Aims: To assess oestrogen receptor (ER)α, ERβ, and progesterone receptor (PR) expression in stage I ovarian adult-type granulosa cell tumours (AGCTs) and correlate the findings with clinical outcome.
Methods: ERα, ERβ and PR immunohistochemistry was performed on 56 primary, stage I AGCTs. Twelve cases (21%) recurred and hormone receptor staining was compared in the corresponding primary and metastatic tumours.
Results: All primary AGCTs expressed ERβ and PR, usually with strong and diffuse staining, whereas only 20% of tumours were focally ERα positive. There was no correlation between ERα or PR expression and outcome. However, primary AGCTs with low ERβ expression had a significantly higher risk of recurrence. In contrast, all metastatic tumours exhibited strong ERβ staining. No relationship between ER staining and tumour morphology was identified but there was more consistent PR expression in cells at the tumour-stromal interface.
Conclusions: Primary AGCTs typically show an ERα negative and ERβ/PR positive immunophenotype. Low ERβ expression is an adverse prognostic factor in primary AGCT but metastatic tumours often show up-regulation of ERβ. Local microenvironmental factors may influence PR expression. Hormone receptor expression in AGCT may become increasingly relevant due to developments in selective therapy.