Staging gastrointestinal cancer as a precondition for multimodal treatment.

Staging gastrointestinal cancer is useful only if it has an impact on treatment. When applying modern multimodal therapies (i.e., neoadjuvant, adjuvant, or additive treatment), meticulous staging is mandatory. Preoperative staging should include all relevant prognostic factors. If possible, modern cellular biology-related parameters should also be investigated, although their validity has not yet been analyzed properly. Using such modern techniques as endoluminal ultrasonography or video-laparoscopy, a preoperative diagnostic accuracy of 85% can be achieved, providing a sound foundation for therapeutic decisions. Assessment by TNM staging (UICC) and surgical resection without residual tumor (UICC/R0) are crucial, as it has been shown by multivariate analyses that these factors have the most impact on prognosis. Postoperative staging is mainly done by pathohistologic evaluation of the surgical specimen. It is the basis for any postoperative adjuvant or additive therapy. In this paper the diagnostic methods and their validity are discussed in relation to the various gastrointestinal tumors.