Development of a Novel Serum Exosomal MicroRNA Nomogram for the Preoperative Prediction of Lymph Node Metastasis in Esophageal Squamous Cell Carcinoma

Abstract

Preoperative prediction of lymph node (LN) metastasis is accepted as a crucial independent risk factor for treatment decision-making for esophageal squamous cell carcinoma (ESCC) patients. Our study aimed to establish a non-invasive nomogram to identify LN metastasis preoperatively in ESCC patients. Construction of the nomogram involved three sequential phases with independent patient cohorts. In the discovery phase ( N = 20), LN metastasis-associated microRNAs (miRNAs) were selected from next-generation sequencing (NGS) assay of human ESCC serum exosome samples. In the training phase ( N = 178), a nomogram that incorporated exosomal miRNA model and clinicopathologic was developed by multivariate logistic regression analysis to preoperatively predict LN status. In the validation phase ( n = 188), we validated the predicted nomogram's calibration, discrimination, and clinical usefulness. Four differently expressed miRNAs (chr 8-23234-3p, chr 1-17695-5p, chr 8-2743-5p, and miR-432-5p) were tested and selected in the serum exosome samples from ESCC patients who have or do not have LN metastasis. Subsequently, an optimized four-exosomal miRNA model was constructed and validated in the clinical samples, which could effectively identify ESCC patients with LN metastasis, and was significantly superior to preoperative computed tomography (CT) report. In addition, a clinical nomogram consisting of the four-exosomal miRNA model and CT report was established in training cohort, which showed high predictive value in both training and validation cohorts [area under the receiver operating characteristic curve (AUC): 0.880 and 0.869, respectively]. The Hosmer–Lemeshow test and decision curve analysis implied the nomogram's clinical applicability. Our novel non-invasive nomogram is a robust prediction tool with promising clinical potential for preoperative LN metastasis prediction of ESCC patients, especially in T1 stage.

Serum exosomal miR-4787-3p as potential lymph node metastasis and prognostic marker in esophageal squamous cell carcinoma.

“…Recently, emerging evidence demonstrated that exosomal miRNAs modulate the tumor lymph node metastasis, which is favorable for tumor growth and invasion, by remodeling extracellular matrix, promoting tumor angiogenesis, inducting in ammation and immune suppression [26][27][28]. Previous studies indicated that serum exosomal miR-766-3p level was association with lymph node metastasis, which cloud predict ESCC lymph node metastasis (AUC = 0.778; 95% CI, 0.672-0.884) [22]. Another study pointed that four exosomal miRNAs model identi ed lymph node metastasis metastases with an AUC value of 0.865 [23].…”

“…No patients had any anti-cancer treatment before surgery. The ESCC with lymph node metastasis was de ned according the previous study [22]. Based on histopathology, 79 ESCC were divided into two groups: 42 ESCC with lymph node metastasis and 37 ESCC without lymph node metastasis .…”

“…The protein was analyzed by western blot as previously described [22]. The primary antibodies used in this study were as follows: anti-CD81(ABclonal, Wuhan, China), anti-CD63(ABclonal, Wuhan, China).…”

“…The characterization of serum exosomes and screening serum exosomal miRNAs pro les was reported by our previous study [22]. In this study, we selected the candidate serum exosomal miRNAs according to the previous experimental ndings that serum exosomal miR-4787-3p was associated with lymph node metastasis.…”

“…So far, only two studies investigated the role of exosomal miRNAs in ESCC lymph node metastasis. Our previous study showed that upregulated expression of serum exosomal miRNA-766-3p was association with lymph node metastasis and short overall survival rate [22]. Another study explored a novel serum four exosomal miRNAs model for the identi cation of lymph node metastasis cases in ESCC [23].…”