Implementing an Antimicrobial Stewardship Program in an Oncology Center in Lima, Peru: A Model for Low- and Middle-Income Countries.

Our center launched the first antimicrobial stewardship program in Peru. From 2016 to 2023, the proportion of antimicrobial prescriptions audited increased from 60% to 95%, and 65% to 95% of recommendations were accepted. Vancomycin and meropenem use dropped by 95% and 84%, respectively. The proportion of recommendations for surgical prophylaxis exceeded 90%.

Socioeconomic disparities and the genomic landscape of gastric cancer.

The genomic characteristics of Peruvian patients with gastric adenocarcinoma from diverse socioeconomic backgrounds were examined in consideration of the possibility that patients from different socioeconomic backgrounds may be exposed to different risk factors. We conducted a prospective pilot study in two Peruvian cities (Lima and Ica). This study enrolled 15 patients from low socioeconomic status (LSES) and 15 patients from medium/high socioeconomic status (MHSES). The genomic profiling of gastric adenocarcinoma samples was done through the FoundationOne CDx platform. We compared the genomic characteristics and the need for targeted therapy and immunotherapy between LSES and MHSES. The genes with higher rates of alterations were TP53 (73.3% vs. 50.0%, P = 0.2635); CDH1 (26.7% vs. 28.6%, P = 1); CDKN2A (20.0% vs. 28.6%, P = 1); KRAS (33.3% vs. 7.1%, P = 0.1686); ARID1A (20.0% vs. 14.3%, P = 1); MLL2 (13.3% vs. 21.4%, P = 1) and SOX9 (33.3% vs. 0.0%, P = 0.0421) in LSES versus HMSES, respectively. There was no significant difference in tumor mutational burden (P = 0.377) or microsatellite status (P = 1). The LSES group had a higher need for targeted therapy or immunotherapy according to gene involvement and alterations. A significant genomic difference exists among patients with gastric adenocarcinoma of different socioeconomic status, which may result in a different need for targeted therapy and immunotherapy.

Association between Helicobacter pylori infection, mismatch repair, HER2 and tumor-infiltrating lymphocytes in gastric cancer.

BACKGROUND: The influence of Helicobacter-pylori (H. pylori) infection and the characteristics of gastric cancer (GC) on tumor-infiltrating lymphocyte (TIL) levels has not been extensively studied. Analysis of infiltrating-immune-cell subtypes as well as survival is necessary to obtain comprehensive information. AIM: To determine the rates of deficient mismatch-repair (dMMR), HER2-status and H. pylori infection and their association with TIL levels in GC. METHODS: Samples from 503 resected GC tumors were included and TIL levels were evaluated following the international-TILs-working-group recommendations with assessment of the intratumoral (IT), stromal (ST) and invasive-border (IB) compartments. The density of CD3, CD8 and CD163 immune cells, and dMMR and HER2-status were determined by immunohistochemistry (IHC). H. pylori infection was evaluated by routine histology and quantitative PCR (qPCR) in a subset of samples. RESULTS: dMMR was found in 34.4%, HER2+ in 5% and H. pylori-positive in 55.7% of samples. High IT-TIL was associated with grade-3 (P = 0.038), while ST-TIL with grade-1 (P < 0.001), intestinal-histology (P < 0.001) and no-recurrence (P = 0.003). dMMR was associated with high TIL levels in the ST (P = 0.019) and IB (P = 0.01) compartments, and ST-CD3 (P = 0.049) and ST-CD8 (P = 0.05) densities. HER2- was associated with high IT-CD8 (P = 0.009). H. pylori-negative was associated with high IT-TIL levels (P = 0.009) when assessed by routine-histology, and with high TIL levels in the 3 compartments (P = 0.002-0.047) and CD8 density in the IT and ST compartments (P = 0.001) when assessed by qPCR. A longer overall survival was associated with low IT-CD163 (P = 0.003) and CD8/CD3 (P = 0.001 in IT and P = 0.002 in ST) and high IT-CD3 (P = 0.021), ST-CD3 (P = 0.003) and CD3/CD163 (P = 0.002). CONCLUSION: TIL levels were related to dMMR and H. pylori-negativity. Low CD8/CD3 and high CD163/CD3 were associated with lower recurrence and longer survival.

Human Presenilin-1 delivered by AAV9 rescues impaired γ-secretase activity, memory deficits, and neurodegeneration in Psen mutant mice.

Mutations in the Presenilin (PSEN1 and PSEN2) genes are the major cause of early-onset familial Alzheimer's disease (FAD). Presenilin (PS) is the catalytic subunit of the γ-secretase complex, which cleaves type I transmembrane proteins, such as Notch and the amyloid precursor protein (APP), and plays an evolutionarily conserved role in the protection of neuronal survival during aging. FAD PSEN1 mutations exhibit impaired γ-secretase activity in cell culture, in vitro, and knockin (KI) mouse brains, and the L435F mutation is the most severe in reducing γ-secretase activity and is located closest to the active site of γ-secretase. Here, we report that introduction of the codon-optimized wild-type human PSEN1 cDNA by adeno-associated virus 9 (AAV9) results in broadly distributed, sustained, low to moderate levels of human PS1 (hPS1) expression and rescues impaired γ-secretase activity in the cerebral cortex of Psen mutant mice either lacking PS or expressing the Psen1 L435F KI allele, as evaluated by endogenous γ-secretase substrates of APP and recombinant γ-secretase products of Notch intracellular domain and Aß peptides. Furthermore, introduction of hPS1 by AAV9 alleviates impairments of synaptic plasticity and learning and memory in Psen mutant mice. Importantly, AAV9 delivery of hPS1 ameliorates neurodegeneration in the cerebral cortex of aged Psen mutant mice, as shown by the reversal of age-dependent loss of cortical neurons and elevated microgliosis and astrogliosis. These results together show that moderate hPS1 expression by AAV9 is sufficient to rescue impaired γ-secretase activity, synaptic and memory deficits, and neurodegeneration caused by Psen mutations in mouse models.

Ibero-American Consensus Review and Incorporation of New Biomarkers for Clinical Practice in Colorectal Cancer.

Advances in genomic technologies have significantly improved the management of colorectal cancer (CRC). Several biomarkers have been identified in CRC that enable personalization in the use of biologic agents that have shown to enhance the clinical outcomes of patients. However, technologies used for their determination generate massive amounts of information that can be difficult for the clinician to interpret and use adequately. Through several discussion meetings, a group of oncology experts from Spain and several Latin American countries reviewed the latest literature to provide practical recommendations on the determination of biomarkers in CRC based on their clinical experience. The article also describes the importance of looking for additional prognostic biomarkers and the use of histopathology to establish an adequate molecular classification. Present and future of immunotherapy biomarkers in CRC patients are also discussed, together with several techniques for marker determination, including liquid biopsy, next-generation sequencing (NGS), polymerase chain reaction (PCR), and fecal immunohistochemical tests. Finally, the role of Molecular Tumor Boards in the diagnosis and treatment of CRC is described. All of this information will allow us to highlight the importance of biomarker determination in CRC.

Adjuvant chemotherapy after curative D2 gastrectomy in Latin American patients with gastric cancer.

Background: Gastric cancer (GC) is the fourth most common cause of cancer deaths around the world and the first cause of cancer deaths in Peru; however, there are no prospective trials for adjuvant chemotherapy in GC after curative gastrectomy in this country. The objective of this study was to evaluate the effectiveness of adjuvant chemotherapy in stage II-III gastric cancer patients who underwent D2 gastrectomy. Methods: We included patients with stage II-III gastric cancer who underwent radical gastrectomy and D2 dissection between 2014 and 2016 at our institution. Patients received 3-week cycles of capecitabine (1,000 mg/m2 twice daily on days 1-14) plus oxaliplatin (130 mg/m2 on day 1) for 6 months. Survival curves were estimated with the Kaplan-Meier method, and the Cox proportional hazards model was used to identify prognostic factors for survival. Results: In total, 173 patients were included: 100 (57.8%) patients received adjuvant chemotherapy and surgery (AChS) and 73 (42.2%) surgery alone (SA). Three-year disease-free survival (DFS) was higher in the AChS groups (69%) than in the SA group (52.6%) (p = 0.034). Regarding overall survival (OS), 31 patients (31%) died in the AChS group compared with 34 (46.6%) in the SA group (p = 0.027). In the multivariate analysis, adjuvant chemotherapy was an independent prognostic factor for DFS (HR = 0.60; 95% CI = 0.37-0.97; p = 0.036) and OS (HR = 0.58; 95% CI = 0.36-0.95; p = 0.029). ACh showed consistent benefit in DFS and OS for patients with albumin >3.5 g/dL, lymphovascular and perineural invasion, pT4, pN2-3, pathologic stage (PS) IIIA and IIIB and lymph node ratio (LNR) > 13.1. Conclusion: These data suggest that adjuvant capecitabine and oxaliplatin reduce the recurrence and mortality in patients with stage II-III gastric cancer who underwent D2 gastrectomy. PS IIIA and IIIB and LNR > 13.1 benefited more from receiving adjuvant chemotherapy and poorly cohesive gastric carcinoma did not significantly reduce the rates of survival.

The relationship between tumour infiltrating lymphocytes, Epstein-Barr virus and Helicobacter pylori infection in gastric cancer.

Objective: Epstein-Barr virus (EBV) and Helicobacter pylori (HP) infections have been extensively recognised as gastric cancer (GC) triggers, and recent publications suggest they could behave as predictive markers for immune-modulating therapies. Tumour-infiltrating lymphocytes (TILs) have also been identified as a predictive biomarker for immunotherapy in different malignancies. This study aimed to investigate the association between EBV and HP infection with TIL levels in GC. Methods: TIL evaluation in haematoxylin-eosin was performed by a pathologist and density of CD3, CD8 and CD163 positive (immunohistochemistry staining) immune cells was calculated with the use of digital pathology software. EBV infection was detected by in situ hybridisation (ISH) and by quantitative polymerase chain reaction (qPCR). Methylation status of EBV-related genes was detected by PCR and a methylome analysis was performed by the Illumina Infinium MethylationEPIC BeadChip. HP status was detected by qPCR. Results: We included 98 resected GC Peruvian cases in our evaluation. Median TIL percentage was 30. The proportion of EBV+ detected by ISH was 24.1%, of EBV+ detected by qPCR was 41.8%, while 70% showed methylation of EBV-related genes, and 58.21% of cases were HP+. Younger age (p = 0.024), early stages (p = 0.001), HP+ (p = 0.036) and low CD8 density (p = 0.046) were associated with longer overall survival (OS). High TIL level was associated with intestinal subtype (p < 0.001), with grade 2 (p < 0.001), with EBV qPCR+ (p = 0.001), and with methylation of EBV-related genes (p = 0.007). Cases with high TIL level and cases that are EBV positive share eight genes with similarly methylated status in the metabolomic analysis. High CD8 density was associated with EBV PCR+ (p = 0.012) and HP- (0.005). Conclusion: Lower CD8 density and HP+ predict longer OS. High TIL level is associated with EBV+ and methylation of EBV-related genes, while lower CD8 density is associated with HP+ GC.

Survival after curative pancreaticoduodenectomy for ampullary adenocarcinoma in a South American population: A retrospective cohort study.

BACKGROUND: Ampullary adenocarcinoma (AAC) is a rare neoplasm that accounts for only 0.2% of all gastrointestinal cancers. Its incidence rate is lower than 6 cases per million people. Different prognostic factors have been described for AAC and are associated with a wide range of survival rates. However, these studies have been exclusively conducted in patients originating from Asian, European, and North American countries. AIM: To evaluate the histopathologic predictors of overall survival (OS) in South American patients with AAC treated with curative pancreaticoduodenectomy (PD). METHODS: We analyzed retrospective data from 83 AAC patients who underwent curative (R0) PD at the National Cancer Institute of Peru between January 2010 and October 2020 to identify histopathologic predictors of OS. RESULTS: Sixty-nine percent of patients had developed intestinal-type AAC (69%), 23% had pancreatobiliary-type AAC, and 8% had other subtypes. Forty-one percent of patients were classified as Stage I, according to the AJCC 8th Edition. Recurrence occurred primarily in the liver (n = 8), peritoneum (n = 4), and lung (n = 4). Statistical analyses indicated that T3 tumour stage [hazard ratio (HR) of 6.4, 95% confidence interval (CI) of 2.5-16.3, P < 0.001], lymph node metastasis (HR: 4.5, 95%CI: 1.8-11.3, P = 0.001), and pancreatobiliary type (HR: 2.7, 95%CI: 1.2-6.2, P = 0.025) were independent predictors of OS. CONCLUSION: Extended tumour stage (T3), pancreatobiliary type, and positive lymph node metastasis represent independent predictors of a lower OS rate in South American AAC patients who underwent curative PD.

Personalizing first-line treatment in advanced colorectal cancer: Present status and future perspectives.

BACKGROUND: Colorectal cancer is one of the most frequent neoplasms worldwide, and the majority of patients are diagnosed in advanced stages. Metastatic colorectal cancer (mCRC) harbors several mutations with different prognostic and predictive values; KRAS, NRAS, and BRAF mutations are the best known. Indeed, RAS and BRAF molecular status are associated with a different response to monoclonal antibodies (Anti-epidermal growth factor receptor and anti-vascular endothelial growth factor receptor agents), which are usually added to chemotherapy in first-line, and thus allow to select the optimal therapy for patients with mCRC. Furthermore, sidedness is an important predictive and prognostic factor in mCRC, which is explained by the different molecular profile of left and right-sided tumors. Recently, microsatellite instability-high has emerged as a predictive factor of response and survival from immune checkpoint inhibitors in mCRC. Finally, several other alterations have been described in lower frequencies, such as human epidermal growth factor receptor-2 overexpression/amplification, PIK3CA pathway alterations, phosphatase and tension homolog loss, and hepatocyte growth factor/mesenchymal-epithelial transition factor pathway dysregulation, with several targeted therapies already demonstrating activity or being tested in currently ongoing clinical trials. AIM: To review the importance of studying the predictive and prognostic roles of the molecular profile of mCRC, the changes occurred in recent years and how they would potentially change in the near future, to guide physicians in treatment decisions. RELEVANCE FOR PATIENTS: Today, several different therapeutic options can be offered to patients in the first-line setting of mCRC. Therapies at present approved or under investigation in clinical trials will be thoroughly reviewed, with special emphasis on the molecular rationale behind them. Understanding the molecular status, resistance mechanisms and potential new druggable targets may allow physicians to choose the best therapeutic option in the first-line mCRC.

Telemedicine and the current opportunities for the management of oncological patients in Peru in the context of COVID-19 pandemic.

COVID-19 pandemic is the more challenging public health emergency of the century, producing the collapse of health systems and unprecedented levels of morbidity and mortality around the world, especially in low resource settings. Patients with chronic diseases are the most affected, not only due to the high susceptibility to SARS-CoV-2 infection but also due to the decrease in opportunities for timely care. In this dark landscape, telemedicine, before limited to very specific scenarios, has become one of our main tools to manage cancer patients, particularly in Latin America where COVID-19 has had a strong impact on the public health. Telemedicine can provide rapid access to specialized cancer care in a scenario complicated, reducing the exposure of patients and healthcare personnel to the SARS-CoV-2. In this review, we would like to share our experience and our workflow using telemedicine at Oncosalud-AUNA, a private clinic in Peru.

Detection of Helicobacter pylori in gastric cancer tissue through histopathology, immunohistochemistry and real-time reverse transcription-PCR.

Aim:Helicobacter pylori is usually detected based on hematoxylin-eosin (H-E) features, but, immunohistochemistry (IHC) and real-time PCR (RT-PCR) are more precise in chronic-gastritis. We evaluated the relevance of these tests in Peruvian gastric cancer samples. Materials & methods: We performed and evaluated H-E, IHC staining and RT-PCR in 288 gastric tumors. Slides were independently evaluated by three pathologists. Results:H. pylori was detected in 167/287 through H-E, 140/288 through IHC and 175/288 through RT-PCR, and positive-status were associated (p < 0.001). H. pylori detection by H-E had a good concordance with IHC (kappa index = 0.632) but poor with RT-PCR (kappa index = 0.317). Higher median gene-copies were found in high H. pylori density through H-E or IHC (p < 0.001). Conclusion: H-E evaluation is accurate in gastric cancer, and IHC and RT-PCR can complement its results.

Helicobacter Pylori Detected in Tap Water of Peruvian Patients with Gastric Cancer.

OBJECTIVE: To evaluate the correlation between the presence of H. pylori in paired samples of tap water and gastric cancer (GC) lesion in Lima city (Peru). MATERIAL AND METHODS: Gastric tissue and tap-water samples were prospectively collected from 82 Gastric Cancer who lived in Lima. HspA and ureA genes were evaluated by qPCR in the samples.  Results: The median age of patients with GC was 63 years, 52.4% were men and stage-II in 36.6%. A home-living time> 10 years was reported in 84.1% of patients. Boiling water treatment was indicated in 85.4% of cases. H. pylori was detected in 69.5% of gastric tissues and in 12.2% of analyzed tap-water. There was no differences in gastric infection rates among those with or without water contamination (70% vs. 69.4%, p=0.971). Conclusion & Impact: H. pylori was found in tap-water samples, however, detection rates were lower than in gastric cancer samples. Other sources of infection transmission should be investigated.

Level of tumor-infiltrating lymphocytes and density of infiltrating immune cells in different malignancies.

Aim: To correlate levels of tumor-infiltrating lymphocytes (TIL) evaluated using the International Immuno-Oncology Biomarker Working Group methodology, and both density of tumor-infiltrating immune cell and clinicopathological features in different malignancies. Methods: 209 pathological samples from gastric cancer, cervical cancer (CC), non-small-lung cancer, cutaneous melanoma (CM) and glioblastoma were tested for TIL in hematoxylin eosin, and density of CD3+, CD4+, CD8+, CD20+, CD68+ and CD163+ cells by digital analysis. Results: TIL levels were higher in invasive margin compartments (IMC). TIL in IMC, intratumoral and stromal compartments predicted survival. CC and gastric cancer had higher TIL in intratumoral; CC and CM had higher TIL in stromal compartment and IMC. CM had the highest density of lymphocyte and macrophage populations. CD20 density was associated with survival in the whole series. Conclusion: Standardized evaluation of TIL levels may provide valuable prognostic information in a spectrum of different malignancies.

Prevalence of Helicobacter pylori Infection, Its Virulent Genotypes, and Epstein-Barr Virus in Peruvian Patients With Chronic Gastritis and Gastric Cancer.

PURPOSE: Helicobacter pylori (HP) and Epstein Barr virus (EBV) infections induce chronic gastritis (CG) and are accepted carcinogenics of gastric cancer (GC). Our objective for this study was to determine the prevalence of these agents and clinicopathological features of GC and CG associated with the infection. PATIENTS AND METHODS: A single-center cohort of 375 Peruvian patients with GC and 165 control subjects with CG were analyzed. Evaluation of HP and EBV genes was performed through quantitative polymerase chain reaction. RESULTS: Prevalence of HP was 62.9% in the whole population and 60.8% in the GC subset. The cagA gene was detected in 79.9%; vacAs1 and vacAm1 alleles in 41.6% and 60.7%, respectively; and concurrent expression of vacAs1 and vacAm1 in 30.4% of infected patients in the whole series. The prevalence of EBV was 14.1% in the whole population and was higher in GC (P < .001). Coinfection of HP and EBV was found in 7.8% and was also higher in GC in univariate (P < .001) and multivariate (P = .011) analyses. Infection rates of HP and EBV were not associated with a geographic location in the whole series. Few clinicopathological features have been associated with infectious status. CONCLUSION: Prevalence of HP infection and virulent strains are high in the Peruvian population. Infection by EBV was more frequent in patients with GC.

Alpha-Synuclein Is a Target of Fic-Mediated Adenylylation/AMPylation: Possible Implications for Parkinson's Disease.

During disease, cells experience various stresses that manifest as an accumulation of misfolded proteins and eventually lead to cell death. To combat this stress, cells activate a pathway called unfolded protein response that functions to maintain endoplasmic reticulum (ER) homeostasis and determines cell fate. We recently reported a hitherto unknown mechanism of regulating ER stress via a novel post-translational modification called Fic-mediatedadenylylation/AMPylation. Specifically, we showed that the human Fic (filamentation induced by cAMP) protein, HYPE/FicD, catalyzes the addition of an adenosine monophosphate (AMP) to the ER chaperone, BiP, to alter the cell's unfolded protein response-mediated response to misfolded proteins. Here, we report that we have now identified a second target for HYPE-alpha-synuclein (αSyn), a presynaptic protein involved in Parkinson's disease. Aggregated αSyn has been shown to induce ER stress and elicit neurotoxicity in Parkinson's disease models. We show that HYPE adenylylates αSyn and reduces phenotypes associated with αSyn aggregation invitro, suggesting a possible mechanism by which cells cope with αSyn toxicity.

Personalizing Precision Oncology Clinical Trials in Latin America: An Expert Panel on Challenges and Opportunities.

The participation of patients in precision oncology trials needs to fulfill molecular-based selection criteria. This strongly limits accrual, and as a consequence, screening successes have decreased, costs have increased, and fewer subjects are enrolled. To achieve narrowed targets, studies have been forced to be multicenter and multinational to reach a larger pool of candidates. However, this globalization faces many challenges, as, for example, in the case of precision oncology trials. These trials have a complex structure that is dependent upon a high-tech infrastructure and knowledge in a dynamic environment. Given the movement of precision clinical cancer research to regions other than Europe and the U.S., it is important to evaluate the feasibility of performing such trials in lower-middle- and low-income countries. Here we critically discuss the advantages of conducting precision oncology clinical trials in Latin America and make suggestions on how to overcome the main challenges involved. IMPLICATIONS FOR PRACTICE: Precision clinical trials in oncology are studies that require candidates to have tumors with specific molecular alterations, which are considered the target for the trial experimental therapy. Because many molecular alterations are rare, fewer patients are enrolled. This has led to trials being forced to be multicenter and multinational, including trials in Latin America. This article discusses the challenges and opportunities to conduct precision oncology trials in Latin America, aiming to help sponsors and investigators to solve complex issues that ultimately lead to more of such trials being run in the region, potentially benefiting more Latin American patients with cancer.

Tumor Protein p53 and K-ras Gene Mutations in Peruvian Patients with Gallbladder Cancer

Background: Recent studies have shown that genetic alterations are associated with the effect of patient geographic location on gallbladder cancer development. Peru has a high incidence of gallbladder cancer, but causative factors have not yet been identified. We examined the frequency of mutations in TP53 and K-ras genes in Peruvian patients with gallbladder cancer, and compared this with data from Bolivia, Hungary, Chile, and Japan, which have a high gallbladder cancer incidence. Methods: DNA was extracted from formalin-fixed paraffin-embedded gallbladder tissue sections of 30 gallbladder cancer patients (9 men and 21 women) obtained using microdissection. Mutations in exons 5 to 8 of TP53 and codons 12, 13, and 61 of K-ras were examined using direct sequencing. Results: TP53 mutations were observed in 10 (33.3%) of patients, but K-ras mutations were absent. Nine (90%) TP53 mutations were point mutations (7 missense and 2 silent mutations), and the most frequent substitution was a G:C to A:T transition. G:C to A:T transitions at the CpG site or G:C to T:A transversions were found in one patient each. No significant differences were found in the frequency of TP53 and K-ras mutations among patients in the 5 countries. Conclusions: Our findings suggest that endogenous mechanisms and exogenous carcinogens may affect the carcinogenic process in Peruvian gallbladder cancer patients, similar to that in Bolivian patients. Further studies with a larger sample size are needed to clarify these findings.

Oncological outcomes in extended time intervals betweenpreoperative chemoradiotherapy with capecitabine and surgery inoperable rectal adenocarcinoma.

OBJECTIVE: To assess whether extended time intervals (8-12, 13-20 and >20 weeks) between the end of neoadjuvant chemoradiotherapy and surgery affect overall survival, disease-free survival. MATERIALS AND METHODS: Retrospective study in 120 patients with rectal adenocarcinoma without evidence of metastasis (T1-4/N0-2/M0) at the time of diagnosis that underwent surgery with curative intent after neoadjuvant chemoradiotherapy with capecitabine and obtained R0 or R1 resection between January 2010 to December 2014 at the National Cancer Institute of Peru. Dates were evaluated by Kaplan-Meier method, log- rank test and Cox regression analysis. RESULTS: Of the 120 patients, 70 were women (58%). The median age was 63(26-85) years. All received neoadjuvant chemoradiotherapy. No significant difference was found between the association of the median radial (0.6, 0.7 and 0.8 cm; p=0.826) and distal edge (3.0, 3.5 and 4.0 cm; p=0.606) with time interval groups and similarly the mean resected (18.8, 19.1 and 16.0; p=0.239) and infiltrated nodules (1.05, 1.29 and 0.41); p=0.585). The median follow-up time of overall survival and desease free survival was 40 and 37 months, respectively. No significant differences were observed in overall survival (79.0%, 74.6% and 71.1%; p=0.66) and disease-free survival (73.7%, 68.1% and 73.6%; p=0.922) according to the three groups studied at the 3-year of follow-up. CONCLUSIONS: We found that widening the time intervals between the end of neoadjuvant chemoradiotherapy and surgery at 24 weeks does not affect the overall survival, disease-free survival and pathological outcomes. It allows to extend the intervals of time for future studies that finally will define the best time interval for the surgery.

Oncological outcomes in extended time intervals between preoperative chemoradiotherapy with capecitabine and surgery in operable rectal adenocarcinoma / Resultados oncológicos en intervalos extendidos de tiempo entre quimioradioterapia preoperatoria con capecitabina y cirugía en adenocarcinoma rectal operable

Objective: To assess whether extended time intervals (8-12, 13-20 and >20 weeks) between the end of neoadjuvant chemoradiotherapy and surgery affect overall survival, disease-free survival. Materials and methods: Retrospective study in 120 patients with rectal adenocarcinoma without evidence of metastasis (T1-4/N0-2/M0) at the time of diagnosis that underwent surgery with curative intent after neoadjuvant chemoradiotherapy with capecitabine and obtained R0 or R1 resection between January 2010 to December 2014 at the National Cancer Institute of Peru. Dates were evaluated by Kaplan-Meier method, log- rank test and Cox regression analysis. Results: Of the 120 patients, 70 were women (58%). The median age was 63(26-85) years. All received neoadjuvant chemoradiotherapy. No significant difference was found between the association of the median radial (0.6, 0.7 and 0.8 cm; p=0.826) and distal edge (3.0, 3.5 and 4.0 cm; p=0.606) with time interval groups and similarly the mean resected (18.8, 19.1 and 16.0; p=0.239) and infiltrated nodules (1.05, 1.29 and 0.41); p=0.585). The median follow-up time of overall survival and desease free survival was 40 and 37 months, respectively. No significant differences were observed in overall survival (79.0%, 74.6% and 71.1%; p=0.66) and disease-free survival (73.7%, 68.1% and 73.6%; p=0.922) according to the three groups studied at the 3-year of follow-up. Conclusions: We found that widening the time intervals between the end of neoadjuvant chemoradiotherapy and surgery at 24 weeks does not affect the overall survival, disease-free survival and pathological outcomes. It allows to extend the intervals of time for future studies that finally will define the best time interval for the surgery

Objetivo: Evaluar si los intervalos de tiempo extendidos (8-12, 13-20 y >20 semanas) entre el fin de la quimioradioterapia neoadyuvante y la cirugía afectan la sobrevida global, y la sobrevida libre de enfermedad. Material y métodos: Estudio retrospectivo de 120 pacientes con adenocarcinoma rectal sin evidencia de metástasis (T1-4/N0-2/M0) al momento del diagnóstico que se sometieron a cirugía con intención curativa luego de quimioradioterapia neoadyuvante con capecitabina y tuvieron resección R0 o R1 entre enero 2010 y diciembre 2014 en el Instituto Nacioanal de Enfermedades Neoplásicas de Perú. El análisis se hizo con el método de Kaplan-Meier, la prueba log-rank y la regresión de Cox. Resultados: De 120 pacientes, 70 fueron mujeres (58%). La mediana de la edad fue 63 años (26-85 años). Todos recibieron quimioradioterapia neoadyuvante. No hubo diferencia significativa entre la asociación de las medianas de los bordes radial (0,6, 0.7 y 0,8 cm; p=0,826) y distal (3,0, 3,5 y 4,0 cm; p=0,606) con los intervalos de tiempo de los grupos y similarmente con la media de los ganglios resecados (18,8, 19,1 y 16,0; p=0,239) e infiltrados (1,05, 1,29 y 0,41; p=0,585). No se observaron diferencias significativas en sobrevida global (79,0%, 74,6% y 71,1%; p=0,66) y sobrevida libre de enfermedad (73,7%, 68,1% y 73,6%; p=0,922), en los tres grupos estudiados a 3 años de seguimiento. Conclusiones: Encontramos que aumentar los intervalos de tiempo entre el fin de la quimioradioterapia neoadyuvante y la cirugía hasta 24 semanas no afecta la sobrevida global, sobrevida libre de enfermedad ni los desenlaces patológicos. Esto permitiría extender los intervalos de tiempo en estudios futuros para definir el mejor intervalo de tiempo para la cirugía

Selective dopaminergic neurotoxicity of three heterocyclic amine subclasses in primary rat midbrain neurons.

Heterocyclic amines (HCAs) are primarily produced during high temperature meat cooking. These compounds have been intensively investigated as mutagens and carcinogens. However, converging data suggest that HCAs may also be neurotoxic and potentially relevant to neurodegenerative diseases such as Parkinson's disease (PD). The identification of new potential etiological factors is important because most PD cases are sporadic. Our group previously showed that 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) was selectively neurotoxic to dopaminergic neurons. However, PhIP is one of many HCAs, a class of compounds that exhibits wide structural variability. The goal of this study was to determine the neurotoxicity of the most prevalent and best studied HCAs from three subclasses: aminoimidazoaazarenes (AIA), α-carbolines, and ß-carbolines. Using E17 rat primary midbrain cultures, we tested dopaminergic and non-dopaminergic neurotoxicity elicited by the following compounds: 2-amino-3-methylimidazo[4,5-f]quinoline (IQ), 2-amino-3,4-dimethylimidazo[4,5-f]quinoline (MeIQ), 2-amino-3,8-dimethylmidazo[4,5-f]quinoxaline (MeIQx), 2-amino-3,4,8-trimethylimidazo[4,5-f]quinoxaline (4,8-DiMeIQx), PhIP, 1-methyl-9H-pyrido[3,4-b]indole (harmane), 9H-pyrido[3,4-b]indole (norharmane) and 2-amino-9H-pyrido[2,3-b]indole (AαC) at concentrations ranging from 100 nM-5 µM. All tested HCAs were selectively neurotoxic, though the dose required to elicit selective loss of dopaminergic neurons or decreases in dopaminergic neurite length was compound specific. Non-dopaminergic neurons were unaffected at all tested doses. The sensitivity (determined by threshold dose required to elicit selective neurotoxicity) appears to be unrelated to published mutagenic potency. Both AIA and α/ß-carbolines produced oxidative damage, which was magnified in dopaminergic neurons vs. non-dopaminergic neurons as further evidence of selective neurotoxicity. These studies are expected to prompt clinical and mechanistic studies on the potential role of HCA exposure in PD.