Cancer stem cell marker in circulating tumor cells: expression of CD44 variant exon 9 is strongly correlated to treatment refractoriness, recurrence and prognosis of human colorectal cancer.

BACKGROUND/AIM: The expression of the CD44 variant exon 9 (CD44v9) was investigated in order to elucidate its significance for cancer stem cells in circulating human colorectal cancer cells (CTCs). MATERIALS AND METHODS: After peripheral blood was drawn from patients with colorectal cancer, CTCs were collected. Using the reverse transcription-polymerase chain reaction method, we examined the relationship between expression of CD44v9 mRNA and prognosis. RESULTS: In 60 out of 150 patients with colorectal cancer, expression of CD44v9 mRNA was positive in CTCs. In patients with stage III disease, the 5-year survival rate was 89% for patients with negative CD44v9 expression, whereas it was 52.4% in patients with positive expression (p<0.05). In patients with stage IV unresectable cancer, the 2-year survival rate was 70.1% in cases with CD44v9-negative expression and 33.3% in cases of positive expression (p<0.05). CONCLUSION: CD44v9 mRNA in the CTCs of colorectal cancer is useful as a factor predicting recurrence, prognosis, and treatment efficacy.

A noninvasive partial carbon dioxide rebreathing technique for measurement of pulmonary capillary blood flow is also a useful oxygenation monitor during one-lung ventilation.

STUDY OBJECTIVES: To test the hypothesis that effective pulmonary capillary blood flow can be a useful indicator for estimating appropriate oxygenation and ventilation during one-lung ventilation in lung surgery. DESIGN: Prospective data analysis. SETTING: A 770-bed general teaching hospital. PATIENTS: 15 ASA physical status II and III patients undergoing elective lung surgery. INTERVENTIONS: Patients received general and thoracic epidural anesthesia and underwent lung operation with one-lung ventilation. MEASUREMENTS: We measured effective pulmonary capillary blood flow by a partial CO2 rebreathing method and oxygenation parameters during two-lung ventilation before surgery, during one-lung ventilation, and during two-lung ventilation after lung surgery. MAIN RESULTS: The effective pulmonary capillary blood flow index significantly decreased by 31.6%, which was associated with a significant decrease in arterial oxygen tension (PaO2). The pulmonary shunt fraction increased to 46.3% during one-lung ventilation. During two-lung ventilation, after chest closure, effective pulmonary capillary blood flow index divided by heart rate (i.e., effective pulmonary blood stroke flow index) was still significantly lower than that seen during two-lung ventilation before thoracotomy. There were significant correlations between effective pulmonary capillary blood flow, pulmonary blood stroke flow index, and PaO2. CONCLUSIONS: Effective pulmonary capillary blood flow index and effective pulmonary blood stroke flow index are useful indicators for determining appropriate oxygenation therapy during one-lung ventilation.