A large UK analysis has found no link between active anti-cancer treatment and deaths in patients with haematological cancer and COVID-19.
However the study did confirm previous findings that people with haematological cancers have poor COVID-19 outcomes regardless of therapy.
The evaluation done as part of the UK Coronavirus Cancer Monitoring Project looked at COVID outcome data from more than 2,500 patients with a range of solid tumours and haematological cancers who were receiving active treatment.
It found that overall there was no excess mortality from COVID associated with recent chemotherapy, and similarly no excess deaths for patients who received immunotherapy (mostly checkpoint inhibitors), hormonal therapy, targeted therapy, radiotherapy, or surgery within four weeks of COVID-19 diagnosis.
However the study did show an association between higher mortality in patients with some haematological malignant neoplasms irrespective of recent treatment, particularly in those with acute leukaemias or myelodysplastic syndrome (OR, 2.16; 95% CI, 1.30-3.60) and myeloma or plasmacytoma (OR, 1.53; 95% CI, 1.04-2.26).
The only solid tumour with an increased risk of higher COVID-19-related mortality was lung cancer (OR, 1.58; 95% CI, 1.11-2.25), the researchers reported in JAMA Network Open.
The prospective cohort study was conducted at 69 UK cancer hospitals from August 2020 onwards, among adult patients with an active cancer and a clinical diagnosis of COVID-19.
The finding of an association between higher mortality and haematological cancers was consistent with data that had come from UK primary care, the research team said.
“The COVID-19 immunological signature and post-viral clearance immune state of patients with solid cancer is similar to the signature of people with COVID-19 infection but without cancer,” they wrote.
“In contrast, patients with haematological cancer and COVID-19 have much less immune activation, high levels of CD8+ T-cell exhaustion, severe B cell cytopenia and inconsistent antibody responses,” they pointed out.
One notable finding was an association between higher mortality and immunomodulatory drugs lenalidomide, thalidomide, and pomalidomide, used to treat patients with myeloma. The researchers said these patients are known to have increased mortality following COVID-19 infection.
A novel finding was an association between lower mortality and having received immunotherapy in the four weeks before COVID-19 diagnosis (immunotherapy vs no cancer therapy: OR, 0.52; 95% CI, 0.31-0.86). The analysis was also the first to show significant associations between treatment with checkpoint inhibitors which are used in melanoma as well as lung and renal cancer and lower mortality and less severe COVID-19 symptoms, the study authors noted.
The higher COVID mortality seen in patients with lung cancer may be because it often occurs in the setting of chronic tobacco smoke–mediated damage and reduced respiratory reserve, the researchers suggested.
Commenting on the findings, Professor Adele Field, professor of haematology at the UCL Cancer Institute, London, noted that the number of patients with each type of blood cancer included was small and did not allow for much detailed subgroup analysis. It was also likely that being of an older age compounded the risk of having a blood cancer, she said.
“Importantly, the study was conducted on unvaccinated patients – as such, it is unknown whether the findings are applicable to patients with more recent diagnoses of blood cancer who may already have robust immunity to COVID at the time of diagnosis.”