Cancer – it’s more than just numbers

Cancer continues to kill more New Zealanders than any other cause of death, even though death rates for the illness have fallen by more than 16 percent since 1999.

Each year the total number of cancer deaths increases – driven by population growth and demographic changes to an older age structure – and a small drop in the total number of deaths between 2008 and 2009 is not thought to be the start of a  trend.

The Ministry of Health (MOH) and the National Health Board set up by the Government in 2009 have this week released statistical information in Cancer: New registrations and deaths 2009  and Cancer: Historical summary 1948 – 2009.

The national clinical director of the MOH cancer programme, Dr Andy Simpson, says earlier diagnosis and better treatment largely explain a 16 percent drop in death rates in the decade since 1999, almost 29 percent of all deaths in New Zealand are still from cancer.

“These statistics show there was a small decrease in the total number of deaths between 2008 and 2009, but it is almost certainly due to natural fluctuations in the data and it is too early to identify the beginning of a trend,” says Dr Simpson.

Lung cancer remains the most common cause of cancer death (18.9 percent), followed by colorectal cancer, then breast and prostate cancers, and 72 percent of all cancer deaths were in people aged over 65.

Media Coverage

New Zealand Herald: Death rate from cancer drops 16 per cent

Otago Daily Times: Cancer mortality rate steadily falling

Radio New Zealand: Cancer leading cause of death

Related Research

Observational studies have highlighted the association between diet and the risk of colorectal cancer recurrence, but a study of  patients at Dunedin and Invercargill hospitals showed that though they were prepared to change diet following diagnosis and treatment they complained of receiving insufficient information.

Outside the statistics just released, Canterbury researchers are looking at the potential for national colonscopy screening, initially 18,000 a year rising to 28,000 by 2031 as the level of surveillance increases: “Significant expansion of services is required,” they say.

Maori continue to have higher cancer mortality rates and though the the Maori cancer mortality rate dropped over the decade by 8.9%,  the non-Maori rate fell by 17.4%.

Separately, Auckland research has raised a question over whether Maori and Pacific Island men present with more advanced prostate cancer than European New Zealand men.

The statistics provide a background for debates on many aspects of cancer treatment in New Zealand, including the role being played by molecular tests and computerised prognostic tools.  For instance,  widespread introduction of prostate-specific antigen (PSA) screening here has enhanced the early detection of prostate cancer, but doctors are having problems with which men are low-risk and which require a definitive diagnostic biopsy.

“In consequence, the decisions surrounding prostate cancer treatment become extremely difficult,” doctors say.

Expanded use of  often-expensive tests such as genetic screening also has economic implications.