Aims: To study E-cadherin and β-catenin expression in stage I adult-type granulosa cell tumours (AGCTs) and correlate the findings with tumour morphology and clinical outcome.
Methods and results: The study group comprised 62 FIGO stage I AGCTs, including 48 stage IA and 14 stage IC cases. Fifty patients (80.6%) had negative clinical follow-up over periods from 3.0 to 19.2 years (median 6.4 years), and 12 patients (19.4%) developed metastases at intervals of 3.6–16.2 years (median 8.6 years). β-Catenin and E-cadherin were expressed in 62 (100%) and 53 (85%) primary tumours, respectively, and staining was more consistent and intense in areas showing sex cord-like morphology. In contrast, diffuse tumour areas often showed weak or moderate staining (β-catenin) or were negative (E-cadherin), and there was reduced expression of both proteins in luteinized cells. Reduced β-catenin expression in primary tumours correlated with increased risk of recurrence (P = 0.002) and a shorter time interval to recurrence, whereas there was no correlation between E-cadherin staining and the risk of metastases.
Conclusions: Localized variations in adhesion protein expression may partly explain the diverse morphological patterns exhibited by AGCT, and reduced β-catenin staining in primary tumours may have value as an adverse prognostic factor.