COVID-19 related risks in cancer survivors: a matched cohort study using linked UK electronic health records data

Date of ISAC Approval: 
20/04/2020
Lay Summary: 
Older individuals and people with certain underlying health conditions are known to be at higher risk of having severe disease if they contract the novel COVID-19. People who had certain cancers diagnosed recently and are receiving treatments like chemotherapy are among those known to be at high risk, because some cancers and treatments weaken the immune system. But it is not known whether people who had cancer some time ago and have likely finished their cancer treatments are at higher risk if they catch the virus. This study will investigate this in two ways, using data from routinely collected health records. First, we will look at how common known risk factors for severe COVID-19, such as heart disease and respiratory disease, are in cancer survivors compared to people who have never had cancer. Second, we will investigate whether cancer survivors are more likely than people who have never had cancer to get severe influenza requiring hospitalisation, or leading to death. The second approach is based on the fact that there is likely substantial overlap between people at high risk of severe influenza, and people at high risk of severe COVID-19. Indeed, because COVID-19 is completely new, public health organisations have had to base many of their decisions about how to handle the disease on evidence from influenza. Our study will add to the evidence informing public health organisations and government whether cancer survivors need to be considered high-risk as policies such as isolation and social distancing evolve.
Technical Summary: 
Older individuals and people with certain underlying health conditions are known to be at higher risk of having severe disease if they contract the novel COVID-19. People receiving active treatment for certain cancers (including lung, haematological) are among those considered high risk. But it is not known whether medium to long-term cancer survivors are at higher risk of severe outcomes if they catch the virus. This study will investigate this using linked primary care, hospital, cancer registration and death certificate data. We will analyse a cohort of 1-year cancer survivors, matched to controls with no history of cancer. First, we will look at how common known risk factors for severe COVID-19, such as heart disease and respiratory disease, are in cancer survivors compared to people who have never had cancer. Second, we will conduct a time-to-event analysis to investigate whether cancer survivors are more likely than people who have never had cancer to be hospitalised or die from influenza. The second approach is based on the fact that there is likely substantial overlap between people at high risk of severe influenza, and people at high risk of severe COVID-19. Indeed, because COVID-19 is completely new, public health organisations have had to base many of their decisions about how to handle the disease on evidence from influenza. Our study will add to the evidence informing public health organisations and government whether cancer survivors need to be considered high-risk as policies such as isolation and social distancing evolve.
Health Outcomes to be Measured: 
Aim 1: Prevalences of factors currently recognised as associated with high risk for severe COVID-19 outcomes by the UK government and Public Health England. Aim 2: The primary outcome is influenza hospitalisation or mortality (composite outcome).
Collaborators: 

Krishnan Bhaskaran - Chief Investigator - London School of Hygiene and Tropical Medicine (LSHTM)
Helen Strongman - Collaborator - London School of Hygiene and Tropical Medicine (LSHTM)
Helen Carreira - Collaborator - London School of Hygiene and Tropical Medicine (LSHTM)
Isabel dos-Santos-Silva - Collaborator - London School of Hygiene and Tropical Medicine (LSHTM)
Krishnan Bhaskaran - Corresponding Applicant - London School of Hygiene and Tropical Medicine (LSHTM)
Liam Smeeth - Collaborator - London School of Hygiene and Tropical Medicine (LSHTM)
Susannah Stanway - Collaborator - Royal Marsden Hospital

Linkages: 
Cancer Registration Data;HES Admitted;ONS;Patient IMD