Paulose Roopa R, Ail Divya A, Biradar Shital, Vasudevan Anu, Sundaram K R
Department of Pathology, Amrita Institute of Medical Sciences, Kochi, Kerala, India.
Department of Biostatistics, Amrita Institute of Medical Sciences, Kochi, Kerala, India.
Indian J Cancer. 2019 Oct-Dec;56(4):302-308. doi: 10.4103/ijc.IJC_365_18.
Microsatellite instability (MSI) accounts for 15-20% of colorectal cancer (CRC) and is considered to have favorable stage-adjusted prognosis compared to Microsatellite stable (MSS) CRCs. Determination of MSI in stage II CRC is important for management decisions regarding adjuvant chemotherapy administration. The aim of this study was to determine the prognostic and predictive significance of MSI in stage 2 CRC in the Indian scenario.
A total of 195 patients who underwent curative surgery for stage II CRC from 2010 to 2017 were included. MSI testing by immunohistochemistry (DNA MisMatch Repair proteins) was performed in all. Various clinicopathological factors and disease-free survival and overall survival were assessed between MSI and MSS groups. The effect of treatment in terms of survival benefits with adjuvant therapy in the MSI group was also assessed.
27.1% of the CRCs' showed MSI. Younger age (<50 years), family history of cancer, synchronous/metachronous malignancies, proximal (right sided) location, poor morphological tumour differentiation, mucin production, and presence of peritumoral (Crohn's-like) lymphocytic response showed statistically significant association with MSI. Majority (56%) of our patients showed combined loss of MLH1 and PMS2. Overall, survival among the MSI patients was significantly higher (76.6 ± 4.149 months) than the MSS patients (65.05 ± 3.555)P= 0.04. MSI patients did not show any differences in survival with or without treatment.
This study highlights the distinct clinicopathological features of MSI-related CRC and the relevance of MSI testing of stage II CRC for management decisions and prognostication.
微卫星不稳定性（MSI）在结直肠癌（CRC）中占15%-20%，与微卫星稳定（MSS）的结直肠癌相比，其分期调整后的预后被认为较好。确定II期结直肠癌的MSI对于辅助化疗管理决策很重要。本研究的目的是确定在印度情况下MSI在II期结直肠癌中的预后和预测意义。
纳入2010年至2017年接受II期结直肠癌根治性手术的195例患者。全部进行免疫组织化学（DNA错配修复蛋白）MSI检测。评估MSI组和MSS组之间的各种临床病理因素、无病生存期和总生存期。还评估了MSI组辅助治疗在生存获益方面的治疗效果。
27.1%的结直肠癌显示MSI。年龄较小（<50岁）、癌症家族史、同时性/异时性恶性肿瘤、近端（右侧）位置、肿瘤形态学分化差、黏液产生以及肿瘤周围（克罗恩样）淋巴细胞反应与MSI显示出统计学上的显著关联。我们的大多数患者（56%）显示MLH1和PMS2联合缺失。总体而言，MSI患者的生存期（76.6±4.149个月）显著高于MSS患者（65.05±3.555），P = 0.04。MSI患者无论接受治疗与否，生存期均无差异。
本研究突出了MSI相关结直肠癌独特的临床病理特征以及II期结直肠癌MSI检测对管理决策和预后判断的相关性。
