30th April 2020
Dr Jonine Figueroa, Cancer Epidemiologist at the University of Edinburgh analysis of the latest death registration data in Scotland and looks at excess COVID-related mortality in cancer patients
It’s a stressful time for everyone during the Covid-19 pandemic, but the stresses may be heightened for people living with cancer, who have been reported to be particularly vulnerable to harm from Covid-19. Population specific data is needed to help us better understand these specific vulnerabilities and how cancer care should be modified to protect patients. However, there is growing concern that the lockdown in the UK aimed at reducing virus transmission to allow the NHS to cope with the number of patients with severe Covid-19 disease may be having unintentional adverse impacts for many different patients with comorbidities, including cancer patients.
An interesting analysis from the UK DataCan team reported that there could be an excess of 20% in cancer related deaths because of the Covid-19 pandemic. Understanding the trends in deaths for different diseases during the pandemic are important, to allow, policymakers, public health officials, clinicians and the public at large to understand the effect of COVID-19 on the whole population and whether there are excess deaths beyond what is normally expected. A great strength in Scotland is the high-quality process for the registrations of deaths, including cause of death, which are reported weekly by National Records Scotland (NRS) here. As recently as August of last year, the Royal Statistics Society has been highlighting the need for accurate and timely death registrations in England and Wales. Before the COVID-19 pandemic, when deaths were referred to the coroner for investigation in England, Wales and Northern Ireland, the fact of death is many times not registered until the inquest has determined cause-of-death, meaning deaths are not registered until weeks, months or even years later. This is not the case in Scotland where there is more detail in weekly reported deaths.
Using the most recent report from National Records Scotland (NRS) on 29 April 2020, we wanted to know if there was an excess in cancer deaths above what is normally observed in Scotland over the last five years. To determine if trends were similar or different, we also looked at the trends in cardiovascular disease deaths, another community where there is great concern that there may be effects on mortality.
Below are two figures—the left panel focusing on cancer deaths registered in Scotland compared to the 5-year average of similar times and weekly deaths starting 30 December 2020. During this time there seems to have been a peak in excess deaths between weeks 13-14, about five weeks after the first case in Scotland was detected on 1 March 2020. Why there is an excess at this time remains unknown. It is interesting to note when reviewing the data in the right panel when we look at the 4-week moving average of cancer and cardiovascular disease deaths, there is a similar trend in both conditions of increasing excess deaths after the first Covid-19 case was registered in Scotland at week 10, but these excesses seem to have declined after week 14 when the lockdown began.
There are some important caveats to these observations. There are a number of “other” deaths currently reported by NRS, where the cause of death is not given, which is currently higher for recent weeks because some deaths require a post mortem to determine their cause which generally takes a short time); others require an inquest (which can take much longer). Hence some of “OTHER” deaths reported by NRS will change and get redistributed to specific causes, some of which may be cancer deaths. However, the general trend seems clear. In the short term there may have been an increase of around 20% in cancer related deaths during the pandemic, but this seems to have subsided since lockdown began on 23 March 2020.
These data support the mitigation measures to avoid unintentional consequences to cancer patients from COVID-19. These types of data need to be continually monitored to determine if trends change, especially when lockdowns are lessened and whether we see excesses go beyond what is normally expected. Incidence of cancer will undoubtedly be impacted especially in the short term with cancer screening services halted, but whether this causes an excess in deaths will require more longer term and detailed linkage studies as cancer is an amalgamation of many different diseases with different outcomes in mortality. Understanding the direct and indirect impacts of the Covid-19 pandemic, the changes to cancer services and cancer mortality will need consistent monitoring for the foreseeable future as different measures and changes take place. For now, it’s important for cancer patients and all the public to know that while Covid-19 is a public health crisis, if they feel unwell or need advice to make sure they remember the NHS is still open for business beyond Covid-19 to make sure we care for all our populations health needs including diagnosing and treating cancer.
Dr Jonine Figueroa, Chancellor’s Fellow, University of Edinburgh and Senior Analyst, Edinburgh Cancer Informatics Programme