Choi response criteria for early prediction of clinical outcome in patients with metastatic renal cell cancer treated with sunitinib

BACKGROUND: Because sunitinib can induce extensive necrosis in metastatic renal cell cancer (mRCC), we examined whether criteria defined by Choi might be valuable to predict early sunitinib efficacy. METHODS: Computed tomography was used for measurement of tumour lesions in mm and lesion attenuation in Hounsfield units (HUs). According to Choi criteria partial response (PR) was defined as >= 10% decrease in size or >= 15% decrease in attenuation. RESULTS: A total of 55 mRCC patients treated with sunitinib were included. At first evaluation, according to the Response Evaluation Criteria in Solid Tumours (RECIST) 7 patients had PR, 38 stable disease (SD), and 10 progressive disease (PD), whereas according to Choi criteria 36 patients had PR, 6 SD and 13 PD. Median tumour attenuation decreased from 66 to 47 HUs (P <= 0.001). In patients with PR, Choi criteria had a significantly better predictive value for progression-free survival and overall survival (both Ps <= 0.001) than RECIST (P = 0.685 and 0.191 respectively). The predictive value for RECIST increased (P = 0.001 and <0.001 respectively), when best response during treatment was taken into account. CONCLUSION: Choi criteria could be helpful to define early mRCC patients who benefit from sunitinib, but the use of these criteria will not change the management of these patients. British Journal of Cancer (2010) 102, 803-809. doi: 10.1038/sj.bjc.6605567 www.bjcancer.com Published online 9 February 2010 (C) 2010 Cancer Research UK