1. ¹Cancer Research Program, Garvan Institute of Medical Research, Darlinghurst, NSW 2010, Australia
2. ²Division of Gynecology, University Hospital Zurich, Switzerland
3. ³South Eastern Area Laboratory Service, Prince of Wales Hospital, Randwick, NSW 2031, Australia
4. ⁴Department of Anatomical Pathology, Royal Prince Alfred Hospital, Camperdown, NSW 2050, Australia
5. ⁵Kolling Institute of Medical Research, Royal North Shore Hospital, St Leonards, NSW 2065, Australia
6. ⁶Gynaecological Cancer Centre, Royal Hospital for Women, Randwick, NSW 2031, Australia

Correspondence: Dr PM O'Brien, p.obrien@garvan.org.au

Received 30 August 2005; Revised 5 January 2006; Accepted 17 January 2006; Published online 28 February 2006.

Abstract

Mucinous epithelial ovarian cancers (MOC) are clinically and morphologically distinct from the other histological subtypes of ovarian cancer. To determine the genetic basis of MOC and to identify potential tumour markers, gene expression profiling of 49 primary ovarian cancers of different histological subtypes was performed using a customised oligonucleotide microarray containing >59 000 probesets. The results show that MOC express a genetic profile that both differs and overlaps with other subtypes of epithelial ovarian cancer. Concordant with its histological phenotype, MOC express genes characteristic of mucinous carcinomas of varying epithelial origin, including intestinal carcinomas. Differences in gene expression between MOC and other histological subtypes of ovarian cancer were confirmed by RT–PCR and/or immunohistochemistry. In particular, galectin 4 (LGALS4) was highly and specifically expressed in MOC, but expressed at lower levels in benign mucinous cysts and borderline (atypical proliferative) tumours, supporting a malignant progression model of MOC. Hence LGALS4 may have application as an early and differential diagnostic marker of MOC.