AimIncreased serum alpha-fetoprotein (AFP) levels are associated with
specific molecular sub-classes of hepatocellular carcinoma (HCC), supporting
AFP as a predictive or therapeutic biomarker for precision treatment of this
disease. Considering recent efforts to validate HCC molecular classification
systems across different populations, we applied existing signature-based
classification templates to Hawaii cohorts and examined whether associations
between HCC molecular sub-class, AFP levels, and clinical features found
elsewhere can also be found in Hawaii, a region with a unique demographic
and risk factor profile for HCC.MethodsWhole-genome expression profiling was performed on HCC tumors
collected from 40 patients following partial hepatectomy. Tumors underwent
transcriptome-based categorization into 3 molecular sub-classes (S1, S2, and
S3). Patient groups based on molecular sub-class and AFP level were then
compared with regards to clinical features and survival. Differences
associated with AFP level and other clinical parameters were also examined
at the gene signature level by gene set enrichment analysis.ResultsStatistically confident (false discovery rate < 0.05)
sub-classifications were made in 98% (39/40) of tumors. Patient
sub-groups differed significantly with regards to serum AFP level, with
significantly lower levels in the S3 sub-group as compared to S1
(P = 0.048) and S2 (P = 0.010). Serum
AFP > 400 ng/mL predicted significant tumor enrichment for genes
corresponding to MYC target activation, high cell
proliferation, poor clinical prognosis, and the S2 sub-class. AFP >
400 ng/mL and non-S3 tumor classification were found to be significant
predictors of overall survival.ConclusionDistinct sub-classes of HCC associated with different molecular
features and survival outcomes can be detected with statistical confidence
in a Pacific Island cohort. Molecular classification signatures and other
predictive markers for HCC that are valid for all patient populations are
needed to support multi-center efforts to develop targeted therapies for
HCC.