Browsing by Author "Ojeda-Medina, L"

Now showing 1 - 3 of 3

Gliomas de alto grado en pacientes pediátricos post - radioterapia: reporte de dos casos en el Instituto Nacional de Enfermedades Neoplásicas, Lima, Perú
(Universidad Peruana Cayetano Heredia, Facultad de Medicina Alberto Hurtado, 2022) Mego-Ramírez, FN; Casavilca-Zambrano, S; Negreiros-Chinchihuara, T; Cancino Maldonado, K; Ojeda-Medina, L; orrego-Puelles, JE; Díaz-Coronado, R
Radiation therapy-induced high-degree gliomas (RIGs) are a rare complication with an ominous prognosis. Little is known about the underlying biology of RIGs, although some studies have suggested that there are no unique histologic or cytogenetic features to distinguish them from de novo glioblastomas. Two cases that meet the criteria to be considered RIG are reported, and pertinent pieces of literature are discussed. Two patients under 10 years of age, neither of whom had relevant genetic or clinical history, were diagnosed with primary cerebral gliomas at the National Institute of Neoplastic Diseases in Lima and, after radiation therapy cycles, developed high-degree secondary gliomas, confirmed in both patients by a histopathologic analysis. This report emphasizes the need to identify risk factors, molecular mechanisms of tumor development after radiotherapy, and probable therapeutic targets.
Primary central nervous system sarcoma with DICER1 mutation—treatment results of a novel molecular entity in pediatric Peruvian patients
(John Wiley and Sons Inc, 2022) Diaz Coronado, RY; Mynarek, M; Koelsche, C; Mora Alferez, P; Casavilca Zambrano, S; Wachtel Aptowitzer, A; Sahm, F; von-Deimling, A; Schüller, U; Spohn, M; Sturm, D; Pfister, SM; Morales-La-Madrid, A; Sernaque-Quintana, R; Sarria-Bardales, G; Negreiros-Chinchihuara, T; Ojeda-Medina, L; Garcia-Corrochano, P; Campos-Sanchez, DA; Ponce-Farfan, J; Rutkowski, S; Garcia-Leon, JL
Background: A high frequency of primary central nervous system (CNS) sarcomas was observed in Peru. This article describes the clinical characteristics, biological characteristics, and outcome of 70 pediatric patients. Methods: Data from 70 pediatric patients with primary CNS sarcomas diagnosed between January 2005 and June 2018 were analyzed. DNA methylation profiling from 28 tumors and gene panel sequencing from 27 tumors were available. Results: The median age of the patients was 6 years (range, 2-17.5 years), and 66 of 70 patients had supratentorial tumors. DNA methylation profiling classified 28 of 28 tumors as primary CNS sarcoma, DICER1 mutant. DICER1 mutations were found in 26 of 27 cases, TP53 mutations were found in 22 of 27 cases, and RAS-pathway gene mutations (NF1, KRAS, and NRAS) were found in 19 of 27 tumors, all of which were somatic (germline control available in 19 cases). The estimated incidence in Peru was 0.19 cases per 100,000 children (<18 years old) per year, which is significantly higher than the estimated incidence in Germany (0.007 cases per 100,000 children [<18 years] per year P <.001). Patients with nonmetastatic disease (n = 46) that were treated with a combination therapy had a 2-year progression-free survival (PFS) rate of 58% (95% CI, 44%-76%) and a 2-year overall survival rate of 71% (95% CI, 57%-87%). PFS was the highest in patients treated with chemotherapy with ifosfamide, carboplatin, and etoposide (ICE) after upfront surgery followed by radiotherapy and ICE (2-year PFS, 79% [59%-100%], n = 18). Conclusions: Primary CNS sarcoma with DICER1 mutation has an aggressive clinical course. A combination of surgery, chemotherapy, and radiotherapy seems beneficial. An underlying cancer predisposition syndrome explaining the increased incidence in Peruvian patients has not been identified so far. Lay Summary: A high incidence of primary pediatric central nervous system sarcomas in the Peruvian population is described. Using sequencing technologies and DNA methylation profiling, it is confirmed that these tumors molecularly belong to the recently proposed entity “primary central nervous system sarcomas, DICER1 mutant.” Unexpectedly, DICER1 mutations as well as all other defining tumor mutations (TP53 mutations and RAS-pathway mutations) were not inherited in all 19 patients where analyzation was possible. These tumors have an aggressive clinical course. Multimodal combination therapy based on surgery, ifosfamide, carboplatin, and etoposide chemotherapy, and local radiotherapy leads to superior outcomes.
Prognostic factors of pediatric ependymomas at a National Cancer Reference Center in Peru
(Frontiers Media SA, 2023) Perez-Roca, E; Negreiros, T; Casavilca-Zambrano, S; Ojeda-Medina, L; Diaz-Coronado, R
Background: Ependymomas are central nervous system tumors that significantly impact the quality of life and carry a high mortality rate. Both the disease itself and its treatment cause significant morbidity. At a national level in Peru, there are no reports on clinical characteristics of the disease. Methods: This retrospective study captured patient aged less than 19 years with a diagnosis of ependymoma from 2012 to 2022 at a tertiary center in Lima. Results: 85 patients were included with a median follow-up time was 51.6 months. The 5-year overall survival and progression-free survival were 55.89% (95% CI: 44.28 – 65.99) and 37.71% (95% CI: 26,21-49,16) respectively. The main prognostic factors identified were completed treatment (p=0.019), adjuvant chemotherapy (p=0.048), presence of metastasis (p=0.012), and disease recurrence (p=0.02). Conclusions: The survival of patients with ependymoma is below that reported in high-income countries. Incomplete treatment and treatment abandonment are factors that negatively impact the prognosis. Further studies are needed to identify barriers in the referral and treatment process for patients with ependymoma.