Relations of Current and Past Cancer with Severe Outcomes among 104,590 Hospitalized COVID-19 Patients: The COVID EHR Cohort at the University of Wisconsin

Abstract

Background: There is mixed evidence about the relations of current versus past cancer with severe COVID-19 outcomes and how they vary by patient and cancer characteristics.

Methods: Electronic health record data of 104,590 adult hospitalized patients with COVID-19 were obtained from 21 United States health systems from February 2020 through September 2021. In-hospital mortality and ICU admission were predicted from current and past cancer diagnoses. Moderation by patient characteristics, vaccination status, cancer type, and year of the pandemic was examined.

Results: 6.8% of the patients had current (n = 7,141) and 6.5% had past (n = 6,749) cancer diagnoses. Current cancer predicted both severe outcomes but past cancer did not; adjusted odds ratios (aOR) for mortality were 1.58 [95% confidence interval (CI), 1.46-1.70] and 1.04 (95% CI, 0.96-1.13), respectively. Mortality rates decreased over the pandemic but the incremental risk of current cancer persisted, with the increment being larger among younger vs. older patients. Prior COVID-19 vaccination reduced mortality generally and among those with current cancer (aOR, 0.69; 95% CI, 0.53-0.90).

Conclusions: Current cancer, especially among younger patients, posed a substantially increased risk for death and ICU admission among patients with COVID-19; prior COVID-19 vaccination mitigated the risk associated with current cancer. Past history of cancer was not associated with higher risks for severe COVID-19 outcomes for most cancer types.

Impact: This study clarifies the characteristics that modify the risk associated with cancer on severe COVID-19 outcomes across the first 20 months of the COVID-19 pandemic. See related commentary by Egan et al., p. 3.

Figure 1.

Adjusted odds ratios (and 95% confidence intervals) of the associations (relative to no cancer, current or past) of specific current cancers (top A), current cancer types (middle A), specific past cancers (top B), and past cancer types (middle B) with in-hospital mortality among 104,590 CEC-UW cohort inpatients with COVID-19. Odds ratio point estimates are presented alongside the right of each panel. Note: There was a significantly greater odds of mortality associated with current hematologic (OR, 1.18; 95% CI, 1.02, 1.37) and metastatic (OR, 1.44; 95% CI, 1.21–1.70) cancers relative to current solid non-metastatic cancer (middle A), and a significantly greater odds of mortality associated with past hematologic (OR, 1.38; 95% CI, 1.22–1.58) relative to past solid non-metastatic cancer (middle B). Ns represent the number of patients with the specific cancer or cancer group within the specified time frame (current or past). Cancer types were created by combining any positive diagnosis in either of the three categories of hematologic, metastatic, and solid tumors without metastasis together into a single binary composite. Hematologic cancer was composed of 13 specific cancers (ICD-10-CM codes C81-C88, C90-C95), metastatic cancer was composed of four specific cancers (ICD-10-CM codes C77-C80), and solid tumor without metastasis was composed of 67 specific cancers (ICD-10 codes C00-C26, C30-C34, C37-C41, C43, C45-C58, C60-C75). The sum of the cancer types exceed the number of patients with any cancer because some patients had more than one type of cancer. Odds ratios were adjusted for sex, age, race, ethnicity, BMI, smoking status, insurance status, and past 5-year comorbidity score. See Supplementray Fig. S2 for unadjusted estimates. CEC-UW, COVID EHR Cohort at the University of Wisconsin.

Figure 2.

Percentage (and 95% confidence intervals) of severe outcomes among CEC-UW cohort inpatients with COVID-19 with no (current or past) cancer, past cancer, and current cancer by vaccination status (A and B), pandemic year (C and D), and age group (E and F). Note: Vaccination status analyses were conducted among 54,983 CEC-UW cohort inpatients with COVID-19 who were hospitalized on or after December 11, 2020 when the first SARS-CoV-2 vaccines became available. “Vaccinated” was defined as receipt of at least one vaccine dose before the index hospital admission date, 67.3% had received at least two doses of Pfizer or Moderna or one dose of Janssen. The sample sizes for earlier and later in the pandemic were 57,649 and 46,941, respectively. The sample size for the age group analyses was 104,590. See Supplementary Text S4 for the rationale for the use of these three age groups in lieu of the seven shown in Table 1. The age of individuals greater than 90 years of age were recoded as 90. CEC-UW, COVID EHR Cohort at the University of Wisconsin.