Background: Information about the frequency and timing of subsequent cutaneous squamous cell carcinoma (cSCC), along with associated risk factors, is limited. However, this information is crucial to guide follow-up care for these patients.
Objective: To evaluate the risk and timing of subsequent cSCC in patients who presented with an initial diagnosis of cSCC.
Methods: Retrospective review of an institutional review board-approved, single-institution registry of invasive cSCC. All patients had at least 2 primary cSCCs diagnosed on 2 separate dates 2 months apart.
Results: A total of 299 primary cSCCs were included. At 6 months from initial cSCC diagnosis, 18.06% (n = 54) of patients developed subsequent cSCC; at 1 year, 31.77% (n = 94); at 3 years, 67.56% (n = 202); and at 5 years, 87.96% (n = 263) developed subsequent cSCC. Risk factors associated with subsequent cSCC include age at initial diagnosis (hazard ratio [HR], 1.02; 95% confidence interval, 1.004-1.027; P = .008), T2 stage (HR, 1.66; 95% CI, 1.07-2.57; P = .025), and poor tumor grade. Tumor grades well, moderate, and unknown have HRs of 0.21 (P < .001), 0.16 (P .001), and 0.25 (P = .001), respectively.
Conclusions: Of patients who develop subsequent cSCC, 18.06% do so within 6 months, and 31.77% do so within 1 year of initial cSCC diagnosis. Patients with advanced age, poor histologic differentiation, and American Joint Committee on Cancer T2 stage are at highest risk. Close clinical follow-up after the initial diagnosis is recommended.
Keywords: MMS; Mohs surgery; clinical research; cutaneous oncology; dermatologic surgery; full-body skin examination; general dermatology; medical dermatology; oncology; squamous cell carcinoma; total body skin examination.
Copyright © 2020 American Academy of Dermatology, Inc. Published by Elsevier Inc. All rights reserved.