Detection of circulating tumour cells, spread through air space and lymph-nodal micrometastasis in patients with lung cancer undergoing surgical resection

Introduction Lung cancer is one of the most lethal malignancies worldwide. In early-stage cases, surgery is considered the cornerstone of therapy; however, despite radical resection, recurrence rates remain as high as 20% for stage I. The aim of this project was to analyze the presence of Circulating Tumor Cells (CTCs), Spread Through Air Spaces (STAS), and lymph node micrometastasis in patients with clinical stage IA-IIA Non-Small Cell Lung Cancer (NSCLC) who received surgical treatment. Materials and Methods Clinical stage IA-IIA candidates for surgery were included. Patients who received neoadjuvant therapy were excluded. CTCs were evaluated through peripheral blood samples collected the day before surgery and 30 days postoperatively. The primary endpoints were: to verify whether the presence and/or levels of CTCs, STAS, and lymph node micrometastases are associated with long-term outcomes (DFI, OS) and to evaluate recurrence patterns in patients with CTCs, STAS, and lymph node micrometastases. Results Forty-six patients were enrolled in the study, with 42 meeting the inclusion criteria. Half of the patients were female (21, 50%), and the mean age was 71.8 years (Standard Deviation, SD, ±8.0). Lymph node micrometastasis was found in only 2 cases (4.8%); conversely, STAS was confirmed in half of the patients (21, 50.0%). CTCs were detected in 20 patients (47.6%). Pre- and postoperative CTCs were present in 3 patients (7.1%), while in 11 patients CTCs were detectable only after surgery. The mean number of preoperative CTCs was 2.4 (±1.6), while the mean 30-day CTC count was 4.0 (±6.5). CTCs were more common in squamous cell carcinoma (p=0.047), and there was a trend towards a correlation between STAS presence and postoperative CTCs (p=0.085). Conclusions Our preliminary results confirm that CTCs are present even in early-stage lung cancer and suggest a possible correlation with other pathological features such as STAS.