Detection of Circulating Tumor Cells Using lmmunobead-PCR

Many studies have shown that survival following surgery for solid tumors, such as colorectal and breast, is influenced by the extent of local invasion and the presence of distant metastases, and staging systems based on that are still the main prognostic indicator of survival. However, 20–30% of patients with early stage disease, without evidence of lymph node or distant dissemination, relapse and die within 5 yr of “curative” resection. The inference is that occult or micrometastatic disease was already present at the time of resection, or that tumor cells with metastatic potential were released into the blood stream as a result of surgery. Detection of circulating tumor cells at diagnosis in early stage patients would imply that the disease is more advanced than indicated by conventional staging. These patients might then be offered adjuvant chemotherapy or radiotherapy post surgery.