Human leucocyte antigen (HLA) A2 phenotype incidence in patients with advanced ovarian cancer as negative clinical prognostic factor

Abstract

5096 Background: Major histocompatibility complex (class I-II) antigens are mandatory for the immune response and genetic imbalance may be linked to tumour escape. We characterized a cluster of ovarian cancer patients with high incidence of HLA-A2 phenotype. The prevalence of A2 allele found in Scandinavia decreases with latitude in Europe and correlates to the decrease of ovarian cancer mortality. To find a prognostic relevance, we correlate the HLA-A2 phenotype to well defined clinical parameters. Methods: All patients with ovarian cancer, admitted at our department during 1995 were recorded in a database by age, histology, stage, surgery and treatment. Since the majority of the cases were not alive, HLA-A2 expression was determined by PCR/sequence-specific oligonucleotide hybridisation using DNA extracted from paraffin imbedded tissue specimens. Purified tissue was disrupted at 55°C in 10% SDS, proteinase K buffer twice. Amount and purity of DNA was measured by Nano-Drop technology. Results: 97 patients with ovarian cancer entered the database, median age 65 years (36–87). Forty-six percent were seropapillary, 28% endometrial, 6% mucinous and 20% other tumours. Merged by stage, 32 were I-II and 65 III-IV. At 5 years, 70% stage I-II and 20% stage III-IV patients were alive. So far, 24 out of 97 patients are characterised for HLA-A2 phenotype. Fifteen were HLA-A2 positive (66%) and 10 of 15 with stage III-IV, were 90% seropapillary tumours. At five years, none of A2 positive, but 50% A2 negative patients were alive. Conclusions: The overrepresentation of HLA-A2 phenotype is a possible negative clinical parameter for survival for ovarian cancer patients with stage III-IV and seropapillary type. A stronger statistical power will be reached after analysis of all cases. No significant financial relationships to disclose.