EPSTEIN-BARR-VIRUS INFECTION, SALTED FISH AND NASOPHARYNGEAL CARCINOMA - A CASE-CONTROL STUDY IN SOUTHERN CHINA

Two hundred and five histologically confirmed cases of nasopharyngeal carcinoma (NPC) in southern China, and an equal number of matched cont rols, were investigated for their dietary habits, occupational exposur e, use of tobacco and alcohol, history of relatives with NPC, and IgA against Epstein-Barr virus (EBV) capsid antigen (IgA/VCA), Positive Ig A/VCA and intake of salted fish were associated with a strong excess r isk of NPC. The association persisted after adjustment for other facto rs. The combination of salted fish and EBV was strongly associated wit h NPC, and more so than EBV or salted fish per se. Multivariate analys es showed that IgA/VCA was the most important predictor of NPC, and sa lted fish the second most important. These results suggest that EBV ha s a strong effect on the development of NPC. The exclusion of EBV and genetic factors in earlier epidemiological studies may have resulted i n an overestimation of salted fish as important etiological factor cau sing NPC.