Efficacy of adding high-dose In-111 octreotide therapy during Sandostatin treatment in patients with disseminated neuroendocrine tumors: clinical results of 14 patients

Abstract

This study aimed to assess the outcome of high-dose In-111 octreotide treatment and efficacy of long-acting Sandostatin LAR in patients with disseminated neuroendocrine tumors. A total of 14 patients (mean age 51.8±13.2years; 10 female, 4 male) receiving high-dose In-111 octreotide in our centre for the treatment of neuroendocrine tumors were included in the study. Monthly treatment with long-acting somatostatin analogue [Sandostatin long-acting release (Novartis Pharmaceuticals)] was continued in nine cases. During a 3-year period, a total of 45 courses of high-dose In-111 octreotide treatment were delivered to 14 patients. In seven patients receiving an average of four treatment courses (6 carcinoid tumors, 1 thymoma, patients: 2, 4, 5, 11-14) stable disease was achieved (50%). In two patients with carcinoid tumors (patients 1 and 3) who received four treatment courses, partial response was observed (14%). Five patients (36%; 4 NET, 1 gastrinoma; patients 6-10) died due to progressive disease following on average two treatment courses. On average, deaths occurred 2months after the last treatment dose. No complete responses were seen. Partial response was achieved in two of the nine patients receiving Sandostatin LAR, while four had stable disease. Both treatments were associated with acceptable tolerability. High-dose In-111 octreotide can be safely administered in conjunction with somatostatin analogue in patients with disseminated NET and this treatment may help to stabilize the disease.