Adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) for nasopharyngeal carcinoma (NPC) by fluctuant type of serological status during follow-up among 962 subjects seropositive for VCA/IgA antibodies against EBV capsid antigen compared to 17,093 seronegative subjects at baseline<sup>*</s

*Among the totally 1318 subjects seropositive for VCA/IgA antibodies at baseline, 356 had fewer than 2 repeated tests. Thus these subjects could not be classified into any fluctuant group, thus were excluded from current analysis. Among them, 19 NPC cases were indentified. †Adjusted for sex, age at entry (30–39, 40–49, 50–59 years) and residency by town. ‡Since the proportional hazards assumption did not hold, results were presented separately by attained follow-up duration (≤5 vs >5 years).