Is there any prognostic importance of pretreatment serum M30 and serum M65 levels on progression-free survival of patients with metastatic renal cell carcinoma treated with first-line sunitinib?

Abstract

e15569 Background: Effective cancer biomarkers for early detection, prognosis, or prediction of therapy response are urgently need in metastatic renal cell cancer (RCC). Soluble cytokeratin 18 fragments (M30, M65) are released from human cancer cells during epitelial cell death. Specific enzyme-linked immunosorbent assays (ELISA) using related antibodies distinguish between apoptotic (M30) or apoptotic and necrotic (M65) tumor cell death in serum samples. The aim of this study was to determine the prognostic value of plasma M30 and M65 levels in predicting survival rates of patients with metastatic RCC treated with first-line sunitinib. Methods: Thirty-nine patients with metastatic RCC and 39 healthy controls were included in this study. The patients’ samples were collected prior to the first cycle of sunitinib therapy and serum M30 and M65 levels were measured by ELISA. Results: The median ages of the patients and controls were 60 and 58 years, respectively. No difference was detected in the median serum M30 level between the patients and controls (53.7 vs. 49.1 U/l, P = 0.31). The median serum M65 level was significantly higher in patients than in controls (334.0 vs. 179.1 U/l, P<0.001). Receiver operating characteristic (ROC) analysis revealed that the best cut-off value for serum M65 level for predicting progression-free survival (PFS) was 313.6 U/l. The median PFS of patients whose M65 levels were lower than or equal to 313.6 U/l was better than that of patients whose M65 levels were greater than 313.6 U/l (P = 0.03) in univariate analysis. But serum M65 levels in patient group were not found to be an important prognostic factor for PFS in the multivariate analysis. Conclusions: Serum M65 levels were significantly elevated in patients with metastatic RCC compared to healthy individuals. Future prospective studies with large sample sizes are needed to address the possible impact of M30 and M65 levels on the treatment responses of patients and whether these markers may be prognostic factors for PFS or OS in patients with RCC.