Results of combined treatment with neoadjuvant chemotherapy without radiation therapy and a short-course of radiation therapy in patients with intermediate-risk rectal cancer [Результаты комбинированного лечения с применением неоадъювантной химиотерапии без лучевой терапии и короткого курса лучевой терапии у больных раком прямой кишки промежуточного риска]

Background. Neoadjuvant chemotherapy (NACT) is a potential alternative to chemoradiation therapy (CRT) in intermediate-risk rectal cancer patients, helping to avoid the side effects of radiation therapy and may allow early prevention of distant metastasis. Aim – to study the safety and effectiveness of NACT in patients with intermediate-risk rectal cancer. Material and methods. Patients with histologically confirmed cancer of the mid-ampullar rectum T2–T3cN1–2M0, T2–4aN1–2M0 and T4aN0M0 of the upper ampullary rectum were included in the retrospective study. All patients of the study group underwent NACT according to the CapOx 4 course scheme. Evaluation of the effect was carried out on the basis of MRI of the small pelvis: in the presence of regression or stabilization, surgical treatment was performed, in the presence of progression, CRT, then surgery. After surgery, all patients were scheduled for adjuvant chemotherapy for a total duration of 6 months. Patients in the control group underwent neoadjuvant radiation therapy (25 Gy in fractions of 5 Gy) and then surgery for 4–8 weeks. The primary endpoints included pathological complete response rate (pCR) and 3-year disease-free survival (DFS). Results. The study included 117 patients in each group. 113 (96.5%) patients in the neoadjuvant chemotherapy group completed all 4 courses of chemotherapy. In 12 (10.3%) patients in the NACT group a complete pathological response (pCR) was noted, among patients who received only NACT followed by surgery (n=111) pCR was noted in 11 (9.9%) cases. The median follow-up was 36.2 months for both groups. The distant failure rate was 9 (7.7%) in the NACT group and 20 (17.1%) in the control group (p=0.046). There were no local recurrence. The 3-year OS was 90.6 and 92.5% (p=0.857), and the 3-year DFS was 86.1 and 80.8%, respectively (p=0.394). Conclusion. Neoadjuvant chemotherapy is a promising treatment option for rectal cancer patients with negative prognostic factors. © 2021 GEOTAR Media. All rights reserved.