SARS-CoV-2 infection has been and, in some parts, still is a threat to oncologic patients, making it crucial to understand perception of vaccination and immunologic responses in this vulnerable patient segment. SARS-CoV-2 vaccines in relation to malignant disease characteristics and therapies have so far not been studied consecutively in larger oncologic patient populations. This study captures SARS-CoV-2 vaccination willingness and humoral immune response in a large consecutive oncologic patient collective at the beginning of 2021. 1142 patients were consecutively recruited over 5.5 months at a tertiary department for radiation oncology and were assessed for vaccination willingness via a standardized interview. In already vaccinated patients total SARS-CoV-2 S antibody titres against the spike protein (Anti-SARS-CoV-2 S) and were evaluated 35 days or later after the first dose of SARS-CoV-2 vaccine. Vaccination willingness was high with a rate of 90 %. The most frequent reasons for rejection were: undecided/potential vaccination after therapy, distrust in the vaccine and fear of interaction with comorbidities. Factors associated with lower vaccination willingness were: worse general condition, lower age and female sex. 80 % of the participants had been previously vaccinated, 8 % reported previous infection and 16 % received vaccination during antineoplastic therapy. In 97.5 % of the vaccinated patients Anti-SARS-CoV-2 S was detected. In a univariable analysis parameters associated with non-conversion were: lower performance status, spread to the local lymphatics (N + ), hematologic disease and diffuse metastases. All patients with oligometastatic disease achieved positive Anti-SARS-CoV-2 S titres. For patients with two vaccinations several risk factors were identified, that were associated with low antibody concentrations. SARS-CoV-2 vaccination willingness among oncologic patients was high in the first months after its availability, and most patients had already received one or two doses. Over 97 % of vaccinated patients had measurable anti-SARS-CoV-2 S titres. Our data supports early identification of low humoral responders after vaccination and could facilitate the design of future oncologic vaccine trials (clinicaltrials.gov Identifier: NCT04918888).

Background/Objectives: The COVID-19 pandemic significantly threatened cancer patients and oncologic care. The rollout of vaccines emerged as a critical milestone, despite the initial lack of evidence regarding their safety and efficacy in this population. This systematic review and meta-analysis evaluate the current evidence on COVID-19 vaccination in patients undergoing radiotherapy (RT). Methods: PubMed, Livivo, Scopus, and Cochrane Library were systematically reviewed for relevant publications on COVID-19 vaccination in the context of radiation oncology, published by 19 April 2024. The treatment effects were calculated as the proportion of seroconverted individuals. Results: A total of 22 studies published between 2021 and 2024 were included, covering various aspects of vaccination, including safety, tolerability, qualitative and quantitative humoral responses, cellular responses, vaccination efficacy, and booster vaccinations. Notably, patients undergoing RT exhibited a high willingness to receive vaccination. Vaccination was overall well tolerated and safe, with a low incidence of side effects, which were primarily mild. The primary meta-analysis showed a seroconversion proportion of 91% [95% CI: 84–96%] overall, with a somewhat higher proportion of 93% in patients receiving RT alone, compared to 90% in patients receiving either RT or RT combined with chemotherapy. Furthermore, immunization during RT led to a sustained increase in antibody titers, with a notable long-term persistence of IgG. Conclusions: COVID-19 vaccines demonstrate excellent safety, immunogenicity, and efficacy in patients receiving RT, who also exhibit a high willingness to be vaccinated. The outcomes observed are comparable to those in healthy controls and superior to those seen in patients receiving other cancer treatments, such as chemotherapy. The vaccination of radiation oncology patients in future pandemics or epidemics is strongly advocated even during active treatment.

Background: Cancer patients are highly prone to infectious diseases. While undergoing antineoplastic treatment, the risk of severe symptoms upon infection increases, necessitating efficient protective measures, such as vaccination. For patients receiving radiotherapy, there is no specific information about humoral immunity. During the COVID-19 pandemic, serial antibody measurements were therefore offered to cancer patients, following SARS-CoV-2 vaccination while obtaining radiotherapy. Methods: Out of 74 enrolled patients, 46 met the inclusion criteria. Two cohorts were allocated, depending on an association with chemotherapy or pure radiotherapy. An additional healthy control cohort of 16 healthcare workers was enrolled. All participants followed a two-fold BNT162b2 vaccine schedule. SARS-CoV-2 binding antibodies were measured serially in a 7-day cycle for 35 days and over the long-term, using the Elecsys^® Anti-SARS-CoV-2 immunoassay. Results: Cancer patients under pure radiotherapy have a comparable humoral vaccination response and long-term persistency of antibodies to healthy controls. Patients receiving additional chemotherapy show a significantly delayed immune response and decreased antibody titers. The vaccine was well tolerated in all cohorts. Conclusions: Pure radiotherapy in cancer patients does not interfere with the vaccine-induced humoral immune response or other immunogenetic aspects, whereas previous or simultaneous chemotherapy does. Findings are of particular relevance for future epidemic or pandemic scenarios.

We report the case of a 66-year-old man with a known history of IgD multiple myeloma (MM) which was admitted to hospital because of acute renal failure. Routine PCR testing on admission yielded a positive result for SARS-CoV-2 infection. Examination of the peripheral blood (PB) smear revealed 17% lymphoplasmacytoid cells and a few small plasma cells mimicking morphological changes frequently seen in viral diseases. However, flow cytometric examination showed 20% clonal lambda-restricted plasma cells being consistent with a diagnosis of secondary plasma cell leukemia. Circulating plasma cells as well as similar appearing lymphocyte subtypes such as plasmacytoid lymphocytes are frequently observed in infectious disorders such as COVID-19, so that the lymphocyte morphology in our patient’s case could have been easily misinterpreted as typical COVID-19-induced changes. Our observation highlights the importance of incorporating clinical, morphological, and flow-cytometric data in distinguishing between reactive and neoplastic lymphocyte changes because misinterpretation may affect disease classification and, beyond that, clinical decision-making, which may have serious consequences for patients.

Objectives: In patients with chronic lymphocytic leukemia (CLL), the white progenitor cell (WPC) channel of the Sysmex XN hematology analyzers typically shows a varying proportion of cells in the upper left field of the scattergram, resembling the shape of shark fins. The underlying mechanism causing this phenomenon has not been elucidated so far. In this study we evaluated biological and/or genetic features of CLL cells as a potential background of the “shark fins”. Methods: Automated blood counts and WPC scattergrams of 95 CLL patients were analyzed. The scattergrams were examined for the presence, count and percentage of cells in the “shark fins” using a flow cytometry software. Potential influencing factors on the occurrence of the “shark fin” cells were statistically tested by Spearman correlation. Results: The lymphocyte count was identified as a highly statistically significant predictor of “shark fins” (p<0.0001). Absence of del(17p) (p=0.02), unmutated TP53 (p=0.01), mutated IGHV (p=0.03) and the percentage of smudge cells in peripheral blood smears (p=0.04) showed a statistically significant positive influence on the percentage of cells in the “shark fins” after adjustment for the lymphocyte count. No significant effect was observed for age, sex, del(13q), del(11q), trisomy 12 and treatment. Conclusions: We identified the lymphocyte count, the absence of TP53 mutations and del(17p), a mutated IGHV and the proportion of smudge cells as significant influences on the appearance of “shark fin” cells. Our findings indicate an impact of biological and genetic properties of the leukemic cells on the formation of “shark fins”.

1589 Background: The incidence of Kaposi sarcoma (KS) is high in Southern Africa: KS is the most common cancer in HIV-infected persons. Data on KS in patients receiving antiretroviral therapy (ART) are, however, scarce in Africa. Within the framework of a large multi-cohort project, the International epidemiologic Database to Evaluate AIDS (IeDEA), we studied the incidence and risk factors for the development of KS in HIV-infected patients starting ART in Southern Africa. Methods: We analyzed prospectively collected data of HIV-infected patients who started ART with three antiretroviral drugs from at least two classes. Prevalent KS cases diagnosed before or at start of ART were excluded. Incidence rates and 95% confidence intervals (CI) were calculated based on the Poisson distribution; risk factors were estimated using crude and adjusted Cox models. Hazard ratios (HR) with 95% CI and medians with interquartile ranges (IQR) are presented. Results: 185,924 patients from 7 cohort studies in Botswana, Mozambique, South Africa, Zambia, Zimbabwe with 376,630 person-years of follow-up were included. At start of ART median age was 34 years (IQR 28–41) and median CD4 cell count 145 cells/µl (IQR 73-225). 61% of patients were female. A total of 601 incident KS cases were recorded. The incidence for KS in patients on ART was 160 (95% CI 147-173) per 100,000 person-years. The risk for KS increased with age. Adjusting for age, gender, WHO stage and CD4 cell count adults >40 years had a more than ten-fold increased risk for developing KS compared to infants (HR 11.8, 95% CI 3.0-46.2); men were more likely to develop KS compared to women (HR 1.4, 95% CI 1.1-1.7) and the risk to develop KS was increased in patients with AIDS at start ART (WHO stage IV vs. I: HR 2.2, 95% CI 1.6-3.1). Conclusions: In Southern African countries with a high prevalence of HHV-8 the risk to develop KS in HIV infected patients receiving ART increases steeply with age and is higher in patients with more advanced HIV infection.