Patients and Health Staff of Cancer Centres During the Covid-19 Pandemic

The Covid-19 has, in a few weeks, made the world tremble: the number of deaths (mainly elderly and / or co-morbid) continues to increase, the confinement causes the collapsing of the economy and the decline of relationships inter-human. The data are too fragmented and the disease too recent to know its repercussions on the 3 million French people who have or have had cancer. The investigators would like, in 3 populations: * patients in treatment, * or in follow-up and * health personnel, to constitute a large prospective and longitudinal database of data: i / serological: humoral response, test performance, monitoring of serum immunoglobulin levels , reinfection threshold,…; ii / clinical: incidence, severity, mortality and their favorable factors impact of cancer treatment on Covid-19 infection and modification of the quality of oncological care in the context. In parallel, on a more limited sample of establishments, it will be : * appreciate the economic and functional repercussions, * will try to find out about the infection modalities in patients and health personnel and * will appreciate the levels of anxiety and depression to which health staff are subject.