Treatment of Advanced Hepatocellular Carcinoma With Depot Somatostatin Analogues: a Pilot Prospective Study Based on Somatostatin Receptors Tumors Expression

The hepatocellular carcinoma (HCC) represents more than 5% of all human malignancies, with more than 500,000 deaths per year (1). In Campania region, mortality for HCC is 2 times higher than in the rest of Italy because of a higher locally prevalence of hepatitis-C virus infection.

Development of HCC in liver cirrhosis is associated with increased DNA synthesis and regeneration of hepatocytes (2). Hepatocyte growth factor, the transforming growth factor-α, the fibroblast growth factor are well studied (3,4) while the insulin-like growth factor system (IGF-I, IGF-II and their binding proteins) has been less investigated. IGF-I and IGF-II modulate growth, metabolism and cell differentiation and have specific receptors in the liver (5). IGF-I levels in the upper normal range have been associated with an increased risk to develop prostate cancer (6), breast cancer (7) and colon cancer (8). Some data report increased expression of IGF-II in HCC (9,10) and others suggest a role of increased IGF-I bioavailability in HCC (11). We reported increased IGF-I/IGFBP-3 ratio in patients with HCC compared with those with cirrhosis with a similar liver function, so suggesting increased IGF-I bioavailability in HCC (12).

There is no currently medical treatment for patients with advanced HCC which has a very poor prognosis (survival <6 months). Because of limited liver function, classical chemotherapy cannot be applied (13). In patients with HCC without cirrhosis, surgery is possible only in 5% while in those with cirrhosis first-line treatment is still questioned as survival is <50% three years after operation. Patients suitable for local resection of HCC are only those with Child-Pugh's "hyper A" liver function class, who are a minority (14-16). Percutaneous resection treatments may treat approximately 70%-90% of tumors with maximal diameters of <3 cm (15,17-19).

Somatostatin analogues are indicated in patients with neuroendocrine tumors expressing somatostatin receptors type 2 and 5 and has excellent safety profile. In advanced HCC, some studies demonstrated beneficial effects (20,21) while some others did not (22,23).

Only a few data are available on somatostatin receptor expression in HCC (24,25). Somatostatin analogues have also a clear-cut inhibitory effect on circulating IGF-I levels with a potential additional effect in delaying HCC progression.