Matrix metalloproteinases in carcinoma of unknown primary.

BACKGROUND: The purpose was to study proteolysis-related molecules, matrix metalloproteinase-2 (MMP-2) and MMP-9 and tissue inhibitor of metalloproteinases-1 (TIMP-1), in carcinoma of unknown primary (CUP). METHODS: Paraffin-embedded tumor material from 75 patients diagnosed with CUP was used. Tumor histologies were adenocarcinoma (77%), undifferentiated carcinoma (19%), and squamous cell carcinoma (4%) and patients were categorized into favorable (62%) and unfavorable (38%) subsets. The tissue expression of MMP-2, MMP-9, and TIMP-1 was assessed by use of specific monoclonal antibodies and evaluated by means of a visual staining score. The expression of molecules studied was analyzed against clinicopathological data. RESULTS: MMP-2 was found expressed in 69% (strong expression in 49%), MMP-9 in 49% (strong in 36%), and TIMP-1 in 79% (strong in 44%) of studied cases. The expression of MMP-2 correlated positively with MMP-9. TIMP-1 was significantly higher in unfavorable compared with favorable tumors and was associated with a shorter survival of patients (7.5 vs. 12 mos). No other associations were detected. CONCLUSIONS: MMP-2, MMP-9, and TIMP-1 are widely expressed in CUP, suggesting an essential role of proteolysis in these tumors. TIMP-1 may be considered a possible marker of poor prognosis in CUP patients.

Angiogenesis in cancer of unknown primary: clinicopathological study of CD34, VEGF and TSP-1.

BACKGROUND: Cancer of unknown primary remains a mallignancy of elusive biology and grim prognosis that lacks effective therapeutic options. We investigated angiogenesis in cancer of unknown primary to expand our knowledge on the biology of these tumors and identify potential therapeutic targets. METHODS: Paraffin embedded archival material from 81 patients diagnosed with CUP was used. Tumor histology was adenocarcinoma (77%), undifferentiated carcinoma (18%) and squamous cell carcinoma (5%). The tissue expression of CD34, VEGF and TSP-1 was assessed immunohistochemically by use of specific monoclonal antibodies and was analyzed against clinicopathological data. RESULTS: VEGF expression was detected in all cases and was strong in 83%. Stromal expression of TSP-1 was seen in 80% of cases and was strong in 20%. The expression of both proteins was not associated with any clinical or pathological parameters. Tumor MVD was higher in tumors classified as unfavorable compared to more favorable and was positively associated with VEGF and negatively with TSP-1. CONCLUSION: Angiogenesis is very active and expression of VEGF is almost universal in cancers of unknown primary. These findings support the clinical investigation of VEGF targeted therapy in this clinical setting.