The writer is in New Zealand
HEALTH NZ has released the data for new cancer registrations during 2023. Data by age, sex, cancer type and ethnicity from 2001 to 2023 is now available and can be downloaded using the Cancer Web Tool. These figures are already two years behind so we don’t yet know what has happened in 2024 and 2025.
There are many types of cancer associated with multiple risk factors and causes and care should always be taken when interpreting any data. However the figures show that in 2023 there were a record 29,719 new cancer registrations. This was a rate of 5.69 cancers per 1,000 population compared with 5.27 during 2015 to 2019 of 5.2, a 7.9 per cent increase increased rate of cancer occurrence. There were 4,500 more cancers in 2023 than the average for 2015-2019.
One factor that needs to be taken into account is that NZ has an ageing population. Around 60 per cent of all cancers occur among people who are 65-plus. Therefore there is an expectation that overall cancer rates will increase as the percentage of older people in the whole population increases over time. Between 2015-2019 the average percentage of the NZ population aged 65+ was 15 per cent and in 2023 the equivalent figure was 16.5 per cent.
The conventional wisdom is that increases in rates of cancer incidence are primarily due to the effect of an ageing population along with any modifications due to changes in risk factors. For example any significant increase in smoking rates is known to increase cancer incidence over the longer term. So the question is: ‘Was the 2023 increase in cancer due solely to the effect of a rising and ageing population?’ Have there been any increases in cancer risk factors modifying the data? In order to investigate this question and adjust for the effect of age, the Hatchard Report conducted an analysis of cancer registrations by age bracket.
We looked separately at age ranges 0-4, 5-24, 25-44, 45-64 and 65+.
Cancer rates among the 65+ population remained more or less stable at 21 new cases per 1,000 population in 2023, a rate that has been maintained over the last ten years.
Cancer rates in the 45-64 range rose by 8 per cent in 2023 compared with the 2015-2019 average.
Cancer rates in the 25-44 range rose by 2 per cent.
Cancer rates in the 5-24 range rose by 17 per cent and by 11 per cent for 0-4-year-olds but the numbers of cases in these two age brackets are too small to be statistically significant.
The most notable finding is among mature working-age people aged 45-64. There were 1,215 additional new cancers registered in this age group above the 2015-2019 average and 817 above 2020 (the last year without significant covid infections or covid vaccines). The rate of cancers (7.45 cancers per 1,000 population) was a historical high. The rate of cancers in this age group had been relatively stable in the ten years prior to 2018
Outlier when there was a sudden spike in cancer registrations.
2018 cancer registrations rose due to a cancer screening drive
Prostate is the most common cancer for men and breast for women. From 2015 to 2018 Health NZ instituted the NZ Cancer Plan which aimed to increase the availability of cancer screening. One result of this intensive initiative was a dramatic rise in the number of early prostate diagnoses among mature men and a more modest spike in breast diagnoses which particularly generated a spike in cancer registrations in 2018 in the 45-64 age range. There were no similar new screening initiatives in 2023 for common cancers likely to significantly affect the registration totals. Therefore the 2018 spike in cancer registrations should be regarded as an outlier or anomaly which makes the peak in 2023 cancer registrations all the more significant.
What types of cancer increased?
In 2023 the largest increases among the whole population were breast, melanoma and prostate cancers. The incidence of lung cancer decreased. The 2023 NZ figures do not distinguish what types of cancer particularly affected which age groups. Nor are any figures available for recurrence of cancers or speed of progression of cancers which overseas reports suggest have been significantly affected during the last four years (2022-2025).
Were either covid infection or covid vaccination risk factors for cancer?
We have previously reported on large studies from Korea, Japan and Italy which found relatively higher cancer rates among the covid vaccinated compared with the unvaccinated. It is a matter of regret that Health NZ have so far made no visible effort to find out if covid vaccination has been a risk factor for cancer development here in NZ. This is a serious issue affecting the wellbeing of the whole of society, especially as Health NZ is still recommending many categories of people receive covid booster shots.
The 2023 NZ data which has been released is insufficient on its own to lead to any definitive conclusions. Moreover it is two years out of date. Cancers take time to develop. If there are new risk factors particularly affecting mature working age people, it is not yet clear what these factors are.
Nevertheless, the 2023 NZ cancer data is a red flag which needs immediate investigation, and more rapid compilation of data for 2024 and 2025.
Anecdotal reports we have received indicate that waiting lists to see an oncologist in NZ are becoming longer which makes it likely that the 2023 increases are continuing into 2024 and 2025. It is vital to find out as soon as possible if this is the case. Cancer is our number two killer in NZ, the investigation of its causes demands up to date and comprehensive information. This investigation should include a comparison of cancer outcomes of vaccinated and unvaccinated populations. This should be an urgent public health imperative.
