Expression of CD44(v5-10) splicing variants in primary ovarian cancer and lymph node metastases

Background: This study was designed to detect the expression of CD44v splic ing variants in primary ovarian carcinomas and their lymph node metastases, in order to evaluate the possible role in intraperitoneal and lymphogenic metastasization. Material and Methods: Paraffin-embedded tissue of 50 patie nts with ovarian cancer was available from both the primary tumors and from the lymph node metastases. The expression of the CD44 standard form (CD44) and of the variant isoforms CD44v5, CD44v6, CD44v7 and 8, and CD44v10 was investigated in the tumor cell regions by immunohistochemistry. Results: 45 /50 (90%) primary ovarian carcinoma were found to be immunohistochemically positive for the CD44v4 splicing variant; 10 (20%) tumors expressed both CD 44v5 and CD44v6. Apart from an additional v7 stain, all of the ovarian carc inomas studied were negative for the splicing variants v7,v7-8 and v10. No differences were revealed in the pattern of CD44 variants expression invest igated in primary tumors and in the lymph node metastases. Conclusions: In ovarian cancer the expression of CD44v5 as a possible first step, as well a s CD44v6, probably plays an important role in intraperitoneal implantation. In view of the comparatively heterogenous expression patterns of CD44v in individual organs, it may be assumed that there are organ-specific differen ces in this respect,and that the invasion potential iss influenced by both the expression pattern and the extent of expression.