Impact of preoperative chemotherapy cycles on tumor resectability and surgical timing in hepatoblastoma: a retrospective analysis.

Background: Hepatoblastoma (HB) is the most common malignant liver tumor in children. However, the optimal duration of preoperative chemotherapy remains unclear, particularly regarding its impact on tumor size and proximity to critical blood vessels.

Methods: This retrospective study analyzed 24 patients with HB treated at Shanghai Xinhua Hospital from 2006 to 2022. All patients underwent neoadjuvant chemotherapy. Tumor size and distances to key vasculature, including the confluence of hepatic veins (COHV) and the portal vein bifurcation (PVB), were measured using CT scans after two and four chemotherapy cycles. Statistical analyses assessed changes in these parameters.

Results: The maximum tumor diameter decreased significantly after two cycles of chemotherapy (11.9±2.5 cm to 8.3±2.0 cm, p<0.0001) and further to 7.1±1.9 cm after four cycles. The distance to COHV (DSTCOHV) increased from 0.5±0.9 cm to 1.4±1.2 cm after two cycles (p<0.001) and to 1.6±1.4 cm after four cycles (p<0.0001). However, for distance to PVB (DSTPVB), the increase was more modest, from 0.1±0.3 cm to 0.6±0.5 cm after two cycles (p<0.001) and to 0.8±0.6 cm after four cycles (p<0.0001). Patients with limited response after two cycles gained minimal benefit from additional chemotherapy.

Conclusions: Preoperative chemotherapy significantly reduces tumor size and improves surgical margins, particularly during the first two cycles. For tumors near PVB, prolonged chemotherapy may offer limited benefit, emphasizing the need for individualized treatment planning.