Few gains in testing for cancer at age 40

Extending New Zealand's breast cancer screening programme to women as young as 40 is not a "good choice" based on current evidence, say a group of public health doctors.

Dr Simon Baker, a public health doctor for the National Screening Unit, said an analysis of the latest research from a major trial in Britain showed the benefits of screening women from age 40 were less than previously thought.

But he said younger women were often the focus of media publicity and studies had shown they overestimated their risk of getting breast cancer and of dying from it.

Many were unaware of the risks associated with breast screening.

The New Zealand Breast Cancer Foundation, which launches Breast Cancer Awareness month today, recommends that women aged 40-plus have regular mammograms.

Petitioners have also lobbied the Government to extend state-funded screening to 40.

Breast cancer is the leading cause of cancer deaths for women in New Zealand.

Each year about 2200 women develop the disease and 640 die from it.

The chances of getting breast cancer in women aged 40-44 are one in 820, compared with one in 300 for women aged 60-64.

In February last year, Health Minister Annette King extended free breast screening to women aged 45 to 69, saying it could potentially save a further 32 lives a year.

Lowering the age further would be considered once the results of the British study were released, she said.

Previously the programme, BreastScreen Aotearoa, offered a free mammogram every two years to women aged 50 to 64.

Last year's change meant another 216,000 women were eligible on top of the 328,000 who already qualified. In the year to June, 34,230 of the newly eligible women were screened but capacity constraints and workforce shortages meant priority was given to women aged 50-69 already enrolled on the programme.

Dr Baker, a speaker at a Screening Symposium in Wellington next week, acknowledged some people might think the ministry simply wanted to save money by not extending the programme but he said breast screening for women aged 40 to 45 wasn't "good value for money on top of everything else stacked against it".

Fewer cancers were detected and more women had false positive tests, meaning they had to go through unnecessary extra tests and procedures.

Dr Baker said screening at an earlier age also meant there was a greater possibility of picking up cancers that would have never caused problems in a woman's lifetime, and a greater risk of radiation-induced cancers. Breast cancer in younger women was often more aggressive and spread before a mammogram could pick it up.