The current status of tailor-made medicine with molecular biomarkers for patients with clear cell renal cell carcinoma.

Appropriate use of multiple reliable molecular biomarkers in the right context will play a role in tailormade medicine of clear cell renal cell carcinoma (RCC) patients in the future. A total of 11,056 patients from 53 studies were included in this review. The article numbers of the each evidence levels, using the grading system defined by the Oxford Centre for Evidence-based Medicine, in 1b, 2a, 2b, and 3b were 5 (9%), 18 (34%), 29 (55%), and 1 (2%), respectively. The main goal of using biomarkers is to refine predictions of tumor progression, pharmacotherapy responsiveness, and cancer-specific and/or overall survival. Currently, carbonic anhydrase (CA9) and vascular endothelial growth factor (VEGF) in peripheral blood and p53 in tumor tissues are measured to predict metastasis, while VEGF-related proteins in peripheral blood are used to assess pharmacotherapy responsiveness with sunitinib. Furthermore, interleukin 8, osteopontin, hepatocyte growth factor, and tissue inhibitors of metalloproteinases-1 in peripheral blood enable assessment of responsiveness to pazopanib treatment. Other reliable molecular biomarkers include von Hippel­Lindau gene alteration, hypoxia-inducible factor-1a, CA9, and survivin in tumor tissues and VEGF in peripheral blood for predicting cancer-specific survival. In the future, studies should undergo external validation for developing tailored management of clear cell RCC with molecular biomarkers, since individual institutional studies lack the generalization and consistency required to maintain accuracy among different patient series.

Value of metastin receptor immunohistochemistry in predicting metastasis after radical nephrectomy for pT1 clear cell renal cell carcinoma.

KISS-1 is a metastasis-suppressor gene of human melanoma, and encodes metastin, which was identified as the ligand of a G-protein-coupled receptor (metastin receptor). The precursor protein is cleaved to 54 amino acids, which may be further truncated into carboxy-terminal fragments. Previous studies showed that lack of metastin receptor in clear cell renal cell carcinoma (RCC) is associated with tumor progression, but the prediction of metastasis in patients with pT1 clear cell RCC after radical nephrectomy is difficult. The objective of this study was to evaluate the usefulness of metastin receptor immunohistochemistry in predicting metastasis after nephrectomy for pT1 clear cell RCC. After verification of the correlation between immunostaining and mRNA expression, we evaluated the clinical value of metastin receptor immunohistochemistry. Fifty-four patients were enrolled in this study; following radical nephrectomy, seven patients were found to have lung metastasis. The sensitivity, specificity, positive predictive value, and negative predictive value with negative immunostaining of metastin receptor were 85.7, 97.6, 46.2, and 97.6 %, respectively. Metastasis-free survival rates were significantly higher in patients with positive staining (97.6 %) than in patients with negative staining (53.8 %) (P < 0.001). In univariate analysis for metastasis-free survival, negative immunostaining of metastin receptor was a significant risk factor for metastasis (P = 0.001). Furthermore, negative immunostaining of metastin receptor was an independent predictor for metastasis in multivariate analysis (hazard ratio, 3.735; 95 % CI 0.629-22.174; P = 0.002). In conclusion, our study suggests that negative expression of metastin receptor in clear cell RCC is significantly related to metastasis.

Metastin has potential as a suitable biomarker and novel effective therapy for cancer metastasis (Review).

Cancer metastasis is a leading cause of death in cancer patients and is a multistep process involving complex interactions between tumor and host cells. To metastasize, tumor cells must invade or migrate from the primary tumor and be transported to close or distant secondary sites. A tumor cell should successfully accomplish each step of the pathway or metastasis may not develop. KiSS-1 is a human metastasis suppressor gene that inhibits metastasis of human melanomas and breast carcinomas without affecting tumorigenicity. KiSS-1 encodes a carboxy-terminally amidated peptide with 54 amino-acid residues. The peptide was isolated from human placenta as the endogenous ligand of an orphan G-protein-coupled receptor and termed 'metastin'. The literature reports metastin related to human carcinoma, such as melanoma, thyroid cancer, esophageal squamous cell carcinoma (ESCC), hepatocellular carcinoma, pancreatic carcinoma, as well as breast, ovarian, bladder and kidney cancer. These malignancies are difficult to treat and, even in early-stage cancer, a number of patients develop metastasis shortly after surgery. Studies have suggested that metastin inhibits tumor invasion or migration through focal adhesion kinase, paxillin, MAP kinase or Rho A. Additionally, metastin may be a biomarker in ESCC, pancreatic carcinoma and bladder cancer. Metastin has potential as a suitable biomarker in the identification of tumors with high metastatic potential and as a novel effective treatment modality for patients with metastasis.