S100P as a Marker for Poor Survival and Advanced Stage in Gallbladder Carcinoma
Alka M Mathai, Jacob Alexander, Hsuan-Ying Huang, Chien-Feng Li, Yung-Ming Jeng, Kar-Ming Fung, Matthew M Yeh. University of Washington, Seattle, WA; Chang Gung University, Kaohsiung, Taiwan; Chi-Mei Medical Center, Tainan, Taiwan; National Taiwan University, Taipei, Taiwan; University of Oklahoma, Oklahoma City, OK
Background: The outcome of gallbladder carcinoma remains dismal and identification of biomarkers for prognostic stratification and development of targeted therapeutic modalities is urgently needed. Overexpression of S100P has been shown in several tumors including biliary and pancreatic cancers. However, the association of S100P with the clinicopathological characteristics and clinical outcome of gallbladder carcinoma remains unclear.
Design: Tissue microarray was constructed from 91 surgically resected gallbladder carcinoma specimens. Immunohistochemistry of S100P was performed. The staining intensity was scored as 0 (no stain), 1 (weak), 2 (weak to moderate), 3(moderate to intense) and 4 (intense). Percentages of cells positively stained were semi-quantitatively scored as 0 (<10%), 1 (10-24%), 2 (25-49%), 3 (50-74%) and 4 (>74%). Immunoreactive score (IRS) was calculated by multiplying the intensity of stain with the score of positive cells, producing scores ranging from 0 to 16. Tumors were classified, graded, and staged according to current WHO and AJCC standards.
Results: Higher IRS was significantly associated with TNM staging (p=0.04). 68/91 (75%) of the cases had IRS score ≥3 when compared to 20/91(22%) cases with IRS<3. Cases of staining intensity ≥3 in ≥25% tumor cells were significantly increased in pathological stage T4 (p= 0.01). Staining intensity was significantly associated with poorer survival (p=0.006). Vascular invasion (p=0.01) and perineural invasion (p=0.04) were also predictors of poorer survival. Age, sex, histological type, histological grade, vascular invasion, perineural invasion and necrosis were not found to be associated with S100P expression.
Conclusions: Besides vascular invasion and perineural invasion, staining intensity of S100P is strongly associated with poorer survival in gallbladder carcinomas. Overexpression of S100P is also significantly associated with pathological stage T4 carcinoma. Our results suggest S100P may serve as a surrogate marker for prognosis in gallbladder carcinoma.
Tuesday, March 5, 2013 9:30 AM
Poster Session III # 201, Tuesday Morning