Risk factors of recurrence after postoperative electron beam radiation therapy for keloid: Comparison of long-term local control rate

Aim To investigate the new risk factors for keloid recurrence after postoperative electron beam radiotherapy (RT) and evaluate the effectiveness of tranilast in combination with electron beam RT by comparing the local control rate. Background Identifying patients at high risk of recurrence after postoperative RT for keloids remains a challenge. Besides, no study examined the effectiveness of tranilast in combination with RT after surgery for the prevention of keloids recurrence. Materials and Methods This study included 75 lesions in 59 consecutive patients who had undergone postoperative RT at our institute. The follow-up period and prescription of tranilast were examined beside several potential risk factors, such as multiple lesions, size, and shape. Results The median follow-up was 72 months (range, 6–147 months). Twenty-one lesions in 17 patients recurred in a median of 12 months after treatment (range, 1–60 months). Local control rates of all 75 lesions were estimated as 93%, 78%, 70%, and 68% at 1, 2, 5, and 10 years. Multiple lesions constituted a significant risk of recurrence (P = 0.03). A larger long axis was significantly related to the recurrence (P < 0.01). Irregular shape was associated with a significantly worse local control rate (P = 0.02). There was no significant difference in the local control rate between patients receiving tranilast and those who did not (P = 0.52). Conclusions Multiple lesions and irregular shape were risk factors of keloid recurrence after postoperative electron beam RT. The effectiveness of tranilast was not demonstrated in the study.