Investigators have found that patients undergoing treatment for cancer who have comorbidities, metastatic solid or non–B-cell hematologic malignancies, and those living in areas with lower levels of education and higher levels of unemployment may have lower rates of COVID-19 vaccination, according to a new study published by Kurbegov et al in Cancer.

“The results of this study underscore the critical need for targeted efforts to increase COVID-19 vaccine uptake among [patients with] cancer who fall into these lower vaccination rate categories and are at an increased risk for infection and severe outcomes [because of] their cancer diagnosis and treatment,” explained study author Julie R. Gralow, MD, FACP, FASCO, Chief Medical Officer and Executive Vice President of ASCO. “The findings … serve as a call to action to address disparities in vaccine uptake among vulnerable populations to improve outcomes of patients with cancer and COVID-19 [infections],” she added. 

Study Methods and Results

In the new large-scale study, the investigators used the ASCO Survey on COVID-19 in Oncology Registry to analyze the data of 1,155 patients from 56 clinics who were undergoing cancer treatment, developed a COVID-19 infection prior to the availability of vaccines, and had vaccination information in the registry.  

Among the patients involved in the study, the median age of COVID-19 infection was 64 years of age, and 41% of patients had at least one additional comorbidity besides cancer—including diabetes, pulmonary disease, renal disease, and coronary artery disease. Those who had one or more additional comorbidities were approximately 20% less likely to be vaccinated than patients without any comorbidities. Among the study participants, 9% (n = 109) were Hispanic, 2% (n = 24) were Asian, 12% (n = 138) were Black, 71% (n = 818) were White, and 6% (n = 65) did not disclose their race or ethnicity or identified as “other.”

The investigators also found that compared with individuals in the general population, patients who participated in the new study were more likely to be vaccinated against the COVID-19 infection between June 1, 2021 and August 1, 2021. By mid-April 2021—about 100 days after vaccines were available for patients with cancer—50% of the participants had received at least one vaccine. The investigators found that the timing of vaccine receipt did not differ significantly between groups based on race and ethnicity; by April 1, 2021, 42% of Hispanic patients, 39% of Asian patients, 41% of Black patients, 47% of White patients had received a vaccine.

The investigators noted that 40% of patients had nonmetastatic solid tumors, 34% had metastatic solid tumors, 20% had B-cell malignancies, and 6% had non–B-cell hematologic malignancies. The vaccination rates were approximately 15% lower among patients with metastatic solid tumors than among patients with nonmetastatic tumors, and approximately 30% lower among patients with non-B-cell hematologic malignancies than among patients with nonmetastatic tumors. The investigators emphasized that researchers are still debating the optimal timing for effective vaccination in patients receiving chemotherapy. Moreover, they noted, the lack of consensus may have had an impact on this patient population’s vaccination rates. 

Additionally, patients with cancer over 50 years of age received vaccinations at higher rates than those of younger ages in early 2021. The differences in vaccination rates by age diminished by May 2021.

The investigators also found that patients living in areas with the highest unemployment rates—where unemployment was at 1.6%—had vaccination rates approximately 20% lower than those living in areas with lower unemployment rates. Further, patients living in areas with the lowest levels of education—where 41% of individuals did not pursue education beyond high school—had approximately 30% lower rates of vaccination than those living in areas with lower levels of high school–only education.

Conclusions

“These patients with cancer were in active care and likely regularly in touch with their health-care teams. [These disparities] highlight the opportunity for cancer care teams to educate patients—particularly those at higher risk—about the COVID-19 [infection] and the importance of vaccination,” highlighted Dr. Gralow. 

The researchers concluded that additional research may be needed to further explore the factors contributing to the disparities seen and identify more targeted solutions to address them.  

Disclosure: The research in this study was funded by Conquer Cancer, the ASCO Foundation. For full disclosures of the study authors visit acsjournals.onlinelibrary.wiley.com.