Adolescents and young adults (AYA) with cancer have to deal with a relatively segmented organization of care between pediatric and adult medicine structures in France. However, the third french Plan Cancer 2014-2019 helped in the recognition of the specificities of the AYA affected by cancer and allowed the creation of specific structures in some care units in France, whose primary goal is the preservation of the social link.

Indeed, peer relations contribute to access to quality social support, which is an important variable in patient adjustment with cancer. The adolescents that perceive higher social support report less psychological distress and exhibit higher adaptation scores.

It nevertheless happens that AYA experience negative social support, often from friends because of contact reduction during the disease. Patients can then elect to turn towards non-intimate relations such as support groups. The main risk when a AYA with cancer defines a sick peer as one bringing him quality social support is the installation of a sense of guilt, for example, when a young person is confronted with disease negative progress or with peer death. The more an adolescent identifies with the deceased, the more he is able to consider his own mortality.

AYA units are developing in France, creating a community of sick adolescents. These communities are precious for AYA and allow information and experience sharing, a feeling of reduced isolation and a greater emotional closeness with peers suffering from the same disease.

How is social support from peers and close friends perceived by these young people in AYA units and through the social networks? What can the consequences of the evolution of peer disease be on AYA? What is the impact of the mourning of sick peers on these young people? What are the predictors?

Methodology: Multicentric, prospective, not randomized study.

Inclusion Criteria:

1. Adolescents or young adults from 15 to 27 years old (included) receiving cancer diagnose or recurrence announcement.
2. Patient information and free consent signature by the patient or his legal representative(s).

Exclusion Criteria:

1. Patient with any psychological, familial, sociological or geographical condition potentially hampering compliance with the study protocol.
2. Inability to understand, talk or write in French.
3. Patient individually deprived of liberty or placed under the authority of a tutor.