Assessment and application of tumor regression grade after neoadjuvant chemotherapy in bladder cancer / 中华泌尿外科杂志

ABSTRACT

Objective:To verify the prognostic significance of the tumor regression grade (TRG) for muscle-invasive bladder cancer (MIBC) patients undergoing radical cystectomy (RC) after neoadjuvant chemotherapy.Methods:The data of 70 MIBC patients treated with gemcitabine combined with cisplatin neoadjuvant chemotherapy and RC in Sun Yat-sen University Cancer Center between July 2016 to November 2021 were retrospectively reviewed. There were 65 males and 5 females, with an average age(59.79±10.56)years old. The patients accepted transurethral resection of bladder tumor (TURBT) specimens before neoadjuvant chemotherapy. Clinicopathological characteristics of patients were recorded and TRG was assessed. TRG evaluation criteria: TRG 1 was defined as no cancer residue, TRG 2 was defined as the proportion of residual cancer area to tumor bed area <50%, and TRG 3 was defined as the proportion of residual cancer area to the area of the tumor bed ≥ 50%. Chi-square test or Fisher's exact test were used to compare the relationship between patients' clinicopathological characteristics and TRG. The relationship between post-neoadjuvant therapy tumor and node(ypTN)stage, and survival, including overall survival(OS)and recurrence-free survival (RFS) were analyzed by Kaplan-Meier analysis. The pathologically locally descending disease was defined as (ypT < T 2 and ypN=N 0) and pathologically locally advanced disease was defined as (ypT≥T 2 and/or ypN ≥N 1). Cox regression was used for univariate and multivariate analysis of OS and RFS. Results:Chi-square test or Fisher exact test analysis showed TRG was significantly associated with ypT stage ( P < 0.001), ypN stage ( P = 0.002), lympho-vascular invasion ( P<0.001) and variant histology ( P<0.001). The OS of patients with TRG 1, TRG 2 and TRG 3 were 20.5(10.3, 31.8), 17.0(11.0, 30.8)and 15.0(11.0, 26.0) months, respectively, and the difference was significantly different( P = 0.037). The RFS of patients with TRG 1, TRG 2 and TRG 3 were 15.0(8.3, 25.5), 15.0(8.0, 27.0)and 11.0(4.5, 25.5) months, respectively, and the difference was significantly different ( P=0.029). There were significant differences between patients with pathologically locally descending disease and locally advanced disease in OS [18.5(10.3, 30.8)vs.15.0(11.0, 27.3)months, P = 0.013] and RFS [14.0(8.0, 24.0)vs. 11.5(8.0, 26.8)months, P = 0.012]. Among patients with locally advanced pathology, the OS was 19.5(11.0, 32.5)months for patients with TRG ≤2, 13.5(10.8, 26.0)months for patients with TRG 3( P=0.140). The RFS was 12.0(8.0, 31.0)months for those patients with TRG ≤2 and 11.0(6.0, 26.0)months for those patients with TRG 3( P = 0.180). Cox univariate analyses showed that patients with TRG 3 were associated with decreased OS ( HR = 6.043, 95% CI 1.170-31.213, P = 0.032) and RFS ( HR = 6.354, 95% CI 1.231-31.802, P = 0.027). Conclusions:This study showed that TRG was correlated with OS and RFS among patients. The patients who had the higher TRG had the worse prognosis. It was confirmed that TRG predicted the prognosis of patients undergoing radical cystectomy after neoadjuvant chemotherapy. Therefore, TRG assessment is recommend in pathology report for patients who had radical cystectomy after neoadjuvant chemotherapy.