In this issue

Excerpt

This month’s issue opens with a review paper by Langer et al. (https://​doi.​org/​10.​1007/​s00428-017-2232x), addressing a question that has gained in importance in recent years: how to assess histologically in resection specimens efficacy of neoadjuvant treatment of gastro-intestinal malignancies. Neoadjuvant chemo- or radiochemotherapy induces a variety of regressive and reparative tissue reactions along with the desired reduction in tumor volume and together these have been used repeatedly in attempts to (semi)quantify the response of the tumor to the administered therapy. Several approaches to tumor regression grading have emerged, and unfortunately none of them are in universal use. Even the basic approaches vary significantly, notably between primary assessment of therapy induced fibrosis and primary assessment of the amount of residual tumor. As the tumor regression grade conveys valuable prognostic information, some consensus building seems necessary. In this paper the histopathology of tumor response to treatment is discussed and the currently available regression grade approaches are reviewed and put into a clinical context. Hopefully this will be followed-up by successful attempts to unite existing approaches into a single universally applicable system. …