These and other findings suggest against the continuation of precautionary policies employed early in the pandemic, which advised many cancer patients to stay at home —a major factor for why many patients experienced treatment interruptions. “I think the initial precautionary measures were good because we didn’t have any data in support of one process vs the other, but now they have to be rethought,” Dr Pinato noted.
The findings may also help quell some concerns that the cancer treatment itself will contribute to worse outcomes — due to their immunosuppressive effects — should SARS-CoV-2 infection occur. Though that question is difficult to answer from retrospective studies alone, so far, Dr Pinato said, “the evidence there is reassuring.”
Dr Pinato was involved with a recent study of nearly 900 SARS-CoV-2–infected cancer patients. That patient cohort had an average mortality rate of 33.6%.1 The study, which predominantly focused on hospitalized patients, also reported that continued chemotherapy and immunotherapy treatment had little effect on the severity of COVID-19 and survival rates, Dr Pinato noted. Notably, nosocomial transmission was associated with higher mortality rates. “A lot of patients . . . didn’t have COVID as the main cause of admission, but got it when they were in hospital, and those were the ones [who] had higher mortality,” he said.
Interestingly, a recent analysis of 435 cancer patients with COVID-19 in Europe suggested that the high mortality and poorer clinical outcomes seen in those patients was due to risk factors such as age and underlying comorbidities rather than the cancer itself, according to data presented at the European Society of Clinical Microbiology and Infectious Diseases’ September 2020 conference on coronavirus disease.4 That study — which estimated a mortality rate of 23% — included a high percentage of hospitalized patients, and patients from general practices were underrepresented. Those findings were also in line with the results from Dr Pinato’s study.
Hempel posited several possible explanations for the high proportion of asymptomatic outpatients in her study, which appeared to be higher than that expected in the general population. Across the board, it is thought that approximately 40% to 45% of individuals who are infected with the virus are asymptomatic, Dr Fauci noted during ESMO. (That said, further studies are needed to determine whether the rate of asymptomatic SARS-CoV-2 carriers is lower among cancer patients than the general population, Hempel cautioned.)
It’s possible that immunosuppressive treatments such as chemotherapies may have a protective effect by dampening the exuberant immune reactions that are thought to lead to more severe forms of COVID-19, Hempel said. Perhaps chemotherapy may delete immunological memory for particular antigens that would normally encourage cross-reactions upon SARS-CoV-2 infection and predispose patients to severe disease.