Published in:
01-04-2011 | Original Paper
Pathobiological features of small hepatocellular carcinoma: correlation between tumor size and biological behavior
Published in: Journal of Cancer Research and Clinical Oncology | Issue 4/2011
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Purpose
Increasing evidence has suggested that tumor size is one of the independent prognostic factors of patients with hepatocellular carcinoma (HCC). However, the criteria used to determine when HCC should be classified as small remain controversial. Our objective was to evaluate the relationship between the size of HCC and its clinicopathological features.
Methods
A retrospective study on 618 patients who underwent partial hepatectomy for solitary HCC was performed. These patients were divided into Groups 1–5 according to the tumor diameter: ≤1, 1.1–2, 2.1–3, 3.1–5 and >5 cm, respectively. The clinicopathological variables of the patients in each group were compared statistically.
Results
Except for the microHCC (≤1 cm) which differed significantly from the other four groups in the clinicopathological variables, almost no differences existed among HCC ranging from 1 to 3 cm, or HCCs > 3 cm. If ≤3 cm was used as the cut-off point for small HCC (SHCC), and >3 cm for large HCC (LHCC), significant differences (P < 0.05–0.01) were observed between SHCC and LHCC in: histological grades I–II (48.0 vs. 19.4 %), capsular invasion (15.4 vs. 36.3%), tumor thrombi (6.9 vs. 23.5%), satellite nodules (12.3 vs. 35.5%), noninvasive growth patterns (69.6 vs. 25.4%), the overall survival (OS, 119.6 ± 34.7 vs. 68.5 ± 6.6 months), and the recurrence-free survival (RFS, 67.0 ± 16.7 vs. 29.5 ± 3.2 months). Multivariate Cox regression analyses show that tumor size >3 cm was one of the independent prognostic factors for both OS and RFS.
Conclusions
The 3 cm cutoff seems to best determine the biological behavior and clinical prognosis of patients undergoing partial hepatectomy for early stage HCC. Overall, HCC smaller than 3 cm in diameter was closely related with a better prognosis which reflected the relatively benign pathobiological features at an early developmental stage. As HCC > 3 cm exhibited a tendency towards more aggressive behavior, we suggest that HCC ≤ 3 cm in diameter should be used as a critical size of SHCC at which curative treatment achieves better long-term survivals.