Carbohydrate antigen 125 and carcinoembryonic antigen in the differentiation of tuberculous peritonitis and peritonitis carcinomatosa

Tumor markers could increase in both tuberculous peritonitis and peritonitis carcinomatosa, confusing the differentiation of these diseases. This study aimed to better understand the extent of elevation and diagnostic efficacies of carbohydrate antigen 125 (CA 125), carcinoembryonic antigen (CEA) and combinative use of them in tuberculous peritonitis and peritonitis carcinomatosa. Of 2998 patients reviewed, 101, 120 and 71 patients were assigned to TBP group (tuberculous peritonitis), non-OCA group (non-ovarian carcinoma-related peritonitis carcinomatosa) and OCA group (ovarian carcinoma-related peritonitis carcinomatosa), respectively. The composite index was calculated by CA 125 multiplying CEA. Receiver operator characteristic curves for CA 125, CEA and composite index were acquired. As a result, CA 125 value in OCA group was higher than other two groups (serum CA 125: P < 0.001; ascites CA 125: P < 0.001). On the other hand, non-OCA group had the highest CEA value among three groups (serum CEA: P < 0.001; ascites CEA: P < 0.001). Area under curves of serum/ascites composite index and serum/ascites CEA were larger than those of serum/ascites CA 125. Furthermore, ascites and serum composite index displayed the best sensitivity (0.907) and specificity (0.989), respectively. In conclusion, CA 125 increases in tuberculous peritonitis and non-ovarian carcinoma-related peritonitis carcinomatosa, but it elevates more in ovarian carcinoma-related peritonitis carcinomatosa. CEA is found to increase more significantly in non-ovarian carcinoma-related peritonitis carcinomatosa. CEA and composite index are helpful in distinguishing peritonitis carcinomatosa from tuberculous peritonitis, but composite index is slightly superior to CEA in the differential diagnosis.