More than one quarter of patients with haematologic malignancies who contract a COVID-19 infection die, according to global data presented at the ASH 2020 Annual Meeting.
“Haematologic diseases often induce underlying immune dysregulation or dysfunction,” said Dr William Wood, of the University of North Carolina, who presented the new results.
“Patients with haematologic malignancies are often of advanced age, and have comorbidities related to ageing, underlying haematologic disease, or disease-directed treatments.”
The ASH Research Collaborative Data Hub is an ongoing repository, and Dr Wood encouraged clinicians and institutions from around the world to contribute data. His presentation focused on a total of 656 patients with haematologic malignancies and a COVID-19 infection submitted so far.
Patients were primarily from North America, but many were also from Asia, South America, Europe, and elsewhere. The most common malignancy was leukaemia (57%), followed by lymphoma (25%) and plasma cell malignancies (18%).
The overall rate of mortality among the cohort was 20%. Dr Wood noted that this included patients with outpatient-level COVID-19 infection, representing 38% of the cohort and in whom there were only two deaths.
Among patients who merited hospitalisation or ICU care, the mortality rate was 33%. Specifically among those with ICU-level severity, the mortality rate was 65%.
The severity of COVID-19 was strongly associated with malignancy status at the time of diagnosis, with 69% of those receiving initial cancer treatment suffering from moderate or severe disease, compared with 50% of those in remission and 79% of those with relapsed or refractory cancer.
The mortality rates in the cohort different significantly by prognosis, with 51% mortality in those with a pre-COVID-19 prognosis of less than 12 months. In those with a prognosis longer than 12 months, the mortality rate was 13%. Mortality also varied by malignancy status, and increased with increasing age.
Some patients with haematologic malignancies decided to forego ICU care for COVID-19 infection; this decision was correlated with advanced age and with poorer prognosis. The mortality rate in those who did forego such treatment was 73%, compared with 13% in those who did not decline ICU care.
“Patients with haematologic malignancies are at increased risk for adverse COVID-19 outcomes and could thus be considered a medically vulnerable population,” Dr Wood concluded.
“Risks are greatest in those who are older, have advanced disease or limited prognosis, and forego intensive management. However, risks are not trivial for others.”
During an ASH press briefing, Dr Wood added that the results do show that many patients who do receive ICU-level care survive, suggesting that the most intensive therapy is appropriate for this population.
Dr John Riches, a clinical senior lecturer at Bart’s Cancer Centre, has been involved with studies of haematologic malignancies and COVID-19 outcomes in the UK. He noted that their results showed a higher mortality rate than the ASH study, of about 30% in total, but issues with the baseline population and who received COVID-19 testing early in the pandemic made this difficult to interpret.
“There is going to be a huge number of people that have very mild symptoms, or who may be completely asymptomatic, who we’re not picking up,” which would skew the mortality rate, he told the limbic.
Dr Riches noted that one important point to arise from the UK studies was that chemotherapy treatment did not necessarily appear to exacerbate COVID-19 infections.
“The problem with chemotherapy is not that chemotherapy weakens your immune system and you’re more likely to get a bad outcome from the virus, the problem with chemotherapy is that it probably increases your number of hospital attendances,” he said. “So you increase your risk of getting the virus, not a bad outcome from it.”