Freedom from Recurrence across Age in Non-Melanoma Skin Cancer Treated with Image-Guided Superficial Radiation Therapy

Abstract

Non-melanoma skin cancers (NMSCs) are a significant cause of morbidity and mortality; their incidence is increasing most in older patients. NMSCs have traditionally been treated with surgical excision, curettage, Mohs micrographic surgery (MMS), and superficial radiotherapy (SRT). Image-guided SRT (IGSRT) is a treatment option for poor surgical candidates or patients with low- or high-risk, early-stage NMSC who prefer to avoid surgery. This large retrospective cohort study compared 2-, 4-, and 6-year freedom from recurrence in biopsy-proven NMSC lesions treated with IGSRT (n = 20,069 lesions) between patients aged < 65 years (n = 3158 lesions) and ≥65 years (n = 16,911 lesions). Overall freedom from recurrence rates were 99.68% at 2 years, 99.57% at 4 years, and 99.57% at 6 years. Rates did not differ significantly by age (p = 0.8) nor by sex among the two age groups (p > 0.9). There was a significant difference in recurrence among older patients when analyzed by stage (p = 0.032), but no difference by stage in younger patients (p = 0.7). For early-stage NMSCs, IGSRT is a clinically equivalent alternative to MMS and statistically significant in superiority to non-image-guided SRT. This study demonstrates that there is no significant effect of age on 2-, 4-, or 6-year freedom from recurrence in patients with IGSRT-treated NMSC.