The IMMUNO-TET trial aims to assess the feasibility of characterising the immune environment of TETs and the constitutional and somatic molecular profiles of patients with localised thymic epithelial tumour (TET).

In this prospective study, patients undergoing thymectomy and thymomectomy as part of routine care undergo the following care pathway:

1. During the pre-surgical visit (for n = 50 patients): as part of routine care, a blood sample is collected for analysis of CBC, leukocytes, lymphocytes, CRP, ferritinemia, TSH, T3L, T4L, anti-acetycholine receptor antibodies, …CMV, EBV, HSV, HIV serologies, …and HLA class I and class II typing.

2. During thymectomy and thymomectomy surgery, the following samples are taken (for n = 50 patients):

   • 6 blood samples on EDTA tubes are collected at the time of surgery for analyses.
   • 3 fresh samples of the surgical specimen are taken by the pathologist: tumour T, juxta-tumour J and distant D locations for analyses by flow cytometry and RNA sequencing. Anatomopathology blocks/slides are also cut in the same way (tumour T, juxta-tumour J and distant D locations) for additional exploratory analyses.
   • The feasibility of developing patient-derived xenografts (PDX) from TETs will be tested for n = 20 tumor samples. These models will allow to test potential therapeutic agents for this pathology.

3. During the 1st month (+/- 7 days) post-surgery check-up, a blood sample is taken again (for n = 50 patients) for routine care: CBC, leukocytes, lymphocytes, CRP, ferritinemia, anti-acetycholine receptor antibodies and for peripheral immune system analysis at a distance from surgery and for constitutional molecular analysis.

Informed consent is given to participate in this prospective study.

Inclusion Criteria:

1. Patient with suspicion of localised thymic epithelial tumour.
2. Age ≥ 18 years.
3. Treatment-naïve patient for this disease.
4. Patient with an indication for thymectomy and thymomectomy in one of the partner centers.
5. Signed informed consent form of the patient.

Exclusion Criteria:

1. Neoadjuvant chemotherapy.
2. No social security affiliation.
3. Person under legal protection.
4. Other neoplasia in progress or cured within the last 3 years (except for operated carcinoma in situ).

Sponsor will share de-identified data sets. Documents generated under the project will be disseminated in accordance with Institut Curie policies.

Data requests can be submitted starting 9 months after last article publication and will be made accessible for up to 12 months.

Access to trial individual participant data can be requested by qualified researchers engaging in independent scientific research, and will be provided following review and approval of a research proposal and Statistical Analysis Plan (SAP) and execution of a data sharing agreement (DSA).