Abstract
Purpose: :
Carcinoembryonic antigen-related cell adhesion molecule-1 (CEACAM1) is a novel protein that has been recently recognized as being expressed by immune cells. It appears to function as a coinhibitory receptor after T cell activation. In addition, CEACAM1 expression was found to be upregulated by cutaneous melanoma cells conferring thus resistance against Tumor-Infiltrating Lymphocytes. This melanoma-promoting role of CEACAM1 makes it a potential target for immunotherapeutic interventions. The aim of this study was to examine the expression of CEACAM1 in uveal melanoma and to correlate it with clinicopathologic parameters.
Methods: :
CEACAM1 expression was immunhistochemically evaluated in primary tumors of 80 patients who underwent enucleation at Hadassah-Hebrew University Hospital between the years (1986-2006). Twenty-one liver sections were also stained.
Results: :
Thirty-nine tumors were from females; age range was between 19 and 86 years (mean 61. 47 y). Thirty-six tumors were CEACAM1 positive whereas 44 were CEACAM1 negative. Of the epithelioid-type tumors (n=23), 16 were CEACAM1 positive (69.6%) whereas of the spindle-type tumors (n=17), 13 were CEACAM1 negative (76.5%) (p=0.01). With regard to the extravascular matrix pattern; of the silent pattern (n=18), 16 were CEACAM1 negative (88.9%) whereas of the network pattern (n= 16), 12 were CEACAM1 positive (75%) (p=0.007). Mean tumor diameter was 15.6 mm ±SD 3.2 for CEACAM1 negative tumors, whereas it was 12.6 mm ± SD 4.5 for CEACAM1 positive tumors (p=0.002). A similar non-significant trend was noted for mean tumor height, where it was 10.68 mm ± SD 3.7 for CEACAM1 negative tumors and 9.35 mm ± SD 3.5 for CEACAM1 positive tumors. In patients who developed liver metastasis (n=33), 18 were CEACAM1 positive (54.5%) whereas in patients without metastasis (n=24), 15 were CEACAM1 negative (62.5%) (p=0.2). No information was available on the remaining 23 patients. Twenty-one liver metastatic sections were also studied; 17 were found to positively express CEACAM1.
Conclusions: :
CEACAM1 is expressed in uveal melanoma. Correlation with poor prognostic factors like epithelioid cell type and network extravascular matrix pattern was found. No definitive conclusions can be deduced from the current study on its role as melanoma- promoting in posterior uveal melanoma. Additional validation studies on the use of CEACAM1 expression as a prognostic marker are warranted.
Keywords: melanoma • tumors