Mass testing on cards for bowel cancer

A mass screening programme to reduce the death rate from bowel cancer, New Zealand's second-biggest cancer killer, is being considered by the Government.

The country has the highest rate of bowel cancer in the world. This is linked to a love of eating fatty meat and dairy products and consuming too few fruit and vegetables.

Mass screening for bowel cancer - like the breast and cervical cancer population screening programmes - was last considered in 1998.

The National Health Committee found then that offering screening to those aged 50 to 74 could prevent about 512 colon and bowel cancer deaths in an eight-year period.

But the committee recommended against mass screening because the potential benefits were only "modest", a proper programme would be expensive and there was a small but real potential for harm.

But a Health Ministry report obtained by the Herald under the Official Information Act indicates the Government is likely to adopt bowel screening.

"Colorectal screening is currently subject to pilots in Australia and the UK, which is likely to prove it to be a very cost-effective intervention," says the report, written last month for Health Minister Annette King.

Ms King said yesterday that a bowel cancer screening programme "is on the drawing board [but] we won't be able to make announcements about it until all the research and policy work has been done".

The ministry has appointed experts and consumer representatives to report on bowel screening. It expected to make recommendations to the Government by the end of the year. If the decision is to go ahead, it could take a decade to implement.

Some individuals in New Zealand are already screened for bowel cancer, particularly those with a genetic susceptibility or family history of it.

Each year around 2600 people are diagnosed with the disease and 1100 die, making it New Zealand's second-biggest cancer killer in total after lung cancer, although prostate cancer kills more men and breast cancer more women than bowel cancer.

Cardiovascular disease, mainly heart disease and stroke, remains the country's main cause of death.

Bowel cancer screening generally involves testing the faeces of patients for the presence of blood.

Those diagnosed early tend to have a better outlook and overseas trials have shown that bowel cancer screening can prevent 10 to 15 per cent of deaths from the disease.

The cervical cancer death rate in New Zealand has declined by about 50 per cent since mass cervical screening started in 1991 and the breast screening scheme is expected to reduce the breast cancer death rate by about 25 per cent.

The faecal-blood tests in the bowel-screening trials picked up only about half of the cancer cases, and 2 to 4 per cent of those screened received a falsely positive result, leading to extra, unnecessary investigations. Those who test positive are referred for tests such as colonoscopy. Rarely, patients suffer major complications from colonoscopy, such as bowel perforation.

The health committee said a programme based on two-yearly screening for those aged 50 to 74 would cost more than $20 million a year. It was uncertain if New Zealand could achieve even the modest mortality reduction found in the overseas trials as many things were unknown, such as the likely participation rate and the ability to meet the increased demand for colonoscopy.

The Clinical Oncology Group's chairman, Dr Peter Dady, a Wellington cancer specialist, said screening would potentially be "very useful", but many developments would be needed first, including increasing the number of doctors able to perform colonoscopies. Otago University cancer researcher Dr Brian Cox said better options might emerge, such as a CT scan.


BOWEL CANCER


1st - New Zealand has the highest bowel cancer rate in the world.


2nd - Highest cause of cancer deaths, behind lung cancer.


2600 Cases are diagnosed each year.


1100 People are killed by bowel cancer each year.


10 to 15 Per cent of bowel cancer deaths were prevented among those in overseas trials of mass screening.


512 Estimated lives could be saved over an 8-year period in New Zealand by screening.