Abstract
BACKGROUND: In cutaneous squamous cell carcinoma (cSCC), there is a paucity of data regarding local recurrence (LR) and regional lymph node metastasis (LM) as precursors to tumor death. PATIENTS AND METHODS: We estimated parameters of a multistate model with a proportion of patients without risk of progression using maximum likelihood. For seven risk factors, the relative risks of progression to LR, LM, and LR&LM were compared with the relative risks of cSCC death among patients with progression. RESULTS: Of the 1,400 patients, 124 (8.9%) were diagnosed with either LR (68), LM (42), or LR&LM (14). cSCC-specific death occurred in 33 patients (2.4%), 10 by LR, 14 by LM, and 9 by LR&LM, among these 10 distant metastases. Conversely, 493 patients (35.2%) died from other causes. The risk of death from cSCC was 14.7% for LR, 33.3% for LM, and 64.3% for LR&LM. The median time to disease-related death was 1.3 years. CONCLUSIONS: The risk of progression is limited to approximately 25% of patients. LM has been found to be associated with a higher risk of disease-specific death in comparison to LR. The median interval from progression to disease-specific death was found to be 1.3 years.