Figure 2: CA125 progression criteria proposed by Rustin et al. in 1993 to detect increments among patients with ovarian cancer. It was not specified whether the criteria were used to monitor therapy or follow-up. FIGO stage was not specified [19]. CD denotes the required critical difference. Points connected by dashed lines indicate measurements that are not necessarily consecutive. Points connected by solid lines indicate consecutive measurements. The red solid line indicates the applied cutoff in the individual criteria. a The criterion was based on at least four measurements. The first and second concentrations were <35 U/ml with an increment ≥25% to ≥40 U/ ml for the second latest concentration. The latest concentration could be higher, equal to or less than 10 % lower than the second latest concentration. Intervening concentrations between concentration two and the second latest concentration could decrease ≤10 % as compared to concentration two. The time interval between the first and the second latest concentration was ≥56 days, and the time interval between the second latest and the latest concentration was ≥28 days [19]. b The criterion was based on at least three measurements. The first concentration was ≤30 U/ml with an increment ≥25% to >30 U/ml of the second concentration as compared to the first concentration. The third concentration increased ≥25% to ≥40 U/ml as compared to the second concentration. Intervening concentrations between the first and the second concentration and between the second and the third concentration could decrease <10%. The time interval of the criterion from the first to the third concentration was ≥56 days [19]. c The criterion was based on at least three measurements and all concentrations were ≥100 U/ml. The second concentration was ≥50% of the first concentration. The third concentration could be higher, equal to or less than 10% lower than the second concentration. Intervening concentrations should be >100 U/ml and decrease ≤50% as compared to the first concentration. The time interval of the criterion from the first to the third sample was ≥56 days [19].