Here is the design of a clinical trial:

Official Title: Prospective Study of Oncologic Outcomes After Laparoscopic Modified Complete Mesocolic Excision for Non-metastatic Right Colon Cancer [PIONEER Study]: Multicenter, Single-Arm Study

Included conditions:
- Adenocarcinoma of the Colon

Study Armgroups:
- {'label': 'Laparoscopic modified central mesocolic excision', 'description': 'Patients receiving laparoscopic colectomy with the concept of modified complete mesocolic excision for right-sided colon cancer', 'interventionNames': ['Procedure: Laparoscopic modified complete mesocolic excision']}

Interventions:
- {'type': 'PROCEDURE', 'name': 'Laparoscopic modified complete mesocolic excision', 'description': "First, complete kocherization may be required to clear possible tumor spread if the tumor is infiltrating or adhering to the duodenum or perinephric fat tissue. Second, if the tumor is locally advanced, the entire prerenal soft tissue behind Gerota's fascia may need to be cleared, especially for tumors growing toward the posterior. The third difference of mCME with the conventional CME involves the tailored resection of the mesocolon and ileal mesentery according to tumor location. After identifying the root of the middle colic artery, the site of the vascular ligation depends on the location of the tumor. When the tumor is located in the cecum and ascending colon, only the right branch of the middle colic artery is ligated. If the tumor was present in these latter sites, the root of the middle colic artery is ligated.", 'armGroupLabels': ['Laparoscopic modified central mesocolic excision'], 'otherNames': ['Laparoscopic right hemicolectomy']}

Primary Outcomes:
- {'measure': '3 year disease-free survival (DFS)', 'description': 'The 3 year disease-free survival is defined as the time from surgery until documented recurrence or death from any cause.', 'timeFrame': 'DFS will be measured up to three years after surgery, and the last visit is 14th visit after index surgery.'}

Please estimate the sample size based on the assumption: 
An exact p-value of 0.025 and a power of 0.90 based on the Clopper-Pearson method. A maximum dropout rate of about 10% is considered.
Sample size considerations
        On the basis of previous data, the median 3-year disease-free survival (DFS) rate after CME for right-sided colon cancer is estimated to be approximately 80%, and the null hypothesis is a 3-years DFS rate after laparoscopic mCME for right-sided colon cancer of at least 88% [12, 13]. This will be assessed using an exact p-value of 0.025 and a power of 0.90 based on the Clopper-Pearson method. Thus, the sample size is 225. The total sample size is set to 250, considering a maximum dropout rate of about 10% for this clinical study.