A deeper understanding of the tumor microenvironment in pancreatic cancer: the key to developing effective immunotherapies

The number of pancreatic cancer related deaths is projected to increase while many other cancers fall (1). Pancreatic cancer is the third leading cause of cancer related death and projected to overtake second by 2020 (1). Despite intense research efforts over many years, five-year survival after diagnosis with pancreatic cancer remains grim at around 8% (2). Only 20% of patients present with surgically resectable disease, and even for those, five-year survival is a mere 24.6% (3). For those with more advanced disease, median survival is just 4.2 months (3). Of the small minority of patients who present with resectable disease, standard of care includes surgical resection followed by a limited number of chemotherapeutic options which yield a 19-month median survival (3). Response to available chemotherapeutic regimens varies between patients and the reasons behind these varied responses are unclear. This leave clinicians with a strategy of administering a chemotherapy and abandoning it in lieu of another after disease progression. Regardless of therapeutic approach, and particularly in metastatic disease, the prognosis remains poor (4). There has been little improvement in these dismal statistics despite decades of research