Apoptotic protein expression, glycogen content, DNA ploidy and cell proliferation in hepatoblastoma subtyping and their role in prognostication

To evaluate Bcl-xL, Bax, PCNA, cytokeratin 19 (CK-19), glycogen content and DNA ploidy expression in hepatoblastoma (HB) and their prognostic value.

This retrospective study on 26 cases of HB involved DNA ploidy estimations separately for various subtypes on histological sections using image cytometry of Feulgen-stained smears. Glycogen content, PCNA, CK-19, Bax and Bcl-xL expression on tissue sections were evaluated. THE outcome on follow-up (mean 86 months) and Kaplan–Meier survival analysis were performed.

Fetal areas were diploid (84%); embryonal areas were aneuploid (89.47%) (p < 0.001). PCNA labeling index was low in fetal (10.82%) and high in embryonal areas (59.85%) (p = 0.03). CK-19 was negative in fetal, but focally positive in embryonal areas. Bax was negative in fetal (80%) and positive in embryonal areas (88.23%) (p < 0.001); Bcl-xL was more frequently positive in fetal (90%) than embryonal areas (52.94%) (p = 0.02). Fetal cells were rich in glycogen. Kaplan–Meier survival analysis showed good initial radiological response to chemotherapy (p = 0.009), glycogen content (p = 0.0137) and DNA diploid cases (p = 0.0429) were associated with good outcome on univariate analysis. Histology typing (p = 0.085), Bcl-xL (p = 0.689), Bax (p = 0.27), CK-19 (p = 0.281), PCNA (p = 0.689), age (p = 0.24), sex (p = 0.5661), stage (p = 0.24) and α-fetoprotein levels (p = 0.49) were unrelated to outcome. Multivariate analysis showed glycogen content to be the most statistically significant variable (0.024).

Fetal and embryonal areas show different staining patterns for PCNA, Bax and Bcl-xL. DNA ploidy and glycogen content are significant prognostic variables.