Prognostic factors of rectum carcinoma--experience of the German Multicentre Study SGCRC. German Study Group Colo-Rectal Carcinoma.

A reliable evaluation of results of multimodal treatment requires the knowledge of the course of disease in patients treated by surgery alone and of the relevant prognostic factors. The data of a prospective multicentre observation study (Study Group Colo-Rectal Carcinoma, SGCRC) were analyzed by uni- and multivariate methods for the endpoints locoregional recurrence and observed overall survival. 1121 patients with invasive rectum carcinomas are included. In 1056 (94.2%) patients the tumor was resected, 34 patients (3.0%) received postoperative adjuvant therapy, 61 patients (5.4%) preoperative and 25 (2.2%) pre- and postoperative radiation. The observed 5-year survival rate for R0 (no residual tumor) was 55% (95% confidence interval 52-58%), for R1 and R2 only 7% (3-11%). Following R0 resection the 5-year survival rates varied according to pT (74-24%) and pN (68-33%). The 5-year survival was 74% (68-80%) for stage I, 62% (56-68%) for stage II, 40% (35-45%) for stage III and 9% (0-21%) for stage IV. Stage III is prognostically inhomogeneous: pN1: 5-year survival 47% (39-55%), pN2, 3: 34% (27-41%) (p < 0.01). The rate of locoregional recurrence is influenced by tumor related factors (stage and tumor site) and treatment related factors. Local spillage of tumor cells, the treating institution and the individual surgeon are independent factors influencing locoregional recurrence. Between locoregional recurrence and observed 5-year survival exists a highly significant correlation. The most important tumor related prognostic factors following surgical treatment are residual tumor status (R classification) and anatomic extent as described by pTNM and stage grouping UICC). The treating institution as well as the individual surgeon are further independent "prognostic factors" which determine the frequency of locoregional recurrence and thus survival. In analysis of treatment results the institution and the surgeon should be considered, in studies on adjuvant treatment a stratification according to department and surgeon is needed.