Hosseini Sare, Nguyen NamPhong, Mohammadianpanah Mohammad, Mirzaei Sepideh, Bananzadeh Ali Mohammad
Cancer Research Center, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran.
Department of Radiation Oncology, Howard University Hospital, 2401 Georgia Avenue, NW, Room 2055, Washington, DC, 20060, USA.
J Gastrointest Cancer. 2019 Dec;50(4):716-722. doi: 10.1007/s12029-018-0136-x.
Currently, neoadjuvant fluoropyrimidine-based chemoradiation followed by surgery is considered the standard of care for locally advanced rectal cancer. The current study aimed to investigate the predictive significance of mucinous histology on the pathologic complete response rate following neoadjuvant chemoradiation in locally advanced rectal cancer and to propose potential new treatment protocol for this specific histology.
This retrospective study was conducted on 403 patients with locally advanced (clinically T3-4 and/or N1-2) rectal adenocarcinoma who had been treated at three tertiary academic hospitals between 2010 and 2015. Among those 403 patients, 46 (11%) had mucinous rectal cancer (MRC) and 358 (89%) had non-mucinous rectal cancer (NMRC). All patients underwent neoadjuvant chemoradiation with capecitabine followed by low anterior or abdominoperineal resection.
There were 268 men and 135 women with a median age of 55 years (range, 26-82 years). Patients with MRC were younger (p = 0.002) and presented with a larger tumor size (p < 0.001) and a more advanced tumor stage (p = 0.033) compared to the ones with MNRC. In the univariate analysis, female gender (p = 0.009), distal tumor location (p = 0.035), higher tumor stage (p = 0.049), node positivity (p = 0.001), MRC histology (p = 0.017), and high pretreatment CEA level (p = 0.013) were observed to be predictive of a poor pathologic complete response. However, in the multivariate analysis, tumor stage was the single most predictive factor of response to neoadjuvant chemoradiation.
Mucinous adenocarcinoma is a significant predictive factor for poor pathologic complete response to neoadjuvant capecitabine-based chemoradiation in patients with locally advanced rectal cancer. New treatment modality based on biomarkers may be considered in future prospective studies because of MRC poor prognosis. Immunotherapy combined with chemotherapy and/or radiotherapy may be an attractive option because of the tumor microsatellite instability-high status.
目前，基于氟嘧啶的新辅助放化疗后行手术被认为是局部晚期直肠癌的标准治疗方案。本研究旨在探讨黏液组织学对局部晚期直肠癌新辅助放化疗后病理完全缓解率的预测意义，并针对这种特定组织学提出潜在的新治疗方案。
本回顾性研究纳入了2010年至2015年间在三家三级学术医院接受治疗的403例局部晚期（临床T3-4和/或N1-2）直肠腺癌患者。在这403例患者中，46例（11%）为黏液性直肠癌（MRC），358例（89%）为非黏液性直肠癌（NMRC）。所有患者均接受了以卡培他滨为基础的新辅助放化疗，随后行低位前切除术或腹会阴联合切除术。
共有268例男性和135例女性，中位年龄为55岁（范围26-82岁）。与NMRC患者相比，MRC患者更年轻（p = 0.002），肿瘤体积更大（p < 0.001），肿瘤分期更晚（p = 0.033）。在单因素分析中，女性（p = 0.009）、肿瘤远端位置（p = 0.035）、更高的肿瘤分期（p = 0.049）、淋巴结阳性（p = 0.001）、MRC组织学（p = 0.017）和治疗前CEA水平高（p = 0.013）被观察到可预测病理完全缓解较差。然而，在多因素分析中，肿瘤分期是新辅助放化疗反应的唯一最具预测性的因素。
黏液腺癌是局部晚期直肠癌患者对以卡培他滨为基础的新辅助放化疗病理完全缓解较差的一个重要预测因素。由于MRC预后较差，未来前瞻性研究中可考虑基于生物标志物的新治疗模式。由于肿瘤微卫星高度不稳定状态，免疫治疗联合化疗和/或放疗可能是一个有吸引力的选择。
