Relation between lactate dehydrogenase (LDH) during two first cycles in patients with metastatic renal cell carcinoma (mRCC) treated with sunitinib (SU)

Abstract

14079 Background: LDH is a biomarker of cellular turn over. We evaluated LDH as a surrogate marker of tumor response and tumor necrosis during first cycles of SU. Methods: This is a single center study of immunorefractory patients with mRCC treated in second line with SU (50 mg, 4 weeks on, 2 weeks off). All patients performed CT scan and had serially measured tumor necrosis. Tumor response using the RECIST criteria was evaluated at the end of cycle 2 (C2). Tumor necrosis index was calculated at baseline, at the end of cycle 1 (C1) and C2 by measuring the percent area of the tumor with no enhancement after injection using an electronic calliper. LDH was measured at baseline (D1) and at the end (D28) of C1 and C2 using LD 200 kit on Synchron LX20 (Beckman Coulter). Relations between LDH and tumor response were studied using multivariate analysis of variance (MANOVA) with repeated measures and between LDH and tumor necrosis using Pearson correlation test. Results: Between Feb 2005 and Aug 2006, 56 patients were analyzed (75% men,), 91% Clear Cell Carcinoma. Mean age was 59 years (range: 30–81) and 62% has a performance status ECOG of 0. Median number of metastatic sites was 2 and mean hemoglobin level was 12.7 gr/dl. After C2, 12 (21%) partial responses, 35 (63%) stable diseases and 9 (16%) progressive diseases were noted. Results of LDH are summarized in the table . Mean LDH was statistically different between along time (p < 0.0001). LDH levels were statistically different between responders-stables and progressors patients (p = 0.004). There is a trend for a statistical relation between the index of necrosis and the tumor response measured by RECIST criteria (p = 0.08). No correlation was found between LDH and tumor necrosis. Conclusions: LDH level is higher in progressors compared to responders-stables patients. LDH level is not correlated to tumor necrosis measured by CT scan. [Table: see text] No significant financial relationships to disclose.