Clinical significance of hepatocyte growth factor and c-Met expression in extrahepatic biliary tract cancers

Inflammatory cells infiltrate and angiogenesis in locally advanced and metastatic cholangiocarcinoma

BACKGROUND

Cholangiocarcinoma (CCA) is the second most common subtype of primary hepatobiliary cancer and one of the most aggressive characterized by an extremely poor prognosis with limited treatment options. Inflammatory cells in tumour microenvironment support tumour growth in term of progression, angiogenesis and metastatic capacity. A link between inflammation and biliary carcinogenesis has been previously observed but the mechanisms involved remain to be determined.

METHODS

We investigated the microvascular density (MVD) and inflammatory cells in tissue samples from 40 patients with CCA with locally advanced CCA and metastatic CCA by means of immunohistochemical analysis of macrophages, mast cells, B and T lymphocytes and we correlated inflammatory infiltrate with MVD.

RESULTS

We observed significant decrease in the levels of CD31 positive vessels, and CD8, CD4, CD68 and tryptase-positive cells in metastatic lesions as compared to the localized ones. A negative correlation between CD31 and CD8 and CD31 and CD4 in localized CCA samples was found as assessed by Spearman correlation analysis.

CONCLUSIONS

In locally advanced CCA patients, there is a significant increase of immune cell infiltrate constituted by CD8⁺ and CD4⁺ lymphocytes, macrophages and mast cells as compared to the metastatic ones. This alteration in the tumour microenvironment infiltrate is related to a significant increased MVD in localized CCA lesions compared with the metastatic ones. Moreover, we observed a negative correlation between MVD and CD8⁺ , CD4⁺ cells in localized CCA patients.

The Clinical Impact of c-MET Over-Expression in Advanced Biliary Tract Cancer (BTC)

Background: c-MET is a proto-oncogene that encodes the tyrosine kinase receptor for hepatocyte growth factor (HGF). Activation of HGF-c-MET signaling involves cell invasiveness and evokes metastasis through direct involvement of tumor angiogenesis. However, the value of c-MET overexpression is still unknown in metastatic biliary tract cancer (BTC).

Methods: We analyzed the incidence and clinicopathologic characteristics of c-MET overexpression in advanced BTC. Moreover, we investigated the value of c-MET overexpression in predicting response to gemicitabine plus cisplatin (GC), a first line standard regimen, and as a prognostic marker in metastatic BTC.

Results: The BTC subtype distribution (N=44) was as follows: intrahepatic cholangiocarcinoma (IHCC, n=7), extrahepatic cholangiocarcinoma (EHCC, n=25) and gallbladder cancer (GBC, n=12). Liver (52.3%) was the predominant metastatic site, followed by lymph nodes (36.4%) and bone (15.9%). Among the 44 patients analyzed for c-MET expression, 15 (34.1%) exhibited c-MET overexpression in tumor tissues. There was no significant difference in the prevalence of c-MET overexpression among primary sites in EHCC (7/25, 28.0%), IHCC (3/7, 42.9%), and GBC (5/12, 41.7%). There was also no significant correlation between specific clinicopathologic variables and c-MET expression. Comparing the tumor-response to GC according to c-MET expression (overexpression vs. non-overexpression), there was no significant difference in either RR or DCR (p=0.394 and p >0.999, respectively). The median PFS for all 44 patients was 9.00 months (95% CI, 7.5-10.5 months) and there was no significant difference for PFS between patients with c-MET overexpression and those without (p=0.917). The median OS was 14.4 months (95% CI, 11.9-16.9 months). There was no significant difference in OS between patients with c-MET overexpression compared to those without (13.7 vs. 14.4 months, respectively; p=0.708).

Conclusions: c-MET overexpression was detected in 34.1% of advanced BTC patients irrespective of tumor location. c-MET overexpression did not predict response to GC or survival. Further studies are needed to fully elucidate the value of c-MET overexpression as a novel biomarker in these patients.

A plasma cytokine and angiogenic factor (CAF) analysis for selection of bevacizumab therapy in patients with metastatic colorectal cancer

This study intends to identify biomarkers that could refine the selection of patients with metastatic colorectal cancer (mCRC) for bevacizumab treatment. Pretreatment 36 plasma cytokines and angiogenic factors (CAFs) were first measured by protein microarray analysis in patients who received first-line bevacizumab-containing therapies (discovery cohort, n = 64), and further evaluated by enzyme-linked immunosorbent assay in patients treated on regimens with or without bevacizumab (validation cohort, n = 186). Factor levels were correlated with clinical outcomes, predictive values were assessed using a treatment by marker interaction term in the Cox model. Patients with lower pretreatment levels of hepatocyte growth factor (HGF) or VEGF-A¹²¹ gain much more benefit from bevacizumab treatment as measured by progression-free survival (PFS) and overall survival (OS), while angiopoietin-like 4 (ANGPTL4) levels negatively correlated with PFS and response rate following bevacizumab (all adjusted interaction P < 0.05). A baseline CAF signature combining these three markers has greater predictive ability than individual markers. Signature-negative patients showed impaired survival following bevacizumab treatment (PFS, 7.3 vs 7.0 months; hazard ratio [HR] 1.03; OS, 29.9 vs 21.1 months, HR 1.33) compared with signature-positive patients (PFS, 6.5 vs 11.9 months, HR 0.52; OS, 28.0 vs 55.3 months, HR 0.67). These promising results warrant further prospective studies.

Is c-Met oncoprotein expression an adverse prognosticator in extrahepatic bile duct cancer treated with curative resection followed by adjuvant chemoradiotherapy?

PURPOSE

To analyze the expression of c-Met, and to investigate correlations between the expression of c-Met, clinicopathologic variables, and survival in patients undergoing curative surgery followed by adjuvant chemoradiotherapy for extrahepatic bile duct (EHBD) cancer.

METHODS

Ninety EHBD cancer patients who underwent curative resection followed by adjuvant chemoradiotherapy were enrolled. Expression of c-Met was assessed with immunohistochemical staining on tissue microarray. The correlation between clinicopathologic variables and survival outcomes was evaluated using Kaplan-Meier method and Cox proportional hazard model.

RESULTS

On univariate analysis, 66 patients (76.7 %) showed c-Met expression. c-Met expression had a significant impact on 5-year overall survival (OS) (43.0 % in c-Met(+) vs. 25.0 % in c-Met(-), p = 0.0324), but not on loco-regional relapse-free survival or distant metastasis-free survival (DMFS). However, on multivariate analysis incorporating tumor location and nodal involvement, survival difference was not maintained (p = 0.2940). Tumor location was the only independent prognostic factor predicting OS (p = 0.0089). Hilar location tumors, nodal involvement, and poorly differentiated tumors were all identified as independent prognostic factors predicting inferior DMFS (p = 0.0030, 0.0013, and 0.0037, respectively).

CONCLUSIONS

This study showed that c-Met expression was not associated with survival outcomes in EHBD cancer patients undergoing curative resection followed by adjuvant chemoradiotherapy. Further studies are needed to fully elucidate the prognostic value of c-Met expression in these patients.

Metabolic Characteristics of Advanced Biliary Tract Cancer Using 18F-Fluorodeoxyglucose Positron Emission Tomography and Their Clinical Implications

BACKGROUND

In advanced biliary tract cancer (BTC), the metabolic landscape has not been evaluated by (18)F-fluorodeoxyglucose (FDG) positron emission tomography (PET) yet. Furthermore, reports of the clinical implications of these metabolic features are limited. We aimed to evaluate the metabolic features and their clinical relevance in advanced BTC using (18)F-FDG PET.

PATIENTS AND METHODS

We consecutively enrolled patients with advanced BTC who underwent (18)F-FDG PET prior to palliative chemotherapy between 2003 and 2013. We evaluated the findings of PET, such as SUV(max), the number of lesions and organs with FDG uptake, pathologic findings, and clinical outcomes.

RESULTS

A total of 106 patients were enrolled: (53 intrahepatic cholangiocarcinoma [ICC], 7 extrahepatic BTC, 30 gallbladder cancer [GB Ca], and 16 ampulla of Vater cancer [AoV Ca]). The median SUV(max) differed according to the primary origin (ICC, 9.10; extrahepatic BTC, 5.90; GB Ca, 9.10; and AoV Ca, 6.37; p = .008) and histologic differentiation (well differentiated, 4.95; moderately differentiated, 6.60; poorly differentiated, 14.50; p = .004). Patients in the high metabolic group (SUV(max) of ≥7.5) had more poorly differentiated histology and more organs and lesions with FDG uptake than did those in the low metabolic group (SUV(max) of <7.5). The low metabolic group had a significantly longer OS (11.4 vs. 7.4 months, p = .007) and PFS (6.6 vs. 4.3 months, p = .024) than high metabolic group. In multivariate analysis, SUV(max) was a significant prognostic factor for overall survival (OS; p = .047) and progression-free survival (PFS; p = .039).

CONCLUSION

Metabolic characteristics of advanced BTC differ according to primary origin and histology. These metabolic features could be prognostic factors for OS and PFS in advanced BTC.

Single-nucleotide polymorphism rs41736 located in MET was significantly associated with prognosis of small cell lung cancer patients

MET has been suggested to have an intimate relationship with small cell lung cancer (SCLC) and might be a promising therapeutic target. To date, relatively limited reports have been explored on MET mutational status in SCLC patients. To investigate the relationship between MET mutations and SCLC, 68 Chinese patients surgically treated for SCLC were enrolled. MET mutational analyses were performed in tumors, adjacent normal tissues as well as in lymph nodes with no metastasis nonadherent to tumor tissues using Sanger sequencing after PCR. The same mutation types were found in tumors, adjacent normal tissues as well as lymph nodes, including the only missense mutation N375S encoding semaphorin domain in exon 2 in 4 patients (5.9%), one single-nucleotide polymorphism (SNP) rs35775721: C>T also encoding semaphorin domain as heterozygous in 10 cases (14.7%) and another SNP rs41736: C>T encoding tyrosine kinase domain in exon 20 existing in 49 cases (72.1%). In survival analysis, the wild genotype CC-carriers of rs41736 conferred a significantly shorter progression-free survival (PFS) and overall survival (OS) compared to CT + TT-carriers (HR 0.455, 95% CI 0.229-0.904; HR 0.226, 95% CI 0.099-0.515, for PFS and OS, respectively) in limited-stage SCLC patients. We also found that the lymph node status was significantly associated with OS, and the shorter OS was present in positive group (HR 2.187, 95% CI 1.170-4.088). In this study, rs41736 polymorphism of MET was first found to be associated with prognosis of limited-stage SCLC patients and could be considered as a prognostic marker for limited-stage SCLC.

Prognostic significance of overexpression of c-Met oncoprotein in cholangiocarcinoma

Background:

Cholangiocarcinoma (CC) is a highly malignant carcinoma. We attempted to clarify the prognostic significance of c-Met overexpression and its association with clinicopathological factors in patients with CC.

Patients and methods:

One hundred and eleven patients with intrahepatic CC (IHCC) and 136 patients with extrahepatic CC (EHCC) who had undergone curative surgery were divided immunohistologically into c-Met^high and c-Met^low groups. Clinicopathological factors and outcomes were compared between the groups. c-Met and epidermal growth factor receptor (EGFR) expression was also examined in 10 CC cell lines.

Results:

The positivity of c-Met was 45.0% in IHCC and 68.4% in EHCC; c-Met^high expression was demonstrated in 11.7% of IHCC and 16.2% of EHCC. c-Met^high expression was significantly correlated with the 5-year survival rate for CC overall (P=0.0046) and for IHCC (P=0.0013), histopathological classification in EHCC, and for EGFR overexpression in both IHCC and EHCC. Coexpression and coactivation of c-Met and EGFR were also observed in CC cell lines. Multivariate analysis revealed that c-Met^high expression was an independent predictor of poor overall and disease-free survival in patients with IHCC.

Conclusions:

c-Met overexpression is associated with EGFR expression and is a poor prognostic factor in CC.

Expression of hepatocyte growth factor and its receptor c-Met in human pituitary adenomas

Hepatocyte growth factor (HGF) and its receptor c-Met have been known as key determinants of growth and angiogenesis in some brain tumors like gliomas, meningiomas, and schwannomas. But little is known about their expression in pituitary adenomas. In this study, the expression of HGF and c-Met in pituitary adenomas of different histology types was investigated by immunohistochemistry, and correlative analysis of their expression with microvessel density (MVD), Ki-67 expression, and other clinicopathologic factors was made. The results showed that the expression of HGF and c-Met exists in 98% (64 of 65) and 92% (60 of 65) pituitary adenomas, respectively, and co-expression of them existed in 91% (59 of 65) adenomas. HGF had significant correlation with MVD (Spearman's correlation coefficient, r = .31, P = .01) and Ki-67 (r = .32, P = .01). c-Met had significant correlation with MVD (r = .30, P = .02) and Ki-67 (r = .38, P = .00). HGF and c-Met expression had no significant correlation with age or extrasellar extension. There were no significant differences in HGF and c-Met expression between pituitary adenomas of different histology types. The results indicate that HGF and c-Met are widely expressed in pituitary adenomas, and their expression correlates with MVD and Ki-67 expression.

c-Met targeted therapy of cholangiocarcinoma

Cholangiocarcinoma continues to be a challenging disease to treat. Systemic therapy is used in unresectable disease, disease progression after surgery, and in the palliative setting. Unfortunately, results of multiple phase II trials have rarely yielded positive results. As data on the molecular carcinogenesis of cholangiocarcinoma is developing, we are more able to understand the disease process and can use this understanding to create unique targeted therapies. We reviewed the role of c-Met/hepatocyte growth factor (HGF) in the development of cholangiocarcinoma. Furthermore, we explored the use of the c-Met guided cascade as a target to treat cholangiocarcinoma. We reviewed the current use and options for future development of c-Met agents to treat this disease.

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Overexpression of c-met as a prognostic indicator for transitional cell carcinoma of the urinary bladder: a comparison with p53 nuclear accumulation

PURPOSE

The c-met proto-oncogene encodes a receptor tyrosine kinase (Met) and has been shown to play a role in oncogenesis. Given that high titers of hepatocyte growth factor, the specific ligand for Met, are excreted in the urine and tend to reflect disease activity of bladder cancer, we performed this study to examine the clinical significance of Met in human bladder cancer.

MATERIALS AND METHODS

We studied the mRNA expression and genomic alteration of c-met in five bladder cancer cell lines. Significance of Met overexpression was then compared with p53 nuclear accumulation (TP53) in primary bladder cancer (n = 142 patients).

RESULTS

Expression of c-met mRNA tended to positively correlate with differentiation of cancer cell lines in the absence of point mutation. High expression of Met was found in seven cases (4.9%), low expression in 32 cases (22.5%), and negative expression in 103 cases (72.5%). Expression of Met was positively associated with histologic grade, stage classification, tumor size, and nodular tumor growth (P <.05, respectively); however, it was not related to TP53 status. Factors that predicted disease progression were tumor stage, Met status, and TP53 accumulation (P <.05, respectively). Indicators for poor long-term survival were invasive cancer, multiple tumors, and Met overexpression (P =.0006,.01, and.04, respectively).

CONCLUSION

The c-met proto-oncogene plays a more important role in the progression of bladder carcinogenesis than p53. Evaluation of Met expression could identify a subset of bladder cancer patients who may require a more intensive treatment strategy.