As flu season rears its ugly head, new findings suggest that cancers survivors should be extra cautious, as they’re more likely than the general population to land in the hospital or die from the flu, even years after their cancer diagnosis, reports the London School of Hygiene & Tropical Medicine (LSHTM).

For the study, published in the journal EClinicalMedicine, LSHTM researchers analyzed the medical records of more than 630,000 people in the United Kingdom, including over 100,000 cancer survivors. The goal was to compare flu hospitalization rates and the rates of death between cancer survivors and those without cancer.

Findings showed that those who once had lymphoma, leukemia or multiple myeloma were more than nine times as likely to be hospitalized or die from the flu. The risk of hospitalization and death persisted for at least 10 years after a cancer diagnosis. For those with other types of cancer, the risk of severe flu outcomes was double for up to five years from diagnosis.

However, though elevated, the absolute risk of developing severe flu among cancer survivors remains relatively low, the scientists reported. About 1 in 1,000 survivors of these cancers were hospitalized with the flu annually, they found.  

Researchers also focused on severe COVID-19 outcomes for cancer survivors. They found that some survivors are likely to be at greater risk than the general population and have diseases that can further increase their risk of such outcomes. Cancer survivors were more likely to have heart disease, diabetes, respiratory disease and kidney disease. 

Studies have also shown that certain cancers render a person more susceptible to COVID-19. For example, those with lung cancer or blood cancers, such as leukemia and lymphoma, are more likely to have worse COVID-19 outcomes.

According to lead study author Helena Carreira, Msc, PhD, a research fellow at LSHTM, the findings point to the importance of vaccination and other preventive strategies for the much broader population of longer-term cancer survivors.

The flu vaccine is available now, and COVID-19 vaccines will be available to priority populations soon. For related coverage, read “Cancer, Flu, and You” and  “Flu Season Tips for Cancer Patients.” To get the latest on COVID-19 vaccines, click here.