Objectives: To compare RECIST and EORTC criteria in an evaluation of response to therapy in metastatic bladder cancer and to assess their influence on decisions to administer additional therapy.
Materials and methods: A total of 42 untreated patients (38 male, 4 female) with metastatic bladder cancer were included in the study, which took place between July 2007 and April 2013. The mean age was 66.1 ± 9.93 years (range 41-84 years). A total of 144 metastatic foci were evaluated using multislice CT and (18)FDG-PET/CT before and after first-line chemotherapy. The locations, sizes, numbers and SUV(max) of the metastatic foci before and after chemotherapy were recorded, and the response to therapy was evaluated separately using RECIST and EORTC criteria, after which a statistical comparison was made.
Results: According to the RECIST and EORTC criteria, the rate of complete remission (CR) was 9.5 and 16.6 %, the rate of partial remission (PR) was 28.6 and 40.5 %, the rate of stable disease (SD) was 23.8 and 14.3 %, and the rate of progressive disease (PD) was 31.0 and 28.6 %, respectively. The overall response rate (ORR) was 38.1 versus 57.1 %, respectively, and there were no differences between the two criteria in terms of their detection of progressive disease. The rate of SD was higher with RECIST criteria; however, the difference between the two criteria was not significant in terms of PR and CR.
Conclusion: A group of patients that had been determined as having a SD according to RECIST criteria were grouped as PR and/or CR according to EORTC criteria. Additional chemotherapy protocols can be used in second-line chemotherapy and/or cisplatin-resistant patients, according to RECIST criteria. In evaluating the response to first-line chemotherapy for metastatic bladder cancer, EORTC criteria, using (18)FDG-PET/CT scans, can be considered as a more applicable and accurate diagnostic tool. The anatomical findings obtained through imaging methods and from functional/metabolic data obtained by PET/CT can be useful in the planning of second- or third-line chemotherapy, and a high accuracy in re-staging can spare patients from second-line or even third-line chemotherapy.
Keywords: Chemotheraphy; EORTC; Metastatic bladder cancer; PET/CT; RECIST; Response to chemotheraphy.