The Clinical Study Of Safe Distance To Distal Resection Margin From Tumor In Radical Operation For Rectal Cancer

Background: Surgical operation is the most efficient method in treating rectal cancer, but local recurrence is major factor that cause the curative operations failed. It is an important reason of local recurrence after rectal cancer operations that distal distance margin from tumor is not excised completely. There is no still right answer about the length of distal resection margin of rectal cancer now. To find out the safe distal distance from tumor in the radical operations of rectal cancer and to provide evidence for the radical operations of rectal cancer, the experiment study is about pathological change of 5cm Transitional Mucosae (TM) from distal resection margin of the rectal cancer in the molecular level.Methods: Specimens of thirty-six patients with rectal cancer who had been operatedfrom April, 2002 to April, 2003, were collected and l~5cm TM of fresh specimens were made into cellular suspension. Quantitative analysis of DNA ploidy and p53 protein expression in the cellular suspension were carried out by Flow cytometry (FCM) . In the end, the experimental data was analyzed by statistics.Results: From 1 centimeter to 5 centimeter in TM of the rectal cancer specimens, Thepositive rate of DNA aneuploid and DNA Index (DI) was significantly differential between the 1-3 centimeter and the 4-5 centimeter (P<0.05) , whereas difference was not significant in the positive rate of p53 protein expression. There was no difference among the positive rate of DNA aneuploid in all sorts of gross morphology and all grades of differentiation (P>0.05) . However, there was significant difference in TNM stage of tumor about the positive rate of DNA aneuploid (P<0.05). There was no significant difference about the positive rate of p53 protein expression among the clinical feature of tumor.Conclusion: The results of study suggest that the safe distance of distal resection margin from tumor in radical operations of rectal cancer should be 3 centimeter at least,and the distal resection distance of the poorly differentiation, infiltrate type cases should be enlarged more.