Proposal for a new carcinoid tumour staging system based on tumour tissue infiltration and primary metastasis; a prospective multicentre carcinoid tumour evaluation study. West German Surgical Oncologists' Group.

In order to evaluate the significance of different prognostic factors, a multicentre prospective carcinoid tumour study was launched in early 1987, under the auspices of CAO (Chirurgische Arbeitsgemeinschaft Onkologie, a West German surgical oncologists' collaboration group) and UICC (Union Internationale Contre le Cancer). Up to March 1990 we received and evaluated clinical data from 94 patients from 16 hospitals. Carcinoid localization was distributed as follows: stomach 4, duodenum 7, pancreas 3, jejunum 5, ileum 21, Meckel's diverticulum 1, appendix 29, colon 5, rectum 14, and 5 cases of tumour metastases of unknown origin. The mean age was 54.7 years, overall sex ratio (m/w) was 1:1.09. Thirty-one patients presented with simultaneous lymph-node metastases and 27 with distant metastases. Based on these data, a metastases staging system (four stages) has been defined for study stratification. This work also aims at evaluating the correlation of tumour diameter and tumour tissue invasion with primary metastases occurrence; primary tumour diameter remains the most important prognosis-related factor for appendiceal location. For other locations, tumour tissue invasion can be markedly better correlated with regional lymphatic and distant spread than is the case with tumour diameter. Tumour tissue invasion has, therefore, been selected to define a local staging (four stages) for further study stratification. Tumour location, metastases stage and local stage combined, best describe the current state of the disease and will serve to evaluate further pathological stratification and to correlate survival data.