Outcomes of Patients With Multiple Cutaneous Squamous Cell Carcinomas: A 10-Year Single-Institution Cohort Study

Patients with multiple cutaneous squamous cell carcinomas (CSCCs) pose a management challenge for physicians, but their prognosis is unknown because outcomes have not been compared between patients who form single vs multiple CSCCs.

To compare outcomes in patients with 1 vs multiple CSCCs.

A 10-year retrospective single-institution cohort study at an academic tertiary care center of patients with dermally invasive (non-in situ) primary CSCC diagnosed from January 1, 2000, through December 31, 2009.

Electronic medical records were reviewed to determine the tumor stage (Brigham and Women's Hospital tumor stage) and outcomes (local recurrence [LR], nodal metastases [NM], and death due to CSCC). Outcomes were compared between patients with 1 vs more than 1 CSCC via multivariable competing-risk regression adjusted for other significant cofactors.

Of 985 patients with CSCC, 727 had 1 CSCC, 239 had 2 to 9 CSCCs, and 19 had 10 or more CSCCs. Most patients with 10 or more CSCCs were immunosuppressed (15 of 19 [78.9%]). The median follow-up time was 50 months (range, 2-142 months). Patients with more than 1 CSCC had a higher risk of LR (subhazard ratio for 2-9 CSCCs, 1.8; 95% CI, 1.1-4.3; and for ≥10 CSCCs, 3.8; 95% CI, 1.4-10.0) and NM (subhazard ratio for 2-9 CSCCs, 3.0; 95% CI, 1.4-6.5; and for ≥10 CSCCs, 4.2; 95% CI, 1.4-10.4) compared with patients with 1 CSCC, adjusted for Brigham and Women's Hospital tumor stage. The 10-year cumulative incidence of LR and NM was higher in patients with 2 to 9 CSCCs and markedly higher in those with 10 or more CSCCs compared with patients who had 1 CSCC (10-year cumulative incidence for 1 CSCC: LR, 3.0%; 95% CI, 2.0%-4.5%; and NM, 2.3%; 95% CI, 1.5%-3.8%; for 2-9 CSCCs: LR, 6.7%; 95% CI, 4.2%-10.6%; and NM, 5.9%; 95% CI, 3.5%-9.6%; and for ≥10 CSCCs: LR, 36.8%; 95% CI, 19.2%-59.0%; and NM, 26.3%; 95% CI, 11.8%-48.8%).

Patients with multiple CSCCs warrant frequent follow-up because they have an elevated risk of LR and NM. In particular, patients with 10 or more CSCCs have markedly elevated risks of recurrence and metastasis.