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.

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.