Association of oncofetal protein expression with clinical outcomes in patients with urothelial carcinoma of the bladder

Abstract

Purpose: Oncofetal proteins are expressed in the developing embryo. Oncofetal protein expression correlates with the clinical outcome of nonmuscle invasive bladder urothelial carcinoma. IMP3, MAGE-A, glypican-3 and TPBG are oncofetal proteins that have not been well characterized in urothelial carcinoma of the bladder.

Materials and methods: We investigated the expression of these 4 proteins and their association with clinical outcomes using tissue microarrays from 384 consecutive patients treated with radical cystectomy between 1988 and 2003 at 1 academic center. We stained for IMP3, MAGE-A, glypican-3 and TPBG. Univariable and multivariable Cox regression analyses were done to evaluate the association of oncofetal protein expression with disease recurrence and cancer specific mortality.

Results: IMP3, MAGE-A, glypican-3 and TPBG were expressed in 39.5%, 45%, 6% and 85% of urothelial bladder carcinomas, respectively. Expression was tumor specific and did not correlate with pathological features except for TPBG. At a median followup of 128 months 176 patients (46%) experienced disease recurrence, 175 (45.5%) had died of the disease and 96 (27.5%) had died of another cause. On univariable analysis IMP3 and MAGE-A expression was associated with an increased risk of disease recurrence (p <0.001 and 0.03) and cancer specific mortality (p = 0.004 and 0.03, respectively). On multivariable Cox regression analysis adjusted for the effects of standard clinicopathological features IMP3 and MAGE-A expression was independently associated with disease recurrence (p = 0.004, HR 1.55, 95% CI 1.15-2.11 and p = 0.02, HR 1.44, 95% CI 1.05-1.99, respectively) but not with cancer specific mortality.

Conclusions: Oncofetal proteins are commonly and differentially expressed in urothelial carcinoma of the bladder compared to normal urothelium. IMP3 and MAGE-A expression was associated with disease recurrence and cancer specific mortality but glypican-3 and TPBG expression was not.

Keywords: carcinoma; oncofetal antigens; risk; urinary bladder; urothelium.