Regressionsgrading gastrointestinaler Tumoren

For locally advanced gastrointestinal tumors, pre- and perioperative neoadjuvant therapy followed by surgical resection is standard treatment. The histopathological evaluation of neoadjuvant tumors is used to determine the response of the tumor to preoperative and perioperative neoadjuvant therapy. Various regressive changes can be observed and tumor response is categorized using tumor regression grading (TRG) systems. Various TRG systems exist for gastrointestinal tumors. A complete or almost complete tumor response is associated with an improved prognosis. Therefore, the common TRG systems for the individual tumors should be mentioned in the histopathological report in addition to the vital tumor component. Unfortunately, no standardized TRG systems currently exist. In this review, the most common TRG systems for esophageal squamous carcinomas and adenocarcinomas, gastric and rectal adenocarcinomas, ductal adenocarcinomas of the pancreas and for liver metastases of colorectal adenocarcinomas are listed and current recommendations are presented.