[954] CXCL-16 Is a Marker for Papillary Renal Cell Carcinomas Type 2

C Reyes, JR Chapman-Fredricks, M Cioffi-Lavina, I Reis, M Jorda. University of Miami Jackson Memorial Hospital and Sylvester Comprehensive Cancer Center, Miami, FL

Background: CXCL-16 is a transmembrane chemokine involved in recruitment of T cells and leucocytes to the inflammation site and it is expressed in normal kidney. Chemokines have also been shown to be expressed in cancer cells of different origin. Recently, CXCL-16 has been shown to correlate with better survival in patients with renal cell carcinoma. The purpose of this study was to analyze the expression of CXCL-16 in adult renal cell carcinomas and correlate the expression pattern with both, the histologic tumor subtype and patient survival.
Design: Histologic samples from 160 adult patients with renal cell neoplasms who underwent radical nephrectomy were included in this study. Carcinomas were evaluated for the immunohistochemichal expression of CXCL-16 using monoclonal antibody (Santa Cruz, SC 27344, dilution 1:50). Positive cytoplasmic staining was recorded as focal (1) or diffuse (2); and the intensity of reaction graded as weak (1), intermediate (2) or strong (3).
Results: Histologically, 80 (50 %) carcinomas were classified as conventional, 30 (19%) as chromophobe, and 32 (20 %) as papillary (17 type 1, 15 type 2). Eighteen (11%) cases were classified as oncocytoma. Fourteen papillary type 2 (93%) carcinomas showed strong and diffuse cytoplasmic CXCL-16 expression, while most of the papillary type 1 (14 or 83%) were negative (p<.0001).The three positive papillary type 1 tumors showed only a focal weak reaction. Most oncocytomas (15 of 18 cases; 83%) and 17 chromophobe carcinomas (57%) showed a strong diffuse cytoplasmic staining for CXCL-16. Only 11 cases (13%) of conventional renal cell carcinoma showed focal and weak positive reaction for CXCL-16. CXCL-16 increased the risk of death by 2.57 fold, however this effect was not statistically significant (p=0.133).
Conclusions: A strong diffuse cytoplasmic CXCL-16 expression can be used to differentiate type 2 from type 1 papillary renal cell carcinomas. The majority of oncocytomas and over one-half of chromophobe carcinomas also expressed CXCL-16. None of conventional renal cell carcinomas showed strong cytoplasmic expression for CXCL-16; CXCL-16 immunohistochemical expression failed to correlate with patient survival.
Category: Genitourinary (including renal tumors)

Tuesday, March 23, 2010 9:30 AM

Poster Session III # 139, Tuesday Morning


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