Nakayama Yujiro, Iijima Takeru, Inokuchi Takuhiko, Kojika Ekumi, Takao Misato, Takao Akinari, Koizumi Koichi, Horiguchi Shin-Ichiro, Hishima Tsunekazu, Yamaguchi Tatsuro
Department of Surgery, Tokyo Metropolitan Cancer and Infectious Diseases Center Komagome Hospital, 3-18-22, Honkomagome, Bunkyo-ku, Tokyo, 113-0021, Japan.
Department of Minimally Invasive Surgical and Medical Oncology, Fukushima Medical University, Hikarigaoka, Fukushima, 960-1247, Japan.
Int J Clin Oncol. 2021 Oct;26(10):1881-1889. doi: 10.1007/s10147-021-01968-y. Epub 2021 Jun 19.
The clinical and pathological features of sporadic microsatellite instability-high (MSI) colorectal cancer (CRC) are still unclear. The present study aimed to clarify the clinicopathological features of sporadic MSI CRC in comparison with those of Lynch syndrome (LS) exploratorily.
The present study was a single-center, retrospective cohort study. Sporadic MSI CRC was defined as MSI CRC with aberrant promoter hypermethylation of the MLH1 gene, while hereditary MSI CRC was defined colorectal cancer in patients with LS.
In total, 2653 patients were enrolled; of these, 120 (4.5%) had MSI CRC, 98 had sporadic MSI CRC, and 22 had LS. Patients with sporadic MSI CRC were significantly older (p < 0.001) than those with LS and had a right-sided colonic tumor (p < 0.001) which was pathologically poorly differentiated or mucinous (p = 0.025). The overall survival rate was significantly lower in patients with stage I, II or III MSI CRC than in those with LS (p = 0.024). However, the recurrence-free survival rate did not differ significantly (p = 0.85).
We concluded that patients with sporadic MSI are significantly older, tumors more likely to locate in the right-sided colon, pathologically poorly differentiated or mucinous, and worse overall survival than in those with LS.
散发性微卫星高度不稳定（MSI）结直肠癌（CRC）的临床和病理特征仍不清楚。本研究旨在探索性地阐明散发性MSI CRC与林奇综合征（LS）相比的临床病理特征。
本研究为单中心回顾性队列研究。散发性MSI CRC定义为伴有MLH1基因启动子异常高甲基化的MSI CRC，而遗传性MSI CRC定义为LS患者的结直肠癌。
共纳入2653例患者；其中，120例（4.5%）患有MSI CRC，98例患有散发性MSI CRC，22例患有LS。散发性MSI CRC患者比LS患者年龄显著更大（p<0.001），且患有右侧结肠肿瘤（p<0.001），其病理表现为低分化或黏液性（p=0.025）。I、II或III期MSI CRC患者的总生存率显著低于LS患者（p=0.024）。然而，无复发生存率无显著差异（p=0.85）。
我们得出结论，散发性MSI患者年龄显著更大，肿瘤更可能位于右侧结肠，病理表现为低分化或黏液性，且总生存率低于LS患者。
