Background: Previously, about 70% of HCCs in Japan developed on the basis of hepatitis C virus (HCV) infection. However, the establishment of HCV screening system for blood transfusion resulted in a remarkable decrease of the chronic HCV hepatitis followed by a general reduction of HCV-related HCCs. The problem we now have is that we are observing not only a distinct increment of non-B non-C (NBNC) HCCs, not only proportionally but also absolutely.
Aim: To clarify the causal background of NBNC HCCs.
Methods: A total of 348 patients surgically treated for a HCC at C.I.H. from 2005 to 2014 were examined in terms of serological virus markers and clinicopathological features.
Results: Viral status: 81 hepatitis B virus（HBV）, 137 HCV, 3 Double infection, 126 NBNC, 1 others. HCV(including double infection)/NBNC ratio were 1.43(43/30) and 0.59(26/44) for 2005- 2007 and 2012- 2014, respectively (p<0.05).
M/F ratio were 6.4(109/17) for NBNC and 2.5(100/40) for HCV, respectively (p<0.05).
Since metabolic disorder（MD）is thought to be an important cause of NBNC HCCs, NBNC patients were divided into MD+ and MD- groups. MD was defined as positive therapeutic history for any of following diseases; alcoholic liver disease, diabetes mellitus(DM), hypertension(HT), cardiovascular disease and/or hyperlipidemia and/or obesity (BMI>25).
Of 113 MD+ NBNC patients, 102 were male with average age(aa) of 68.5 and 11 were female with aa of 71.1. Of 13 MD- patients, 7 male with aa of 63.7 and 6 female with aa of 56.3. Thus, most of NBNC HCC patients suffered MD. MD+ patients were older and male predominant in comparison with MD- (both p<0.05).
Among MD, DM(54) and HT(50) were most frequent(including double).
Conclusions: While HCV-related HCCs are rapidly and remarkably decreasing in recent years, MD appears to have become a quite important causal factor of HCC and thus a target of HCC prevention in Japan.