Non-Small Cell Lung Cancer (NSCLC) is the most common cause of cancer related deaths in both men and women. Some lung cancer patients have a unique challenge of a tissue access due to tumor location or baseline lung disorders such as emphysema and chronic obstructive pulmonary disease (COPD). Liquid biopsy technologies can overcome tissue assess difficulties. However, as of today there are no commercially approved assays for CTC enumeration in lung cancer. Multiple non-commercial assays exist and some show correlation of CTC enumeration and changes in CTC counts on therapy with prognosis and response to therapy. Outside of absolute number of CTC there is little published data regarding prognostic significance of CTC morphologic heterogeneity in late stage NSCLC and its ability to predict treatment outcomes. Here we investigate CTC counts in 81 patients with stage IV NSCLC using a fluid phase biopsy and high definition (HD) diagnostic pathology imaging of all nucleated cells. HD-CTCs were detected in 51 (63%) patients at initiation of therapy with a median of 2.20 (range 0-509.20) and a mean of 26.21 HD-CTCs/mL (±15.64). There was no correlation between the absolute number of HD-CTCs at the time of initiation of new therapy and patient outcomes. A subset of 25 patients was further analyzed to determine the significance of HD-CTC kinetics, which may follow three distinct patterns: an increase in HD-CTCs with therapy, unchanged HD-CTCs numbers (stable), and a decline in HD-CTCs numbers. Patients that experienced an increasing, stable, or decreasing HD-CTC profile had an overall change of 118.40, 0.54, and 81.40 HD-CTCs/mL respectively during the first 3 months. The overall survival (OS) for increasing profiles was 31.08 months (±13.08, median 32.46, range 15.11-43.50), for stable profiles OS was 8.82 months (±3.57, median 7.23, range 3.91-19.75), and for decreasing profiles it was 15.30 months (±6.39, median 14.06, range 3.81-28.06) months. CTCs are identifiable in patients with stage IV NSCLC, but correlation of absolute HD-CTC counts with disease progression was not statistically significant. However, change in CTC counts were predictive of OS in patients with metastatic lung cancer receiving chemotherapy.

Citation Format: Stephanie N. Shishido, Lyudmila Bazhenova, Anders Carlsson, James Hicks, Peter Kuhn. Detection of circulating tumor cells in stage IV non-small cell lung cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 1712. doi:10.1158/1538-7445.AM2017-1712