Preliminary Investigation of the Clinical Significance of Detecting Circulating Tumor Cells Enriched from Lung Cancer Patients

Enumeration of circulating tumor cells (CTCs) may be valuable for lung cancer treatment and monitoring cancer patient relapse. In the present study we report clinical significance of lung cancer CTC. CTCs were enriched from peripheral blood of 47 lung cancer patients by means of a modified enrichment strategy, followed by identification with immunofluorescence staining using anticytokeratins 18 and 19 monoclonal antibodies. A control group consisted of 18 healthy donors and 13 nonmalignant pulmonary tuberculosis patients had no positive subject detected. Among 41 newly diagnosed and 6 recurrent lung cancer patients (3 stage I–II, 22 stage III and 22 stage IV) including 27 adenocarcinoma (ADC), 7 squamous cell carcinoma and 13 small cell lung cancer (SCLC), positive detection rate of newly diagnosed patients with CTC ≥2/7.5 ml blood was 78% (ADC stage III), 75% (squamous cell carcinoma stage III) and 60% (SCLC stage III), respectively. Whereas 46% (ADC IV) and 71% (SCLC IV) were observed for stage IV patients. Recurrent patients showed highest detection sensitivity of 83%. A small scale follow-up study was performed on 12 patients following 2 courses of first line chemotherapy. This demonstrated a good correlation of CTC enumeration with radiographic response. Results of the present study suggest potential clinical utilities of CTC enumeration on lung cancer patients in terms of rapid evaluation of chemotherapy effect in real time and monitoring lung cancer recurrence. A large scale of study which is necessary for further validation of the significance of lung cancer CTC is being performed.