Oestrogen receptor-beta as a potential target for treatment in advanced colorectal cancer: a pilot study.
OBJECTIVE
Oestrogen receptor-beta (ER-β) is expressed in colorectal cancer. Theoretically, ER-β stimulation could slow down tumour proliferation, and this is supported by preclinical research data. While preparing a Phase II trial for advanced colorectal cancer patients we performed a pilot study with three questions: (i) in what percentage of patients do metastases display strong ER-β1 expression; (ii) is there any concordance in expression between primary tumours and metastases; and (iii) is the immunohistochemical (IHC) scoring procedure reproducible?


RESULTS
Thirty patients were selected, 15 with locoregional lymph node metastases and 15 with either synchronous or metachronous hepatic metastases. All primary tumours and metastases were analysed for immunohistochemical ER-β1 expression according to a predefined scoring system. The scoring was performed independently by two pathologists in order to calculate the weighted kappa value. Strong ER-β1 expression was found in four of 15 hepatic metastases and four of 15 lymph node metastases. In 15 of 30 patients, the level of ER-β1 expression in the metastasis was concordant with that observed in the primary tumour. Weighted kappa values of IHC ER-β1 expression were satisfactory.


CONCLUSIONS
In twenty-five per cent of patients there was strong ER-β1 expression in metastases, biopsy of which will be considered mandatory for trial inclusion.
Department of Internal Medicine, Admiraal de Ruijter Hospital, Goes, the Netherlands.
Henk
H
van Halteren
Dries
D
Mulder
Emiel
E
Ruijter
colorectal cancer; metastasis; oestrogen receptor-beta; targeted therapy