The Clinical Implication of Cancer-Associated Microvasculature and Fibroblast in Advanced Colorectal Cancer Patients with Synchronous or Metachronous Metastases

<div><p>Background</p><p>We aimed to evaluate the clinical significance of microvessel density (MVD), lymphatic vessel density (LVD), and cancer-associated fibroblasts (CAFs) in relation to tumor location in advanced colorectal cancer (CRC).</p><p>Methods</p><p>Using immunohistochemistry, we examined 181 advanced CRC patients for CD31 and D2-40 to measure MVD and LVD, respectively, α-smooth muscle actin (SMA) and desmin to identify CAFs, and PTEN to examine genetic changes of CAFs. To evaluate the regional heterogeneity of these properties, we examined tissue from four sites (the center and periphery of the primary cancer, a distant metastasis, and a lymph node metastasis) in each patient.</p><p>Results</p><p>MVD, LVD, and CAFs showed significant heterogeneity with respect to the tumor location. LVD was the greatest in the center of the primary cancers and the amount of CAFs was the lowest in distant metastases. In distant metastases, those from the lung had higher LVD and MVD, but fewer CAFs than those from the liver, peritoneum, or ovary. Patients with low MVD and LVD in the center of the primary cancer had worse outcomes and patients with few CAFs in distant metastases and in the primary tumor had a lower survival rate. PTEN expression in CAFs in distant metastases was lost in 11 of 181 CRC patients (6.1%), which was associated with a worse prognosis.</p><p>Conclusions</p><p>The microenvironment, including cancer-associated microvasculature and fibroblasts, is heterogeneous with respect to the tumor location in CRC patients. Therefore, heterogeneity of microenvironments should be taken into account when managing CRC patients.</p></div

Heterogeneity of lymphatic vessel density (LVD), microvessel density (MVD), and amount of cancer-associated fibroblasts (CAFs) with respect to tumor location.

<p>The LVD (A), MVD (B) and CAF area (C) was significantly different according to each tumor location.</p

Univariate and multivariate survival analysis according to clinicopathologic features.

<p>Univariate and multivariate survival analysis according to clinicopathologic features.</p

Clinicopathologic factor and LVD, MVD and CAFs.

<p>*, p<0.05; **, p<0.01; †, chemotherapy prior to metastatectomy of distant metastasis.</p

LVD, MVD, and CAF area at different distant metastasis sites.

<p>The characteristics of cancer-associated stroma differed with respect to the metastatic site. LVD (A) and MVD (B) were greater in the metastatic tumor samples collected from the lung than in samples collected from other metastatic sites (p<0.001). However, the amount of CAFs was not significant different between metastatic sites (C).</p

<i>HER2</i> Status in Colorectal Cancer: Its Clinical Significance and the Relationship between <i>HER2</i> Gene Amplification and Expression

<div><p>This study aimed at determining the incidence and clinical implications of <i>HER2</i> status in primary colorectal cancer (CRC). <i>HER2</i> status was investigated in two retrospective cohorts of 365 consecutive CRC patients (cohort 1) and 174 advanced CRC patients with synchronous or metachronous distant metastasis (cohort 2). <i>HER2</i> status was determined by performing dual-color silver in-situ hybridization (SISH), mRNA in-situ hybridization (ISH), and immunohistochemistry (IHC). The incidence of HER2 protein overexpression (IHC 2+/3+) was approximately 6% (22 of 365 in cohort 1; 10 of 174 in cohort 2). <i>HER2</i> gene amplification was observed in 5.8% of the patients from cohort 1 and 6.3% of the patients from cohort 2. <i>HER2</i> gene amplification was more frequently observed in CRCs located in the rectum than in the right and left colon (<i>P</i> = 0.013 in cohort 1; <i>P</i> = 0.009 in cohort 2). <i>HER2</i> status, determined by IHC, ISH, and dual-color SISH, was not significantly associated with aggressive CRC behaviour or patients' prognosis in both the cohorts. Of the combined cohort with a total of 539 cases, the concordance rate was 95.5% between dual-color SISH and IHC detection methods. On excluding equivocally immunostained cases (IHC 2+), the concordance rate was 97.7%. <i>HER2</i> mRNA overtranscription, detected by ISH, significantly correlated with protein overexpression and gene amplification (<i>P</i><0.001). <i>HER2</i> gene amplification was identified in a minority of CRC patients with high concordance rates between dual-color SISH and IHC detection methods. Although <i>HER2</i> status did not predict patients' prognosis, our findings may serve as a basis for future studies on patient selection for <i>HER2</i> targeted therapy.</p></div

Representative figures of <i>HER2</i> status by IHC, ISH, and dual-color SISH in CRC patients.

<p>(A) IHC 0 (40× objective); (B) score 0 by mRNA ISH (40× objective); (C) <i>HER2</i> gene disomy (60× objective); (D) IHC 3+; (E) score 4 by mRNA ISH; (F) <i>HER2</i> gene amplification (<i>HER2</i>/CEP17 ratio ≥2).</p

Additional file 3: of Favorable prognosis in colorectal cancer patients with co-expression of c-MYC and ß-catenin

Raw data of c-MYC and ß-catenin status obtained from cohort1. (XLSX 51 kb

Additional file 1: Table S1. of Favorable prognosis in colorectal cancer patients with co-expression of c-MYC and ß-catenin

The number at risk in each category, at each interval for all Kaplan-Meier plots in Fig. 2. (DOCX 21 kb

The correlation between immunohistochemistry and silver in situ hybridization for <i>HER2</i> in all CRCs of combined cohort.

<p>Abbreviations: CRC, colorectal cancer; <i>HER2</i>, human epidermal growth factor receptor 2; SISH, silver in-situ hybridization; <i>N</i>, number; mRNA, messenger RNA.</p><p>All the IHC 3+ cases and all the ISH score 4 cases showed <i>HER2</i> gene amplification by dual-color SISH. The concordance rate was 95.5% between dual-color SISH and IHC detection methods.</p