Cancer survival – new international study and local stats

A large study released today in the Lancet medical journal compares cancer survival rates in several countries, with good news for Australia, Canada and Sweden, and less favourable findings for the UK and Denmark.

The study focused on four types of cancer — lung, breast, colorectal and ovarian — finding that one- and five-year relative survival rates in the UK and Denmark lag consistently behind those in the countries mentioned above. Researchers involved in the study argue that this means thousands of avoidable deaths are occurring each year, and action is required to close the “survival gap”.

Yesterday, the Ministry of Health released updated cancer survival statistics for New Zealand for twenty-four types of cancer, collected over a similar time period to the international study.

For the four types of cancer above, these stats show survival rates that fall broadly within the range found overseas (though there are important differences in the way these data sets were collected and analysed).

Both sets of data show that, overall, cancer survival is improving over time.

Australian expert reaction to the international study (gathered by our colleagues at the AusSMC) can be found here.

Matthew Soeberg – Assistant Research Fellow, University of Otago, Wellington comments:

“The report released by the Ministry of Health shows that there have been good improvements over time for most cancers and this is encouraging. There are still substantial differences by ethnic group and socioeconomic group and that we must continue to monitor and commit to reducing these disparities.

“A strength of the international studies comparing cancer survival rates between countries is the standard approach used for data collection and analysis. New Zealand is not yet part of these studies so it is difficult to make direct comparisons between the survival rates from these studies and the ones recently published by the Ministry of Health. The introduction of cancer detection technology such as PSA testing to detect prostate cancer can also make it more complex to interpret cancer survival rates over time.

“Cancer survival statistics like the ones published this week were not available at the time that New Zealand developed its cancer control strategy. This is different from a country like Engliand where there has been a more explicit goal in their cancer plans to focus on improving cancer survival rates because of the information obtained from international cancer survival rate comparisons. There is now a number of studies that give us good information about cancer survival rates in New Zealand and the reasons for differences between ethnic and socioeconomic groups. This provides an important opportunity for organisations like the Ministry of Health to refresh the national cancer control strategy based on more up-to-date evidence.

“A study is currently underway in New Zealand to look at ethnic and socioeconomic trends in survival for cancer patients diagnosed between 1989 and 2004 and followed up to 2006. What is unique about this study is that it includes the ability to look at the impact of different factors on cancer survival such as the age of cancer patients, ethnicity, household income, the extent of disease, and the period of diagnosis at the same time. It also uses census data that has been linked to cancer and mortality records which enables accurate time trend analysis. This study is being led by the University of Otago Wellington and is funded by the Health Research Council of New Zealand.”

To follow up with this or other local experts please contact the Science Media Centre on (04) 499 5476 or