The diagnosis of cancer can be a major trigger for new sleep problems, especially insomnia, in people who did not have sleep issues before. Insomnia may appear early in the care pathway and can continue over time, often interacting with other physical or emotional symptoms.

The main goal of this preliminary study is to describe how insomnia develops during the first months after a cancer diagnosis in patients who had no sleep problems at the time of diagnosis. This will be done through regular follow-up over time.

A secondary aim is to identify the factors that may contribute to the onset or persistence of insomnia, such as the cancer treatments patients receive, as well as any medical or non-medical therapies used to manage sleep difficulties.

The study will also look at whether patients who develop sleep problems are referred to psychologists trained in specific therapies for insomnia, and how well they follow and adhere to these treatments.

Inclusion Criteria:

• Confirmed diagnosis of metastatic or non-metastatic cancer,
• Cancer treated with intravenous chemotherapy and/or immunotherapy administered intravenously or subcutaneously,
• Age ≥ 18 years,
• Ability to read and understand French,
• Patient covered by a social security system,
• Signed informed consent.

Exclusion Criteria:

• SCI questionnaire score <16
• Diagnosed or controlled sleep disorders
• Presence of severe cognitive disorders (e.g., Alzheimer's disease) or major psychiatric disorders (e.g., psychosis), as noted in the medical record, observed at recruitment, or reported by the patient
• Patient in an emergency situation, or subject to a legal protection measure (guardianship, curatorship, or judicial protection) and unable to provide consent

The study includes adult patients (≥18 years) with a confirmed diagnosis of metastatic or non-metastatic cancer, who are scheduled to receive intravenous chemotherapy and/or immunotherapy (intravenous or subcutaneous). Eligible participants must be able to read and understand French, be covered by a social security system, and provide signed informed consent. Patients must not have pre-existing sleep disorders (SCI score ≥16) and must not have severe cognitive or major psychiatric disorders that could interfere with participation. Patients in emergency situations or under legal protection measures unable to consent are excluded.