Determination of circulating tumor cells for detection of colorectal cancer progression or recurrence.

The role of circulating tumor cells (CTCs) in the management of colorectal cancer has not yet established. In present study, we aimed to investigate the relationship between clinicopathological characteristics and CTC levels in patients with colorectal carcinoma. The isolation of CTCs in blood was performed with the semi-automated CellSearch System (Veridex TM). Ninety-three patients were analyzed. Median age of patients at the time of diagnosis was 56 (24-78). Total number of blood samples collected for CTCs were 130. CTCs were detected in 46 patients (> or =1 per 7.5 mL), but only thirty (32%) patients were interpreted as positive (> or = 3/7.5 mL). In the 27 patients in whom 2 blood samples were taken, levels of CTCs were found to be decreased in 8 patients, increased in 14 patients and did not change in 5 patients after therapy. Although only 2 (25%) of 8 patients in whom CTCs decreased after therapy had disease progression, 13 (93%) of 14 patients with increased CTCs had disease progression (p = 0.001). Similarly, 4 (80%) of 5 patients with stable CTCs had also disease progression. Our findings indicate that decreased CTCs after therapy is related with remission while increased CTC level is associated with disease recurrence or progression.