COVID-19 and Cancer Patients: Risk Is With Recent Treatment

For people with cancer and the clinicians who take care of them, the early days of the COVID-19 pandemic were frightening. Concern that cancer patients might be especially vulnerable to the severe cases of the new disease ran high, partly because cancer patients often have compromised immune systems.

But research since has painted a nuanced picture. Some of the early concerns that all cancer patients would be at higher risk of suffering a serious case of COVID-19 have been allayed. But it’s hardly a carefree situation, either. Several large studies have found that recently treated cancer patients — what recent means varies with the study — are more likely to experience a severe case of COVID-19 and death from the disease than people without cancer.

Results of a large study reported last week JAMA Oncology add to that evidence and elaborate upon it. Mariana Chavez-MacGregor, M.D., M.Sc., a researcher at the MD Anderson Cancer Center in Houston, and her colleagues found that cancer patients with no recent treatment (treatment within three months of their COVID-19 diagnosis) had similar and sometimes better outcomes when they contracted COVID-19 than patients without cancer histories who contracted COVID-19. They also found that the type of cancer treatment made a difference in the severity of the COVID-19 outcomes. Chemotherapy and chemoimmunotherapy were associated with adverse COVID-19 outcomes (mortality, hospitalization, ICU care) but immunotherapy, targeted therapy and endocrine therapy were not (with the exception of mechanical ventilation. Chavez-MacGregor and her colleagues offered two possible explanations: the immunosuppressive effects of chemotherapy make patients more vulnerable to experiencing a severe case of COVID-19 or the patients treated with other types of treatment (they only specifically mention endocrine treatment) are a healthier population that can fight off the COVID-19’s worst effects.

The study is impressive partly because it includes so many patients. With access to Optum de-identified database of electronic health records, the researchers compared more than 490,000 COVID-19 patients without cancer to nearly 10,000 with a cancer diagnosis to about 4,200 who had been recently treated.

In a rough first cut of the data, patients with cancer, regardless of when they received treatment, were more likely to experience a serious case of COVID-19 — and death from the disease — than patients without cancer. But after statistical adjustments for other risk factors, that difference disappeared except for patients who had been recently treated.

Chavez-MacGregor and her colleagues also parsed the data by tumor type: Patients with metastatic solid tumors and hematologic cancers fared worse than with solid tumors.

The MD Anderson researchers said their results are consistent with those reported from the National COVID Cohort Collaborative in June in the Journal of Clinical Oncology. That study, which included almost 400,000 adult cancer patients found a relationship between recent chemotherapy and increased risk of mortality from COVID-19 but no increased risk among those treated with immunotherapy and targeted therapy