Response evaluation criteria in solid tumors response of the primary lesion in metastatic renal cell carcinomas treated with sunitinib: does the primary lesion have to be regarded as a target lesion?

BACKGROUND: We evaluated whether best overall response changes by designating primary renal lesions as either target or nontarget lesions and assessing response per Response Evaluation Criteria in Solid Tumors in mRCC patients treated with sunitinib. In addition, we evaluated whether discordance, if any, leads to a difference in predictive value of response in terms of time to progression (TTP) and overall survival (OS). PATIENTS AND METHODS: Patients with mRCC with an intact primary tumor and at least 1 extrarenal measurable lesion were included in this study. The variation of the sum of diameters (ΔSOD) of target lesions and best overall response, assessed from all target lesions and from metastasis-only target lesions, was documented separately. RESULTS: There were 41 patients included. Median ΔSOD of the primary lesion and metastatic target lesion were -6.0% (range, -34.0% to 17.6%), and -18.0% (range, -100.0% to 120.0%), respectively. For metastasis-only target lesions, the best overall response of 2 patients (4.9%) changed from stable disease to partial response. When we categorized patients into responders and nonresponders, response determination using metastasis-only target lesions resulted in significantly better discrimination of time to progression (14.9 vs. 4.3 months, P = .001) and overall survival (18.5 vs. 9.6 months, P = .036) between 2 groups. Using all target lesions, both TTP (14.9 vs. 5.4 months, P = .056) and OS (18.0 vs. 10.6 months, P = .155) were not statistically significant. CONCLUSION: When treating nonnephrectomized mRCC patients, selecting metastasis-only lesions as target lesions might be better to determine response, which might be more representative of survival end point.

Comparative efficacy of vascular endothelial growth factor (VEGF) tyrosine kinase inhibitor (TKI) and mammalian target of rapamycin (mTOR) inhibitor as second-line therapy in patients with metastatic renal cell carcinoma after the failure of first-line VEGF TKI.

Sequential therapy is a standard strategy used to overcome the limitations of targeted agents in metastatic renal cell carcinoma. It remains unclear whether a mammalian target of rapamycin (mTOR) inhibitor is a more effective second-line therapy after first-line vascular endothelial growth factor tyrosine kinase inhibitor (VEGF TKI) has failed than the alternative, VEGF TKI. A clinical database was used to identify all patients with renal cell carcinoma who failed at first-line VEGF TKI and then treated with second-line VEGF TKI or mTOR inhibitors in the Asan Medical Center. Patient medical characteristics, radiological response and survival status were assessed. Of the 83 patients who met the inclusion criteria, 41 received second-line VEGF TKI [sunitinib (n = 16) and sorafenib (n = 25)] and 42 were treated with mTOR inhibitors [temsirolimus (n = 11) and everolimus (n = 31)]. After a median follow-up duration of 23.9 months (95 % CI, 17.8-30.0), progression-free survival was 3.0 months for both groups [hazard ratio (HR, VEGF TKI vs. mTOR inhibitor) = 0.97, 95 % CI 0.59-1.62, P = 0.92]. Overall survival was 10.6 months for the VEGF TKI group and 8.2 months for the mTOR inhibitor group (HR = 0.98, 95 % CI 0.57-1.68, P = 0.94). The two groups did not differ significantly in terms of disease control rate (51 % for VEGF TKI and 59 % for mTOR inhibitor, P = 0.75). Second-line VEGF TKI seems to be as effective as mTOR inhibitors and may be a viable option as a second-line agent after first-line anti-VEGF agents have failed.

Efficacy and safety of vascular endothelial growth factor receptor tyrosine kinase inhibitors in patients with metastatic renal cell carcinoma and poor risk features.

BACKGROUND: Temsirolimus is a standard of care in patients with metastatic renal cell carcinoma (mRCC) with poor risk factors. The role of vascular endothelial growth factor receptor (VEGFR) tyrosine kinase inhibitors (TKI) remains poorly defined in this setting. METHODS: Records of our center were examined to identify patients with mRCC and 3 or more poor prognosis factors, as determined in the Advanced Renal Cell Carcinoma (ARCC) trial, who had been treated with VEGFR TKIs. Their baseline characteristics, radiologic response, adverse events, and survival status were assessed. RESULTS: The 88 patients who met our inclusion criteria had a median age of 56 years (range 17-83 years). We observed clear cell histology in 71 (81%) patients, and 52 (59%) underwent prior nephrectomy. Seventy-six patients (86%) were treated with sunitinib and 10 (11%) with sorafenib. Of 85 patients with measurable lesions, 19 (22%) showed objective response, with disease control achieved in 49 (56%). At a median follow-up of 29.6 months, the median time to progression was 5.0 months (95% CI, 3.5-6.5 months) and the median overall survival (OS) was 9.3 months (95% CI, 7.1-11.5 months). Neutrophil count (>ULN), bone metastasis, and lymph node metastasis were independent prognostic factors for OS, whereas prior nephrectomy was not. CONCLUSIONS: VEGFR TKIs, especially sunitinib, are active and tolerated by mRCC patients with poor risk features.

Comparative efficacy of sunitinib versus sorafenib as first-line treatment for patients with metastatic renal cell carcinoma.

BACKGROUND: This study investigated the efficacy and toxicity of sorafenib and sunitinib as primary treatment for patients with metastatic renal cell carcinoma (mRCC). METHODS: We identified 49 and 220 patients treated with sorafenib and sunitinib, respectively, as first-line therapy in the Asan Medical Centre from April 2005 to March 2011. RESULTS: Disease control rates of 71 and 74% were achieved with sorafenib and sunitinib, respectively (p = 0.687). After a median follow-up of 27.6 months, progression-free survival (PFS) and overall survival (OS) were not significantly different between the sorafenib and the sunitinib group (PFS 8.6 vs. 9.9 months, respectively, p = 0.948, and OS 25.7 vs. 22.6 months, p = 0.774). Patients treated with sorafenib required dose reduction due to toxicities less frequently than those treated with sunitinib (37 vs. 54%, p = 0.034). Haematological toxicity of grade 3 or 4 was more common in the sunitinib group than in the sorafenib group (45 vs. 4%, p < 0.001). Multivariate analysis showed old age, Heng's risk group, and bone and liver metastases, but not the type of vascular endothelial growth factor tyrosine kinase inhibitor, were independent prognostic factors affecting OS. CONCLUSION: The results of this study indicate that sorafenib has comparable efficacy to sunitinib in the treatment of mRCC patients and fewer and less severe toxicities, but the number of patients included in the study was small.