Changing Pathology with Changing Drugs: Tumors of the Gastrointestinal Tract

Gastrointestinal cancer treatment is being based more and more on pathology that yields integrated information leading to targeted therapy, i.e. morphological identification of the histological type of the tumor and its context, staging of the tumor, and identification of various targets. This provides a realistic appraisal of the tumor and allows surgeons and oncologists to choose the best treatment from an increased range of drug options. An accurate diagnosis remains the major determinant of treatment, but new drugs and new insights into molecular pathways acting in carcinogenesis enhance molecular diagnosis in cancer. In most adenocarcinomas, therapy is only organ orientated and staging dependent, and not patient targeted. Currently, the identification and validation of new targets as well as molecular classification of the tumors are inducing the incorporation of new tests into the daily practice of surgical pathology. These new tests require appropriate tissue preservation and selection of the tissue to be analyzed and harmonized to morphological criteria. In colorectal adenocarcinoma, which is the second most common malignant tumor in both genders, the biomarkers that are relevant at the present time are the genetic instability status of the tumor, the KRAS muDr. Pascale Cervera Service d’Anatomie et Cytologie Pathologiques Hôpital Saint-Antoine, 184, rue du Faubourg Saint-Antoine FR–75012 Paris (France) Tel. +33 149 282 172, E-Mail pascale.cervera @ sat.aphp.fr © 2011 S. Karger AG, Basel 1015–2008/11/0782–0076$38.00/0 Accessible online at: www.karger.com/pat D ow nl oa de d by : 54 .7 0. 40 .1 1 11 /2 3/ 20 17 2 :4 3: 58 A M