AIM:To investigate the relationship between loss of heterozygosity (LOH) for mannose 6-phosphate/insulin-like growth factor 2 receptor (M6P/IGF2R) and the outcomes for primary HCC patients treated with partial hepatectomy.METHODS:The LOH for M6P/IGF2R in primary HCC patients was assessed using six different gene-specific nucleotide polymorphisms.The patients studied were enrolled to undergo partial hepatectomy.RESULTS:M6P/IGF2R was found to be polymorphic in 73.3% (22/30) of the patients,and of these patients,50.0% (11/22) had tumors showing LOH in M6P/IGF2R.Loss of heterozygosity in M6P/IGF2R was associated with significant reductions in the two year overall survival rate (24.9% vs 65.5%; P = 0.04) and the disease-free survival rate (17.8% vs 59.3%; P = 0.03).CONCLUSION:These results show M6P/IGF2R LOH predicts poor clinical outcomes in surgically resected primary HCC patients.