Background: Cutaneous squamous cell carcinoma (cSCC), the most common cancer capable of metastasis, has variable reported metastatic rates and the impact of individual risk factors for metastasis is unknown.
Methods: This study examined pathology records of excised cSCC over a 10-year period. Uni-variate and multi-variate analyses including patient demographics, maximum clinical diameter (MCD), anatomical sub-site, histological differentiation, perineural invasion (PNI), and lymphovascular invasion (LVI) of the lesion were performed. The primary endpoint was time to metastasis.
Results: Six thousand one hundred sixty four patients (median age 74 years) underwent excision of 8,997 primary cSCC. During the median follow-up of 70 months, the metastatic rate of cSCC was 1.9-2.6%. Multi-variate analysis showed that MCD (hazards ratio 1.41 [95% CI 1.25-1.60] P < 0.001), PNI (5.29; P < 0.0001), poor histological differentiation (4.26; P < 0.0001), location in the ear and retro-auricular area (3.31 [1.17-9.33]; P = 0.0024), cheek (3.18 [1.15-8.81]; P = 0.026), and lip (4.84; P = 0.009) increased the risk of metastasis.
Conclusions: We show a 1.9-2.6% metastatic rate for cSCC with MCD, histologic differentiation, PNI, and certain anatomical sub-sites being independent risk factors for metastasis. A prospective study on our proposed risk stratification scheme based on these parameters may lead to identification of high-risk lesions that would benefit from more intensive treatment and/or routine post-operative follow-up.Inc.
Copyright © 2012 Wiley Periodicals, Inc.