A cisplatin plus pirarubicin-based JPLT2 chemotherapy for hepatoblastoma: experience and future of the Japanese Study Group for Pediatric Liver Tumor (JPLT)

The Japanese Study Group for Pediatric Liver Tumor (JPLT) has conducted cooperative treatment studies on hepatoblastoma (HBL) since 1991. The JPLT2 protocol was launched in 1999 to evaluate the efficacy of cisplatin/pirarubicin (CITA) under risk stratification. European and North American groups showed the improvement of HBL patients by pre- and postoperative chemotherapeutic regimens. Therefore, we evaluated the results of JPLT study and considered the future aspect of JPLT. A total of 389 children with malignant hepatic tumors were enrolled in JPLT-2 until 2010. Data from 331 HBL cases were analyzed. Of the 331 patients enrolled, their 5-year overall survival and event-free survival rates were 83.3 and 68.0 %, respectively. While outcomes of standard-risk cases (tumors involving 3 or fewer sectors of the liver) were excellent, those of high-risk cases (tumors involving 4 sectors of the liver or with distant metastases) remained poor. For 26 high-risk or relapse/refractory HBL cases, high-dose chemotherapy (HDC) with stem cell transplantation (SCT) was carried out. Among them, 6 of 12 relapse or refractory cases died. Compared with other regimens, the CITA regimen achieved similar or superior rates of survival among children with standard-risk HBL, while HDC with SCT was not effective in patients with high-risk HBL. Presently, a global Children's Hepatic Tumor International Consortium (CHIC) project is ongoing, with a focus on international cooperation and risk stratification in the field of rare liver cancers in children. More promising strategies, including liver transplantation and new targeting drugs under global risk stratification, are being proposed.