Review of risk of COVID-19 in cancer patients and their cohabitants

BACKGROUND: Patients with a history of active malignancy are at increased risk of infection and COVID-19-related complications. Sanitary protection measures are not specifically recommended within households. This study examined the risk of seroconversion in cancer patients according to their household exposure. PATIENTS AND METHODS: This seroprevalence study was a prevalence study conducted in Torrejon de Ardoz (Spain). It analysed the seroprevalence of IgM and IgG antibodies in 104,299 volunteers (participation rate of 74.8% of population) from 29 May to 05 June 2020. Personal authorisation was requested to collect by questionnaire the test results from cancer patients, who attended the Outpatient Department of the University Hospital of Torrejón, and their cohabitants between 01–19 June 2020. RESULTS: A total of 229 cancer patients were included in the study. Sixty-four of the 229 individuals tested positive for SARS-CoV-2 IgG antibodies (27.9%) and 22 were positive for SARS-CoV-2 IgM antibodies (9.6%). The overall seroprevalence (IgG or IgM positive) was 31.4% (general population seroprevalence was 10% in Spain). Of 72 seropositive patients, 54.2% had intrafamilial exposure vs 45.8% who did not. Among seronegative patients, 30.6% had seropositive cohabitants. The probability of seropositivity for a cancer patient was significantly related to intrafamilial exposure (OR 2.684, 95% CI 1.51–4.76, p = 0.001). CONCLUSIONS: Cancer patients are a high-risk group for SARS-CoV-2 infection. Recommendations against virus transmission need to be implemented even in a household scenario, as it was the main factor significantly related to seroconversion.