Table 4 Description of COVID-19-related deaths

Patient #1 was a 69-year-old woman with a history of diabetes, hypertension, hypertrophic cardiomyopathy, and rheumatoid arthritis treated by abatacept (a CTLA-4 immunoglobulin). She was diagnosed with stage IIB triple-negative breast cancer in February 2020 and started neoadjuvant chemotherapy (epirubicin and cyclophosphamide) in March. Three days after the first cycle, she was referred to the emergency room (ER) with chest pain, fever, and lung infection (day 1). SARS-CoV-2 infection was diagnosed based on positive RNA PCR and chest CT scan. She was admitted to ICU for acute respiratory distress on day 7, treated with antibiotics, antiviral therapy (chloroquine and lopinavir/ritonavir), and endotracheal intubation and ventilation. She died 19 days later (day 26).

Patient #2 was a 44-year-old patient with no relevant medical history, diagnosed with de novo stage IV hormone-sensitive breast cancer (node, bone, and hepatic metastases, with 4N cytolysis) in February 2020. She received a first-line combination of CDK4/6 inhibitor, aromatase inhibitor, and complete ovarian function suppression. On day 17 of her first month of treatment, she was referred to the ER for asthenia, dyspnea, grade IV thrombocytopenia (14 G/L), and grade IV neutropenia (0.2 G/L). She was diagnosed with SARS-CoV-2 lung infection complicated by thrombotic microangiopathy, based on positive RNA test, chest CT scan, and laboratory data. She was treated symptomatically, including antibiotics, and was not transferred to ICU due to her metastatic disease and major multiple organ failure. She died 8 days after ER admission.

Patient #3 was a 78-year-old woman with a history of hypertension. She had been treated since November 2013 for stage IV hormone-sensitive breast cancer (lung and bone metastases). In March 2020, she received two cycles of weekly paclitaxel as second-line chemotherapy. Five days after the last injection, she was referred to the ER with dyspnea and hypoxia. SARS-CoV-2 infection was diagnosed based on a typical chest CT scan with extensive consolidation involving approximately 50% of the lungs. PCR RNA test was negative. Hydroxychloroquine and antibiotics were rapidly initiated on day 1, but the patient was not transferred to ICU due to her limited oncological life expectancy. She died on day 4.

Patient #4 was an 80-year-old woman treated for metastatic hormone-sensitive breast cancer (bone metastasis only) since February 2016. Since January 2020, after tumor progression, systemic therapies were stopped in favor of best supportive care. She had been hospitalized for tumor-related symptoms since February 2020. In late March, she presented signs of lung infection, followed by acute respiratory distress. Nosocomial SARS-CoV-2 infection was diagnosed based on positive RNA PCR and chest CT scan with ground-glass opacities involving approximately 20% of the lungs. Palliative symptomatic treatments with nasal oxygen therapy were initiated, and the patient died 12 days after onset of the first symptoms.