Figure 5.

Preclinical serologic profiles and time of subsequent diagnosis of NPC cases. One hundred and seven NPC cases were diagnosed 8 months to 15 years after enrollment; 56 cases were from seropositive group (+) and 51 from seronegative group (−). Cases were separated according to their preclinical serologic profiles into three categories, designated types I, II and to III, as described in Figure 4. Whiskers, boxes and lines in the diagram depict range, interquartile and median times of diagnosis, respectively. Time of diagnosis of the three types of cases is significantly different (χ²=39.332, df=2, P<0.0001).