Prognostic value of the grade of cellular differentiation, of mucus presence and the growth pattern of the invasive margin in colorectal adenocarcinomas Dukes B

The unfavorable evolution of approximately 1/3 of the patients with colorectal cancer, classified in the Dukes B stage, shows to be desirable the addition of another approaches morphologic prognostics. The reports of the literature about prognostic significance of cellular differentiation, mucus presence and the pattern of growth of the invasive margin in colorectal cancer were controversial. To evaluate the prognostic significance of tumor differentiation, mucus presence and the growth pattern of the invasive margin in patients with colorectal carcinomas classified in Dukes B stage. A retrospective study of 156 patients who had undergone curative resection for colorectal cancer was made at the Department of Gastroenterology Surgery of the "Hospital do Servidor Público Estadual", in São Paulo, SP, Brazil. Their mean age was 58 (range 28-83) years and consisted of 94 (60.26%) women and 62 (39.74%) men. The cellular differentiation was classified in two degrees: low and high malignancy degree, in agreement with the area of predominant differentiation of the tumor. Tumors with at least 60% of its volume in mucus were called mucinous carcinoma. The growth of the invasive margin was classified as expanding when the tumor showed a well-delineated and circumscribed border pushing the adjacent structures and infiltrating when the tumor advances by a process of seemingly effortless dissection between the normal structures of the bowel wall. There were predominance of tumors of low malignancy (139 (89.10%)), non-mucinous (142 (91.03%)) and with margin of the infiltrating type (123 (78.85%)). Only the growth of the invasive margin influenced the survival of 5 years. Patients with tumor exhibiting margin of the expanding type, presented a favorable outcome than those with margin of the infiltrating type -- 81.82% x 60.98%. The type of growth of the invasive tumor margin may help to identify the prognosis of low and high-risk subgroups of patients.