This study will allow the investigators to better assess the efficiency of neoadjuvant chemotherapy before cystectomy by training a predictive model on different patient cohorts with bladder cancer.

The project is based on three prospective cohorts of patients with MIBC: the VESPER trial (n=296), the St-Louis Hospital cohort (n=99), and the COBLAnCE cohort (n=312). Using WES and RNAseq, the investigators will determine genomic instability, DDR gene mutation and molecular subtypes. After digitization of tumour slides, the investigators will train and test predictive models based on deep learning approaches to predict outcome after neoadjuvant chemotherapy, either by estimating molecular subtypes and genetic features from pathological images, or by directly defining a prognostic signature. The statistical analyses will assess the performance of the models combining genomic instability, DNA Damage Response mutations and/or molecular subtyping to predict outcome after neoadjuvant chemotherapy and compare them with the models based on WSI deep learning approaches. These results will help to design new therapeutic strategies.

Inclusion Criteria:

- Inclusion Criteria of Patients enrolled in VESPER study:

Blood and tumors from patient having muscle invasive bladder cancer who benefit from neoadjuvant chemotherapy with cisplatine included in VESPER cohort and :

having signed an informed consent form for the participation to the collection or dead/lost to follow-up without prior opposition expressed against research program, genetic analysis will only be carried out for patients who have signed the genetic consent form.

- Inclusion Criteria of Patients from St Louis cohort not enrolled in VESPER study:

Blood and tumors from patient having muscle invasive bladder cancer who benefit from neoadjuvant chemotherapy with cisplatine included in Saint-Louis cohort and :

being informed for the participation to the collection and not having expressed opposition against research program or dead/lost to follow-up without prior opposition expressed against research program,

- Inclusion Criteria of Patients from St Louis cohort not enrolled in COBLaNCE study:

Blood and tumors from patient having muscle invasive bladder cancer who benefit from neoadjuvant chemotherapy with cisplatine included in COBLaNCE cohort and :

being informed for the participation to the collection and not having expressed opposition against research program or dead/lost to follow-up without prior opposition expressed against research program,

Exclusion Criteria:

• Patients not fulfilling eligibility criteria

cohorts of patients with MIBC (Muscle-invasive bladder cancer)