Pancreatic cancer is highly malignant and has a very poor prognosis, with a 5-year survival rate of less than 5%. Approximately 80-85% of patients are already in a locally progressive or advanced stage at the time of presentation, thus losing the opportunity for surgical treatment. Gemcitabine monotherapy is the standard of care for pancreatic cancer, but only about 15-20% of patients are treated effectively with this regimen. After failure of first-line gemcitabine-based chemotherapy regimens, NCCN guidelines recommend fluorouracil-based regimens as second-line chemotherapy, but there is a lack of support from randomized controlled phase III clinical trials. The CONKO003 clinical trial, a randomized controlled phase III clinical trial initiated by the CONKO pancreatic cancer research group in Germany, was designed to explore which regimen provided the greatest benefit to pancreatic cancer patients after failure of gemcitabine monotherapy in advanced pancreatic cancer, OFF (oxaliplatin + fluorouracil + formyltetrahydrofolate) versus FF (fluorouracil + formyltetrahydrofolate). The study randomized a total of 168 patients with advanced pancreatic cancer who failed first-line gemcitabine monotherapy in 19 medical centers in Germany into 2 groups, 77 in the OFF group and 91 in the FF group, and showed that the disease-free survival was 2.9 months in the OFF group and 2 months in the FF group; the overall survival was 5.9 months in the OFF group and only 3.3 months in the FF group, both with The differences were statistically significant. Further subgroup analysis revealed that patients with pancreatic cancer with metastases, KPS score 70-80 and duration of first-line gemcitabine chemotherapy >6 months benefited better from the OFF regimen. In terms of common adverse effects (anemia, gastrointestinal reactions, leukopenia, etc.), there was no significant difference between the two. The study was successfully published in 2014 in the journal of clinical oncology, a leading oncology journal in the United States, and the NCCN guidelines recommend the OFF regimen as one of the standard second-line treatment options for advanced pancreatic cancer after failure of first-line gemcitabine chemotherapy.