Inducible Nitric Oxide Synthase (iNOS) Immunoreactivity and Its Relationship to Cell Proliferation, Apoptosis, Angiogenesis, Clinicopathologic Characteristics, and Patient Survival in Pancreatic Cancer.

Human pancreatic adenocarcinoma remains oneof the most difficult cancers to treat, as evidencedby the minimal improvement in survival, even withthe addition of chemotherapy or radiation therapy. Epidemiological and experimental studies indicatethat the risk of developing pancreatic cancer may bethe result of the combined actions of environmentalfactors and endogenous promoting agents (1,2).Recently, much attention has been given to endogenousfactors, which appear to be directly responsiblefor the growth, spread, and invasion of tumorcells. The identification of such endogenous factorsshould lead to an understanding of the processes oftumor cell progression and metastasis, and also providenew strategies for developing agents that specificallysuppress these processes.