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.

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.

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.

Comprehensive analysis via exome sequencing uncovers genetic etiology in autosomal recessive nonsyndromic deafness in a large multiethnic cohort.

PURPOSE: Autosomal recessive nonsyndromic deafness (ARNSD) is characterized by a high degree of genetic heterogeneity, with reported mutations in 58 different genes. This study was designed to detect deafness-causing variants in a multiethnic cohort with ARNSD by using whole-exome sequencing (WES). METHODS: After excluding mutations in the most common gene, GJB2, we performed WES in 160 multiplex families with ARNSD from Turkey, Iran, Mexico, Ecuador, and Puerto Rico to screen for mutations in all known ARNSD genes. RESULTS: We detected ARNSD-causing variants in 90 (56%) families, 54% of which had not been previously reported. Identified mutations were located in 31 known ARNSD genes. The most common genes with mutations were MYO15A (13%), MYO7A (11%), SLC26A4 (10%), TMPRSS3 (9%), TMC1 (8%), ILDR1 (6%), and CDH23 (4%). Nine mutations were detected in multiple families with shared haplotypes, suggesting founder effects. CONCLUSION: We report on a large multiethnic cohort with ARNSD in which comprehensive analysis of all known ARNSD genes identifies causative DNA variants in 56% of the families. In the remaining families, WES allows us to search for causative variants in novel genes, thus improving our ability to explain the underlying etiology in more families.Genet Med 18 4, 364-371.

Cáncer colorrectal en los jóvenes: factores pronósticos y características clínico patológicas en un instituto del cáncer de Perú.

OBJECTIVE: To determine clinicopathological features and prognostic factors among young colorectal cancer (CRC) patients in a Peruvian Cancer Institute. METHODS: Data of patients 40 years or younger, admitted between January 2005 and December 2010, were analyzed. RESULTS: During the study period, 196 young patients with CRC were admitted. The tumor was located in the rectum, left colon and right colon in 45.9%, 28.6% and 25.5% of cases. Family history of CRC was found in 13.2% and an autosomal pattern of inheritance, in 8.6% of the cases. The most common symptoms were pain (67.9%) and bleeding (67.3%). The majority (63.1%) of colon cancer cases and more than a third (34.4%) of rectal cancer cases were diagnosed in stage III or IV. The histologic type was tubular, mucinous and signet ring cell adenocarcinoma in 73.5%, 14.8% and 8.6%, respectively. The depth of invasion was T3 in 21.4% and T4 in 53%. Nodal involvement was detected in 44.5%. Five-year overall survival (OS) was 44.3%. In the multivariate analysis, only the stage resulted an independent prognostic factor for survival. CONCLUSIONS: CRC in Peruvian young patients is mostly sporadic. It presents more often in the distal colon or rectum and at advanced stages of the disease. Mucinous and signet ring cell carcinoma were requent histological types. Five-year OS stage by stage is similar to that reported in the literature for older patients. Stage was the only independent prognostic factor for survival.

Novel domain-specific POU3F4 mutations are associated with X-linked deafness: examples from different populations.

BACKGROUND: Mutations in the POU3F4 gene cause X-linked deafness type 3 (DFN3), which is characterized by inner ear anomalies. METHODS: Three Turkish, one Ecuadorian, and one Nigerian families were included based on either inner ear anomalies detected in probands or X-linked family histories. Exome sequencing and/or Sanger sequencing were performed in order to identify the causative DNA variants in these families. RESULTS: Four novel, c.707A>C (p.(Glu236Ala)), c.772delG (p.(Glu258ArgfsX30)), c.902C>T (p.(Pro301Leu)), c.987T>C (p.(Ile308Thr)), and one previously reported mutation c.346delG (p.(Ala116ProfsX26)) in POU3F4, were identified. All mutations identified are predicted to affect the POU-specific or POU homeo domains of the protein and co-segregated with deafness in all families. CONCLUSIONS: Expanding the spectrum of POU3F4 mutations in different populations along with their associated phenotypes provides better understanding of their clinical importance and will be helpful in clinical evaluation and counseling of the affected individuals.

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.

[Adjuvant chemo radiotherapy after gastrectomy and D2 lymphadenectomy in patients with gastric cancer in the National Institute of Cancer, Lima, Peru]. / Tratamiento adyuvante con quimioterapia y radioterapia luego de gastrectomía y disección ganglionar D2 en pacientes con cáncer gástrico en el Instituto Nacional de Enfermedades Neoplásicas, Lima, Perú

INTRODUCTION: Adjuvant chemo radiotherapy is the standard treatment in Western countries in gastric cancer patients submitted to curative resection. INT0116 pivotal trial established adjuvant chemo radiation as the standard care for resected high risk adenocarcinoma of the stomach in US however was hampered by suboptimal surgery. There is controversial data about efficacy of this adjuvant therapy in patients who have undergone D2 lymphadenectomy predominantly. In our hospital D2 lymphadenectomy is standard surgery for gastric cancer. OBJECTIVE: To prove that chemo and radio therapy post gastrectomy and D2 linphadenectomy in patients' with gastric cancer is effective. MATERIAL AND METHODS: Retrospective study with gastric adenocarcinoma patients stage II to IV M0 who underwent curative resection at INEN (Instituto Nacional de Enfermedades Neoplasicas) Lima-Peru between 2001 and 2006. Standard treatment at institution is D2 lymphadenectomy. Chemo radiotherapy according to INT0116 was given like adjuvant therapy. Survivalcurves were calculated according to Kaplan-Meier method and compared with log-rank test. RESULTS: 84 patients were included 60.7% male and 39.3% female. Mean age was 49.5 years old. The pathologic stages were T1-T2 (15.5%), T3- T4 (84.5%), N0-N1 (10.7%), N2-N3 (89.3%). D2 lymphadenectomy was performed in all patients. The 3-year DFS was 17% and 3-year overall survival was 23.9%. However when we analyzed by subgroups the overall survival, was in group N1 (66.7%) and in group N2 (58.9%) and N3 (18.3%) and 3 years DFS by subgroups were N1 (100%), N2 (51.9%) and N3 (16.3%). CONCLUSIONS: Adjuvant chemo radiotherapy decreased risk of death and relapse to three years mainly in patients with node positive N1-N2, who underwent curative resection with D2 lymphadenectomy, but recurrence was most frequent in N3 node positive, maybe is necessary improve the chemotherapy in this group of patients for decrease the rate of relapse.

Implementing medical abortion through telemedicine in Colombia: a qualitative study.

The non-governmental organisation Profamilia developed and implemented medical abortion through telemedicine in response to the Covid-19 pandemic. This service is now integrated as an alternative to in-person care and available to abortion-seekers across Colombia. Previous research has emphasised bottlenecks in abortion provision, but less is known about implementation processes and experiences. We assessed the feasibility and acceptability of telemedicine for medical abortion from the perspectives of key informants involved in the implementation in Colombia. We conducted 15 in-depth interviews with healthcare professionals, coordinators and support staff implementing telemedicine for medical abortion in the early phase of implementation, between March and October 2021. We analysed the data using the framework method and applied the normalisation process theory in our analysis and interpretation of findings. Our findings show that strong leadership, organisational efforts on pre-implementation training, monitoring and evaluation, and collaboration between diversely skilled and experienced providers are essential for successful implementation. Participants were generally positive towards the use of telemedicine for medical abortion; concerns related to effectiveness, safety and safeguarding existed mainly among providers with less clinical experience. We identified contextual barriers, such as social opposition, regulatory barriers, providers' unavailability, and poor phone and internet connections in rural areas, which impacted the feasibility of the intervention negatively. In conclusion, to ensure stakeholders' buy-in and for the service to reach all abortion seekers in need, future implementation endeavours must address concerns about safety and effectiveness, and tackle identified contexual barriers.Plain Language SummaryIn telemedicine for medical abortion, all or some components of abortion care, such as initial consultations, home delivery of abortion medication, and post-abortion follow up are provided with the use of telecommunications. Telemedicine for medical abortion has been shown to be a safe and effective form of service delivery.In this study, we interviewed 15 healthcare providers and staff involved in the implementation of a telemedicine service for medical abortion in Colombia to determine whether they deemed the service to be acceptable and feasible. We found that collaboration between providers of different backgrounds and levels of experience, appropriate training and strong leadership were key factors for successfully implementing the service. However, some healthcare providers, especially those with less clinical experience, were concerned that telemedicine for medical abortion may not be safe and may risk the health and well-being of abortion-seekers. Further, social opposition to abortion, unclear regulation and limited access to technology were identified as barriers that need to be addressed to ensure the service reaches all abortion-seekers in need.In conclusion, despite contextual barriers and some provider's concerns about medical safety, telemedicine for medical abortion was viewed as a positive and feasible form of service delivery in Colombia.

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.

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.

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.

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.

The TGFBR1*6A allele is not associated with susceptibility to colorectal cancer in a Spanish population: a case-control study.

BACKGROUND: TGF-beta receptor type I is a mediator of growth inhibitory signals. TGFBR1*6A (rs11466445) is a common polymorphic variant of the TGF-beta receptor I gene and has been associated with tumour susceptibility. Nevertheless, the role of this polymorphism as a risk factor for colorectal cancer is controversial. The aim of this study was to assess the association between TGFBR1*6A and colorectal cancer, age, sex, tumour location and tumour stage in a Spanish population. METHODS: The case-control study involved 800 Spanish subjects: 400 sporadic colorectal cancer patients and 400 age-, sex-, and ethnic-matched controls. The odds ratio (OR) and 95% confidence interval (95% CI) for the TGFBR1*6A polymorphism were calculated using unconditional logistic regression adjusted for age and sex. Analysis of somatic mutations at the GCG repeat of TGFBR1 exon 1 and germline allele-specific expression were also conducted to obtain further information on the contribution of the TGFBR1*6A allele to CRC susceptibility. RESULTS: There was no statistically significant association between the TGFBR1*6A allele and CRC (p > 0.05). The OR was 1.147 (95% CI: 0.799-1.647) for carriers of the TGFBR1*6A allele and 0.878 (95% CI: 0.306-2.520) for homozygous TGFBR1*6A individuals compared with the reference. The frequency of the polymorphism was not affected by age, sex or tumour stage. The TGFBR1*6A allele was more prevalent among colon tumour patients than among rectal tumour patients. Tumour somatic mutations were found in only two of 69 cases (2.9%). Both cases involved a GCG deletion that changed genotype 9A/9A in normal DNA to genotype 9A/8A. Interestingly, these two tumours were positive for microsatellite instability, suggesting that these mutations originated because of a deficient DNA mismatch repair system.Allele-specific expression of the 9A allele was detected in seven of the 14 heterozygous 9A/6A tumour cases. This could have been caused by linkage disequilibrium of the TGFBR1*6A allele with mutations that cause allele-specific expression, as was recently suggested. CONCLUSION: Our results suggest that the TGFBR1*6A allele does not confer an increased risk of colorectal cancer in the Spanish population.

The Int7G24A variant of transforming growth factor-beta receptor type I is a risk factor for colorectal cancer in the male Spanish population: a case-control study.

BACKGROUND: The Int7G24A variant of transforming growth factor-beta receptor type I (TGFBR1) has been shown to increase the risk for kidney, ovarian, bladder, lung and breast cancers. Its role in colorectal cancer (CRC) has not been established. The aims of this study were to assess the association of TGFBR1*Int7G24A variant with CRC occurrence, patient age, gender, tumour location and stage. METHODS: We performed a case-control study with 504 cases of sporadic CRC; and 504 non-cancerous age, gender and ethnically matched controls. Genotyping analysis was performed using allelic discrimination assay by real time PCR. RESULTS: The Int7G24A variant was associated with increased CRC incidence in an additive model of inheritance (P for trend = 0.005). No significant differences were found between Int7G24A genotypes and tumour location or stage. Interestingly, the association of the Int7G24A variant with CRC risk was significant in men (odds ratio 4.10 with 95% confidence intervals 1.41-11.85 for homozygous individuals; P for trend = 0.00023), but not in women. We also observed an increase in susceptibility to CRC for individuals aged less than 70 years. CONCLUSION: Our data suggest that the Int7G24A variant represents a risk factor for CRC in the male Spanish population.

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.