Browsing by Author "Rebaza, P"

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Barriers in Latin America for the management of locally advanced breast cancer
(Cancer Intellilgence, 2019) Pinto, JA; Pinillos, L; Villarreal-Garza, C; Morante, Z; Villarán, MV; Mejía, G; Caglevic, C; Aguilar, A; Fajardo, W; Usuga, F; Carrasco, M; Rebaza, P; Posada, AM; Tirado-Hurtado, I; Flores, C; Vallejos-Sologuren, CS
Breast cancer (BC) is a highly prevalent malignancy in Latin American women, most cases being diagnosed at locally advanced or metastatic stages when options for cancer care are limited. Despite its label as a public health problem in the region, Latin American BC patients face several barriers in accessing standard of care treatment when compared with patients from developed countries. In this review, we analyse the landscape of the four main identified barriers in the region: i) high burden of locally advanced/advanced BC; ii) inadequate access to medical resources; iii) deficient access to specialised cancer care and iv) insufficient BC research in Latin America. Unfortunately, these barriers represent the main factors associated with the BC poor outcomes seen in the region. Targeted actions should be conducted independently by each country and as a region to overcome these limitations and create an enhanced model of BC care.
Critical review of axillary recurrence in early breast cancer
(Elsevier Ireland Ltd, 2018) Castaneda, Carlos; Rebaza, P; Castillo, Miluska; Gomez, HL; De La Cruz, M; Calderon, G; Dunstan, J; Cotrina, JM; Abugattas, J; Vidaurre, T
Around 2% of early breast cancer cases treated with axillary lymph node dissection (ALND) underwent axillary recurrence (AR) and it has a deleterious effect in prognosis. Different scenarios have incorporated Sentinel Lymph Node (SLN) Biopsy (SLNB) instead of ALND as part of the standard treatment and more effective systemic treatment has also been incorporated in routine management after first curative surgery and after regional recurrence. However, there is concern about the effect of SLNB alone over AR risk and how to predict and treat AR. SLN biopsy (SLNB) has been largely accepted as a valid option for SLN-negative cases, and recent prospective studies have demonstrated that it is also safe for some SLN-positive cases and both scenarios carry low AR rates. Different studies have identified clinicopathological factors related to aggressiveness as well as high-risk molecular signatures can predict the development of locoregional recurrence. Other publications have evaluated factors affecting prognosis after AR and find that time between initial treatment and AR as well as tumor aggressive behavior influence patient survival. Retrospective and prospective studies indicate that treatment of AR should include local and systemic treatment for a limited time.
Neutrophil-to-lymphocyte ratio predicts early mortality in females with metastatic triple-negative breast cancer
(Public Library of Science, 2020) de la Cruz-Ku, G; Chambergo-Michilot, D; Torres-Roman, JS; Rebaza, P; Pinto, J; Araujo, J; Morante, Z; Enriquez, D; Flores, C; Luque, R; Saavedra, A; Lujan, M; Gomez, H; Valcarcel, B
Background: The aim of this study was to determine the utility of the neutrophil-to-lymphocyte ratio (NLR) as a biomarker for predicting early-mortality (<2 years) among females with metastatic triple-negative breast cancer (mTNBC). Methods: We reviewed 118 medical records of females with mTNBC. The cut-off value for the NLR (<2.5 and ≥2.5) was determined with receiver operating characteristic curves (area under the curve: 0.73; 95% CI: 0.62-0.85). Survival curves were estimated using the Kaplan-Meier method and compared with the Log-rank test. Multivariate Cox regression was used to identify the risk of mortality at two years. Moreover, we performed sensitivity analyses with different cut-off values and a subgroup analysis in females that only received chemotherapy. Results: The median follow-up was 24 months. Females with NLR ≥2.5 had a poor overall survival compared to females with NLR <2.5 (6% vs. 28%, p<0.001) at two years. This outcome remained when we stratified for females that only received chemotherapy (8% vs. 36%, p = 0.001). Multivariate analyses identified NLR ≥2.5 as a poor prognostic risk factor for mortality in the entire population (HR: 2.12, 95% CI: 1.32-3.39) and among females that received chemotherapy (HR: 2.68, 95% CI: 1.46-4.92). Conclusion: The NLR is an accessible and reliable biomarker that predicts early mortality among females with mTNBC. Our results suggest that females with high NLR values have poor prognosis despite receiving standard chemotherapy. Health providers should evaluate the possibility to enroll these patients in novel immunotherapy trials.
PUM1 and RNase P genes as potential cell-free DNA markers in breast cancer
(Wiley-Liss Inc., 2021) Murillo Carrasco, A; Acosta, O; Ponce, J; Cotrina, J; Aguilar, A; Araujo, J; Rebaza, P; Pinto, JA; Fujita, R; Buleje, J
Background: Cell-free DNA (cfDNA) is used in clinical research to identify biomarkers for diagnosis of and follow-up on cancer. Here, we propose a fast and innovative approach using traditional housekeeping genes as cfDNA targets in a copy number analysis. We focus on the application of highly sensitive technology such as digital PCR (dPCR) to differentiate breast cancer (BC) patients and controls by quantifying regions of PUM1 and RPPH1 (RNase P) in plasma samples. Methods: We conducted a case-control study with 82 BC patients and 82 healthy women. cfDNA was isolated from plasma using magnetic beads and quantified by spectrophotometry to estimate total cfDNA. Then, both PUM1 and RPPH1 genes were specifically quantified by dPCR. Data analysis was calibrated using a reference genomic DNA in different concentrations.Results: We found RNase P and PUM1 values were correlated in the patient group (intraclass correlation coefficient [ICC] = 0.842), but they did not have any correlation in healthy women (ICC = 0.519). In dPCR quantification, PUM1 showed the capacity to distinguish early-stage patients and controls with good specificity (98.67%) and sensitivity (100%). Conversely, RNase P had lower cfDNA levels in triple-negative BC patients than luminal subtypes (p < 0.025 for both), confirming their utility for patient classification.Conclusion: We propose the PUM1 gene as a cfDNA marker for early diagnosis of BC and RNase P as a cfDNA marker related to hormonal status and subtype classification in BC. Further studies with larger sample sizes are warranted.