Shed urinary ALCAM is an independent prognostic biomarker of three-year overall survival after cystectomy in patients with bladder cancer

// Shanna A. Arnold Egloff 1, 2 , Liping Du 3 , Holli A. Loomans 4 , Alina Starchenko 5 , Pei-Fang Su 6 , Tatiana Ketova 2 , Paul B. Knoll 7 , Jifeng Wang 2, 8 , Ahmed Q. Haddad 9, 10 , Oluwole Fadare 2, 11 , Justin M. Cates 2 , Yair Lotan 10 , Yu Shyr 3, 12 , Peter E. Clark 12, 13 , Andries Zijlstra 2, 12 1 Department of Veterans Affairs, Nashville, TN, USA 2 Department of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center, Nashville, TN, USA 3 Center for Quantitative Sciences, Vanderbilt University Medical Center, Nashville, TN, USA 4 Department of Cancer Biology, Vanderbilt University Medical Center, Nashville, TN, USA 5 Department of Cell and Developmental Biology, Vanderbilt University Medical Center, Nashville, TN, USA 6 Department of Statistics, National Cheng Kung University, Taiwan 7 Meharry Medical College, Nashville, TN, USA 8 Department of Urology, The Fifth People’s Hospital of Shanghai, Shanghai, China 9 Department of Urology, The University of Louisville, Louisville, KY, USA 10 Department of Urology, The University of Texas Southwestern Medical Center, Dallas, TX, USA 11 University of California San Diego, La Jolla, CA, USA 12 Vanderbilt Ingram-Cancer Center, Vanderbilt University Medical Center, Nashville, TN, USA 13 Department of Urology, Vanderbilt University Medical Center, Nashville, TN, USA Correspondence to: Andries Zijlstra, email: Andries.Zijlstra@Vanderbilt.Edu Keywords: ALCAM, bladder cancer, transitional cell carcinoma, urothelial cell carcinoma, metastasis Received: July 06, 2016      Accepted: October 19, 2016      Published: November 24, 2016 ABSTRACT Proteins involved in tumor cell migration can potentially serve as markers of invasive disease. Activated Leukocyte Cell Adhesion Molecule (ALCAM) promotes adhesion, while shedding of its extracellular domain is associated with migration. We hypothesized that shed ALCAM in biofluids could be predictive of progressive disease. ALCAM expression in tumor ( n = 198) and shedding in biofluids ( n = 120) were measured in two separate VUMC bladder cancer cystectomy cohorts by immunofluorescence and enzyme-linked immunosorbent assay, respectively. The primary outcome measure was accuracy of predicting 3-year overall survival (OS) with shed ALCAM compared to standard clinical indicators alone, assessed by multivariable Cox regression and concordance-indices. Validation was performed by internal bootstrap, a cohort from a second institution ( n = 64), and treatment of missing data with multiple-imputation. While ALCAM mRNA expression was unchanged, histological detection of ALCAM decreased with increasing stage ( P = 0.004). Importantly, urine ALCAM was elevated 17.0-fold (P < 0.0001) above non-cancer controls, correlated positively with tumor stage ( P = 0.018), was an independent predictor of OS after adjusting for age, tumor stage, lymph-node status, and hematuria (HR, 1.46; 95% CI, 1.03–2.06; P = 0.002), and improved prediction of OS by 3.3% (concordance-index, 78.5% vs. 75.2%). Urine ALCAM remained an independent predictor of OS after accounting for treatment with Bacillus Calmette-Guerin, carcinoma in situ , lymph-node dissection, lymphovascular invasion, urine creatinine, and adjuvant chemotherapy (HR, 1.10; 95% CI, 1.02–1.19; P = 0.011). In conclusion, shed ALCAM may be a novel prognostic biomarker in bladder cancer, although prospective validation studies are warranted. These findings demonstrate that markers reporting on cell motility can act as prognostic indicators.