Abstract 1596P
Background
Cancer p represent a high-risk population for severe COVID-19. Cancer-associated immunosuppression may hinder in the development of anti-SARS-CoV-2 antibodies.
Methods
Data regarding baseline characteristics (age, cancer type, cancer activity, cancer treatment), COVID-19 infection and anti-SARS-CoV-2 IgG were collected from p with solid tumors who tested positive for COVID-19 (PCR+) between 10th March and 9th December 2020 at Catalan Institute of Oncology. We prospectively assessed anti-SARS-CoV-2 IgG seroprevalence at different timepoints (<2, 2-6, >6 months [m] since first PCR+) and explored factors associated with long-term IgG positivity.
Results
Out of 79 registered p, 19 died without IgG testing (all of them <3 months after a PCR+), and 8 refused to participate, leaving 52 tested for IgG. Tested and not-tested p were similar according to baseline characteristics, cancer treatment and COVID-19. At the 1st timepoint, 19/23p were IgG+; at the 2nd, 29/33p were IgG+ and 1 inconclusive; at the 3rd timepoint, 18/22 were IgG+ (median time from PCR + to 3rd timepoint determination was 9.4 m (Interquartile range [IQR]: 8.5-9.7). Importantly, 1 p changed from IgG+ (2nd timepoint) to IgG- (3rd timepoint), and 1 inconclusive result (2nd timepoint) changed to negative (3rd timepoint). Potential factors associated to IgG+ >6 m are shown in the table. Table: 1596P
Characteristics by IgG result determined >6m after COVID-19 diagnosis
| IgG- (n=4) | IgG+ (n=18) | |
| Median age (years) | 49.0 [46.8;49.5] | 66.0 [59.0;69.8] |
| Neoplasms breast | 2 (50.0%) 1 (25.0%) | 6 (33.3%) 4 (22.2%) |
| Urogenital digestive | 0 (0.0%) 0 (0.0%) | 3 (16.7%) 1 (5.6%) |
| Lung others | 1 (25.0%) | 4 (22.2%) |
| Active cancer | 3 (75.0%) | 5 (27.8%) |
| Active chemotherapy (last treatment <1.5 m) | 3 (75.0%) | 5 (45.5%) |
| O2 support during COVID-19 | 0 (0.0%) | 12 (66.7%) |
| Hospitalization | 1 (25.0%) | 12 (66.7%) |
Conclusions
High seroprevalence of anti-SARS-CoV-2 IgG was observed at several timepoints after COVID-19 diagnosis in solid tumor p. P with IgG+ at >6 m were older, and more likely to have required hospitalization and oxygen during prior COVID-19 in comparison to IgG- p >6m, suggesting that infection severity may promote durable immunity. Frequency of active cancer and active chemotherapy at COVID-19 diagnosis were higher among p with IgG- >6m, suggesting deeper immunosupression.
Clinical trial identification
Editorial acknowledgement
Legal entity responsible for the study
The authors.
Funding
Has not received any funding.
Disclosure
E. Felip: Financial Interests, Personal, Other: Pfizer; Financial Interests, Personal, Other: Lilly; Financial Interests, Personal, Other: Eisai; Financial Interests, Personal, Other: Novartis; Financial Interests, Personal, Sponsor/Funding: Pfizer. M. Romeo Marin: Financial Interests, Personal, Advisory Board: MSD; Financial Interests, Personal, Advisory Board: MSK; Financial Interests, Personal and Institutional, Other: MSD; Financial Interests, Personal and Institutional, Principal Investigator: AZ; Financial Interests, Personal and Institutional, Principal Investigator: GSK Tesaro; Financial Interests, Personal and Institutional, Principal Investigator: Merck. All other authors have declared no conflicts of interest.