Clinical, histological and demographic predictors for recurrence and second primary tumours of head and neck basal cell carcinoma. A 1062 patient-cohort study from a tertiary cancer referral hospital.

Basal cell carcinoma (BCC) accounts for nearly 25% of all cancers in the human body and for almost 75% of skin malignancies; approximately 85% of basal cell carcinomas develop in the head and neck region. Limited demographic, clinical and histological predictors for second primary and/or recurrent BCC have been identified to date. Our objective was to identify predictors of recurrence and second primary tumour development of BCC in the head and neck region. We included 1062 patients with a histologically confirmed diagnosis of BCC. Multivariate and Cox regression analysis were used to access demographic, clinical and histological predictors. Study follow up included 4,302 patient-years, each patient was followed-up for an average 4.0 +/- 1.8 years (range 1-12). Overall recurrence rate was 4%. High-risk histology type was associated with an increased risk for recurrence (odds ratio (OR) = 3.47, 95%CI: 1.07-11.25). We calculated a 4-fold increased risk for recurrence with positive excision margins (OR = 4.31, 95%CI: 1.82-10.22), a 21% increased risk for recurrence (OR = 1.21, 95%CI: 1.06-1.37) and a 25% increased risk for second primary BCC development (OR = 1.25, 95%CI: 1.17-1.34) per year of follow-up. The median time free of second primary tumour was 7 years, while the median time free of recurrence was 12 years. The strongest predictors for recurrence are positive excision margins and high-risk histology type, indicating the need for additional patient care in such cases.