Preoperative staging of periampullar cancer with US, CT, EUS and CA 19-9.

BACKGROUND/AIMS: Several diagnostic methods are available for preoperative staging of periampullary cancers. It happens that on the basis of preoperative findings the patient is prepared for radical surgery, but during the operation the lesion turns out to be unresectable.
METHODOLOGY: We studied 43 patients operated on for periampullary cancer. Preoperatively, all patients were evaluated by ultrasonography, computed tomography, endoscopic ultrasonography and the level of carbohydrate antigen 19-9 was assessed. Statistical parameters were calculated and compared.
RESULTS: Endoscopic ultrasonography has specificity of 70.8% and positive predictive value regarding tumor resectability 55.8%. Computed tomography has a specificity of 45.8% and carbohydrate antigen 19-9 of 66.7%. Positive predictive value for computed tomography and carbohydrate antigen 19-9 is 40.6% and 52.6%, respectively. Ultrasonography is the least accurate method with specificity of 12.5% and positive predictive value 29.7%. A combined use of different diagnostic methods has higher positive predictive value, highest (65.1%) being found for the combination of endoscopic ultrasonography and carbohydrate antigen 19-9. Statistical tests showed statistically significant differences between diagnostic methods.
CONCLUSIONS: Among the diagnostic methods studied, endoscopic ultrasonography showed the highest accuracy in predicting tumor resectability. The use of either endoscopic ultrasonography and carbohydrate antigen 19-9 or computed tomography and carbohydrate antigen 19-9 is accurate enough for assessing tumor resectability.