-Original-

Effect of Tranilast on the Frequency of Invasive Treatment for Extra-Abdominal Desmoid Fibromatosis

Shintaro Fujita¹, Masanobu Takeyama¹, Shingo Kato², Yusuke Kawabata¹, Yutaka Nezu³, Kenta Hayashida¹, Keiju Saito¹, Ikuma Kato⁴, Kota Washimi⁵, Hyonmin Choe¹, Toru Hiruma³ and Yutaka Inaba¹

¹Department of Orthopaedic Surgery, Yokohama City University Hospital, Kanagawa, Japan
²Department of Clinical Cancer Genomics, Yokohama City University Hospital, Kanagawa, Japan
³Department of Musculoskeletal Tumor Surgery, Kanagawa Cancer Center, Kanagawa, Japan
⁴Department of Molecular Pathology, Yokohama City University Hospital, Kanagawa, Japan
⁵Department of Pathology, Kanagawa Cancer Center, Kanagawa, Japan

Background: Active surveillance (AS) has been suggested for managing extra-abdominal desmoid fibromatosis (EADF), but a substantial percentage of such patients transitioned to invasive secondary treatments. The anti-keloid medication tranilast is frequently used in Japan but its effectiveness for EADF is not well understood.
Methods: We retrospectively analyzed the medical records of EADF patients treated with tranilast between January 2009 and March 2021. EADF has been reported to shrink spontaneously, so the effects of all drugs must be compared with AS. To assess the effect of tranilast, we compared the clinical courses of patients receiving tranilast with those managed by AS (as identified in a systematic review). A systematic review of AS outcomes was conducted on July 22, 2021, in accordance with PRISMA guidelines. The primary endpoint was rate of conversion to secondary treatment. Secondary endpoints were progression-free survival, objective response rate (ORR), disease control rate (DCR), and adverse events. The rates of conversion to secondary treatment, ORRs, and DCRs were compared between the two groups by using the Fisher exact test.
Results: Eighteen patients who received tranilast as initial treatment for EADF were included. Two patients (11.1%) underwent surgical resection for treatment of tumor growth and persistent pain. The rate of conversion to secondary treatment was significantly lower for tranilast than for a pure AS approach (40.1%; p = 0.01). ORR and DCR did not differ between groups.
Conclusions: Tranilast was better than AS for initial management of EADF.

J Nippon Med Sch 2023; 90: 79-88

Keywords
desmoid fibromatosis, extra-abdominal desmoid fibromatosis, tranilast, active surveillance

Correspondence to
Shintaro Fujita, Department of Orthopaedic Surgery, Yokohama City University Hospital, 3-9 Fukuura, Kanzawa-ku, Yokohama City, Kanagawa 236-0004, Japan
mst.ycu.med@gmail.com

Received, July 19, 2022
Accepted, September 28, 2022