Tumorigenic and prognostic significance of RASSF1A expression in low-grade (WHO G1 and G2) non-muscle-invasive bladder cancer - Abstract

OBJECTIVE: To investigate RASSF1A expression in an attempt to understand the effect of RASSF1A in low-grade, nonmuscle-invasive bladder cancer (NMIBC).

METHODS: A total of 101 tumor tissues and normal donor-matched adjacent tissues from patients with primary low-grade NMIBC were selected. RASSF1A expression was measured by quantitative real-time polymerase chain reaction and is expressed as the ratio between the normal tissue level and the tumor tissue level (N/T ratio). RASSF1A promoter methylation was assessed using methylation-specific polymerase chain reaction.

RESULTS: RASSF1A mRNA expression was significantly lower in patients with RASSF1A methylation than in those with no methylation (P = .046), and RASSF1A mRNA expression was lower in the tumor tissues than in the matched normal bladder mucosa (P < .001). The RASSF1A N/T ratio was greater in grade 2 and large tumors than in grade 1 and small tumors (P < .05 for each). Kaplan-Meier estimates revealed that the differences in the RASSF1A N/T ratio were associated with significant differences in the interval to tumor recurrence (P = .018) in low-grade NMIBC. Multivariate Cox regression analysis showed that the RASSF1A N/T ratio (hazards ratio 2.354, P = .015) was an independent predictor of recurrence.

CONCLUSION: Decreased RASSF1A expression correlates with the transition from normal mucosa to bladder cancer and has prognostic value in low-grade NMIBC.

Written by:
Ha YS, Jeong P, Kim JS, Kwon WA, Kim IY, Yun SJ, Kim GY, Choi YH, Moon SK, Kim WJ   Are you the author?
Department of Urology, Chungbuk National University College of Medicine, Cheongju, South Korea; Section of Urologic Oncology, Cancer Institute of New Jersey, Robert Wood Johnson Medical School, New Brunswick, New Jersey

Reference: Urology. 2012 Jun;79(6):1411.e1-6
doi: 10.1016/j.urology.2012.01.042

PubMed Abstract
PMID: 22446336