Purpose: hENT1 is a transmembrane protein which acts as a nucleoside transporter and is the main mediator of Gemcitabine (GEM) uptake into human cells. In this retrospective study we compared GEM versus FOLFIRINOX in patients with metastatic pancreatic cancer in which hENT1 evaluation was available.
Methods: 149 patients affected by unresectable metastatic pancreatic cancer, treated in our institution from 2009 to 2013, have been screened for inclusion in this retrospective study. Seventy patients, treated with GEM or FOLFIRINOX in first-line therapy, fulfilled clinical inclusion criteria for survival analysis. Thirty-one patients were available and contained sufficient quality/quantity RNA for evaluation of hENT1 expression by RT-PCR. The primary endpoint was OS and the secondary endpoint was PFS.
Results: The survival analysis, carried out on 70 patients regardless of hENT1 expression, showed a statistically longer OS and PFS in the group treated with FOLFIRINOX compared to GEM. Within the exploratory analysis, which included 31 patients, no differences were found in hENT1 positive patients treated with FOLFIRINOX compared to GEM in terms of OS (8.5 vs 7 months, HR: 0.89; 95 % CI 0.3-2.5; p = 0.8) and PFS (5.5 vs 5 months, HR: 0.8, 95 % CI 0.2-2.2; p = 0.61). GEM-treated hENT1 positive patients showed a statistically significant improvement both of OS (8 vs 2 months; p = 0.0012) and PFS (5 vs 1 months; p = 0.0004) in comparison to GEM-treated hENT1 negative patients.
Conclusions: In our exploratory analysis GEM seems as effective as FOLFIRINOX in terms of survival with a better safety profile in hENT1 positive metastatic pancreatic cancer.
Keywords: FOLFIRINOX; Gemcitabine; Metastatic pancreatic adenocarcinoma; hENT1.