Thoc1 Protein as a Novel Prognostic Marker for Prostate Cancer
Yanping Li, Jun Yang, Junqi Qian, David W Goodrich, Jorge A Almenara, Ema Dragoescu. Virginia Commonwealth University Health System, Richmond, VA; Virginia Department of Health, Richmond, VA; Roswell Park Cancer Institute, Buffalo, NY
Background: Good prognostic markers to predict prostate cancer (PrCa) recurrence are in great demand for clinical decision-making due to the indolent nature of the disease. Our study focuses on pThoc1, an essential component of transcription elongation-export (TREX) complex. pThoc1 is upregulated in multiple cancer types and cell lines, and is required for survival of cancer cells, but not normal cells. We have previously shown that pThoc1 is required for early stage tumorigenesis in cell culture models (Li, 2007) and PrCa mouse models (in press). However, the role of pThoc1 in human PrCa has not been investigated. The purpose of this study is to evaluate the association of pThoc1 expression with clinicopathologic features in human PrCa.
Design: Radical prostatectomy cases of prostatic adenocarcinoma between 1999 and 2006 at VCUHS with at least 5 years follow up or PSA recurrence (≥0.4ng/ml) were selected. Tissue microarrays were constructed with at least 3 tumor and 2 normal cores/case. IHC staining was performed with a rabbit polyclonal antibody to pThoc1. Each case was reviewed independently by two pathologists. Thoc1 score was calculated by intensity (0∼3) X percentage (0∼100%) of positive cells. Statistical analysis was performed using Chi-square test, Kaplan-Meier Survival Analysis and Cox Proportional hazards regression.
Results: Thoc1 score was elevated in tumor compared to normal tissue (124 vs. 43, p<0.001). Tumors with low Gleason score (5 to 7) appeared to have lower Thoc1 score, although the correlation was not significant possibly due to the small sample size (figure 1). Most interestingly, high Thoc1 score (>100) correlates with higher rate of PSA recurrence (p = 0.04, hazards ratio = 2.48)(figure 2). No significant correlation with tumor volume, invasion, or lymph node status was observed.
Conclusions: Our results indicate that strong pThoc1 expression in PrCa may predict early PSA recurrence. Therefore, pThoc1 is a potential useful marker for risk stratification and further management decision-making for prostate cancer patients.
Category: Genitourinary (including renal tumors)
Monday, March 4, 2013 9:30 AM
Poster Session I Stowell-Orbison/Surgical Pathology/Autopsy Awards Poster Session # 141, Monday Morning