Role of histological regression grade after two neoadjuvant approaches with or without radiotherapy in locally advanced gastric cancer

Abstract

Background:The degree of histopathological response after neoadjuvant therapy in locally advanced gastric cancer (GC) is a key determinant of patients' long-term outcome. We aimed to assess the pattern of histopathological regression after two neoadjuvant approaches and its impact on survival times.Methods:Regression grade of the primary tumour (Becker criteria) and the degree of nodal response by a 4-point scale (grades A–D) were assessed. Grade A—true negative lymph nodes (LNs); grade B and C—infiltrated LNs with any or little evidence of nodal response; and grade D—complete pathological response in a previously infiltrated LN. A favourable pathological response was defined as Becker Ia–b and grade D.Results:From 2004 to 2014, 80 patients with GC (cT3–4/N+ by CT-scan/EUS) were treated with either preoperative chemotherapy (ChT, n=34) or chemoradiation (CRT, n=46). Patients in the CRT group had a higher likelihood of achieving a Becker Ia–b response (58 vs 32%, P=0.001), a grade D nodal regression (30 vs 6%, P=0.009) and a favourable pathological response (23 vs 3% P=0.019). Patients with a grade D nodal response had a longer 5-year PFS and OS compared with those with a grade B or C response. Patients with a baseline negative LN status had similar outcomes irrespective of the preoperative therapy received (5-year OS; ChT vs CRT, 58 vs 51%, P=0.92).Conclusions:Preoperative chemoradiation increases the likelihood of achieving favourable histopathological features that correlate with a 5-year OS>70% in GC patients.

Evaluation and Comparison of Predictive Value of Tumor Regression Grades according to Mandard and Becker in Locally Advanced Gastric Adenocarcinoma

“…For the Mandard TRG, some studies supported that TRG 1-2 should be classified into responders, which was in accordance with our study [7,18,19], while some others believed that TRG 1-3 was better in distinguishing the prognosis [20][21][22]. For the Becker TRG, there were studies supporting the same consequence as ours [1,[23][24][25], while others suggested TRG 1-2 owned a better prognosis than TRG 3 [9,10,26,27]. This discrepancy might partly derive from the differences in subjective evaluations of the pathologists.…”

“…Tumor regression grade (TRG) is a system to assess the quantity of residual tumor, which could provide extra information to evaluate the curative effects and prognosis [1,4]. Nevertheless, there are various systems without a consensus [7][8][9][10].…”

Progress in the treatment of advanced gastric cancer

“…Gastric cancer is an adenocarcinoma, and a radiotherapy dose of 45-50.4 Gy can lead to serious adverse reactions. 20 This has led to a strong requirement for the development of radiotherapy technology, particularly as related to precision, delineating the radiotherapy target area, and the formulation and implementation of a radiotherapy plan. With radiotherapy for gastric cancer, uncertain factors such as changes in the body position during radiotherapy, the influence of diaphragmatic respiratory movements, and the change in gastric volume and gastrointestinal motility should be considered.…”

Tumor Regression Grade Predicts Survival in Locally Advanced Gastric Adenocarcinoma Patients with Lymph Node Metastasis

“…In addition to stratification, the combination of TRG and lymph node stage was also used to predict the survival [ 2 , 3 , 18 , 26 ]. Based on the MAGIC trial, Smyth et al [ 3 ] found that patients in TRG 3-5 and node positive group owned worse overall survival than others, while patients with TRG 1-2 and node negative were the best, which is consistent with our result.…”

“…Another paper from the UK showed similar outcome, while they suggested the boundary should be TRG 1-3 vs. 4-5 [ 18 ]. Holscher et al [ 26 ] and Martin-Romano et al [ 2 ] also considered the responders with node negative owned better prognosis when using the TRG of proportion.…”