Efficacy of mRNA anti-SARS-CoV-2 vaccination and dynamics of humoral immune response in patients with solid tumors: results from the institutional registry of an Italian tertiary cancer center.

Background: Systemic immunosuppression characterizing cancer patients represents a concern regarding the efficacy of anti-severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccination, and real-world evidence is needed to define the efficacy and the dynamics of humoral immune response to mRNA-based anti-SARS-CoV-2 vaccines. Methods: We conducted an observational study that included patients with solid tumors who were candidates for mRNA anti-SARS-CoV-2 vaccination at the Fondazione IRCCS Istituto Nazionale dei Tumori, Milan, Italy. The primary objective was to monitor the immunologic response to the mRNA anti-SARS-CoV-2 vaccination in terms of anti-spike antibody levels. All the patients received two doses of the mRNA-1273 vaccine or the BNT162b2 vaccine. Healthcare workers served as a control group of healthy subjects. Results: Among the 243 patients included in the present analysis, 208 (85.60%) and 238 (97.94%) resulted seroconverted after the first and the second dose of vaccine, respectively. Only five patients (2.06%) had a negative titer after the second dose. No significant differences in the rate of seroconversion after two vaccine doses were observed in patients as compared with the control group of healthy subjects. Age and anticancer treatment class had an independent impact on the antibody titer after the second dose of vaccination. In a subgroup of 171 patients with available data about the third timepoint, patients receiving immunotherapy with immune checkpoint inhibitors seem to have a higher peak of antibodies soon after the second dose (3 weeks after), but a more pronounced decrease at a late timepoint (3 months after). Conclusions: The systemic immunosuppression characterizing cancer patients did not seem to dramatically affect the humoral response to anti-SARS-CoV-2 mRNA vaccines in our population of patients with solid tumors. Further investigation is needed to dissect the interplay between immunotherapy and longitudinal dynamics of humoral response to mRNA vaccines, as well as to analyze the cellular response to mRNA vaccines in cancer patients.

Systemic Treatment of Patients With Gastrointestinal Cancers During the COVID-19 Outbreak: COVID-19-adapted Recommendations of the National Cancer Institute of Milan.

The current severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) outbreak poses a major challenge in the treatment decision-making of patients with cancer, who may be at higher risk of developing a severe and deadly SARS-CoV-2 infection compared with the general population. The health care emergency is forcing the reshaping of the daily assessment between risks and benefits expected from the administration of immune-suppressive and potentially toxic treatments. To guide our clinical decisions at the National Cancer Institute of Milan (Lombardy region, the epicenter of the outbreak in Italy), we formulated Coronavirus-adapted institutional recommendations for the systemic treatment of patients with gastrointestinal cancers. Here, we describe how our daily clinical practice has changed due to the pandemic outbreak, with the aim of providing useful suggestions for physicians that are facing the same challenges worldwide.