Pathologic significance of tumor progression in locally recurrent rectal cancer - Different nature from primary cancer

PURPOSE: It has recently been demonstrated that the tumor growth rate is a stronger determinant of survival than the extent of the growth in local rec urrence of rectal cancer. We studied which factors controlled the tumor gro wth rate using modern immunohistochemical methods. METHODS: In 51 patients who underwent extended resection for this condition, paraffin-embedded spec imens were examined for 1) tumor angiogenesis by CD31 staining and microves sel counting, 2) apoptosis by terminal deoxynucleotide transferase-mediated deoxyuridine triphosphate-biotin nick end-labeling staining, and 3) cellul ar proliferative activity using anti-proliferative cell nuclear antigen ant ibody. The results were compared with carcinoembryonic antigen doubling tim e and survival. RESULTS. The five-year survival rate was 20 percent. The po stoperative carcinoembryonic antigen doubling time, which was the strongest predictor of survival, correlated highly with proliferative cell nuclear a ntigen labeling index, but did not correlate with the apoptotic index or mi crovessel counts. CONCLUSION: Our study shows that cancer cell proliferatio n rather than apoptosis or angiogenesis is a major determinant of tumor gro wth rate and survival in patients with locally recurrent rectal cancer.