Treatment of malignant endocrine pancreatic tumors with a combination of alpha-interferon and somatostatin analogs.

Somatostatin analogs and alpha-interferon induce good responses as single drugs in the treatment of endocrine pancreatic tumors. We examined the efficacy and tolerability of the combination of alpha-interferon and somatostatin analogs in 16 patients with metastatic endocrine pancreatic tumors. All patients except one had received prior treatment and were in a progressive state. Doses of alpha-interferon and somatostatin analogs were individually titrated. The alpha-interferon doses varied between 9 and 25 million units per week and were combined with 100-1500 microg of octreotide or 6000 microg of lanreotide daily. Radiological response was seen in 3 of 16 (19%) patients (median duration 23 mo). Biochemical response was seen in 10 of 16 (62.5%) patients (median duration 22 mo). All three patients previously progressing on both alpha-interferon and somatostatin analog as single drugs achieved a stabilization of the disease when treated with the combination (median duration 10 mo). Seven of eight (88%) patients previously progressing on alpha-interferon treatment benefited from the combination with biochemical partial response or stabilization. All six patients previously progressing during somatostatin analog treatment achieved biochemical partial response or stabilization. More than 80% of patients who progressed during previous treatment with either drug benefited from the combined treatment, which also was well tolerated. Thus, a combination of alpha-interferon and somatostatin analogs may be considered for patients previously progressing on treatment with alpha-interferon or somatostatin analogs. However, in this study, the value of sequential treatment has not been evaluated.