The course of history in a collaborative study of pediatric renal tumors in Japan

<p>In 1971, “Wilms” tumor was intensively discussed at the Pediatric Oncology Meeting hosted by The Japan Pediatric Society and The Japanese Society of Pediatric Surgery, with the support of the Children’s Cancer Association of Japan. This Meeting was taken over by the Japanese Study Group for Pediatric Cancer in 1985 and by the Japanese Society for Pediatric Cancer in 1991. The Japan Wilms Tumor Study (JWiTS) was founded in 1996 by Haruo Ohkawa. This project aimed to:</p><p>1. Introduce a nationwide unified protocol (NWTS protocol).</p><p>2. Introduce a central pathological diagnosis system.</p><p>3. Establish a database.</p><p>4. Promote molecular biology research.</p><p>In 2003, the JWiTS was extensively developed by Masahiro Fukuzawa and was taken over by the Japan Children’s Cancer Research Group Renal Tumor Committee (JCCG-RTC). As the results of the JWiTS-1 (1996–2005) have shown, the concordance rate between the facility and central pathology was poor (81.7%). The JWiTS-2 (2006–2014) requesting to submit the specimens to the central pathology, Wilms tumors at stages I to III had a relapse-free survival (RFS) and overall survival (OS) of 90% or higher. However, in stage IV, RFS was 66.2%, and OS was 84.6%, which demands improvement. The subtypes of Wilms tumor—anaplastic Wilms tumor, blastemal predominant Wilms tumor, and bilateral Wilms tumor—are noteworthy. Clear cell sarcoma of the kidney has an RFS of 33.3%, and the rhabdoid tumor of the kidney has a poor prognosis with an OS of 25% and RFS of 18.8%. In 2014, the JCCG-RTC decided to participate in the Umbrella Protocol of the International Society of Pediatric Oncology (SIOP) Renal Tumor Study Group.</p>