DEVELOPMENT OF UNFAVORABLE HEPATOBLASTOMA IN CHILDREN OF VERY-LOW-BIRTH-WEIGHT - RESULTS OF A SURGICAL AND PATHOLOGIC REVIEW

BACKGROUND. The incidence of hepatoblastoma in children of very low bi rth weight (< 1500 g) is increasing in Japan. The authors reviewed sur gical and pathologic aspects of the tumor to clarify the characteristi cs of the patients. METHODS. Fifteen patients (9 boys and 6 girls) who were diagnosed between the ages of 6-77 months (median, 16 months) we re identified from the data in the Japan Children's Cancer Registry an d the data base of medical journals. The patients' birth weights range d from 560-1380 g (median, 826 g) and the gestational age ranged from 23-33 weeks (median, 25 weeks). The medical records of all patients we re reviewed and the patient's stage of disease according to the classi fication of the Japanese Society of Pediatric Surgeons, treatment, and outcome were analyzed. RESULTS. Ten tumors (67%) were classified as S tage II or IIIA and 5 (33%) were classified as Stage IIIB or IV. There was a significant correlation between the gestational age and tumor s tage (correlation coefficient -0.6851; P = 0.0048). The gestational ag e of the 5 patients with Stage IIIB or IV tumors was 23-25 weeks (medi an, 24 weeks), whereas it was 25-33 weeks (median, 27.5 weeks) for the 10 patients with Stage II or IIIA tumors (P = 0.0036). Birth weight r anged from 560-826 g (median, 734 g) in Stage IIIB and IV patients, wh ich was significantly lower than that in Stage II and IIIA. patients ( range, 607-1380 g, median, 909 g; P = 0.0500). Complete tumor resectio n was achieved in 7 patients (47%). The actuarial 2-year survival of a ll patients was 0.42, and the 2-year survival of patients who underwen t complete tumor resection was 0.69, which was significantly better th an the 2-year survival of those who underwent incomplete resection (0. 17; P = 0.0211). The 2-year survival of the patients with tumors of we ll differentiated histology was 0.60, which also was significantly bet ter than the 2-year survival of those with tumors of poorly differenti ated histology (0.19; P = 0.0453). CONCLUSIONS. These results indicate that children of very low birth weight (< 1500 g) are at high risk of developing advanced hepatoblastomas and that hepatoblastoma with unfa vorable biologic behavior develops in children who are extremely prema ture at birth. These new findings suggest the presence of etiologic fa ctors relevant to the patient's immaturity and the development of unfa vorable hepatoblastoma. (C) 1998 American Cancer Society.