Despite growing information on the clinical behavior of hepatocellular carcinoma (HCC), the histologic features associated with survival are not well characterized.
Hence, an international team has evaluated the prognostic histologic indicators of curatively resected hepatocellular carcinomas.
Clinical and pathologic data on 425 patients who underwent complete resection for HCC were reviewed.
Six microscopic features, namely, microvascular invasion, nuclear pleomorphism, mitosis, tumor architecture, growth interface, and tumor necrosis, were examined.
By univariate analysis, microvascular invasion (seen in 51% of patients), nuclear grade 3 (present in 42% of the cases), and mitosis were significant predictors of poor survival.
Hepatocellular carcinoma with a compact growth pattern had a better prognosis, as compared with macrotrabecular and acinar patterns.
The team found that, by multiple regression analysis, only microvascular invasion and nuclear grade 3 were independent predictors of poor survival.
|Prognostic indicators of poor survival:|
- Microvascular invasion
- Nuclear grade 3
| American Journal of Surgical Pathology |
The predictive values of microvascular invasion and nuclear grade allowed the construction of a hepatocellular prognostic index (HPI), whereby HPI = (microvascular invasion status x 0.459) + (nuclear grade x 0.287). In this index, microvascular invasion was either absent (0) or present (1) and nuclear grade was scored as 1, 2, or 3.
Using a cut-off value of 0.746 (corresponding to at least nuclear grade 2 with microvascular invasion), it was found that HCC could be stratified into two groups. These were fair prognosis (HPI ≤ 0.746), with a 50% survival of 5.1 years, and poor prognosis (HPI > 0.746) with a 50% survival of 2.7 years.
HPI was found to be more discriminating than Edmondson grade, with Edmondson II HCCs dispersed in both fair and poor prognosis groups.
Gregory Y. Lauwers, of the Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts, USA, said on behalf of his colleagues, "Microvascular invasion and nuclear grade 3 are strong prognostic indicators of poor survival.
"Their combination provides adequate prognostic stratification," he concluded.