Efficacy of preoperative therapy in patients with high and low risk of distant metastasis in non-small cell lung cancer

Background. To select the optimal treatment for non-small cell lung cancer (NSCLC), it is important to predict the risk of distant metastasis and the effectiveness of therapy. The effect of neoadjuvant chemotherapy (NAC) on distant metastasis remains poorly understood. In this study we evaluated the feasibility of predicting the risk of distant metastasis and effectiveness of various treatment options for pre- and intraoperative therapy in NSCLC patients with high and low risk of distant metastasis, divided based on the assessment of morphological changes in the epithelium of small bronchi located near the primary tumor. Material and Methods. The study included 171 patients with NSCLC (T1-4N0-3M0). Various premalignant lesions: isolated basal cell hyperplasia (BCH+SM-D-), basal cell hyperplasia with squamous cell metaplasia (BCH+SM+D-) and squamous cell metaplasia with dysplasia (BCH-SM+D+) were identified in the bronchial epithelium of small bronchi taken at a distance of 3-5 cm from the tumor. Preliminary studies have shown that the detection of BCH+SM-D- or BCH-SM+D-in small bronchi are the markers of high risk of NSCLC distant metastasis, and the detection of BCH+SM+D- and BCH-SM-D- are the markers of low risk of NSCLC distant metastasis. 52.6 % of patients (90/171) received 2-3 courses of neoadjuvant chemotherapy (NAC), 41.1 % (37/90) of patients underwent intraoperative radiation therapy (IORT) at a single dose of 10-15 Gy and 47.4 % (81/171) of patients received platinum-based adjuvant chemotherapy (AC). Results. Both treatment options (NAC+IORT+ and NAC+IORT-) effectively reduced the incidence of distant metastases in the high-risk group patients during the first 2 years of follow-up compared with the high-risk group patients who did not received therapy. In the low-risk group patients, distant metastases rarely occurred, regardless of the treatment option. Adjuvant chemotherapy was found to have no influence on the frequency of distant metastases. Metastasis-free and overall survival rates were better in the low-risk group patients or in patients who received the NAC+IORT+ regimen. Conclusion. Combination of NAC and IORT resulted in the increase in metastasis-free and overall survival rates.