Circulating tumor cell (CTC) as a significant prognostic factor in resected primary lung cancer.

Abstract

e23044 Background: Circulating tumor cell (CTC) is a potentially useful marker in early diagnosis and monitoring therapeutic effects for patients with malignant tumors, but clinical significance of CTC in primary lung cancer remains unclear. We previously showed that CTC was a useful surrogate marker of distant metastasis in primary lung cancer (Clin Cancer Res 2009). In this study, we evaluated the prognostic value among completely resected patients after long-term follow-up. Methods: A total of 94 patients (median age, 68 years; 30 females and 64 males) who underwent complete resection for primary lung cancer (4 with small cell and 90 with non-small cell) were prospectively evaluated. At the time of enrollment into the study, 7.5mL of peripheral blood was sampled from each patient, and an EpCAM-based detection system (CellSearch) was used for detection of CTC. CTC was detected in 16 patients (CTC-positive, 14.9%). Results: CTC-positivity was significantly associated with a poor recurrence-free survival (5-year recurrence-free survival rate, 40% versus 72%; p<0.01) (Table 1), which was confirmed by a multivariate analysis (hazard ratio, 2.57 [95% CI, 1.26-5.26]; P=0.010). CTC-positivity was also associated with a poor overall survival (5-year recurrence-free survival rate, 62% versus 84%; p<0.05) (Table 1), which was confirmed by a multivariate analysis (hazard ratio, 2.76 [95% CI, 1.14-6.71]; P=0.025). Conclusions: CTC-positivity was associated with poor recurrence-free survival and poor overall survival in resected lung cancer. [Table: see text]