Expression of laminin receptor 1 in gestational trophoblastic diseases and normal placenta and its relationship with the development of postmolar tumors.

Objectives: To investigate the expression of laminin receptor 1 (LR1), a non-integrin-type laminin receptor, in gestational trophoblastic diseases and normal first-trimester placenta, since it may play a role in controlling trophoblast invasion in normal and molar pregnancies.

Methods: Paraffin sections from 24 gestational age controlled normal first-trimester placentas, 47 partial moles, 56 complete moles, 3 invasive moles, 4 gestational choriocarcinomas, and 1 placental-site trophoblastic tumor were studied immunohistochemically for expression of LR1.

Results: In complete and partial moles, decidual cells showed significantly stronger LR1 protein staining compared to the normal placenta (p<0.01). When compared to the partial moles, weak staining in less than 33% of decidual cells was also more prominent in the normal placenta (p<0.05). Complete and partial moles, invasive moles, choriocarcinomas, and placental-site tumors did not differ from each other with respect to staining intensity. Strong immunostaining for LR1 in decidual cells, cytotrophoblasts, syncytiotrophoblasts, and extracellular matrix cells of partial and complete moles was not significantly correlated with the development of persistent postmolar gestational trophoblastic tumors.

Conclusions: LR1 may be important in the pathogenesis of gestational trophoblastic diseases. The increased expression of LR1 in decidual cells of partial and complete moles may not influence the development of persistent gestational trophoblastic tumor. Since they are seen rarely, multicentric studies should be planned to study LR1 expression in invasive moles and gestational trophoblastic neoplasms.