To study sensitivity of a blood test to detect cancer cells in human blood for early diagnosis of cancer.

Primary outcome(s): The number of circulating tumor cells (CTCs) per milliliter of whole blood. Reported unit of measure will be the number of CTCs/milliliter.
Timepoint: Blood samples will be collected from study subjects at a single timepoint and analyzed for the number of circulating tumor cells (CTCs) within 7 days (168 Hrs) of blood collection.