Prognosis of Colorectal Cancer Patients with Elevated Endothelin-1 Concentrations

Permissive role of endothelin receptors in tumor metastasis

Metastasis remains the major driver of mortality in patients with cancer. The multistep metastatic process requires the concerted actions of several genes and involves tumor cell invasion, epithelial mesenchymal transition (EMT), shedding from primary tumor, intravasation, arrest, extravasation and colonization at a preferential site. Understanding this complex process would provide the basis for the development of molecularly targeted therapeutics aimed at the tumor cell or its interaction with the host microenvironment. The neuropeptide hormones endothelins (specially, ET-1) have been correlated with invasiveness and metastasis of several cancers and high ET-1 levels are associated with decreased disease-specific survival. The mechanism(s) by which ET-1 promotes metastasis are being gradually unraveled. Through preferential binding to cognate receptors (ET(A)R or ET(B)R), ET-1 triggers autocrine and paracrine signaling cascades in tumor, immune and stromal cells, at both primary and distant sites, supporting cancer progression and metastasis. In this review, we will summarize the role of the ET axis in metastasis of different cancers and potential targeting of ET receptors in the therapeutic setting.

Elevation of circulating big endothelin-1: an independent prognostic factor for tumor recurrence and survival in patients with esophageal squamous cell carcinoma

BACKGROUND

Endothelin(ET) axis plays a key role in many tumor progression and metastasis via various mechanisms such as angiogenesis, mediating extracellular matrix degradation and inhibition of apoptosis. However, there is limited information regarding the clinical significance of plasma big ET-1 levels in esophageal cancer patients. Circulating plasma big ET-1 levels were measured in patients with esophageal squamous cell carcinoma(ESCC) to evaluate the value of ET-1 as a biomarker for predicting tumor recurrence and patients survival.

METHODS

Preoperative plasma big ET-1 concentrations were measured by an enzyme linked immunosorbent assay(ELISA) in 108 ESCC patients before surgery, and then again at 1,2,3,10 and 30 days after curative radical resection for ESCC. The association between preoperative plasma big ET-1 levels and clinicopathological features, tumor recurrence and patient survival, and their changes following surgery were evaluated.

RESULTS

The preoperative plasma big ET-1 levels in ESCC patients were significantly higher than those in controls. And there was a significant association between plasma big ET-1 levels and disease stage, as well as invasion depth of the tumor and lymph node status. Furthermore, plasma big ET-1 levels decreased significantly after radical resection of the primary tumor and patients with postoperative recurrence had significantly higher plasma big ET-1 levels than that of patients without recurrence. Finally, the survival rate of patients with higher plasma big ET-1 concentrations (>4.3 pg/ml) was significantly lower than that of patients with lower level (< or = 4.3 pg/ml). Multivariate regression analysis showed that plasma big ET-1 level is an independent prognostic factor for survival in patients with ESCC.

CONCLUSION

Plasma big ET-1 level in ESCC patients may reflect malignancy and predict tumor recurrence and patient survival. Therefore, the preoperative plasma big ET-1 levels may be a clinically useful biomarker for choice of multimodality therapy in ESCC patients.

Elevated plasma big ET-1 is associated with distant failure in patients with advanced-stage nasopharyngeal carcinoma

BACKGROUND

Endothelin-1 (ET-1) is a potent vasoactive peptide and a hypoxia-inducible angiogenic growth factor associated with the development and spread of solid tumors. The clinical significance of plasma big ET-1 in patients with advanced-stage nasopharyngeal carcinoma (NPC) is not known.

METHODS

Pretreatment plasma big ET-1 levels were measured in 62 patients with advanced-stage NPC using a sandwich enzyme-linked immunoassay and compared with the levels from a control group (n = 19 participants).

RESULTS

The median pretreatment plasma big ET-1 level in patients with advanced-stage NPC was 4.6 pg/mL (range, 1.9-15.2 pg/mL) and was significantly elevated compared with median plasma big ET-1 levels in healthy controls, 2.6 pg/mL (1.6-4.5 pg/mL) (P < .001). Using the upper limit (4.5 pg/mL) of control subjects as the cut-off value, plasma big ET-1 was < or = 4.5 pg/mL in 29 (46.8%) patients and > 4.5 pg/mL in 33 (53.2%) patients. A pretreatment plasma big ET-1 level > 4.5 pg/mL was associated with a significantly poorer 2-year distant metastasis-free survival rate (56.7% vs. 81.1%, P = .031). Multivariate analysis showed that N classification (hazard ratio [HR], 2.416; 95% confidence interval [CI], 1.071-5.447; P = .034) and pretreatment plasma big ET-1 level (HR, 3.151; 95% CI, 1.099-9.028, P = .033) were independent significant prognostic factors for posttreatment distant failure in patients with advanced-stage NPC.

CONCLUSIONS

Pretreatment plasma big ET-1 levels may be useful in predicting posttreatment distant failure in patients with advanced-stage NPC.

Staging of colorectal cancer: past, present, and future

Since the inception of staging for colorectal cancer (CRC), anatomic extent of disease has provided a solid foundation for predicting prognosis and guiding treatment in patients with CRC. However, the rapid advances in biologic and genetic technology have provided many new possibilities for enhancing the predictive power of the staging system. In this article, we will briefly discuss the history of CRC staging, identify the current parameters for American Joint Committee on Cancer staging including recent changes, and offer guidelines for future staging modifications. Although anatomic parameters have served us well for many years, their continued use as sole contributors to CRC staging is questionable. Staging in the future is likely to be a complicated combination of anatomic and biologic markers used together in mathematic modeling to group patients into prognostic risk groups, which can be used to guide tailored therapy.