NEOADJUVANT CHEMOTHERAPY WITHOUT RADIATION THERAPY IN UPPER RECTAL CANCER

S.N. Lukmonov1, Ya.V. Belenkaya1,2, S.S. Gordeev1,3, Z.Z. Mamedli1

1N.N. Blokhin National Medical Research Center of Oncology, Moscow

2Sechenov First Moscow State Medical University (Sechenov University), Moscow

3Tyumen State Medical University, Tyumen

Lukmonov Saidrakhim N. ― postgraduate student of the Department of Surgical Methods of Treatment №3 (Coloproctology) of the N.N. Blokhin National Medical Research Center of Oncology

24 Kashirskoe highway, Moscow, 115522, Russian Federation, tel. +7-989-580-84-95, e-mail: drrakhim46@gmail.com 

Abstract

Introduction. The option of radiation therapy in rectal cancer is proposed in domestic and foreign clinical guidelines, however, radiation therapy is associated with delayed side effects. An alternative to radiation therapy may be the use of NACT. There is little information in the scientific literature about the role of neoadjuvant chemotherapy (NACT) in upper  rectal cancer (u/p RC), so we conducted the present study.

The purpose of our study is to study the safety and effectiveness of NACT without the use of radiation therapy in upper rectal cancer.

Methods. We conducted a retrospective cohort multicenter study, during which we analyzed data from medical dates of patients with upper rectal cancer from 2007 to 2020. The main parameter assessed was 3-year disease-free survival (DFS). The pathological complete response (pCR) rate, treatment toxicity, postoperative complications rate (Clavien ― Dindo), tumor regression rate, local recurrence and metastasis rate, 3-year overall survival (OS), and completion rate of the full course of treatment were also assessed.

Results. 118 patients were included in the study. Median follow-up was 37,14 months (Q1=25 months, Q3=50,2 months). The 3-year DFS was 90,7%, the 3-year OS was 94,5%. The local recurrence rate was 0%, the rate of metastases was 13,6%. In multivariate analysis, the factors that significantly influenced in DFS were: age (p=0,010), pN+ (p=0,033). 15 (12,7%) patients receiving NACT registered a complete pathological response (pCR). The frequency N downstaging (from cN+ to ypN0) was 34,7%. The completion rate of the full course of NACT was 91,5%. Hematological toxicity of grade 3-4 was observed in 4 patients (3,3%), non-hematological toxicity in 4 patients (3,3%). 1 patient died from acute myocardial infarction during NACT. The incidence of anastomotic leakage (AL) was 6,8%. R1 rectal resection was performed in 1 (0,9%) patient.

Conclusion. NACT without the use of radiation therapy in upper rectal cancer has an acceptable toxicity profile, does not worsen oncological treatment outcomes, and can potentially be used for early initiation of systemic therapy in a selected group of patients.

Key words: upper rectal cancer adenocarcinoma, neoadjuvant chemotherapy.