POP-UP: a Single-arm, Two-cohort Study: Trimodal Prehab for Upper GI and Pancreatic Cancer

Who May Qualify: - Signed and dated patient willing to sign a consent form form (ICF) and willingness to comply with all study procedures and availability for the study duration, - Histologically or cytologically localized PDAC or OGC validated by the multidisciplinary team, - Indication to a preoperative treatment withtriplet chemotherapy for ≥ 4 cycles (8 weeks), Note: Patient treated for PDAC, first cycle without oxaliplatin is authorized. - Age \> 18 years; If aged ≥ 75 years: G8 score must be ≥ 14 and if \< 14 validation of oncogeriatric specialist, - Eastern Cooperative Oncology Group performance status (ECOG PS) of 0-1 at inclusion visit (first prehabilitation hospital-day), - No prior treatment for PDAC or OGC before screening visit, - At least one measurable or evaluable lesion as assessed by Computerized Tomography scan or Magnetic resonance imaging according to RECIST 1.1 and feasibility of repeated radiological assessments on baseline imaging before starting chemotherapy, - Adequate hematologic and end-organ function allowing the triple combination chemotherapy protocol, - Registration in a national health care system (PUMa - Protection Universelle Maladie included). Who Should NOT Join This Trial: - Evidence of metastatic disease at imaging (validated in multidisciplinary team evaluation), - Histology of other than adenocarcinoma, - Any medical (including cardiovascular, respiratory, psychiatric, musculoskeletal, or neurological) condition contra-indicating exercise practice, - Patients with medical contraindication to surgery due to general condition or comorbidities - Pregnancy or breast-feeding, - Patient under a legal protection regime (guardianship, curatorship, judicial safeguard) or administrative decision or incapable of giving his/her consent, Always talk to your doctor about whether this trial is right for you.