Evolution of the chemotherapeutic landscape and survival outcome in patients with metastatic pancreatic cancer: a four-institute cohort study in Taiwan, 2010–2016

Wen-Chi Chou,1 Yen-Yang Chen,2 Chia-Yen Hung,1,3 Jen-Shi Chen,1 Chang-Hsien Lu,4 Pei-Hung Chang5 1Division of Hematology-Oncology, Department of Internal Medicine, Chang Gung Memorial Hospital at Linkou and Chang Gung University College of Medicine, Taoyuan, Taiwan; 2Division of Hematology-Oncology, Department of Internal Medicine, Chang Gung Memorial Hospital at Kaohsiung, Kaohsiung, Taiwan; 3Division of Hematology-Oncology, Department of Internal Medicine, Mackay Memorial Hospital, Taipei, Taiwan; 4Division of Hematology-Oncology, Department of Internal Medicine, Chang Gung Memorial Hospital at Chiayi, Chiayi, Taiwan; 5Division of Hematology-Oncology, Department of Internal Medicine, Chang Gung Memorial Hospital at Keelung, Keelung, Taiwan Background: Only 5-fluorouracil (5-FU), cisplatin, and gemcitabine have been reimbursed for metastatic pancreatic cancer (mPC) treatment in Taiwan since 2003. It is uncertain whether the reimbursement of S-1 in June 2014 might change the treatment pattern and improve the survival of mPC patients in Taiwan. Patients and methods: A total of 645 patients with newly diagnosed mPC who received palliative chemotherapy between 2010 and 2016 in Taiwan were analyzed retrospectively. Patients were stratified according to year at diagnosis of mPC for analysis of chemotherapeutic treatment pattern and survival. Results: Overall, the most common chemotherapeutic agents used for the treatment of mPC were gemcitabine (94.8%), followed by cisplatin (52.4%), S-1 (38.1%), and 5-FU (29.7%). The percentage of patients treated with S-1 between 2010 and 2016 increased from 2.6% to 74.0% (P<0.001), while the percentage of patients treated with 5-FU decreased from 31.6% to 21.2% (P<0.001). The percentage of patients treated with gemcitabine, cisplatin, etc. remained consistent. An increase in the number of lines of treatment was observed throughout the study period, with 27.6% of patients receiving two or more lines of treatment in 2010, compared with 50.0% of patients in 2016 (P=0.013). The 12-month survival rate increased from 11.8% in 2010 to 41.4% in 2016, corresponding to an adjusted average annual percent change of 13.6% (0.3–28.7, P<0.05). Conclusion: Based on this multi-institute cohort study in Taiwan, the reimbursement of S-1 changed the clinical practice and is associated with an improvement in survival outcome of mPC patients. Keywords: palliative chemotherapy, pancreatic cancer, S-1, survival outcom