Characterisation of Levonorgestrel-Resistant Endometrial Cancer Cells

Development of a long term, ex vivo, patient-derived explant model of endometrial cancer

Incidence of endometrial cancer (EC) is rising in the developed world. The current standard of care, hysterectomy, is often infeasible for younger patients and those with high body mass index. There are limited non-surgical treatment options and a lack of biologically relevant research models to investigate novel alternatives to surgery for EC. The aim of the present study was to develop a long-term, patient-derived explant (PDE) model of early-stage EC and demonstrate its use for investigating predictive biomarkers for a current non-surgical treatment option, the levonorgestrel intra-uterine system (LNG-IUS). Fresh tumour specimens were obtained from patients with early-stage endometrioid EC. Tumours were cut into explants, cultured on media-soaked gelatin sponges for up to 21 days and treated with LNG. Formalin-fixed, paraffin embedded (FFPE) blocks were generated for each explant after 21 days in culture. Tumour architecture and integrity were assessed by haematoxylin and eosin (H&E) and immunohistochemistry (IHC). IHC was additionally performed for the expression of five candidate biomarkers of LNG resistance. The developed ex vivo PDE model is capable of culturing explants from early-stage EC tumours long-term (21 Days). This model can complement existing models and may serve as a tool to validate results obtained in higher-throughput in vitro studies. Our study provides the foundation to validate the extent to which EC PDEs reflect patient response in future research.

Serum HE4 predicts progestin treatment response in endometrial cancer and atypical hyperplasia: A prognostic study

OBJECTIVE

To investigate serum human epididymis-4 (HE4) as a predictive biomarker of intrauterine progestin response in endometrial cancer and atypical endometrial hyperplasia (AEH).

DESIGN

Prospective prognostic factor study.

SETTING

Consecutive sample of women attending a tertiary gynaecological oncology centre in northwest England.

POPULATION

Women with AEH or early-stage, low-grade endometrial cancer who were unfit for or declined primary surgical management.

METHODS

A total of 76 women, 32 with AEH and 44 with endometrial cancer, were treated with a levonorgestrel intrauterine system (LNG-IUS) for 12 months. Endometrial biopsies and imaging were performed to assess treatment response. Pretreatment serum HE4 was analysed by chemiluminescence immunoassay and diagnostic accuracy and logistic regression analyses were performed.

MAIN OUTCOME MEASURES

Progestin response at 12 months defined by histology and imaging.

RESULTS

The median age and body mass index (BMI) of the final cohort were 52 years (interquartile range [IQR] 33-62 years) and 46 kg/m2 (IQR 38-54 kg/m2 ), respectively. Baseline serum HE4 was significantly higher in non-responders than responders (119.2 pmol/L, IQR 94.0-208.4 pmol/L versus 71.8 pmol/L, IQR 56.1-84.2 pmol/L, p < 0.001). Older age (odds ratio [OR] 0.96, 95% CI 0.93-0.99, p = 0.02), baseline serum HE4 (OR 0.97, 95% CI 0.96-0.99, p = 0.001) and endometrial cancer histology (OR 0.22, 95% CI 0.72-0.68, p = 0.009) were associated with a lower likelihood of progestin treatment response. Serum HE4 remained independently associated with progestin treatment failure when adjusted for age and histology (adjusted hazard ratio 0.97, 95% CI 0.96-0.99, p = 0.008).

CONCLUSION

Serum HE4 shows promise as a predictive biomarker of progestin treatment response in endometrial cancer and AEH.