Today, JAMA Oncology published two studies and a research letter on COVID-19 and cancer, including a retrospective cohort study showing that COVID-19 booster vaccinations offered significant protection against severe infection.
A second study determined risk factors for hospitalization and death in patients with cancer and
COVID-19 infection, and a third research letter describes the pandemic’s effect on breast cancer surveillance and outcomes.
In an editorial on the first two studies, Larry Han, PhD, writes that the new studies help close the gap in knowledge about using vaccines in cancer patients, who are excluded from randomized controlled trials due to their illness.
“Carefully designed observational studies leveraging data from clinical practice are essential to estimating potentially heterogeneous vaccine effects in populations at higher risk for complications,” Han writes.
Booster vaccines offer protection against hospitalization
In the first study, on booster doses and cancer patients, the authors used data from the National Cancer Institute COVID-19 and Cancer Patients Study (NCCAPS), a prospective cohort study of 1,572 adults with cancer and confirmed SARS-CoV-2 infection.
The current retrospective cohort study was conducted in four US healthcare systems among 72,831 cancer patients receiving chemotherapy or immunotherapy.
In total, 69% received a monovalent booster by January 1, 2022. The COVID-19 hospitalization rate was 30.5 per 1,000 person-years among patients who received a monovalent booster, compared to 41.9 per 1,000 person-years among patients who received the primary series alone, with an adjusted vaccine efficacy (VE) of 29.2% (95% confidence interval [CI], 19.9% to 37.3%).
VE against COVID-19–related intensive care unit admission was also high (35.6%; 95% CI, 20.0% to 48.3%). Adjusted VE against COVID-19 among cancer patients with booster shots was not significant.
The study did not explore the issue of waning efficacy, but the authors said interventions are justified to increase COVID-19 vaccine uptake in this high-risk population.
Lymphoma patients had highest rate of COVID death
In the second study, cancer patients with lymphoma had the highest cumulative incidence of COVID-19–specific death in the first 90 days after infection.
The study was based on 1,572 eligible adult patients (median age, 60 years; 53.4% women). Of the participants, 1,066 (67.8%) had a solid tumor, with 683 (64.0%) having metastatic disease; breast (252 [23.6%]) and lung cancer (148 [13.9%]) were the most common.
“At enrollment, 1,013 patients (64.4%) were unvaccinated for SARS-CoV-2. COVID-19–related mortality at 90 days was 3.0% and did not increase at subsequent time points,” the authors wrote.
Use of chemotherapy (hazard ratio [HR], 1.97; 95% CI, 1.52 to 2.54) and baseline history of stroke, atrial fibrillation, or pulmonary embolism (HR, 1.78; 95% CI, 1.33 to 2.38) were associated with a higher risk of hospitalization. Overall, 290 patients (18.4%) had at least 1 hospitalization for COVID-19 within 90 days of enrollment in the study.
Among patients who were hospitalized for COVID-19, the incidence of COVID-19–specific death was highest among patients with lung cancer.
“Patients with solid non–lung tumors and other hematologic cancers were least likely to require hospitalization for COVID-19,” the authors wrote. “Among patients who were hospitalized for COVID-19, the incidence of COVID-19–specific death was highest among patients with lung cancer.”
Vaccination prior to SARS-CoV-2 infection was associated with a lower risk of hospitalization (HR, 0.52; 95% CI, 0.38 to 0.70).
“The present study found that patients who were vaccinated had a 50% reduction in risk of hospitalization, even during the early phases of the vaccine rollout,” the authors concluded. “This is important because there is concern that vaccination response is not as robust in patients with hematologic cancers, particularly those receiving B-cell–depleting therapy. The current data suggest that, despite a potentially suboptimal response, vaccination is still an important preventive strategy in this population.”
Breast cancer patients 6% less likely to receive imaging during pandemic
During a 20-year follow-up in the second study, 50.8% of all reported cancer treatment disruptions were attributed to COVID-19, with most disruptions occurring within the first 30 days after infection.
In a research letter, the authors look at surveillance disruptions for breast cancer patients during the pandemic by comparing the use of surveillance imaging in pre– and post–COVID-19 periods for patients with early-stage breast cancer seen at Kaiser Permanente Southern California (KPSC) and evaluating detection of short-term breast cancer recurrence.
All patients in the study had early (stage 1 or 2) breast cancer. Patients were grouped into two periods, pre– and post–COVID-19, each with 2 years of surveillance. In adjusted models, patients were 6% less likely to receive imaging post–COVID-19 (odds ratio [OR], 0.94; 95% CI, 0.92 to 0.96).
There was no significant difference between the pre– and post–COVID-19 periods among patients with breast cancer recurrence or progression (91 [2.7%] vs 98 [2.5%]).
“Given the less frequent surveillance in the post–COVID-19 period, cancer recurrence should be evaluated during 5- and 10-year periods as data become available,” the authors concluded.
