Tumor angiogenesis predicts recurrence with normal serum carcinoembryonic antigen in advanced rectal carcinoma patients

Many studies have established the usefulness of serum carcinoembryonic anti gen (CEA) oriented serial monitoring for predicting recurrence and prognosi s; however, few studies have so far investigated serum CEA-negative recurre nce. The aim of this study was to elucidate the nature of CEA-negative recu rrence regarding tumor angiogenesis. Fifty-seven patients with T3/T4 rectal cancer were divided into the two groups according fe the serum CEA status. Angiogenesis was defined as the intratumoral vessel count by immunohistoch emical staining using CD31. The CD31 count was significantly higher in the recurrent patients in both groups and the ratio of nodal involvement was si gnificantly higher in the recurrent patients of the CEA-negative group. Loc al recurrence mainly developed in the CEA-negative group; however, the CD31 count did not predict the sites of recurrence nor the relapse period in th e both groups. A multivariate analysis showed a high CD31 count >26) to be a prognostic factor not only for recurrence but also for survival (P = 0.00 1, 0.043, respectively). These results suggest that a high degree of tumor angiogenesis in sections of T3/T4 rectal cancer may therefore be an importa nt predictor for CEA-negative recurrence.