HLA-G expression in effusions is a possible marker of tumor susceptibility to chemotherapy in ovarian carcinoma.
OBJECTIVE
We recently showed that the levels of secreted human leukocyte antigen-G (HLA-G), a nonclassical MHC class I antigen, are significantly elevated in malignant effusions in ovarian carcinoma compared to benign ones. The objective of this study was to evaluate the expression and clinical role of HLA-G in effusions and corresponding solid tumors from patients diagnosed with advanced-stage ovarian carcinoma.


METHODS
Effusions (= 148), corresponding primary tumors (= 66), and metastatic lesions (= 122) were analyzed using immunohistochemistry with an anti-HLA-G monoclonal antibody.


RESULTS
HLA-G was detected in cancer cells in 49/148 (33%) effusions, 33/66 (50%) primary tumors, and 59/122 (48%) solid metastases. These differences did not reach statistical significance. Expression in effusions and solid metastases significantly correlated (P = 0.029). HLA-G expression in tumor cells was significantly lower in effusions obtained during or following chemotherapy (P = 0.038). The presence of HLA-G-positive tumor cells in effusions obtained prior to the institution of chemotherapy correlated with better overall survival (P = 0.042). HLA-G expression in primary tumors and solid metastases did not correlate with any of the clinicopathologic parameters studied.


CONCLUSIONS
HLA-G is expressed in a significant number of ovarian carcinomas at all anatomic sites. The reduced expression of HLA-G in post-chemotherapy effusions and its correlation with improved survival may be related to preferential susceptibility of HLA-G-expressing cells at this site. Our findings suggest a new role for HLA-G as a prognostic indicator in advanced-stage ovarian cancer in effusions.
Davidson
Ben
B
Department of Pathology, The Norwegian Radium Hospital, University of Oslo, Montebello N-0310 Oslo, Norway. bend@ulrik.uio.no
Elstrand
Mari Bukholt
MB
McMaster
Michael T
MT
Berner
Aasmund
A
Kurman
Robert J
RJ
Risberg
Björn
B
Trope
Claes G
CG
Shih
Ie-Ming
IeM
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000911:Antibodies, Monoclonal / Q000737:chemistry; D001202:Ascitic Fluid / Q000276:immunology; D014408:Biomarkers, Tumor / Q000096:biosynthesis* / Q000276:immunology; D005260:Female; D006680:HLA Antigens / Q000096:biosynthesis* / Q000276:immunology; D059951:HLA-G Antigens; D015395:Histocompatibility Antigens Class I / Q000096:biosynthesis* / Q000276:immunology; D006801:Humans; D007150:Immunohistochemistry; D008875:Middle Aged; D009362:Neoplasm Metastasis; D009367:Neoplasm Staging; D010051:Ovarian Neoplasms / Q000188:drug therapy* / Q000276:immunology* / Q000473:pathology; D010996:Pleural Effusion / Q000276:immunology; D011379:Prognosis
D000911:Antibodies, Monoclonal; D014408:Biomarkers, Tumor; D006680:HLA Antigens; D059951:HLA-G Antigens; D015395:Histocompatibility Antigens Class I