Hepatoblastoma: the Indiana experience with preoperative chemotherapy for inoperable tumors; clinicopathological considerations.

Analysis of the prognostic importance of various clinicopathological parameters in 17 hepatoblastomas (HBs) confirmed the utility of preoperative chemotherapy to convert inoperable to resectable tumors. There was no significant survival advantage for patients who underwent initial tumor resection compared with those resected following chemotherapy, although complete resection, with or without prior chemotherapy, was critical for cure. Young age was associated with better survival but did not correlate with histologic subtype or clinical stage. A relationship between low initial alpha-fetoprotein (AFP) level and tumor resectability was noted, perhaps related to tumor size, but tumor location was of greater importance than size in determining resectability. Neither the mean proportions of fetal and embryonal epithelium, nor their mitotic activity, nor the presence of vascular invasion in the prechemotherapy biopsy specimens was predictive of outcome, but the low mitotic activity of the fetal component correlated with ultimate resectability. On the other hand, although complete resection was necessary for survival, histologic examination of postchemotherapy specimens had additional predictive value; the presence of vascular invasion, the amount of viable mesenchyme, the extent of tumor necrosis, the proportion of embryonal epithelium, and the mitotic activity of the epithelial component in postchemotherapy resection specimens were each predictive of outcome. Although the presence of osteoid was not predictive, both the proportion of HBs that contained osteoid and the extent of mature mesenchymal tissues within individual HBs were increased by chemotherapy, suggesting that maturation of previously immature clones had been induced. We conclude that although complete resectability remains the fundamental goal of therapy, evaluation of the clinicopathologic characteristics that we have found to be predictive of outcome may permit tailoring of therapeutic regimens to individual patients; those whose tumors are deemed likely to respond well may require less toxic preoperative chemotherapy, and those deemed likely to progress in spite of complete resection may be considered for more aggressive postoperative regimens.