Increased haematopoietic progenitor cells are associated with poor outcome in patients with metastatic renal cancer treated with sunitinib.

BACKGROUND: Haematopoietic progenitor cells (HPCs) are present in blood in metastatic renal cell cancer (mRCC). We investigate their expression in mRCC patients treated with sunitinib and correlate their expression with plasma growth factor levels [insulin-like growth factor (IGF)-1]. METHODS: Circulating HPCs (CD34(+)/CD45(+)) and plasma IGF-1 levels were measured at specific sequential time points (0, 6, 18 and 28 weeks) in 43 untreated mRCC patients receiving sunitinib (50 mg for 28 days followed by 14-day off treatment). Univariate and multivariate analysis assessed the prognostic significance of HPCs and IGF-1. RESULTS: HPCs levels were raised in 40 of 43 (93%) of patients. IGF-1 levels were raised in 9 of 43 patients (21%). Univariate and multivariate analysis revealed that high HPCs before treatment were associated with a significantly shorter overall survival (hazard ratio 3.3, 95% confidence interval 1.23-8.8, P=0.01), which was not the case for IGF-1 levels. Both HPC and IGF-1 levels fell with sunitinib (61% and 14% fall, respectively, P <0.05 for both). A positive correlation between the falls in HPC and IGF-1 occurred (P<0.001). CONCLUSIONS: HPCs are over expressed in the peripheral blood in the majority of patients with mRCC. Higher levels are associated with poor prognosis. A concurrent fall in HPCs and growth factor expression (IGF-1) with sunitinib occurs.

The safety and efficacy of sunitinib before planned nephrectomy in metastatic clear cell renal cancer.

BACKGROUND: The safety and efficacy of upfront sunitinib, before nephrectomy in metastatic clear cell renal cancer (mCRC), has not been prospectively evaluated. METHODS: Two prospective single-arm phase II studies investigated either two cycles (study A: n = 19) or three cycles (study B: n = 33) of sunitinib before nephrectomy in mCRC. RESULTS: Overall, 38 of 52 (73%) of patients obtained clinical benefit (by RECIST) before surgery. The partial response rate of the primary tumour was 6% [median reduction in longest diameter of 12% (range 8%-35%)]. No patients became ineligible due to local progression of disease. A nephrectomy was carried out in 37 (71%) of patients. Necrosis (>50%) was a prominent feature at nephrectomy in 49%. Surgical complications (Clavien-Dindo classification) occurred in 10 (27%) patients, including one death (3%). The median blood loss and surgical time were 725 (90-4200) ml and 189 (70-420) min, respectively. The median progression-free survival was 8 months (95% confidence interval 6-15 months). A comparison of two versus three pre-surgery cycles showed no significant difference in terms of surgical complications or efficacy. CONCLUSIONS: Nephrectomy after upfront sunitinib can be carried out safely. It obtains control of disease. Randomised studies are required to address if this approach is beneficial.