Evaluation of incidence, significance, and prognostic role of circulating tumor microemboli and transforming growth factor‐β receptor I in head and neck cancer

Background Circulating tumor microemboli (CTM) are clusters of circulating tumor cells (CTCs), involved in metastasis, as also transforming growth factor-β (TGF-β). The purpose of this study was to verify their role in progression-free survival (PFS). Methods Blood from patients with locally advanced head and neck squamous cell carcinoma (HNSCC; n = 53) was analyzed in 2 moments. TGF-β receptor I (TGF-βRI) expression was evaluated by immunocytochemistry. Results Comparing CTM1 (baseline) with CTM2 (first follow-up), patients with CTM1-positive disease who became CTM2-negative were classified as favorable (PFS 20 months). Patients with unfavorable evolution (CTM1-negative/CTM2-positive), had PFS of 17.5 months. Patients always CTM-negative showed PFS of 22.4 months, those always positive, 4.7 months (P < .001). The TGF-βRI expression in the first follow-up correlated with poor PFS (12 × 26 months; P = .007), being an independent prognostic factor (hazard ratio [HR] = 6.088; P =  .033). Conclusion CTM1/2, TGF-βRI expression, and unfavorable CTM kinetics may represent poor prognosis in locally advanced HNSCC.