Expression of oestrogen and luteinising hormone receptor in testis cancer

INTRODUCTION & OBJECTIVES: Sex steroids and/or gonadotropins are believed to play an important role in pathogenesis of testicular germ cell cancer (TGCC). Whereas expression of the androgen receptor was found in carcinoma-in-situ testis (CIS) and in seminomas, such information regarding oestrogen and gonadotropin receptors is lacking. The aim of present study was, therefore, to map possible expression of the oestrogen receptor beta (ERß) and luteinising hormone receptor (LHR) in CIS and in seminomas (S) as well as non-seminomas (NS). MATERIAL & METHODS: Immunohistochemistry was used to localize the expression of ERß and LHR in 26 archival testicular cancers and 4 morphologically normal testes. Expression of the steroid receptors at the transcript level was assessed by in situ hybridisation in 3 specimens of normal testis and in corresponding number of tumours. RESULTS: Expression of ERß at protein level was shown in 13/13 S, 5/5 CIS adjacent to S, 6/13 NS and 7/12 CIS adjacent to NS. In NS, the ERß expression was mainly found in teratomas and endodermal sinus tumours and to a less degree in embryonal carcinomas. Immunohistochemistry data were, thereafter, confi rmed by in situ hybridisation. Expression of LHR was found in 4/4 non-seminomas and 1/7 seminomas. LHR was also localised in spermatagonia of the normal testis. CONCLUSIONS: Our results provide the fi rst evidence that ER-ß is highly expressed in S. Its expression is less pronounced in NS, mainly embryonal cell carcinomas but remains high in endodermal sinus tumours and in teratomas. LHR was occasionally expressed in NS tumour cells. Collectively, these fi ndings provide a possible link between steroid hormone/gonadotropin exposure and testicular cancer pathogenesis, an the differences in receptor expression between S and NS, might at least partly explain the discrepancý in age-related incidence and metastasing capacity of these two subtypes of TGCC.