[The influence of the preoperative radiotherapy upon the pathological characteristic of the rectal cancer].
The preoperative radiotherapy, leads to the reduction of the tumor, mainly through the destruction of the peripheral, well oxygenized tumor cells. These could change the remoteness of the tumor, from the sphincter and to influence on the type of operation, increasing the share of the conserving surgery. The aim of this study is to determine the frequency of these changes and their influence on the surgical approach.


METHODS
Preoperative radiotherapy of 40-45 Gy over 35 patients with rectal cancer was applied, since 1999 till 2002 year. The visible position of the tumor according to the anal verge was measured, with the help of rigid rectoscop, before and after the radiation. During the operation, the grade of infiltration of the bowel wall distal from the tumor was verified histologicaly. The changes in the structure, form and the size of the tumor was examined and the distance to the anal verge, was measured on the macroscopic pathological sample.


RESULTS
Change in the macroscopic appearance of the tumor from polypoid, protruding in the lumen to ulcerous-infiltrative tumor, with slight protruding and reduced thickness was noticed in 83% of the patients. The cranial-caudal size of the tumor was reduced in 80% of the patients. The histological examination of the slices from the parts of the bowel, liberated from tumor showed the lack of tumor cells. The change in the size of tumor and the removing of the tumor from the anal verge was reported in 49% of the cases. Operation, preserving rectum was performed in 9% instead of planned extirpation.


CONCLUSIONS
The preoperative radiotherapy, leads to the reduction of the sizes of the tumor and to its remove from the anal verge. The possibility, these changes to contribute to modification of the surgical method in some patients, without changing the chances for their healing, allows us to recommend this method and to apply it in the routine practice.
Mikhaĭlova
I
I
Deliĭski
T
T
Todorov
I
I
D000230:Adenocarcinoma / Q000473:pathology / Q000532:radiotherapy / Q000601:surgery; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D018714:Radiotherapy, Adjuvant; D012004:Rectal Neoplasms / Q000473:pathology / Q000532:radiotherapy / Q000601:surgery; D016896:Treatment Outcome