Circulating Tumor Cells and Breast Cancer Metastasis: From Enumeration to Somatic Mutational Profile

Chengjun Zhu; Jing Xu; Jinyu Sun; Shiyun Cui; Yue Sun; Tao Yu; Cenzhu Wang; Tianyao Wang; Yufeng Wu; Feng Ju; Jiafeng Yao; Kai Liu; Wenwen Zhang; Xiaoxiang Guan

doi:10.3390/jcm11206067

Circulating Tumor Cells and Breast Cancer Metastasis: From Enumeration to Somatic Mutational Profile

J Clin Med. 2022 Oct 14;11(20):6067. doi: 10.3390/jcm11206067.

Authors

Chengjun Zhu¹, Jing Xu¹, Jinyu Sun¹, Shiyun Cui¹, Yue Sun¹, Tao Yu¹, Cenzhu Wang¹, Tianyao Wang², Yufeng Wu², Feng Ju³, Jiafeng Yao³, Kai Liu³, Wenwen Zhang⁴, Xiaoxiang Guan¹

Affiliations

¹ Department of Oncology, The First Affiliated Hospital of Nanjing Medical University, No. 300 Guangzhou Road, Nanjing 210029, China.
² Stomatological College, Nanjing Medical University, Nanjing 210029, China.
³ College of Mechanical and Electrical Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, China.
⁴ Department of Oncology, Nanjing First Hospital, Nanjing Medical University, 68 Changle Road, Nanjing 210006, China.

Abstract

Aims: This study investigates the association between circulating tumor cells (CTCs) and breast cancer metastasis. Methods: A retrospective study was conducted using patients with histologically confirmed breast cancer recruited from the First Affiliated Hospital of Nanjing Medical University during the period of August 2017−October 2020. We used adjusted logistic regression, the random forest algorithm, and sensitivity analysis to study the association between CTC enumeration and tumor metastasis. Further, we performed next-generation sequencing (NGS) on the CTCs obtained from two patients with breast cancer brain metastasis. Results: A total of 41 out of 116 enrolled patients were identified with tumor metastasis. CTC enumeration was significantly higher in patients with liver metastasis than in those without liver metastasis. Patients with CTCs ≥ 5 exhibited a higher risk of tumor metastasis than those with CTCs < 5 in the adjusted model (odds ratios (OR) = 6.25, 95% confidence interval (CI) = 2.63−15.58). The random forest model identified CTC enumeration as a significant metastasis-related variable with the highest mean decrease accuracy and mean decrease Gini score. No significant association was found between CTCs and visceral metastasis with an OR of 1.29 (95% CI = 0.98−2.05, p = 0.232). Upon further investigating organ-specific metastasis, we found that patients with high CTC levels were more likely to develop liver metastasis (OR = 4.87, 95% CI = 1.34−20.17, p = 0.021). The NGS study of CTCs identified a total of 120 indel mutations (e.g., CNGB1, NTSR1, ZG16). The enriched biological processes were mechanoreceptor differentiation and macrophage activation involved in the immune response. The enriched KEGG pathways included focal adhesion, the PI3K-Akt signaling pathway, and microRNAs involved in cancer. Conclusions: Our study revealed that CTCs ≥ 5 are a risk factor for tumor metastasis in breast cancer patients. In addition, we reported that CTCs ≥ 5 might be associated with a higher risk of liver metastasis in patients with metastatic breast cancer. We have provided the mutational profiles of CTCs based on next-generation sequencing.

Keywords: biomarker; breast cancer; circulating tumor cells; liver metastasis; metastasis.

Grants and funding

This research was supported by the National Natural Science Foundation of China (No. 81773102), the Key International Cooperation of the National Natural Science Foundation of China (No. 81920108029), and the Key Foundation for the Social Development Project of the Jiangsu Province (BE2021741) (to X.G.).