Early Detection of Triple Negative Breast Cancer Relapse (CUPCAKE)

Inclusion criteria

• Patients must have signed a written informed consent before inclusion
• Patients must be female ≥ 18 years old
• Patients diagnosed with a non-metastatic TNBC (ER \& PR \<10%, HER2- per ASCO/CAP guidelines). Patients must have been previously evaluated by a 18F-FDG PET-CT or a bone scintigraphy combined with a thorax, abdomen and pelvis CT scan with contrast
• Patients who have undergone surgery with curative intent for their non-metastatic TNBC. Surgery must have been performed between 3 to 24 months before inclusion. Patients must have initiated their adjuvant therapy, whenever indicated, since at least 12 weeks. For patients receiving an experimental adjuvant treatment in a clinical trial, any intervention planned as part of this trial must be completed before inclusion.
• High-risk primary tumor, defined as:
• Lack of pathological complete response after neoadjuvant chemotherapy (RCB I, II or III; RCB I being capped to a maximum of 30% of included patients) OR, in the absence of neoadjuvant chemotherapy,
• Stage IIB-III (i.e., T2N1, any T3-T4, any N2-3) OR
• Any loco-regional relapse occurring after a prior ipsilateral, curatively treated TNBC
• No sign of local or distant relapse, as per investigator assessment
• Performance status \< 2
• Available FFPE tumor block with \> 10% cellularity or 11 tumor sections with \>10% cellularity
• Patient able to comply with protocol requirements
• Patients covered by a health insurance

Exclusion criteria

• Any uncontrolled disease, metabolic dysfunction, physical examination finding, or clinical laboratory finding or any other medical condition that, in the opinion of the investigator, interferes with the trial procedures
• Male participants
• Patients with altered mental status or psychiatric disorder that, in the opinion of the investigator, would preclude a valid patient informed consent.
• Patients who have difficulty undergoing trial procedures for geographic, social or psychological reasons
• Person deprived of liberty or under guardianship
• History of another primary malignancy except for the following :
• Basal cell carcinoma or any in situ carcinoma treated with curative intent
• Any stage I-II malignancy treated with curative intent with no evidence of active disease in the last five years
• For step #2 (randomization after ctDNA detection): clinical/radiological metastatic relapse before the detection of the molecular relapse.