Distinguishing pancreatic cancer subtypes

Gene signatures can help define different types of pancreatic tumours reports research published online this week in Nature Medicine. The gene signatures that characterize these subtypes of tumours may be useful in treating specific patients with specific drugs to maximize their responses.

Pancreatic ductal adenocarcinoma (PDA) is a deadly form of cancer; overall survival is typically 6 months from diagnosis. Numerous clinical trials of agents effective in other cancers have failed to benefit unselected PDA patient populations, although some patients do occasionally respond. Studies in other tumours have shown that variability in response is determined in part by molecular differences between tumours and that treatment outcomes improve by targeting drugs to tumour subtypes in which they are selectively effective ― breast and lung cancers provide some of the best examples.

Identification of PDA molecular subtypes has previously been limited by a lack of tumor specimens available for study. Joe Gray and his colleagues overcame this problem by combining analysis of gene-expression profiles of primary PDA samples from several studies, along with human and mouse PDA cell lines. On the basis of this analysis, the authors defined three PDA subtypes and showed evidence for differences in clinical outcome and therapeutic response among them.

The gene signatures that characterize these subtypes may be useful for the design of clinical trials of new drugs targeted to individual tumor subtypes.