Long Acting Octreotide in PTS with Disseminated Neuroendocrine Tumors

ABSTRACT Objectives To evaluate the effectiveness of long acting octreotide at the doses 30 - 40 mg per month in heavily pretreated pts (pts) with disseminated neuroendocrine tumors (NET). Patients and methods 31 pts with disseminated NET, progressing on different treatment regimens. We used long acting octreotide: Sandostatin-LAR, Octreotide-Depo, Octreotide-LONG. Origin of the tumor were: pancreas (3 pts, 9.7%), intestines (15 pts, 48.4%), lung (1 pt, 3.2%), kidney (1 pt, 3.2%), or unknown (11 pts, 35.5%).Tumor grades were as follows: G1 - 8 (25.8%), G2 - 14 (45.2%), G3 -1 (3.2%), unknown - 8 (25.8%). Isolated liver metastases were found in 15 pts (48.4%). 12 pts (38.7%) had liver metastases in combination with other sites of involvement. Carcinoid syndrome along with high levels of serum chromogranin A, serotonin and 5-OIAA were present in 29 pts (93.5%). Initially, 29 pts received long acting octreotide 20 mg for an average of 20 months (range, 3-60). The reasons for dose escalation were disease progression in 19 pts (61.3%), increase in markers and lack of control of carcinoid syndrome in 12 pts (38.7%). In 18 pts (58%) the dose was 30 mg, in 13 pts (42%) — 40 mg. 14 pts received long acting octreotide only (45.1%), 6 pts (19.4%) — in combination with α-interferon, 11 pts (35.5%) - in combination with chemotherapy. Results In 14 pts receiving long acting octreotide only, objective responses were not observed; 11pts (78.6%) had stable disease (SD), 3 pts (21.4 %) progressed. Median time to progression was not reached. The pts were followed for a median of 13.5 months. 5 pts (35.7%) are still receiving the treatment after 20 months. In the total group PR (partial response) was observed in 1 pts (3.2%), receiving octreotide with chemotherapy, SD — in 25 pts (80.7%), PD — in 5 pts (16.1%). Control of tumor growth was achieved in 83.9% of cases, these pts got a biochemical response and obtained symptom relief. In the total group the median time to progression was 18 months. Median survival was not reached. Tolerability of long-acting octreotide in a dose of 30-40 mg was satisfactory for all pts. Conclusion long acting octreotide at doses of 30-40 mg, alone or in combination with other types of drug treatment, controls the growth of disseminated tumors in most pts progressing on a lower dose, and has a good tolerability. Disclosure All authors have declared no conflicts of interest.