The Role of Serum CEA and CA19-9 in Efficacy Evaluations and Progression-Free Survival Predictions for Patients Treated with Cetuximab Combined with FOLFOX4 or FOLFIRI as a First-Line Treatment for Advanced Colorectal Cancer

Table 2

Efficacy of using CEA and CA19-9 as tumor markers.

Evaluation parameter	CEA	CA19-9
Sensitivity	162/172 (94.2%)	151/165 (91.5%)
Specificity	45/63 (71.4%)	47/56 (83.9%)
Positive predictive value	162/180 (90.0%)	151/160 (94.4%)
Negative predictive value	45/55 (81.9%)	47/61 (77.0%)

If the levels of CEA or CA19-9 were higher than those in the previous cycle or higher than the normal reference value, tumor progression was indicated. The opposite pattern indicated disease control. A total of 162 cycles and 151 cycles of CT/MRI observations were compared with the RECIST standards. There were 45 and 47 false-negative cycles, 10 and 14 true-negative cycles, and 18 and 9 false-positive cycles, respectively, in each case.