Here is the design of a clinical trial:

Official Title: The Efficacy of Neoadjuvant Atezolizumab Treatment in Patients With Advanced Urothelial Bladder Cancer According to the BASQ Classification

Included conditions:
- Urothelial Carcinoma

Study Armgroups:
- {'label': 'Luminal type', 'type': 'EXPERIMENTAL', 'description': 'Luminal type in previous transurethral resection of bladder tumor pathology. Luminal type in Immunohistochemistry (KRT5/6-KRT14-FOXA1+GATA3+)', 'interventionNames': ['Drug: Neoadjuvant atezolizumab']}
- {'label': 'Basal typr', 'type': 'EXPERIMENTAL', 'description': 'Basal type in previous transurethral resection of bladder tumor pathology. Basal type in Immunohistochemistry (KRT5/6+KRT14+FOXA1-GATA3-)', 'interventionNames': ['Drug: Neoadjuvant atezolizumab']}

Interventions:
- {'type': 'DRUG', 'name': 'Neoadjuvant atezolizumab', 'description': 'Atezolimumab\n\n* At a fixed dose of 1200 mg as a 60-minute intravenous infusion (1st), then as a 30-minute intravenous infusion (2nd and 3rd)\n* Every 3 weeks, for a total of 3 cycles prior to radical cystectomy', 'armGroupLabels': ['Basal typr', 'Luminal type']}

Primary Outcomes:
- {'measure': 'objective pathological responses (pT0 change)', 'description': 'Final pathology of bladder after operation (radical cystectomy)', 'timeFrame': '4weeks'}

Please estimate the sample size based on the assumption: 
80% power, 5% significance level, consideration of patient refusal and dropout rates.
Sample size consideration
        The efficacy of atezolizumab as a neoadjuvant chemotherapy for radical cystectomy has not yet been published and is still under study. This study is a pilot study concept. To maximise its excellence in research progress and feasibility, we set the number of patients prospectively to 40, divided into two groups of 20. To detect a difference with 80% power and 5% significance level, we needed at least about 15 patients per cohort. About 80â100 patients had undergone radical cystectomy in our institution. We considered the number of patients diagnosed with MIBC who had undergone TURB in our institution and who could have a BASQ classification. Considering patientsâ refusal to take part in the study and drop out of the study, about 40 patients are considered to be able to participate in the study for about 3â4 years.