Prognostic significance of circulating tumor cells in patients with metastatic colorectal cancer

• Published in: Annals of oncology Vol. 20; no. 7; pp. 1223 - 1229
• Main Authors: Cohen, S.J., Punt, C.J.A., Iannotti, N., Saidman, B.H., Sabbath, K.D., Gabrail, N.Y., Picus, J., Morse, M.A., Mitchell, E., Miller, M.C., Doyle, G.V., Tissing, H., Terstappen, L.W.M.M., Meropol, N.J.
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 01-07-2009; Oxford University Press; Oxford Publishing Limited (England)
• Subjects: Aged; Aged, 80 and over; Antibodies, Monoclonal - therapeutic use; Antibodies, Monoclonal, Humanized; Antineoplastic agents; Bevacizumab; Biological and medical sciences; Camptothecin - analogs & derivatives; Camptothecin - therapeutic use; circulating tumor cells; Colorectal cancer; Colorectal Neoplasms - drug therapy; Colorectal Neoplasms - pathology; Disease Progression; Disease-Free Survival; Female; Follow-Up Studies; Gastroenterology. Liver. Pancreas. Abdomen; Humans; Irinotecan; Kaplan-Meier Estimate; Male; Medical sciences; metastatic; Middle Aged; Neoplasm Metastasis - pathology; Neoplastic Cells, Circulating - pathology; Organoplatinum Compounds - therapeutic use; Oxaliplatin; Pharmacology. Drug treatments; Predictive Value of Tests; Prognosis; Stomach. Duodenum. Small intestine. Colon. Rectum. Anus; Survival Rate; Time Factors; Treatment Outcome; Tumors; metastatic; circulating tumor cells; colorectal cancer; Human; Rectal disease; Prognosis; Colorectal cancer; Patient; Malignant tumor; Metastasis; Colonic disease; Digestive diseases; Intestinal disease; Advanced stage; Tumor cell; Cancer
• ISSN: 0923-7534; 1569-8041
• DOI: 10.1093/annonc/mdn786

Background: We demonstrated that circulating tumor cell (CTC) number at baseline and follow-up is an independent prognostic factor in metastatic colorectal cancer (mCRC). This analysis was undertaken to explore whether patient and treatment characteristics impact the prognostic value of CTCs.
Patients and methods: CTCs were enumerated with immunomagnetic separation from the blood of 430 patients with mCRC at baseline and on therapy. Patients were stratified into unfavorable and favorable prognostic groups based on CTC levels of ≥3 or <3 CTCs/7.5ml, respectively. Subgroups were analyzed by line of treatment, liver involvement, receipt of oxaliplatin, irinotecan, or bevacizumab, age, and Eastern Cooperative Oncology Group performance status (ECOG PS).
Results: Seventy-one percent of deaths have occurred. Median follow-up for living patients is 25.8 months. For all patients, progression-free survival (PFS) and overall survival (OS) for unfavorable compared with favorable baseline CTCs is shorter (4.4 versus 7.8 m, P=0.004 for PFS; 9.4 versus 20.6 m, P<0.0001 for OS). In all patient subgroups, unfavorable baseline CTC was associated with inferior OS (P<0.001). In patients receiving first- or second-line therapy (P=0.003), irinotecan (P=0.0001), having liver involvement (P=0.002), ≥65 years (P=0.0007), and ECOG PS of zero (P=0.04), unfavorable baseline CTC was associated with inferior PFS.
Conclusion: Baseline CTC count is an important prognostic factor within specific subgroups defined by treatment or patient characteristics.