(HealthDay News) – The number of circulating tumor cells (CTCs) and the change in CTC number after one cycle of chemotherapy predict prognosis in patients with small-cell lung cancer (SCLC), according to a study published online January 17 in the Journal of Clinical Oncology.
Jian-Mei Hou, PhD, of the University of Manchester in the United Kingdom, and colleagues examined serial blood samples from 97 SCLC patients receiving chemotherapy. The samples were analyzed using EpCam-based immunomagnetic detection and a filtration-based technique. Proliferation status and apoptotic morphology were investigated, and the association of CTC and circulating tumor microemboli (CTM) number was examined in relation to clinical factors and prognosis.
The researchers found that CTCs were present and abundant in 85% of patients (mean number, 1,589). CTM were detected in 32% of patients and apoptotic CTCs were detected in 57%, both of which were associated with total CTC number. Independent prognostic factors included pretreatment CTCs, change in CTC number following one cycle of chemotherapy, CTM, and apoptotic CTCs. Overall survival was 5.4 and 11.5 months for patients with ≥50 and <50 CTCs/7.5 mL of blood, respectively, before chemotherapy (hazard ratio, 2.45). Subpopulations of apoptotic and proliferating solitary CTCs were found but neither were seen within CTM.
“Both baseline CTC number and change in CTC number after one cycle of chemotherapy are independent prognostic factors for SCLC,” the authors write.