Table 2

Sensitivities and specificities of serum CA19-9, biliary brushings/biopsies and BiliSeq for at least high-grade biliary dysplasia

ParameterSensitivity, n (95% CI)Specificity, n (95% CI)PPV, n (95% CI)NPV, n (95% CI)AUC, n (95% CI)
Training cohort (n=57)
 Elevated CA19-9 (n=56)*62 (0.44 to 0.77)77 (0.54 to 0.91)
 Pathological evaluation of biliary brushings/biopsies46 (0.29 to 0.63)100 (0.82 to 1.00)
 BiliSeq testing63 (0.45 to 0.78)100 (0.82 to 1.00)
 Elevated CA19-9* and BiliSeq testing79 (0.62 to 0.91)77 (0.54 to 0.91)
 Pathological evaluation and BiliSeq testing77 (0.60 to 0.89)100 (0.82 to 1.00)
 Elevated CA19-9*, pathological evaluation and
 BiliSeq testing
88 (0.72 to 0.96)77 (0.54 to 0.91)
Validation cohort (n=163)
 Elevated CA19-9 (n=144)*81 (0.72 to 0.88)65 (0.48 to 0.79)
 Pathological evaluation of biliary brushings/biopsies49 (0.39 to 0.58)98 (0.88 to 1.00)
 BiliSeq testing76 (0.67 to 0.83)100 (0.91 to 1.00)
 Elevated CA19-9* and BiliSeq testing97 (0.91 to 0.99)65 (0.48 to 0.79)
 Pathological evaluation and BiliSeq testing84 (0.76 to 0.90)98 (0.88 to 1.00)
 Elevated CA19-9*, pathological evaluation and
 BiliSeq testing
97 (0.91 to 0.99)63 (0.46 to 0.77)
Overall cohort (n=220)
 Elevated CA19-9 (n=200)*76 (0.68 to 0.83)69 (0.56 to 0.80)85 (0.77 to 0.90)57 (0.45 to 0.68)0.73 (0.65 to 0.81)
 Pathological evaluation of biliary brushings/biopsies48 (0.40 to 0.56)99 (0.91 to 1.00)99 (0.92 to 1.00)47 (0.39 to 0.55)0.73 (0.67 to 0.80)
 BiliSeq testing73 (0.65 to 0.80)100 (0.94 to 1.00)100 (0.96 to 1.00)63 (0.53 to 0.72)0.86 (0.82 to 0.91)
 Elevated CA19-9* and BiliSeq testing93 (0.87 to 0.96)69 (0.56 to 0.80)87 (0.80 to 0.92)81 (0.68 to 0.90)0.81 (0.74 to 0.88)
 Pathological evaluation and BiliSeq testing83% (0.75 to 0.88)99 (0.91 to 1.00)99 (0.95 to 1.00)73 (0.62 to 0.81)0.91 (0.87 to 0.95)
 Elevated CA19-9*, pathological evaluation and
 BiliSeq testing
95 (0.89 to 0.98)68 (0.55 to 0.79)87 (0.80 to 0.92)86 (0.72 to 0.94)0.81 (0.74 to 0.89)
  • *On the basis of cases where serum CA19-9 was performed concurrently where elevated CA19-9 was defined as ≥44 U/mL.

  • AUC, area under the curve; CA19-9, carbohydrate antigen 19–9; NPV, negative predictive value; PPV, positive predictive value.