SER-ONCOVID: Seroconversion in solid-tumor cancer patients after COVID-19 diagnosis.

person Anna Pous ICO Badalona, Barcelona, Spain info_outline Anna Pous, Eudald Felip, Olatz Etxaniz, Ainhoa Hernandez Gonzalez, Sofia España, Margarita Romeo, David James Pinato, Anna Esteve, Ricard Mesia

Authors person Anna Pous ICO Badalona, Barcelona, Spain info_outline Anna Pous, Eudald Felip, Olatz Etxaniz, Ainhoa Hernandez Gonzalez, Sofia España, Margarita Romeo, David James Pinato, Anna Esteve, Ricard Mesia Organizations ICO Badalona, Barcelona, Spain, Medical Oncology Department, Germans Trias i Pujol Hospital, Catalan Institute of Oncology (ICO), Badalona, Spain, Medical Oncology. Institut Català d'Oncologia (ICO) Hospital Germans Trias i Pujol, Badalona, Spain, Institut Catala d'Oncologia Badalona. Applied Research Group in Oncology (B- ARGO Group), Institut Investigació Germans Trias i Pujol (IGTP), Badalona Barcelona, Spain, Medical Oncology Department, Institut Català d’Oncologia (ICO) Badalona, B-ARGO, Badalona, Spain, Institut Català d'Oncologia Badalona, Hospital Germans Trias i Pujol, Badalona, Spain, Department of Surgery and Cancer, Imperial College, London, United Kingdom, Cancer Statistics Department, Catalan Institute of Oncology-Hospital Germans Trias i Pujol, Badalona, Spain, Catalan Institute of Oncology, IDIBELL, Barcelona, Spain Abstract Disclosures Research Funding No funding received None Background: Cancer patients (pts) 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, COVID-19 and anti-SARS-Cov2 IgG were collected from cancer pts (solid tumors) who tested positive for COVID-19 (PCR+) between March and April 2020 at Catalan Institute of Oncology. We prospectively assessed anti-SARS-Cov2 IgG seroprevalence at 3 and 9 months post infection and explored clinico-pathologic factors associated with IgG positivity. We explored the impact of potential factors influencing antibody production at >9 months. Results: Of 49 pts registered between 10 th March-26 th April 2020, 21 died <3 months after the infection and 5 pts refused to participate, leaving 23 eligible pts for IgG testing. With respect to those not tested, IgG tested cohort was younger (median age: 64.0 vs 72.9 years, p = 0.001) and presented oncologic remission in 68.2% of cases (vs 34.6%, p = 0.043) at COVID-19 diagnosis. Median time from PCR+ to first and second IgG determination was 3.2 months (Interquartile range [IQR]: 2.9-4.1) and 9.5 months (IQR: 8.8-9.8), respectively. Out of 23 pts, 15 had both determinations and 8 had only one (3 in the first time point, 5 in the second one). We identified 16/18 pts IgG+ (88.9%) at 3 months and 17/20 pts IgG+ (85%) at 9 months. One IgG+ pt became IgG- at the second determination, one was IgG- at both timepoints, and one had an inconclusive result at the first but negative at the second timepoint. Key characteristics of patients by IgG result 9 months after COVID-19 diagnosis are shown in the table. Conclusions: We describe a high seroprevalence of anti-SARS-CoV-2 IgG at 3 and 9 months after COVID-19 diagnosis in solid tumour patients, irrespective of anti-cancer therapy exposure. Pts who were IgG+ at 9 months were older, and more likely to have required oxygen during prior COVID-19 in comparison to IgG- pts suggesting that infection severity may promote durable immunity. Frequency of early stage cancers was higher among IgG+ pts, suggesting less cancer-related immunosupression. Older (>70 years) and advanced cancer pts were under-represented in this series, warranting confirmation of these preliminary results in a larger cohort. Characteristics of patients by IgG result determined at 9 months after COVID-19 diagnosis. Characteristics assessed at COVID infection IgG- (n=3) IgG+ (n=17) Median Age (years) 49.0 [49.0; 50.0] 66.0 [62.0; 70.0] Neoplasms Breast Urogenital Digestive Others 1 (33%) 1 (33%) 0 (0%) 1 (33%) 6 (35%) 4 (24%) 3 (17%) 4 (24%) Early stage/Metastatic cancer 1(33%)/2(67%) 13(77%)/4(24%) Active Cancer Treatment* 3 (100%) 14 (82%) O2 support during COVID-19 0 (0%) 12 (61%) COVID treatment (Tocilizumab/Remdesivir) 0 (0%) 4 (24%) *Chemotherapy, immunotherapy, hormonal therapy, targeted therapy.