Somatostatin receptors in resected hepatocellular carcinoma: status and correlation with markers of poor prognosis

Aims To investigate the status of somatostatin receptors ( SSTR s) in resected hepatocellular carcinoma ( HCC ). Methods and results Transcript and protein levels of SSTR 2, SSTR 3 and SSTR 5 were investigated, with real‐time polymerase chain reaction ( PCR ) and manual and automated immunohistochemistry ( IHC ), in 53 resected HCC s and paired non‐tumour tissues. SSTR 1, SSTR 4, SSTR 5 TMD 4 and SSTR 5 TMD 5 were analysed with real‐time PCR . SSTR 3 and SSTR 5 transcripts were expressed in ~25% of HCC s, but not in adjacent non‐tumour tissues. SSTR 1 and SSTR 2 transcripts were overexpressed in 42% and 32% of HCC s, respectively. SSTR 4, SSTR 5 TMD 4 and SSTR 5 TMD 5 were not detected. Membrane staining for SSTR 2 was detected in 38% of HCC s, whereas SSTR 5 protein was detectable in only 11% of HCC s. SSTR 3 protein was detected in the majority of HCC s and adjacent non‐tumour liver tissues, but membrane staining was <20% of that in HCC s. The results obtained with the two IHC methods were highly correlated ( P < 0.0001). Statistical analyses also showed a positive correlation between SSTR 2 membrane staining and cytokeratin 19 expression ( P = 0.04), serum α‐fetoprotein level ( P = 0.002), and poor differentiation ( P = 0.05). Conclusions Membrane SSTR 2 is detected reliably in HCC s by IHC , and is a potential therapeutic target, as it is coexpressed with markers of poor prognosis.