JMIR Publications

ABSTRACT

Background:

Prior studies, generally conducted at single centers with small sample sizes, found that individuals with cancer experience more severe outcomes due to coronavirus disease 2019 (COVID-19), caused by severe acute respiratory coronavirus-2 (SARS-CoV-2) infection. Although early examinations revealed greater risk of severe outcomes for cancer patients, the magnitude of the increased risk remains unclear. Furthermore, prior studies were not typically performed using population-level data. Given robust prevention measures (e.g., vaccines) are available for populations, examining cancer patients’ increased risk due to COVID-19 infection using robust population-level analyses of electronic medical records is warranted.

Objective:

To evaluate the association between SARS-CoV-2 infection and all-cause mortality among recently diagnosed adults with cancer.

Methods:

We conducted a retrospective cohort study of newly diagnosed adults with cancer between January 1, 2019 and December 31, 2020 using electronic health records (EHRs) linked to a statewide SARS-CoV-2 testing database. The primary outcome was all-cause mortality. We used the Kaplan-Meier estimator to estimate survival during the COVID-era (January 15, 2020 to December 31, 2020). We further modeled COVID-19 diagnosis as a time-dependent covariate in a multivariable Cox proportional hazards model adjusting for clinical and demographic variables to estimate the hazard ratios (HRs) among newly diagnosed adults with cancer.

Results:

During the study period, 46,957 adults were identified with newly diagnosed cancer, of which 2,923 (6.2%) tested positive for SARS-CoV-2. The population consisted of White (84.5%), Black (6.9%) and Other (8.6%) race with males (51.4%) and females (48.4%). In the adjusted time-dependent analysis, SARS-CoV-2 infection was associated with an increase in all-cause mortality (HR: 10.46, 95% CI: 9.20-11.89). Mortality increased 30% with a 10-year increase in age (HR: 1.30, 95% CI: 1.27-1.34), among males (HR: 1.27, 95% CI: 1.18-1.36) compared to females and those with two or more chronic conditions (HR: 2.05, 95% CI: 1.89-2.23) compared to those with no comorbidities. In the COVID-period analysis, the risk of death increased by 82% (HR: 1.82, 95% CI: 1.60-2.06) compared to the pre-COVID era (January 1, 2019 to January 14, 2020) after adjusting for other covariates. In a sensitivity analysis (N=9,968) which included information about cancer staging, the risk of death was more than 7 times greater after SARS-CoV-2 infection (HR: 7.65, 95% CI: 5.94-9.84) after adjusting for demographic and clinical variables.

Conclusions:

The findings highlight increased risk of death due to SARS-CoV-2 infection among patients with cancer. Elevated risk underscores the importance of adhering to social distancing, mask adherence, vaccination, and regular testing among an adult cancer population.