Clinical significance of postoperative folate receptor‐positive circulating tumor cells (FR + CTCs) for long‐term prognosis in patients with invasive adenocarcinoma (IAC) of the lung

Abstract Background The aim of the study was to evaluate the prognostic value of postoperative folate receptor‐positive circulating tumor cell (FR + CTC) detection in patients with stage I–III invasive adenocarcinoma (IAC) treated with surgery. Methods Patients with lung adenocarcinoma (LUAD) who underwent surgical resection in Peking University Cancer Hospital and received postoperative FR + CTC analysis from July 2016 to January 2021 were retrospectively collected. Comparisons between or among groups were made using the Kruskal‐Wallis or Mann–Whitney U tests. Survival curves were estimated using the Kaplan–Meier method and compared using the log‐rank test. Cox proportional hazard regression analyses were performed to explore the factors predicting recurrence and survival. Results There were significant differences between the high and low groups in terms of age (p = 0.002), postoperative CA199 (p = 0.038), and postoperative SCC (p = 0.024). There were no significant differences in the other indicators (all p>0.05). N stage 1, N stage 2, and neoadjuvant therapy (NAT) were independent risk factors for disease recurrence and death; pleural invasion (PI), and nerve invasion were independent risk factors for death. The Kaplan–Meier curve showed a notable trend for a worse disease‐free survival (DFS) or overall survival (OS) for patients with high levels of FR + CTCs in our study, but none of these were statistically significant. Conclusion The detection of FR + CTCs postoperatively was an independent predictor of recurrence in patients treated for stage I–III IAC. Standardized detection methods and optimal time points for assessment should be established in future studies.