COVID-19 impact on pathological cancer diagnoses in Netherlands, Aotearoa New Zealand, & N. Ireland

The COVID-19 pandemic was managed in Aotearoa New Zealand (NZ) by a COVID-19 elimination policy, involving border closure and an initial national lockdown. This was different to most other countries including Northern Ireland (NI) and the Netherlands (NED). We quantify the effect of these policies on the diagnosis of three major cancers comparing NZ with these two European countries.

Methods
Data from NED, NZ and NI population-based cancer registries were used to assess trends in all pathologically diagnosed (PD) lung, breast, and colorectal cancers from March to December 2020 (COVID period) and compared to the similar pre-pandemic period 2017-2019. Trend data were also collated on COVID-19 cases and deaths per 100,000 in each population.

Results
Comparing the pre-pandemic period to the COVID-19 period there were statistically significant reductions in numbers of lung (↓23%) and colorectal (↓15%) PD cancers in NI and numbers of breast (↓18%) and colorectal cancer (↓18.5%) diagnosed in the NED. In NZ there was no significant change in the number of lung (↑10%) or breast cancers (↑0.2%) but a statistically significant increase in numbers of colorectal cancer diagnosed (↑5%).

Conclusions
The impact of COVID-19 on cancer services was mitigated in NZ as services continued as usual reflecting minimal healthcare disruption and protected cancer services linked with the elimination approach adopted. The reduction in PD cases diagnosed in NED and NI were linked with higher COVID-19 rates and reflect societal restrictions which resulted in delayed patient presentation to primary and secondary care, disruption to screening and healthcare services because of COVID-19 infections on staff and the need to shift intensive care to COVID-19 patients.