Department of Surgery, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea.
Dig Liver Dis. 2010 Sep;42(9):611-5. doi: 10.1016/j.dld.2010.02.002. Epub 2010 Mar 15.
Microsatellite unstable CRC is associated with female gender, large tumours, and poor differentiation. However, there are few reports about the characteristics and differences of sporadic microsatellite unstable CRC based on tumour location.
Site-specific heterogeneity of sporadic microsatellite unstable colorectal cancer (CRC) based on location was elucidated.
We enrolled 164 CRC patients with high-frequency microsatellite instability (MSI-H) from the prospective database of 2686 consecutive CRC patients who underwent surgical resection. We analysed microsatellite instability (MSI) and expression of mismatch repair (MMR) proteins (MLH1, MSH2, and MSH6).
Among the 164 MSI-H CRC, 105 (64.0%) were located in the proximal colon and 59 (36.0%) were located in the distal colon. The proximal MSI-H CRC was predominantly in female (p=0.014), had a more aggressive differentiation (p=0.001), was of advanced stage (p=0.035), and had a frequent loss of MLH1 expression (p=0.005) compared to the distal MSI-H CRC.
There were different clinicopathologic characteristics and MMR protein expression between proximal and distal MSI-H CRC. These findings suggest that the underlying carcinogenic pathway or molecular background differs according to location, despite being microsatellite unstable CRC.
微卫星不稳定型 CRC 与女性、大肿瘤和低分化相关。然而，基于肿瘤位置，关于散发性微卫星不稳定型 CRC 的特征和差异的报道很少。
阐明基于位置的散发性微卫星不稳定型结直肠癌（CRC）的部位特异性异质性。
我们从 2686 例接受手术切除的连续 CRC 患者的前瞻性数据库中招募了 164 例高频微卫星不稳定（MSI-H）CRC 患者。我们分析了微卫星不稳定性（MSI）和错配修复（MMR）蛋白（MLH1、MSH2 和 MSH6）的表达。
在 164 例 MSI-H CRC 中，105 例（64.0%）位于近端结肠，59 例（36.0%）位于远端结肠。与远端 MSI-H CRC 相比，近端 MSI-H CRC 主要发生在女性（p=0.014），分化更具侵袭性（p=0.001），分期更晚（p=0.035），且 MLH1 表达缺失更频繁（p=0.005）。
近端和远端 MSI-H CRC 之间存在不同的临床病理特征和 MMR 蛋白表达。这些发现表明，尽管是微卫星不稳定型 CRC，但致癌途径或分子背景因位置而异。
