Researchers recommend EpCAM testing in cancer patients prior to targeted therapy
Innsbruck/Meran – Until now, there has been no consensus on how and when to evaluate EpCAM expression in patients with cancer. Austrian and Italian oncologists have now presented the first systematic investigation on occurrence of over expression of the epithelial cancer drug target in several tumour entities (J Clin Pathol. 2011 May;64(5):415-20). For assessing EpCAM over expression, Gilbert Spizzo from university hospital Meran and his colleagues from Tyrolean Cancer Research Institute (Innsbruck) stained samples from 2291 primary tumour tissues and 108 metastases with an the EpCAM-specific antibody and defined intense immunohistochemical staining as EpCAM overexpression. EpCAM was highly expressed in most tumours of gastrointestinal origin and in some carcinomas of the genitourinary tract. However, hepatocellular carcinomas, clear cell renal cell cancer, urothelial cancer and squamous cell cancers were frequently EpCAM negative. EpCAM expression in breast cancer depended on the histological subtype; lobular histology usually showed no or weak expression. Most metastases were EpCAM positive and they frequently reflected the expression phenotype of the primary tumour. The authors recommend the evaluation of immunohistochemical evaluation of EpCAM expression prior to therapy, particularly in patients with renal cell cancer, hepatocellular carcinoma, urothelial carcinoma, breast cancer and squamous cell carcinomas. The recommendation would affect marketed antibody drugs such as Catumaxomab and mAbs under development such as Adecatumumab.