Histological architectural classification determines recurrence pattern and prognosis after curative hepatectomy in patients with hepatocellular carcinoma

Aim The clinical impact of pathological classification based on architectural pattern in hepatocellular carcinoma (HCC) remains elusive in spite of its well-known and common feature. Methods The prognostic impact of pathological classification was examined with prospective database. Three hundred and eighty HCC patients who underwent curative hepatectomy as an initial treatment in Kumamoto University were enrolled as a test cohort. The outcome was confirmed with a validation cohort in Kyushu University. Results Macrotrabecular (macro-T) subtype (n = 38) and compact subtype (n = 43) showed similar biological and prognostic features. Both showed higher AFP level and worse overall survival than microrabecular (micro-T) subtype (n = 266). Multivariate analysis for overall survival revealed that DCP ≥ 40, multiple tumor and macro-T/compact subtype were associated with poor overall survival (risk ratio = 2.2, 1.6 and 1.6; p = 0.002, 0.020, and 0.047, respectively). Of note, 32% of macro-T/compact subtype showed early recurrence within 1 year, which showed substantially low (5%) 5 year overall survival, whereas 16% of micro-T/PG subtype did. Twenty-one percent of macro-T/compact subtype showed multiple intrahepatic metastases (≥ 4) or distant metastases, which resulted in non-curative treatment, whereas 5% of micro-T/PG subtype did. In validation cohort, macro-T/compact subtype was an independent predictor of worse overall survival. Conclusion Macro-T/compact subtype is biologically discriminated from micro-T and PG subtypes due to its aggressive features and poor prognosis after curative treatment. Additional treatment with curative hepatectomy on Macro-T/compact subtype should be discussed because of high possibility of systemic residual cancer cell.