Postoperative radiation therapy for extramammary Paget's disease. (1st April 2015)

• Record Type: Journal Article
• Authors: Hata, M.; Koike, I.; Wada, H.; Miyagi, E.; Kasuya, T.; Kaizu, H.; Mukai, Y.; Inoue, T.
• Is Part Of: British journal of dermatology. Volume 172:Number 4(2015:Apr.)
• Page Start: 1014
• Page End: 1020
• Publication Date: 2015-04-01
• Subjects: Dermatology -- Periodicals; Skin -- Diseases -- Periodicals; 616.5
• DOI: 10.1111/bjd.13357
• Languages: English
• ISSNs: 0007-0963

Abstract

Summary: Background: Extramammary Paget's disease (EMPD) is a rare cutaneous malignancy that is usually treated with surgery. Patients with positive surgical margins require adjuvant therapy, but there have been few reports on the use of radiation therapy. Objectives: To investigate the effectiveness of postoperative radiation therapy in EMPD. Materials and methods: Twenty‐one patients with EMPD involving the genitalia underwent radiation therapy as adjuvant therapy after surgery. Ten patients had inguinal lymph node involvement before radiation therapy, but none had distant metastases. A median total dose of 59·4 Gy (range, 45–64·8 Gy) was delivered to the tumour bed in 30 fractions (range, 23–36 fractions). Results: At a median follow‐up period of 38 months, all patients had local control. However, six patients had developed distant metastases 6–43 months after radiation therapy. The distant metastasis‐free rates were 66% at 3 years and 55% at 5 years. Inguinal lymph node involvement was a significant risk factor for distant metastases. Four patients died 33–58 months after irradiation; the causes of death were tumour progression in three patients and infectious pneumonia in one. The overall and cause‐specific survival rates were both 92% at 3 years, and 62% and 71% at 5 years, respectively. No therapy‐related toxicities of grade ≥ 3 were observed. Conclusions: Postoperative radiation therapy is safe and effective in maintaining local control in patients with EMPD.