medwireNews: Having a high prevalence of chronic conditions associated with severe COVID-19 and an increased risk for influenza hospitalization or death may indicate that cancer survivors are at increased risk poor COVID-19 outcomes, UK study data suggest.
Helena Carreira (London School of Hygiene and Tropical Medicine) and co-investigators say that these factors “should be taken into account in policies targeted at clinical risk groups, and vaccination for both influenza, and, when available, COVID-19, should be encouraged in cancer survivors.”
The researchers carried out their study to address the lack of evidence “to inform policy around managing COVID-19 related risks in cancer survivors” when compared with that available for people undergoing active cancer treatment.
They used English national databases to identify 108,215 survivors (≥1 year after diagnosis) of the 20 most common cancers and 523,541 age-, sex-, and general practice-matched cancer-free controls.
Carreira and team found that the majority of comorbidities thought to be associated with poor COVID-19 outcomes were more common in the cancer survivors than the cancer-free controls, but the prevalence varied by cancer site.
In general, cancer survivors had significantly higher rates of diabetes, asthma, and other respiratory disease, as well as more chronic heart, liver, and renal disease, and neurologic conditions, than controls.
Conversely, the cancer survivors were less likely to be obese than controls.
The investigators also looked at the risk for severe influenza in the cohort, using this as a marker of susceptibility to severe outcomes from epidemic respiratory viruses.
They found that during a median 5 to 6 years of follow-up, there were 190 influenza hospitalizations and 15 influenza deaths overall.
After adjustment for baseline demographics, deprivation, smoking, and risk factors distribution, the cancer survivors had a significant 2.78-fold higher risk for influenza hospitalization or death than the controls.
The risk was substantially higher, with a hazard ratio of 15.17, among individuals with hematologic malignancies and varied with time since diagnosis.
For the people with hematologic malignancies, the risk for influenza hospitalization or death was a significant 29.56-fold higher than for controls during years 1–4 postdiagnosis, 9.56-fold higher during years 5–9, and still 10.06-fold higher 10 or more years after diagnosis.
By comparison, individuals with nonhematologic malignancies had a significant 2.22-fold increased risk for poor influenza outcomes versus controls up to 5 years from diagnosis, but no significantly increased risk thereafter.
Writing in EClinicalMedicine, the authors conclude: “The high prevalence of several established COVID-19 risk factors in cancer survivors, and the increased risk of influenza hospitalisation and death in survivors of haematological cancers even many years from diagnosis, and in survivors from other cancers in the first five years of survivorship, indicate a likely increased risk of severe COVID-19 outcomes in these patient groups.”
They add: “These findings suggest that cancer survivorship should be considered a potentially important risk factor for severe COVID-19 outcomes in public health policy.”
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