Basic surgical principles for locally advanced rectal cancer in complex therapy

Background. Compliance with principles of surgical oncology is necessary to choose effective treatment options for locally advanced rectal cancer (LARC). Objective: to show the basic surgical principles for LARC using a new option of complex therapy. Material and Methods. The basic surgical principles for LARC using a new option of complex therapy with polyradiomodifcation (local microwave hyperthermia + intrarectal administration of a polymer composition with Metronidazole) in combination with polychemotherapy (oral administration of Capecitabine + intravenous administration of Oxaliplatin) with concurrent prolonged hypofractionated radiation therapy were presented. Results. The treatment outcomes of the new option of complex neoadjuvant therapy with the compliance of surgical oncology principles were studied in 46 patients with LARC (T3cd-T4a N1c-2ab M0, CRM+, EMVI+). An analysis of the immediate outcomes showed that postoperative complications were diagnosed in only 4 (8.7 %) of 46 patients and no deaths were recorded. The local control was achieved: cancer recurrence was diagnosed in only 1 (2.2 %) and distant metastases in 4 (8.7 %) of patients. The 5-year recurrence-free survival rate in these patients was signifcantly higher than that observed in patients who received conventionally fractionated radiotherapy in combination with Capecitabine (81.0 vs 56.8 %, p=0.02). The improvement of results was achieved both by adhering to the principles of surgical oncology and increasing the radiosensitivity of the tumor: pathologic complete response was achieved in 35 (76.1 %) patients. This made it possible to perform sphincter-preserving surgeries in 71.7 % (33 out of 46) patients and in 66.7 % (18 out of 27) with lower-ampullary cancer. Conclusion. The use of a new method of complex therapy for LARC and compliance with the basic principles of surgical oncology allowed the improvement of long-term treatment outcomes by achieving local control of the tumor, contributing to the expansion of indications for performing sphincter-preservingsurgeries.