Antiproliferative effect of somatostatin analogs in gastroenteropancreatic neuroendocrine tumors

Table 1 Receptor binding affinities of somatostatin, octreotide and lanreotide

	sst1	sst2	sst3	sst4	sst5
Receptor binding affinity (IC50 nmol/L)
Somatostatin[12]	0.93	0.15	0.56	1.50	0.29
Octreotide[12]	280.00	0.38	7.10	> 1000	6.30
Lanreotide[13]	> 1000	0.80	107	> 1000	5.20

Table 2 Receptor mediation of cell proliferation

	sst1	sst2	sst3	sst4	sst5
Induction of G1 cell cycle arrest	+	+		+	+
Induction of apoptosis		+	+

Table 3 Summary of non-randomized clinical trials evaluating the antiproliferative effect of somatostatin analogs n (%)

Analog	Author	n	CR/PR	SD	PD
Patients with documented tumor progression
Lanreotide	Faiss et al[62], 2003	22	1 (4)	7 (32)	14 (64)
Lanreotide	Aparicio et al[63], 2001	35	1 (3)	20 (57)	14 (40)
Octreotide	Arnold et al[64], 1993	52	0 (0)	19 (36)	33 (63)
Octreotide	Saltz et al[58], 1993	34	0 (0)	17 (50)	17 (50)
Octreotide	di Bartolomeo et al[19], 1996	58	2 (3)	27 (46)	29 (50)
		201	4 (1)	90 (45)	107 (53)
Patients without documented tumor progression
Lanreotide	Wymenga et al[60], 1999	31	2 (6)	25 (80)	4 (13)
Lanreotide	Ducreux et al[59], 2000	39	2 (5)	21 (54)	16 (41)
Lanreotide	Eriksson et al[65], 1997	19	1 (5)	12 (63)	6 (32)
Lanreotide	Tomasetti et al[66], 1998	18	0 (0)	14 (77)	4 (22)
Octreotide	Tomasetti et al[67], 2000	16	0 (0)	14 (87)	2 (12)
Octreotide	Ricci et al[68], 2000	15	1 (6)	6 (40)	8 (53)
		138	6 (4)	92 (67)	40 (29)

CR: Complete response; PR: Partial response; SD: Stable disease; PD: Progressive disease.