Correlation between mesenchymal circulating tumor cells and prognosis of urologic malignancies: a single-center retrospective analysis

Objective: To evaluate the correlation of circulating tumor cells (CTCs) and mesenchymal CTCs (M-CTCs) with clinical characteristics and survival of patients with urologic malignancies.

Methods: The clinical data of 52 patients with urinary system malignancy in Henan Provincial People's Hospital were retrospectively analyzed (40 cases of renal malignant tumor, 7 cases of prostate cancer, 3 cases of urothelial carcinoma, 1 case of testis cancer, and 1 case of penile cancer). The CTC counts of patients were collected, and the expression of epithelial-mesenchymal transition phenotype in CTCs was evaluated. The relationship of different types of CTC counts with tumor stage, location, size, metastasis, and differentiation, as well as their effect on progression-free survival (PFS) were analyzed.

Results: We detected CTCs in all patients with urinary system malignancy. The positive rates of epithelial CTCs (E-CTC), M-CTCs, and epithelial/mesenchymal CTCs (E/M-CTCs) were 34.62%, 26.92% and 94.23%, respectively. Total CTCs (T-CTCs), M-CTCs and E/M-CTCs were correlated with distant metastasis (Z=-3.052, -3.574, -2.898; all P<0.005). M-CTC count was correlated with lymph node metastasis (Z=-3.125; P=0.002). Furthermore, the presence of T-CTCs ≥13.5, M-CTC ≥0.5 or E/M-CTCs ≥9.5 per 5 ml of blood was correlated with worse PFS in patients with urinary system malignancy.

Conclusions: M-CTC and E/M-CTC counts correlate with the prognosis of patients with urinary system malignancy. Higher M-CTC and E/M-CTC counts are risk factors for worse prognosis in patients with urinary system malignancies. All in all, M-CTC count is a valuable tumor biomarker for urologic malignancies.