Sequential Everolimus and Sunitinib Treatment in Pancreatic Metastatic Well-Differentiated Neuroendocrine Tumours Resistant to Prior Treatments.

OBJECTIVE: Alternating treatment with sunitinib and everolimus has been shown to be efficacious in renal cell carcinoma. However, no data currently exist for the role of alternate sequence administration of these agents in well-differentiated pancreatic neuroendocrine tumours (pNETs). METHODS: Thirty-one patients were administered one compound and upon progression were switched to the other. All patients had grade 1 or 2 tumours and stage IV disease with similar metastatic load. The primary end point included estimation of the median overall progression-free survival (mPFS) along with each drug's mPFS as a first-line (mPFS1) and a second-line treatment (mPFS2); tolerability and serious adverse events were also evaluated. Secondary end points included overall survival (OS), 2-year mortality rate, and incidence of disease progression. RESULTS: Overall, mPFS did not differ between the everolimus to sunitinib group (36.5 months) and the sunitinib to everolimus group (31.6 months) with a hazard ratio of 0.94 ([95% CI, 0.45-1.97], p = 0.7). Although mPFS1 after first-line everolimus was longer (16.3 months) compared to sunitinib (9 months), this was not statistically significant (p = 0.15). Sequential second-line treatment showed no difference in the mPFS2 (p = 0.3). No difference in OS between the 2 groups was observed. Tolerability was better for everolimus compared to sunitinib. CONCLUSIONS: Treatment with sequential molecular target agents was well tolerated and associated with similar overall mPFS in both schemes of administration. Larger prospective studies are required to investigate the long-term efficacy and sequence of administration of alternate therapy with molecular targeting agents in metastatic pNETs and their effect on OS.

Distinctive features of pancreatic neuroendocrine neoplasms exhibiting an increment in proliferative activity during the course of the disease.

PURPOSE: Neuroendocrine neoplasms (NENs) differ in their biological behavior and growth potential in a way that can be predicted using histological classification and grading systems. A subset of pancreatic NENs (pNENs) may develop a more aggressive phenotype during the course of the disease, associated with an increase in the Ki-67 proliferation index (PI). The purpose of the study was to present the clinical characteristics of these patients. METHODS: Using re-biopsy of growing lesions, we investigated the increase in Ki-67 PI sufficient to change initial grading (G). RESULTS: Of 264 patients with well differentiated (WD) pNENs who showed progressive disease during follow-up, 15 (6%) exhibited an increase in Ki-67 PI at a median time 36.8 (9.3-255.8) months. All neoplasms had WD-morphology: five had G1 (Ki-67 median value 1%), nine G2 (median value 5%), one G3 (25%) grades. Upon change of Ki-67 PI, 3 patients had G2 (8%) and 12 G3 (57.5%) NENs, while all retained their WD-morphology. At last follow-up, eight patients were alive with a median overall survival (OS) of 52.5 (9.5-264.3) months. Μedian OS was shorter in patients who had a change in Ki-67 PI before 36 months compared to those who had a change of Ki-67 PI at a later stage (27.5 95%CI: 11.88-43.06 vs. 120.87 95%CI: 96.05-145.69; log-rank p = 0.018). CONCLUSIONS: During the course of their disease, 6% patients with progressive pNENs develop an increase in Ki-67 PI resulting in an increase in grading status while maintaining their morphology. This process is associated with worse OS when it occurs at an early stage.