Report of the Tumor Evaluation Committee workshops at ISHAGE 2001

Multiple factors impact polymerase chain reaction (PCR) detection of tumor cells ranging from the fundamental, such as selection of targets for amplification, to the practical, including the timing of sample processing, granulocyte contamination and anticoagulant used. Much more work, including standardization studies, remains to be performed. Tumor enrichment can be achieved either by positive selection, generally by use of antibodies or by depletion of (CD45(+)) hematopoietic cells. Both approaches work and each has advantages and disadvantages. Enriched tumor cells can be further analyzed for expression of prognostic markers. A future area of emphasis should be to establish a dialogue between practitioners of tumor detection and developers of new therapies who are in search of surrogate markers of outcomes.