In recent years, treatment of advanced pancreatic cancer is changing. Currently, there are several active schedules of chemotherapy that can be used, such as gemcitabine as monotherapy or in combination with capecitabine or erlotinib, and FOLFIRINOX. Moreover, the development of biomarker (therapeutic targets) that can predicte response to treatment is a new important tool to be used in clinical practice to select the best scheme for each patient. Preliminary studies showed that therapeutic target determination, using tumor tissue collected from patients, could determine the presence of groups of "chemotherapy responders". Such is the case of EGFR amplification and/or K-Ras gene status and correlation with response to erlotinib. Moreover, Thymidilate Synthase, Thimidine Phosphorylase, ERCC-1 and Topoisomerase I expression by immunohistochemistry in GI tumor samples has been related to resistance or response to 5FU-capecitabine, oxaliplatin and irinotecan respectively. Based on this data the investigators designed a phase II clinical trial to evaluate the efficacy of selected treatment for pancreatic cancer patients based on the determination of therapeutic targets. The therapeutic target-driven treatment efficacy will be compared to the prospective treatment of a control group of patients treated at the discretion of the physician-researcher

Study Phase: Phase 2 Trial

Study Objetives:

• Primary end-point. Proportion of patients alive after 12 months in patients with advanced pancreatic carcinoma individually selected and grouped according to the expression in tumor tissue for therapeutic targets.
• Secondary end-points. 1. Assessing the feasibility of the method of patient-treatment-selection based on tumor tissue expression of therapeutic targets. 2. Overal survival comparison between Gemcitabine single agent treatment and the rest of chemotherapy schedules. 3. Determination of progression-free survival for each treatment group. 4. Determination of toxicity in all the patients.

Study population and Number of subject: A total of 60 pancreatic cancer patients with advanced pancreas cancer with no previous systemic treatment are expected to be enrolled.

Study design and schedule. Patients will be randomized (1:1) to a control arm or an experimental treatment arm guided by therapeutic targets. In the control arm, patients are treated with conventional chemotherapy regimens at the discretion of the investigator. In the experimental arm, patients are treated as determined in tumor tissue available for biomarker TS, TP, ERCC-1, Topo-1, K-Ras mutation and EGFR FISH, choosing FOLFIRINOX schemas, FOLFOX, FOLFIRI, Gemcitabine-Capecitabine Gemcitabine-Erlotinib, Gemcitabine single agent. All patients will be analyzed by intention to treat

Inclusion Criteria:

• Histologic diagnosis of pancreas adenocarcinoma
• Clinical stage IV
• Feasible patient for chemotherapy
• Availability of tumor tissue or possibility of a tumor biopsy to define therapeutic targets
• Informed written consent

Exclusion Criteria:

• Previous systemic treatment for advanced pancreas adenocarcinoma
• Contraindication to the administration of any of the drugs used in the study: capecitabine, 5Fluouracil, irinotecan, oxaliplatin, gemcitabine or erlotinib