Tumor Recurrence 5 Years after Treatment of Cutaneous Basal Cell Carcinoma and Squamous Cell Carcinoma

For most cutaneous basal cell and squamous cell carcinomas (nonmelanoma skin cancers [NMSC]) data are insufficient to permit evidence-based choices among treatments. To compare tumor recurrence after treatments, we conducted a prospective cohort study of consecutive patients with primary NMSC treated with the most common treatments in two practices in 1999–2000. Recurrence was determined from medical records by observers blinded to treatment type. 24.3% of tumors (N=361) were treated with destruction with electrodessication / curettage, 38.3% (N=571) with excision, and 37.4% (N=556) with histologically-guided serial excision (Mohs surgery). Follow-up was available for 1174 patients with 1488 tumors (93.8%) at median 7.4 years; overall 5-year tumor recurrence rate [95% Confidence Interval] was 3.3% [2.3, 4.4]. Unadjusted recurrence rates did not differ after treatments: 4.9% [2.3, 7.4] after destruction, 3.5% [1.8, 5.2] after excision, and 2.1% [0.6, 3.5] after Mohs surgery (P=0.26), and no difference was seen after adjustment for risk factors. In tumors treated only with excision or Mohs surgery, the hazard of recurrence was not significantly different, even after adjustment for propensity for treatment with Mohs surgery. These data indicate that common treatments for NMSC were at least 95% effective, and further studies are needed to guide therapeutic choices for different clinical subgroups