Pancreatic cancer patients with circulating tumor cells tend to have worse outcomes:

[News]

Fox Chase Cancer Center investigators find that pancreatic cancer patients who have circulating tumor cells tend to have worse outcomes than patients without circulating tumor cells. Additionally, the team has uncovered evidence that not all circulating tumor cells are the same, and some may predict worse outcomes than others.

More... (http://www.news-medical.net/news/20100529/Pancreatic-cancer-patients-with-circulating-tumor-cells-tend-to-have-worse-outcomes-Study.aspx)