Current staging paradigms have significant limitations. Histopathology has been the gold standard for staging patients with colorectal cancer. Although the clinical limitations of histopathology have been well established scientifically, a viable alternative has not been available. These limitations include:

Clinical Limitations of Histopathology

Sampling Error <1.0% of available tissue is reviewed
Sensitivity Reliable lower limit of detection of 1 cancer cell in 200 normal cells

Since staging is the single most important prognostic indicator and determines treatment decisions, the accuracy of the assay used to establish stage can significantly influence patient management and their disease-free and overall survival. This is particularly relevant for patients classified as lymph node-negative, who typically are denied chemotherapy, since their lymph nodes may harbor occult micrometastases that escape detection by standard methodologies. Indeed, these occult micrometastases likely underlie the high (30%) recurrence rates in patients who are lymph node negative.