at each stage.

I am unsure how relating an anecdote regarding the adverse effects of treatment by a respondent to an article on Mr Koch's television piece, and quoting an unsubstantiated number of medical colleagues who support the conclusion, qualifies as evidence-based.

Dr Simon McCredie, Red Hill

Michael White (Letters, February 24) states that the PSA test "is the only way of getting an early indication of a potential problem". In my view this is a dangerously incorrect statement.

I am also a prostate cancer survivor. I had had six-monthly PSA tests for at least 10 years before my non-PSA-based diagnosis. My PSA test results showed little variation, yet I had very advanced pain-free cancer. By itself the PSA test is not a foolproof prostate cancer marker.

Males need to accept the need for regular finger tests. It a very simple procedure which does not hurt, but like the PSA test is also not 100 per cent reliable. Men should also undertake regular colonoscopies and make sure their doctor checks the prostate.

That is how my cancer was detected. There may be other tests, insist that your doctor considers them. All post-diagnosis tests merely confirm the cancer and treatment options. Because there is no pain warning on prostate cancer growth men should use all risk assessment options available, before and after an operation. My specialist also tells me there is a 20 per cent chance of re-occurrence.

He's a cheerful soul!

John Maclean, Weetangera

We felt so sad as animal lovers to read about the numerous kangaroos unable to get themselves out of Lake Burley Griffin ("Peril of the lake", February 25, p1).

Some of the ones not able to be rescued would have had a horrible death. Do I think the ACT government will do anything about this problem, No! The Barr government gives approval each year to slaughter hundreds of kangaroos and kill the joeys in an horrendous way, in so-called "protecting the flora and fauna", so to save one or two from drowning wouldn't be a concern.

Hundreds of these native animals are killed in the name of "protecting the environment" but strangely ugly apartments and housing developments start to pop up within close proximity of some sites where culling has taken place.

This ACT government along with the developers will not stop until our beautiful Bush Capital with so many native animals is covered in concrete.

B. M. Cooke, Latham

Once again the ACT government is manufacturing more problems for itself. There's overflow parking elsewhere in O'Malley other than on Bulwarra Close ("Alcatraz embassy", February 23, p5).

The government's going to sell the public car park near the corner of Numeralla Street and Kareelah Vista. Up to 17 cars per day, Monday to Friday are parked in this car park.

When it's sold, these cars will then have to park on nearby streets, like Pindari Crescent. Up to 12 cars per day, Monday to Friday are parked on this street.

Most of these cars belong to the staff and visitors of diplomatic and consular premises who work in O'Malley. Their need for car parking is understandable and should not be ignored by the ACT government which wants to sell the entire corner block – to help pay for the tram?

Suzanne Vidler, O'Malley

I agree wholeheartedly with the sentiments of Luba Thompson (Letters, February 22) regarding the denial of a catering licence to the Burrunju Art Gallery on the shores of Lake Burley Griffin.

This is one of the most beautiful sections of the lake and a peaceful place to sit and ponder the breathtaking view through the magnificent gumtrees to the water's edge.

On a recent visit with family from Geelong and Hobart (places where interesting eateries abound), we were not only disappointed because we couldn't have a cuppa and a snack, but dismayed at the lost opportunity that a small cafe might provide by training young people in the conduct and management of a small business.

It would be particularly enriching if the employees were in some way associated with the gallery and/or the artists and could share their knowledge with visitors.

Every time I drive or cycle past the colourful buildings where the Burrunju gallery is located and glance towards the lake through the trees, I'm reminded of this lost opportunity and hope the ACT government will take action. The wonderfully enthusiastic and hardworking group of people operating the gallery are worthy of our support.

Jenny Osborne, Yarralumla

Cultural, economic and infrastructure problems are obvious in our major cities, with the rate and mix of immigration being a major contributing factor. Population growth in Australia is 1.6 per cent compared to 0.4 per cent to 0.9 per cent in most developed countries. This growth rate is due mainly to immigration. A reduction in numbers and more selective immigration policy is only common sense.

Owen Reid, Dunlop

The report "The global race in company tax cuts" (Forum, , February 24, p4) discusses the pros and cons of reducing Australia's current company tax rate of 30 per cent. John Edwards, former board member of the Reserve Bank and now associated with the Lowy Institute argues that the true rate paid by Australian companies is reduced by numerous deductions, including depreciation and research and development offsets, and the ability to carry forward losses.

How much tax, then, do Australian companies really pay when growth in workers' wages has stagnated?

I am reminded of the article "Report reveals which big companies pay no tax" in The West Australian (December 8, 2017), based on data from the Australian Taxation Office.

It found that a third of big companies and 60 per cent of mining companies paid no tax at all in the 2015-16 financial year. In the latter case this was due "in part because of a big fall in iron ore and coal prices in 2014 and 2015."

Non-mining companies that paid no tax included Glencore Investments $18.3 billion income), Toll Holdings ($5.1billion), Bluescope Steel ($4.9 billion), Newscorp Australia ($2.9 billion), Transurban ($2.5 billion) and Chevron Australia ($2.1 billion).

Hancock Prospecting paid $225 million in tax (11.8 per cent) on $1.9 billion in total income, BHP paid $1.3 billion (4.87 per cent) on income of $26.7 billion, Fortescue Metals Group paid $393 million (4.41 per cent) on income of $8.9 billion, and Rio Tinto paid $1 billion (3.60 per cent) in tax on total income of $27.8 billion.

It's quite clear that, no matter how little tax the big companies ultimately pay, it has had little effect on how much they pay their workers.

I, for one, can see little or no justification for handing out further tax cuts to these companies.

Douglas Mackenzie, Deakin

Kevin Rudd has a nerve criticising Malcolm Turnbull in his letter dated February 26. It is a case of the saucepan calling the kettle black.

Whilst I would prefer Australia to have a more conservative prime minister, Malcolm Turnbull is not obsessed with China as if it were "the land of opportunity". And I am still happy to put in my Liberal vote at federal election time.

Anne Prendergast, Reid

It now appears improbable that the ACT government will release to the public the patronage forecasts and business case for the proposed City-Woden light rail service.

This is hardly surprising given the rubbishing that the case for the City-Gungahlin report got from all credible economists.

My studies, based on patronage forecasts with internationally recognised modelling, fully credible economic analysis and costing based on the current costs in Canberra, shows that, compared with 0.56 for the City-Gungahlin project, the City-Woden project earns a benefit-cost ratio of 0.47. The whole Gungahlin-Woden project, instead of improving the B/C ratio, actually reduces it to 0.41 as there is insufficient forecast travel between Gungahlin and Woden. It is normal for B/C ratios to be expected to be well in excess of 1 and more than 2 is the normal expectation for implementation of transport projects in Australia. This is partly because many of the benefits are real but intangible and therefore risky.

Therefore it is also normal for the economic evaluation to include risk assessment allowing for the compounding of potential risk effects.

Including risk assessment reduces the B/C ratio for the City-Woden project to 0.39 and for the combined Gungahlin-Woden to 0.32 (City-Gungahlin was 0.48).

I believe this analysis of the probable economic results should be made public.

Bob Nairn, Hawker

People such as Bill Meani (Letters, February 26) are finally awakening to the bitter reality of the tram, something about which many Gungahlin residents are already aware.

That is, existing bus services will be cannibalised and a metaphorical gun held to patrons' heads in order to force them onto the tram. The government has to attempt to justify this folly somehow. Who wants to use two different transport modes when one currently suffices? One would assume one fare would cover both modes but, with this rapacious government, nothing can be taken for granted. And no tram stop for Mitchell.

David Jenkins, Casey

What a great idea Kevin Connor (Letters, February 26). If the light rail opponents of the southside don't want light rail, make it work for the east-west axis to the airport like you suggest, perhaps with a spur to Kingston.

The only problem with this is that we'll then have to endure more letters from the southside complaining they haven't got it. But, then, we are becoming used to this as light rail seems to be the reason advanced for every failure in this city. Give it a rest, people. It is happening.

James Mahoney, McKellar

Mike Quirk (Letters, February 23) complains "The lack of an effective and electable opposition is contributing to poor decisions of which light rail is the most obvious..."

The opposition before the election on the tram was definitely opposed to it. If the electorate which is so vehemently against the tram had voted for it instead of all the offshoot independents such as Can the Tram, we may now have saved a lot of anguish on this matter.

P. Swaffield, Curtin

So the inhabitants of Collector are up in arms again. This time it is because there is to be a police firing range four kilometres away. The last concerted objection was when artist Tony Phantastes shocked them with his "Dreamers Gate". Gunning Shire Council ordered it to be demolished "for structural reasons". While that failed, the artist was hit with $27,000 costs, and was effectively driven away.

Maybe this strongly independent community should secede; but what would they do for a police force; where would it be trained?

Jack Palmer, Watson

Peter Waterhouse, Craigieburn, (Letters, February 24) just letting you know Billy Graham's worth was $25 million when he died.

Could have actually helped a lot of poor and needy people with that.

Not a very humble Christian.

V. Harris, Yass

INVERSE PROPORTIONS

On Barnaby's hat: "The bigger the Akubra, the smaller the holding."

Greg Simmons, Lyons

A REGION FAR FAR AWAY

With his rural background, perhaps Barnaby Joyce could be appointed Australia's next ambassador to Mongolia?

John Milne, Chapman

CONFUSION REIGNS

A third umpire may be needed to resolve whether Barnaby was out, hit wicket or retired hurt.

Peter Baskett, Murrumbateman, NSW

THE FINAL STRAW

What irony. Barnaby Joyce has been replaced by a journalist.

Robyn Lewis, Raglan, NSW

AN ILL WIND

As Dylan could have said "you don't need a weatherboard nine to know which way the wind blows".

Peter Harris, Belconnen

NOT A GOOD LOOK

The most depressing thing about the appointment of Michael McCormack is that he's the best they've got.

Fred Pilcher, Kaleen

RATING GAME

Kevin Rudd, (Letters, February 26) rates himself as 26th prime minister of Australia.

On a scale of one to 30, he's about right

Mark Sproat, Lyons

TRAM DAMPENER

First the damn tram — now the tram dam. It never rains but it pours.

Neville Exon, Chapman

A LONG TRADITION

Turnbull is not unique in sucking up to US presidents. I recall Julia Gillard carrying on like a besotted schoolgirl around Obama during her visit to the US.

Alex Wallensky, Broulee, NSW

ACTION MAN TRUMP

Donald Trump says he would have tackled the Florida school shooter unarmed. Boy, I'd like to see that.

Eric Hunter, Cook

BAD MISS ON MCKENZIE

The Nationals' failure to even consider their incumbent deputy leader, the talented, baggage-free, and personable Bridget McKenzie for Barnaby Joyce's job shows what a bunch of misogynistic fossils they really are. To have elevated a woman to Deputy PM in a cabinet almost bereft of women would have sent a very positive message while avoiding Mr McCormack's unfortunate record of homophobia.

M. Moore, Bonython

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