In the early days of the COVID-19 pandemic, many doctors worried that people undergoing treatment for cancer would do particularly poorly if they became infected with the virus that causes the disease. That’s because treatments for cancer, especially chemotherapy, can lower a person’s immune defenses and put them at higher risk for all kinds of infections.
But according to a new study from Memorial Sloan Kettering published June 24 in Nature Medicine, most people in active cancer treatment don’t fare any worse if they get COVID-19 than other people who are hospitalized with the infection. Further research is needed to look at the effects of certain drugs — mainly immunotherapies called checkpoint inhibitors, which did seem to make COVID-19 worse. But the researchers say their findings suggest that no one should delay cancer treatment because of concerns about the virus.
“If you’re an oncologist and you’re trying to figure out whether to give patients chemotherapy, or if you’re a patient who needs treatment, these findings should be very reassuring,” says infectious disease specialist Ying Taur, one of the study’s two senior authors.
Comparing People with Cancer to the Broader Population
The study looked at 423 MSK patients diagnosed with COVID-19 between March 10 and April 7, 2020. Overall, 40% were hospitalized for COVID-19, and 20% developed severe respiratory illness. About 9% had to be placed on a mechanical ventilator, and 12% died. The investigators found that patients taking immunotherapy drugs called immune checkpoint inhibitors were more likely to develop severe disease and require hospitalization. But other cancer treatments, including chemotherapy and surgery, did not contribute to worse outcomes.
Factors that did make COVID-19 worse were the same as those seen in studies of people who didn’t have cancer. “We found that being older, as well as preexisting conditions like heart disease and diabetes, are all drivers of severe COVID-19 illness,” says MSK Chief Medical Epidemiologist Mini Kamboj, the study’s other senior author. “This wasn’t surprising because these connections are well established.”Back to top
Surprising Findings about Some Patient Populations
Although the study wasn’t large enough to make determinations about every treatment and every cancer type, patterns did emerge. Dr. Taur says there was initially great concern about people receiving high doses of chemotherapy for leukemia, especially those who had recently undergone bone marrow or stem cell transplants. That’s because transplants require a person’s entire immune system to be wiped out with chemotherapy before they receive new blood cells, leaving them susceptible to all kinds of infections.
Surprisingly, though, Dr. Taur cared for recent transplant recipients who were infected with COVID-19 but didn’t have any symptoms. “If you think about it more, it makes sense,” he says. “Most of the complications seen in people with COVID-19 seem to be caused by the body’s immune response to the virus.”
On the other hand, immunotherapy drugs called checkpoint inhibitors work by freeing up the immune system to attack cancer. Patients receiving these agents may develop a more robust reaction to the virus that causes COVID-19. This may explain why this study observed higher rates of complications in people with COVID-19 infection who were treated with checkpoint inhibitors.
“Even with immune checkpoint inhibitors, though, these findings should not affect whether patients get treated. Everyone who needs these drugs should still receive them,” Dr. Kamboj says. “It’s just important for doctors to be extra vigilant about testing and monitoring for the virus and for people with cancer to take extra precautions to avoid infection.”
A study published in May 2020 by MSK immunotherapy expert Matthew Hellmann focused exclusively on people with lung cancer who got COVID-19. The researchers didn’t find the same risks from immune checkpoint drugs as this Nature Medicine study. More research in this area is needed.Back to top
A Growing Field of Research
Dr. Kamboj notes that one aspect of this research that sets it apart from other studies is that it included at least 30 days of follow-up after a COVID-19 diagnosis. Also, it reported severe respiratory illness as a main outcome rather than death.
“Having that follow-up time is something that a lot of other studies have not included because everyone is in a rush to get their data out. In addition, reporting death rates can overestimate infection-related mortality, especially in the early phase of an epidemic,” Dr. Kamboj says. “Also, the clinical spectrum and course of this disease is still not fully understood, especially in people with cancer. We wanted to give patients enough time to recover and make sure they didn’t need to be readmitted to the hospital.”
She adds that another strength of the study is that patient outcomes were not affected by constraints caused by a lack of space or supplies — even though MSK is in the heart of the COVID-19 epicenter in New York City, where other hospitals faced overcrowding and other issues. This gave researchers a true picture of how cancer patients fare with COVID-19. “We saw a surge during the peak of the epidemic in New York, but everyone got the care they needed,” Dr. Kamboj explains. “We had enough ventilators for everyone who needed them. We never had to make decisions about who to admit to intensive care because of a lack of critical equipment.”
Drs. Taur and Kamboj agree that this is just one of many studies that will need to be done on the connections between cancer and COVID-19. “We still need to find out more. We need to look at the connections between COVID-19 and particular types of cancer as well as outcomes related to specific chemotherapy drugs,” Dr. Taur concludes. “But the big message now is clear: People should stay vigilant but not stop or postpone checkpoint immunotherapy or any other cancer treatment.”Back to top