L1-CAM is commonly expressed in testicular germ cell tumours

In 2015, an estimated number of 8430 new cases of germ cell tumour (GCT) will be diagnosed in the USA.1 Although GCTs show a high sensitivity to cisplatin-based chemotherapy, 10%–15% of patients fail first-line chemotherapy and 3%–5% of all patients with GCT will eventually die of their disease.2 Despite a response rate above 95% to cisplatin-based chemotherapy, the search for new treatment strategies remains worthwhile in accordance to reduce treatment toxicity and offer therapeutic options in non-responding patients.3–5 Various tumours have been described to express L1 cell adhesion molecule (L1-CAM) including lung carcinoma, gliomas, melanoma, renal, ovarian, endometrial and colon carcinoma.6 L1-CAM is associated with tumour cell dissemination via the regulation of prometastatic MMP-2 and MMP-9 in solid and non-solid tumours7 as well as in brain metastases.8 L1-CAM is involved in epithelial-to-mesenchymal transition.9 In various malignancies, there is evidence showing that the expression of L1-CAM is associated with a subset of highly aggressive tumours with adverse clinical outcome and might serve as a therapeutic target.10 We aimed to investigate the expression of L1-CAM in the different GCT subtypes. The construction of the tissue micro array (TMA) was described before.9 L1-CAM immunohistochemistry (IHC) was performed …