RESUMEN
Patients with head and neck tumours (HNT) have a high risk of early locoregional relapse that is difficult to diagnose. This study evaluated the usefulness of the serum Cyfra 21-1 assay compared to squamous cell carcinoma antigen (SCC) assay for monitoring such patients. Three hundred and twelve HNT patients, including 204 newly diagnosed patients, were followed up for a median of 446 days with serial serum assays for SCC and Cyfra 21-1. Untreated patients showed SCC and Cyfra 21-1 serum levels correlated with each other: concentration was correlated to clinical stage, tumour size (as T1 + T2 vs. T3 + T4) and nodal status. Cyfra 21-1, but not SCC, was related to the presence of metastases and the primary tumour site, with a univariate prognostic value for disease-free survival (p = 0.015). Cox's regression analysis showed that only Cyfra 21-1 was associated with a risk of relapse (p = 0.027). The random coefficient growth curve model applied to serial SCC and Cyfra 21-1 measurements of 111 patients showed that only Cyfra 21-1 exhibited a significant difference between patients with and without relapses. We found Cyfra 21-1 to be more closely related to initial clinical data and disease evolution than SCC, and therefore propose the use of Cyfra 21-1 for monitoring head and neck cancers.