Recently diagnosed cancer patients are more vulnerable to Covid-19 infection and face more severe illness than people without cancer, a risk that is significantly higher for Black people than for white people with both diseases, a large new analysis concludes.
Deploying artificial intelligence to comb through 73 million Americans’ electronic health records, researchers discovered that people who learned they had leukemia, non-Hodgkin lymphoma, or lung cancer in the past year were at the greatest risk for Covid-19 infection compared to those without cancer or those whose cancers had been diagnosed longer ago. For Black people with cancer, the risk of Covid-19 infection was highest in patients who had breast, prostate, colorectal, or lung cancer.
“The important differentiating factor was that African Americans with cancer were more susceptible to Covid-19 infection than Caucasians,” said Nathan Berger, a medical oncologist and professor at Case Western Reserve University School of Medicine. He is a co-author of the study published Thursday in JAMA Oncology.
Black people were more likely than white people to be hospitalized for cancer alone, Covid-19 alone, or both diseases. The difference in death rates did not reach statistical significance — 18.5% for Black patients vs. 13.5% for white patients — but the analysis was limited by small numbers — 100 of 670 patients with Covid-19 and cancer died, 50 Black and 50 white — an editorial appearing with the paper said.
Recent research has found that death rates inside hospitals are similar, but death rates outside hospitals are disproportionately higher among Black people.
The combined cancer-Covid-19 risk was higher than adding numbers for the two diseases together. In all patients, “The combination of the virus and cancer is synergistic and leading to mortality. The death rates are much higher than they are for either of the diseases alone,” Berger said.
The reasons for leukemia, lymphoma, and lung patients being more susceptible to Covid-19 can likely be explained by the biology of those malignancies. Blood cancers such as leukemia and lymphoma arise when immune cells fail to function as they should, so impaired defenses could open the door to a viral infection. While Covid-19 ultimately affects multiple organ systems in the body, it is primarily a pulmonary disease attacking the lungs, so lungs damaged by cancer would be more vulnerable to Covid-19.
The amount of time since cancer diagnosis may contribute to risk of infection because people with lower immunity beginning cancer treatment have more potential exposures than other cancer patients. Newer cancer patients might see more people in hospitals or doctors’ offices, especially health care workers during the pandemic’s first months, when PPE was not recognized as essential or wasn’t available.
The reasons why Black people with Covid-19 and cancer had a greater risk of being hospitalized — 55.6% for Black patients vs. 43.2% for white patients — are probably societal, Berger said, although the study was not able to discern those factors. Societal inequities have loomed as large as medical comorbidities since the pandemic began: lower income, less opportunity to work remotely, crowded housing, poorer access to health care.
The study did account for comorbidities that put people at higher risk for worse Covid-19 illness: obesity, high blood pressure, diabetes, asthma. When those factors were taken out of the equation, Black people still had a higher risk of being infected: 32.5% vs. 19.1% for white people.
Robert Carlson, chief executive officer of the National Comprehensive Cancer Network, said he was surprised by how much more vulnerable cancer patients were to Covid-19, in contrast to reports from earlier in the pandemic suggesting there was no substantially greater risk.
“The part that doesn’t surprise me is the disparity in outcomes between African Americans and whites,” said Carlson, who was not involved in the study. “We see that consistently across our health care system. The magnitude of the differences is pretty big. And it’s also consistent.”
A recent study reinforces the idea that racial disparities in Covid-19 stem from different levels of exposure to the virus. Gbenga Ogedegbe, the director of the division of health and behavior at New York University’s Grossman School of Medicine, led a study analyzing the health records of nearly 12,000 patients admitted to NYU’s Langone Health system during the March pandemic surge. That research, published Dec. 4 in JAMA Network Open, found that Black people had higher rates of infection and hospitalizations but in-hospital death rates were lower or comparable to those in white people. Death rates outside hospitals are disproportionately higher among Black people.
“The higher rates of mortality in Blacks are not due to inherent immunity or biology or comorbidity like cancer but due to exposure and other factors driven by structural inequities,” Ogedegbe said about the new paper based on national data, saying it confirmed his research and other studies. He was not involved in the new paper.
“The disparities noted are driven by exposure, access to care, and other social deprivation factors that are pervasive in Black communities,” he said. “I might add that this unfortunate Covid-19 pandemic has again revealed what we have known for a while: that your ZIP code is a better predictor of your life expectancy than your genetic code.”
Using the AI tool IBM Watson Health Explorys to parse electronic health records allowed the Case Western researchers to cast a wider net and include people who may not be seen in more traditional clinical trials, Berger pointed out.
“I don’t know if this is systemic racism, but part of the problem of doing clinical studies in this country is that studies are usually underpowered for underrepresented [groups] that for one reason or another, they’re not being included,” Berger said. “So when you’re talking about 73 million patients, you’re talking about a lot of underrepresented minorities.”
Carslon praised the speed of the AI analysis bringing these results to light now.
“I think we are quite frustrated by the lack of urgency in terms of addressing disparities,” he said, suggesting the pandemic could be “a tipping point, the crucial moment in history where perhaps we can start addressing this in a meaningful way.”
For now, Berger suggests doctors treating cancer should redouble their efforts to limit patients’ exposures to potentially infectious people in waiting rooms and consider oral medications that can be taken at home as opposed to drugs that must be infused in hospitals or clinics.
Doctors also urge patients to seek medical care for themselves or their children without delay, noting safety measures now in place prevent infection in doctors’ offices and hospitals.
Berger has one other piece of advice:
“Everybody should get vaccinated.”
That could be particularly important for cancer patients. Memorial Sloan Kettering Cancer Center, among others, recommends vaccination against Covid-19. “Although cancer treatment may reduce the effectiveness of vaccines, we believe the COVID-19 vaccine is safe and could offer important protection for cancer patients, who may be at higher risk for complications from Covid-19.”