Resectability and tumor response after preoperative chemotherapy in hepatoblastoma treated by the Japanese Study Group for Pediatric Liver Tumor (JPLT)-2 protocol.

Objective: We aimed to clarify whether surgical resectability and tumor response after preoperative chemotherapy (preCTx) represented prognostic factors for patients with hepatoblastoma (HBL) in the JPLT-2 study (1999-2012).

Methods: Patients (N=342) with HBL who underwent preCTx were eligible. PRETEXT, CHIC risk stratification (standard [SR], intermediate [IR] and high risk [HR]) at diagnosis, POST-TEXT, and tumor resectability were evaluated by imaging. Tumor response was classified into responders (CR or PR) and nonresponders (NC or PD) according to RECIST criteria.

Results: There were 7 PRETEXT I, 106 II, 143 III, and 86 IV, including 71 metastatic HBLs. In POST-TEXT, 12 PRETEXT II, 42 III, and 58 IV were down-staged. The 5-year EFS/OS rates of 198 SR, 73 IR, and 71 HR-HBLs were 82/94%, 49/64%, and 28/34%, respectively. In 198 SR, 154 of 160 responders and 24 of 38 nonresponders survived event-free (P<0.01). In 73 IR, 12 of 24 whose tumors remained unresectable experienced recurrence, 9 of whom were nonresponders (P<0.01). In 71 HR, chemoresponders and tumor resectability after preCTx correlated with favorable outcomes (P<0.05).

Conclusions: Evaluation of response and tumor resectability after preCTx is useful for predicting prognosis in HBLs. To improve outcomes, we should reconsider surgical procedures according to resectability and chemoresponsiveness. Methods: Level II.