Superficial radiotherapy for patients with basal cell carcinoma: recurrence rates, histologic subtypes, and expression of p53 and Bcl-2

Abstract

Background: The histologic subtype of a basal cell carcinoma (BCC) may be an important factor for the success of a certain treatment modality. In the current article, the authors report recurrence rates among patients with BCC after superficial radiotherapy as well as Bcl-2 and p53 expression levels stratified by BCC subtype.

Methods: The authors performed a retrospective study of 175 BCCs in 148 patients (64 female patients and 84 male patients; mean age, 69 years) who were treated with radiotherapy. According to their histologic patterns, BCCs were classified as nodular (n = 103), superficial (n = 25), and sclerosing (n = 47). In addition, six patients with metatypic BCC were reviewed. Bcl-2 and p53 protein expression was examined on a tissue microarray of 60 BCC samples (18 nodular tumors, 12 superficial tumors, and 30 sclerosing tumors).

Results: The estimated 5-year recurrence rate for all patients with BCC was 15.8%: 8.2% for patients with the nodular subtype, 26.1% for patients with the superficial subtype, and 27.7% for patients with the sclerosing subtype (Kaplan-Meier analysis: P = 0.055). The median follow-up was 48 months. The mean time to recurrence was 20 months, and 86.4% of all recurrences occurred within 3 years after treatment. No gender-specific differences were observed. In addition, one of six metatypic BCCs recurred. Nuclear p53 immunoreactivity and low Bcl-2 expression were significantly correlated with the sclerosing subtype. Overall, 61.5% of patients developed additional neoplasms during follow-up (76 developed additional BCCs, 15 developed squamous cell carcinomas, and 6 developed Bowen disease).

Conclusions: The sclerosing subtype of BCC was a risk factor for recurrence after radiotherapy. In contrast, excellent results were achieved for patients with predominant nodular subtype. Nevertheless, radiotherapy may be the therapy of choice for patients with all BCC subtypes, depending on the individual patient's characteristics. Expression analyses confirmed that p53 and Bcl-2 levels may be used as indicators for the aggressiveness of a BCC subtype. Due to the high incidence of additional skin malignancies, patients with BCC need careful follow-up.