Colorectal micropapillary carcinoma has recently been reported as an aggressive variant of adenocarcinoma with a high incidence of lymph node metastasis, but has not been well investigated in terms of survival analysis. This study analyzed the clinicopathological characteristics, including survival data, of the patients with micropapillary carcinoma. We hypothesized that the aggressive features of micropapillary carcinoma might be related to the presence of more tumor cells with stem cell phenotype in colorectal cancer. Fifty-five (10%) micropapillary carcinoma cases were identified among 561 cases of colorectal cancer. We compared the clinicopathological characteristics, including survival data and immunohistochemical profiles of stem cell markers (SOX2, NOTCH3, CD44v6, CD166, ALDH1) of micropapillary carcinomas with those of randomly selected 112 conventional adenocarcinomas lacking micropapillary carcinoma components (non-micropapillary carcinoma) in the colorectum. To exclude the possibility of dilution of control group by patients with microsatellite instability-high carcinomas, we divided non-micropapillary carcinomas into microsatellite instability-high carcinoma and microsatellite stable tumors. Micropapillary carcinomas were characterized by more frequent lymphovascular invasion (Po0.0001) and lymph node metastasis (Po0.0001), higher pathological T and tumor node metastasis stages (P ¼ 0.047 and P ¼ 0.001), and more frequent SOX2 (P ¼ 0.038) and NOTCH3 expressions (P ¼ 0.005). Overall 5-year survival rate for patients with micropapillary carcinoma (37%) was significantly lower than for microsatellite instability-high carcinoma and microsatellite stable carcinoma patients (92 and 72%, Po0.0001). The presence of the micropapillary carcinoma component was shown to be associated with a significantly worse survival rate in univariate (Po0.0001) and multivariate (P ¼ 0.003, Cox hazard ratio 2.402) analyses. In conclusion, recognition of the micropapillary carcinoma component in colonic adenocarcinoma is very important, because the micropapillary carcinoma has been associated with a significantly worse prognosis. We also found a higher expression rate of cancer stem cell markers in micropapillary carcinomas, suggesting their potential contribution to the survival disadvantage of micropapillary carcinoma. Modern Pathology (2013Pathology ( ) 26, 1123Pathology ( -1131 doi:10.1038/modpathol.2012 published online 12 October 2012 Keywords: colorectum; micropapillary carcinoma; prognosis; stem cell marker; TNM stage Colorectal cancer is one of the leading causes of cancer deaths worldwide, and both the prevalence and the incidence rate in South Korea are rapidly rising. 1 For metastatic colorectal cancer, the 5-year survival rate is only about 10%. 2 Micropapillary carcinoma is a relatively uncommon and distinctive tumor characterized by small clusters of tumor cells in the clear lacunar spaces, mimicking lymphatic or vascular channels. 3 Micropapillary carcinoma has high potential to metastasize to the regional l...

Background The aim of this study was to use immunohistochemistry (IHC) and silver in situ hybridization (SISH) to evaluate alterations in EGFR and HER2 in gastric cancer in order to determine the relationship with prognosis in gastric cancer patients following curative resection. Patients and methods In this study, we analyzed EGFR and HER-2 status by IHC and SISH in 254 stage I-III gastric cancer patients who underwent curative surgery. Results Thirteen cases (2.48 %) showed EGFR alteration by IHC or SISH. EGFR alteration was associated with older age (P = 0.021), intestinal type (P = 0.040) and higher stage disease (P \ 0.001). The patients with operable state gastric cancer who had EGFR alteration had an unfavorable prognosis, and multivariate analysis confirmed that EGFR alteration was an independent unfavorable prognostic factor. Twenty-seven cases (10.6 %) showed HER-2 alteration by IHC or SISH. HER-2 alteration was associated with older age (P = 0.006), well or moderately differentiated histology (P \ 0.001) and intestinal type (P = 0.002). Conclusion HER-2 alteration is not an independent prognostic factor for curatively resectable gastric cancer. We observed EGFR alteration in a subset of cases with operable state gastric cancer and determined that it was associated with an unfavorable prognosis.