BACKGROUND/ OBJECTIVES: Pilocytic astrocytomas (PAs) are the most frequent astrocytomas in children and adolescents. Methilthioadenosine phosphorylase(MTAP) is a tumor-suppressor gene, the loss of expression of which is associated with a poor prognosis and better response to specific chemotherapy in leukemia and non-small-cell lung cancer. The expression of MTAP in brain tumors remains largely unknown and its biological role in PA is still unexplored. Our aims were to describe the immunohistochemical MTAP expression in a series of PAs and relate it to the clinicopathological features of the patients. METHODS: We assessed MTAP expression on immunohistochemistry in 69 pediatric and adult patients with PA in a tissue microarray platform. RESULTS: Retained expression of MTAP was seen in >85% of the tumors compared to in the nonneoplastic adjacent tissue. Only 3 supratentorial tumors showed a complete loss of MTAP expression. No significant association with clinicopathological features or overall survival of the patients was found. CONCLUSIONS: MTAP expression is retained in PAs and is not an outcome predictor for these tumors. Nevertheless, a subset of patients with PAs exhibiting a loss of MTAP could potentially benefit from treatment with specific chemotherapy, especially when lesions are recurrent or surgical resection is not recommended.
BACKGROUND/ OBJECTIVES:Pilocytic astrocytomas (PAs) are the most frequent astrocytomas in children and adolescents. Methilthioadenosine phosphorylase(MTAP) is a tumor-suppressor gene, the loss of expression of which is associated with a poor prognosis and better response to specific chemotherapy in leukemia and non-small-cell lung cancer. The expression of MTAP in brain tumors remains largely unknown and its biological role in PA is still unexplored. Our aims were to describe the immunohistochemical MTAP expression in a series of PAs and relate it to the clinicopathological features of the patients. METHODS: We assessed MTAP expression on immunohistochemistry in 69 pediatric and adult patients with PA in a tissue microarray platform. RESULTS: Retained expression of MTAP was seen in >85% of the tumors compared to in the nonneoplastic adjacent tissue. Only 3 supratentorial tumors showed a complete loss of MTAP expression. No significant association with clinicopathological features or overall survival of the patients was found. CONCLUSIONS:MTAP expression is retained in PAs and is not an outcome predictor for these tumors. Nevertheless, a subset of patients with PAs exhibiting a loss of MTAP could potentially benefit from treatment with specific chemotherapy, especially when lesions are recurrent or surgical resection is not recommended.
Authors: Giuseppina Catanzaro; Zein Mersini Besharat; Andrea Carai; Natalie Jäger; Elena Splendiani; Carole Colin; Agnese Po; Martina Chiacchiarini; Anna Citarella; Francesca Gianno; Antonella Cacchione; Evelina Miele; Francesca Diomedi Camassei; Marco Gessi; Luca Massimi; Franco Locatelli; David T W Jones; Dominique Figarella-Branger; Stefan M Pfister; Angela Mastronuzzi; Felice Giangaspero; Elisabetta Ferretti Journal: Biomark Res Date: 2022-06-17
Authors: Lucas Tadeu Bidinotto; Raul Torrieri; Alan Mackay; Gisele Caravina Almeida; Marta Viana-Pereira; Adriana Cruvinel-Carloni; Maria Luisa Spina; Nathalia Cristina Campanella; Weder Pereira de Menezes; Carlos Afonso Clara; Aline Paixão Becker; Chris Jones; Rui Manuel Reis Journal: G3 (Bethesda) Date: 2016-07-07 Impact factor: 3.154
Authors: Gaia Bistulfi; Hayley C Affronti; Barbara A Foster; Ellen Karasik; Bryan Gillard; Carl Morrison; James Mohler; James G Phillips; Dominic J Smiraglia Journal: Oncotarget Date: 2016-03-22