Browsing by Author "Casavilca, S"

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Breast cancer subtype and survival among Indigenous American women in Peru
(Public Library of Science, 2018) Tamayo, LI; Vidaurre, T; Navarro Vásquez, J; Casavilca, S; Aramburu Palomino, JI; Calderon, M; Abugattas Saba, Julio; Gomez, HL; Castaneda, Carlos A; Song, S; Cherry, D; Rauscher, GH; Fejerman, L
Latina women in the U.S. have relatively low breast cancer incidence compared to Non-Latina White (NLW) or African American women but are more likely to be diagnosed with the more aggressive "triple negative" breast cancer (TNBC). Latinos in the U.S. are a heterogeneous group originating from different countries with different cultural and ancestral backgrounds. Little is known about the distribution of tumor subtypes in Latin American regions. Clinical records of 303 female Peruvian patients, from the Peruvian National Cancer Institute, were analyzed. Participants were diagnosed with invasive breast cancer between 2010 and 2015 and were identified as residing in either the Selva or Sierra region. We used Fisher's exact test for proportions and multivariable Cox Proportional Hazards Models to compare overall survival between regions. Women from the Selva region were more likely to be diagnosed with TNBC than women from the Sierra region (31% vs. 14%, p = 0.01). In the unadjusted Cox model, the hazard of mortality was 1.7 times higher in women from the Selva than the Sierra (p = 0.025); this survival difference appeared to be largely explained by differences in the prevalence of TNBC. Our results suggest that the distribution of breast cancer subtypes differs between highly Indigenous American women from two regions of Peru. Disentangling the factors that contribute to this difference will add valuable information to better target prevention and treatment efforts in Peru and improve our understanding of TNBC among all women. This study demonstrates the need for larger datasets of Latin American patients to address differences between Latino subpopulations and optimize targeted prevention and treatment.
MGMT promoter methylation in Peruvian patients with glioblastoma
(Cancer Intellilgence, 2018) Belmar-Lopez, C; Castaneda, CA; Castillo, M; García-Corrochano, P; Orrego, E; Meléndez, B; Casavilca, S; Flores, C; Orrego, E
Purpose: O6-methylguanine-DNA methyltransferase (MGMT) promoter methylation predicts the outcome and response to alkylating chemotherapy in glioblastoma. The aim of this study is to evaluate the prevalence of MGMT methylation in Peruvian glioblastoma cases. Patients and methods: We evaluated retrospectively 50 cases of resected glioblastoma during the period 2008-2013 at Instituto Nacional de Enfermedades Neoplasicas in Peru. Samples consisted of paraffin embedded and frozen tumour tissue. MGMT-promoter methylation status and the expression level of MGMT gene were evaluated by methylation-specific PCR and real-time PCR, respectively. Results: Unmethylated, methylated and partially methylated statuses were found in 54%, 20% and 26% of paraffin-embedded samples, respectively. Methylation status was confirmed in the Virgen de la Salud Hospital and frozen samples. There was an association between the status of MGMT-promoter methylation and the level of gene expression (p = 0.001). Methylation was associated with increased progression-free survival (p = 0.002) and overall survival (OS) (p < 0.001). Conclusion: MGMT-promoter methylation frequency in Peruvian glioblastoma is similar to that reported in other populations and the detection test has been standardised.
Primary central nervous system sarcoma with DICER1 mutation-treatment results of a novel molecular entity in pediatric Peruvian patients
(John Wiley and Sons Inc., 2021) Diaz Coronado, RY; Mynarek, M; Koelsche, C; Mora Alferez, P; Casavilca, 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 Medina, 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.
Relationship between tumor-associated immune infiltrate and p16 staining over clinicopathological features in acral lentiginous melanoma
(Springer-Verlag Italia Srl, 2013) Castaneda, Carlos; Castillo, Miluska; Torres-Cabala, C; Bernabe, LA; Casavilca, S; Villegas, V; Sanchez, J; de la Cruz, M; Dunstan, J; Cotrina, JM; Gomez, HL; Chavez, C; Landa-Baella, MP; Tello, K; Felix, BF; Abugattas, J
Purpose: This study aims to evaluate the association between composition of tumor-infiltrating lymphocytes (TIL) and expression of p16 in acral lentiginous melanoma (ALM), and their impact on prognosis.