Background: Malignant gastric outlet obstruction (mGOO) occasionally occurs due to pancreaticobiliary cancer. Endoscopic duodenal stenting (DS) is a common treatment for MGOO. However, it has been reported that DS does not have a sufficient time to stent dysfunction for it to be used in patients who have a greater potential lifespan. Nowadays, systemic chemotherapy for pancreaticobiliary cancer has developed, and its anti-tumour effect would make time to stent dysfunction longer. We therefore retrospectively evaluated the association between objective response to systemic chemotherapy followed by DS and time to stent dysfunction in patients with advanced pancreaticobiliary cancer.
Methods: This retrospective study included 109 patients with advanced pancreaticobiliary cancer who received systemic chemotherapy after DS. Patients who showed complete or partial response were defined as responders. The rest were defined as non-responders. Time to stent dysfunction was compared between responders and non-responders using the landmark analysis, at 2 months after DS. Death without recurrence of MGOO was considered as a censored case for time to stent dysfunction.
Results: The combination and monotherapy regimens were adopted for 41 and 68 patients, respectively. Median progression-free survival and overall survival were 3.2 4 months (95% confidence interval [CI], 2.4-4.0) and 6.0 months (95% CI, 4.6-7.3). Objective response was observed in 21 patients (19.3%). Patients who received combination regimens had longer progression-free survival and higher response rate than those with monotherapy regimens; progression-free survival was 5.1 months (95% CI, 3.1-7.0) and 2.6 months (95% CI, 1.6-3.5) with a p-value of <0.001, and response rate was 39.0% and 7.4% with a p-value <0.001, respectively. Median time to stent dysfunction was 12.5 months (95% CI, 8.4-16.5) in the entire cohort. In 89 patients, responders had longer time to stent dysfunction than non-responders: 17.4 months (95% CI, 17.3-17.5) and 7.1 months (95% CI, 1.6-12.5) with a p-value of 0.031.
Conclusion: Longer time to stent dysfunction is expected when systemic chemotherapy following DS suppresses tumour progression. DS is slated to be a standard treatment for MGOO, even in patients with pancreaticobiliary cancer and a long lifespan.