[Gastrointestinal tumors : New N classification of the UICC].

Removal and examination of regional lymph nodes play an important role in the surgical therapy of gastrointestinal tumors concerning potential adjuvant treatment strategies. The number of metastatic regional lymph nodes as well as the number of removed and examined lymph nodes are of importance regarding estimation of the prognosis. It is essential to consider which lymph nodes are defined as regional in the UICC TNM classification and which definitions apply for the individual N categories. Furthermore, it is necessary to define which recommendations are valid for the minimum numbers of lymph nodes to be removed and examined for particular tumor entities.