Efficacy of PERT for PEI in Unresectable Pancreatic Cancer.

\- This will a be an open label, multicentre, randomized, controlled study in patients with unresectable pancreatic cancer, locally advanced or metastatic, with significant weight loss, and the tumour located in the head of the pancreas associated with dilated main pancreatic duct. Pancreatic Exocrine Replacement Therapy (PERT) in these patients will be given on top of other required therapies (best standard of care, BSC), including oncologic therapies, diabetes mellitus therapies and acid suppressants and nutritional support as appropriate. The duration of the study will be up to six months. Consecutive patients meeting inclusion criteria and none of the exclusion criteria will be evaluated for the study. Those patients signing the informed consent for study participation will be randomized to one of the following two arms: * The experimental arm will receive the best standard of care (BSC) and PERT (capsules containing pancreatin 35,000 Ph.U.) at a fixed dose of 3 capsules with main meals (breakfast, lunch and dinner) and 2 capsules with snacks over 6 months. * The control arm will receive the BSC over 3 months, followed by a further 3-month open uncontrolled phase of BSC + PERT at the dose mentioned above. All patients will receive in addition a proton pump inhibitor (PPI) bid (any PPI at standard dose is acceptable -omeprazole 20 mg, lansoprazole 30 mg, pantoprazole 40 mg, rabeprazole 20 mg, esomeprazole 40 mg) while on PERT, 20-30 minutes before breakfast and dinner. To make the two arms comparable, patients will be stratified in two groups (locally advanced and metastatic pancreatic cancer) for randomization using computer generated random numbers.