Streptozocin and 5-Fluorouracil for the Treatment of Pancreatic Neuroendocrine Tumors: Efficacy, Prognostic Factors and Toxicity.

Background: In our center, the combination of streptozocin (STZ) and 5-fluorouracil (5-FU) has been used as the first-line treatment in the majority of patients with pancreatic neuroendocrine tumors (pNETs) over the past few decades. The objective of the current study was to assess the efficacy, prognostic factors and safety of the combination of STZ and 5-FU.

Patients And Methods: Medical records and radiological reports of 133 patients with pNETs who received the combination of STZ and 5-FU during the period 1981-2014 were retrospectively evaluated.

Results: The median survival from the start of treatment was 51.9 months in the whole group. In the radiologically evaluable patients (n = 100), progression-free survival was 23 months. Complete response was reached in 3 patients (3%), partial response in 25 patients (25%), 64 patients (64%) had stable disease, and 8 patients (8%) had progressive disease. In a multivariate analysis, surgery of the primary tumor and having a G3 tumor were significant positive and negative prognostic factors of survival from the start of treatment, respectively. Having either a G3 tumor or a stage IV tumor were significant prognostic factors for a shorter progression-free survival. Chemotherapy had to be discontinued in 29 patients due to side effects, of which kidney toxicity (mainly grades 1-2) was the most frequent.

Conclusion: As shown in recent reports, the combination of STZ and 5-FU is effective in the treatment of pNETs in terms of survival and radiological response and has an acceptable toxicity profile.