Beznosenko A. Combined treatment of patients with stage II-III distal rectal cancer applying neoadjuvant long-course radiotherapy

A dissertation is dedicated to increase the effectiveness of combined treatment and life quality of patients with distal rectal cancer. The developed method of combined treatment of rectal cancer patients, applying a long-course neoadjuvant radiotherapy (2 Gy x 15) has a reasonable scientific basis. Morphological changes in anal sphincter tissue after exposing it to different radiotherapy regimens had been examined. Fibrous substitution of anal sphincter tissue appears to be in direct correlation with summary irradiation dosage. The results of combined treatment of 251 patients with stage II-III distal rectal cancer had been assessed. Patients were randomized in two groups: group I - 150 patients, which underwent a course of radiotherapy with summary dose of 20 Gy (5 Gy x 4), followed by curative surgery on day 1-3; group II - 101 patients, which underwent a course of neoadjuvant radiotherapy with summary dose of 30 Gy (2 Gy x 15), followed by curative surgery no earlier than 21 days. Partial and complete response after long-course radiotherapy was observed in 30 % of cases, accompanied by an increase of overall 5-year survival rate - 88,6 %, compared to 76,9 % with stable disease (р=0,038). Long-course radiotherapy resulted in a double increase of sphincter-preserving operations rate, comparing to Group I - 80,2 and 60,1 % respectively (р<0,005). Advantages of the developed method of combined treatment of stage II-III distal rectal cancer patients, applying a long-course neoadjuvant radiotherapy had been proven by the means of increase of sphincter-preserving operations rate after treatment, decrease of local recurrence rate, improvement of 5-year survival.