treatment on the metastatic rate in patients with rectal carcinoids. year metastasis free survival rates for those patients presenting without metastatic 2 Department of Medical Informatics, The Unidisease were 100% for patients with tumors õ 1 cm (n Å 16), 73% for those with versity of Texas M. D. Anderson Cancer Center, tumors 1-2 cm (n Å 8), and 25% for those with tumors ú 2 cm (n Å 4) (P Å 0.04 Houston, Texas.comparing õ1 cm with 1-2 cm and P Å 0.05 comparing 1-2 cm with ú2 cm); tumor size data were not available for 3 patients. The 5-year metastasis free survival rate for patients presenting without metastatic disease with typical histology (n Å 20), regardless of size, was 100%, compared with 50% for patients with tumors with atypical histology (n Å 11) (P Å 0.001). Nine patients underwent extensive surgery for rectal carcinoid tumors but no survival benefit was demonstrated. that are 1 -2 cm is unpredictable. 1,5 Reports indicate that carcinoid tumors 1 -2 cm are associated with a 10 -20% incidence of metastaAddress for reprints: Lee M. Ellis, M.D., Departsis. 1,6,7 The identification of factors that predict aggressive tumor be- The objectives of the current study were to determine 1) the natural history of rectal carcinoid tumors, 2) whether specific histo-
CONCLUSIONS.