肿瘤体积对局部进展期直肠癌预后的影响

目的:探讨肿瘤体积(gross tumor volume,GTV)对接受新辅助放化疗(neoadjuvant chemoradiotherapy,NCRT)和全直肠系膜切除术(total mesorectal excision,TME)后,局部进展期直肠癌(locally advanced rectal cancer,LARC)患者的预后影响。方法:回顾性分析2011年1月至2016年9月湖南省肿瘤医院收治的128例初治直肠癌患者的临床资料,均接受术前同步放化疗+TME。采用受试者工作特征曲线(receiver-operating characteristic,ROC)分析GTV截点值,用Kaplan-Meier生存分析和Cox比例风险回归模型进行预后分析。结果:行NCRT后T分期降期率为58.6%,N分期降期率为69.5%,总体降期率为77.3%,病理完全缓解(pathologi-cal complete response,p CR)率为16.4%,总体保肛率为57.03%。GTV的截点为79.31 m L,GTV≥79.31 m L与GTV<79.31 m L患者的3年总生存率(overall survival,OS)、无病生存率(disease-free survival,DFS)、无局部复发生存率(local relapse free survival,LRFS)、无远处转移生存率(distant-metastasis-free survival,DMFS)有显著性差异。GTV与MRI-T分期(ρ=0.236,P=0.007)、T分期变化(ρ=0.229,P=0.009)、TNM分期变化(ρ=0.219,P=0.013)及肿瘤退缩分级(tumor regression grade,TRG)(ρ=0.517,P<0.001)相关,与MRI-T分期、MRI-N分期及N分期变化无关。结论:GTV与LARC的局部复发、远处转移密切相关,是预后因素之一;肿瘤体积与治疗前T分期、新辅助治疗后的T分期变化、TNM分期变化及TRG相关,与治疗前N分期及N分期变化无关。

The effect of tumor volume on the prognosis of locally advanced rectal cancer

  Objective  To evaluated the prognostic effect of tumor volume in patients with locally advanced rectal cancer (LARC) treated with neoadjuvant chemoradiotherapy (NCRT) and total mesorectal excision (TME).  Methods  This was a retrospective analysis of 128 patients with newly diagnosed rectal cancer who received preoperative concurrent chemoradiation plus TME from January 2011 to September 2016 in Hunan Cancer Hospital. The receiver-operating characteristic (ROC) curve was used to analyze the gross tumor volume (GTV) cut-off point. Prognostic analysis was performed using Kaplan-Meier, Log-rank, and Cox regression models.  Results  After NCRT, T-stage declined 58.6%, N-stage declined 69.5%, and the overall TNM stage declined 77.3%. After NCRT, the pathological complete response (pCR) rate was 16.4% and the anus-protection rate was 57.03%. The GTV cut-off point was 79.31 mL. There were significant differences in OS, DFS, LRFS and DMFS between patients with GTV ≥ 79.31 mL and patients with GTV < 79.31 mL over three years. GTV was significantly related to MRI-T staging (ρ=0.236; P=0.007), T downstaging (ρ=0.229; P=0.009), TNM downstaging (ρ=0.219; P=0.013), and tumor regression grade (TRG) (ρ=0.517; P < 0.001); however, GTV was not significantly related to MRI-N staging and N downstaging.  Conclusions  GTV is closely related to local recurrence and distant metastasis of LARC, and is an important prognostic factor. Tumor volume was significantly related to pretreatment MRI-T staging, T downstaging, TNM downstaging after NCRT, and TRG, but not to pretreatment MRI-N staging and N downstaging.