Outcomes of patients treated with capecitabine and temozolamide for advanced pancreatic neuroendocrine tumors (PNETs) and non-PNETs

Abstract

Background: Retrospective studies have demonstrated high response rates among patients with advanced pancreatic neuroendocrine tumors (PNETs) treated with capecitabine and temozolamide (CapTem), while responses are infrequently seen among non-PNETs. The objective of the study was to describe progression free survival (PFS) among neuroendocrine tumor (NET) patients treated with CapTem, and to identify factors associated with better activity.

Methods: Patients who were referred to one of five provincial cancer treatment centers between 2009 and 2013 for advanced NETs and initiated CapTem were included. Patients received Cap 1,500 mg/m(2) on days 1-14 and TMZ 200 mg/m(2) on days 10-14 every 28 days. Their characteristics and outcomes were retrospectively analyzed.

Results: In our cohort, 29 patients (16 males) with a median age of 59 (range 26-76) received palliative CapTem, 15 of them as first-line chemotherapy. Primary tumors included pancreas (48.3%), small bowel (20.7%), lung (10.3%), unknown (10.3%), rectum (6.9%) and appendix (3.4%). Median number of cycles was three. Fifteen patients (51.7%) received CapTem as first-line chemotherapy and 14 (48.3%) as subsequent lines. Median PFS for the entire cohort was 4.7 months. PNETs had a median PFS of 4.9 months compared to 2.8 months for non-PNETs (P=0.178). Patients with PNETs who received CapTem in the first-line setting had a median PFS of 15.9 months as compared to only 3.1 months for the remainder [P=0.047, hazard ratios (HR) 0.342]. Patients with Ki67 above 5% and ≤5% had median PFS of 4.0 and 4.7 months, respectively (P=0.260).

Conclusions: CapTem showed good activity among PNETs, but its broader role in the treatment of carcinoid tumors remains unclear.

Keywords: Carcinoid tumors; carcinomas; chemotherapy; pancreatic endocrine tumors; pancreatic neuroendocrine tumors (PNETs).

Figures

Figure 1

PFS for the entire cohort (median 4.7 months, 95% CI, 3.11-6.28). PFS, progression free survival.

Figure 2

OS for the entire cohort (median 20.2 months, 95% CI, 9.02-33.37). OS, overall survival.

Figure 3

PFS according to tumor location-PNETs vs. non-PNETs (P=0.178, HR 0.25). PFS, progression free survival; PNETs, pancreatic neuroendocrine tumors; HR, hazard ratios.

Figure 4

PFS according to ki67 ≤5 versus >5 (P=0.26, HR 0.417). PFS, progression free survival; HR, hazard ratios.

Figure 5

PFS for PNETs in 1st-line versus others (P=0.047, HR 0.342). PFS, progression free survival; PNETs, pancreatic neuroendocrine tumors; HR, hazard ratios.