Various diseases affecting digestive system organs may require complete or partial removal of the affected organ: i.e. partial removal of the stomach in gastric ulcer and that of the colon in colon diverticulosis. However removal of the affected organ is not sufficient in case of cancer. In addition thereto, all lymph nodes under the risk of spreading of cancer must be removed. Therefore DII lymphectomy in gastric cancer and total mesorectal excision in colorectal cancer are procedures involving total removal of lymph nodes. Performance of these principles yields better results most of the time. A multidisciplinary approach is adopted in surgical treatment of cancer. In line therewith, patient-specific treatment plans can be determined via discussions as to which method to choose from among open, closed (laparoscopic) and robotic surgery methods in multidisciplinary Tumor Councils held for cancer patients