Sotorasib plus Panitumumab in Refractory Colorectal Cancer with Mutated KRAS G12C.

BACKGROUND: KRAS G12C is a mutation that occurs in approximately 3 to 4% of patients with metastatic colorectal cancer. Monotherapy with KRAS G12C inhibitors has yielded only modest efficacy. Combining the KRAS G12C inhibitor sotorasib with panitumumab, an epidermal growth factor receptor (EGFR) inhibitor, may be an effective strategy. METHODS: In this phase 3, multicenter, open-label, randomized trial, we assigned patients with chemorefractory metastatic colorectal cancer with mutated KRAS G12C who had not received previous treatment with a KRAS G12C inhibitor to receive sotorasib at a dose of 960 mg once daily plus panitumumab (53 patients), sotorasib at a dose of 240 mg once daily plus panitumumab (53 patients), or the investigator's choice of trifluridine-tipiracil or regorafenib (standard care; 54 patients). The primary end point was progression-free survival as assessed by blinded independent central review according to the Response Evaluation Criteria in Solid Tumors, version 1.1. Key secondary end points were overall survival and objective response. RESULTS: After a median follow-up of 7.8 months (range, 0.1 to 13.9), the median progression-free survival was 5.6 months (95% confidence interval [CI], 4.2 to 6.3) and 3.9 months (95% CI, 3.7 to 5.8) in the 960-mg sotorasib-panitumumab and 240-mg sotorasib-panitumumab groups, respectively, as compared with 2.2 months (95% CI, 1.9 to 3.9) in the standard-care group. The hazard ratio for disease progression or death in the 960-mg sotorasib-panitumumab group as compared with the standard-care group was 0.49 (95% CI, 0.30 to 0.80; P = 0.006), and the hazard ratio in the 240-mg sotorasib-panitumumab group was 0.58 (95% CI, 0.36 to 0.93; P = 0.03). Overall survival data are maturing. The objective response was 26.4% (95% CI, 15.3 to 40.3), 5.7% (95% CI, 1.2 to 15.7), and 0% (95% CI, 0.0 to 6.6) in the 960-mg sotorasib-panitumumab, 240-mg sotorasib-panitumumab, and standard-care groups, respectively. Treatment-related adverse events of grade 3 or higher occurred in 35.8%, 30.2%, and 43.1% of patients, respectively. Skin-related toxic effects and hypomagnesemia were the most common adverse events observed with sotorasib-panitumumab. CONCLUSIONS: In this phase 3 trial of a KRAS G12C inhibitor plus an EGFR inhibitor in patients with chemorefractory metastatic colorectal cancer, both doses of sotorasib in combination with panitumumab resulted in longer progression-free survival than standard treatment. Toxic effects were as expected for either agent alone and resulted in few discontinuations of treatment. (Funded by Amgen; CodeBreaK 300 ClinicalTrials.gov number, NCT05198934.).

Colorectal cancer.

Despite decreased incidence rates in average-age onset patients in high-income economies, colorectal cancer is the third most diagnosed cancer in the world, with increasing rates in emerging economies. Furthermore, early onset colorectal cancer (age ≤50 years) is of increasing concern globally. Over the past decade, research advances have increased biological knowledge, treatment options, and overall survival rates. The increase in life expectancy is attributed to an increase in effective systemic therapy, improved treatment selection, and expanded locoregional surgical options. Ongoing developments are focused on the role of sphincter preservation, precision oncology for molecular alterations, use of circulating tumour DNA, analysis of the gut microbiome, as well as the role of locoregional strategies for colorectal cancer liver metastases. This overview is to provide a general multidisciplinary perspective of clinical advances in colorectal cancer.

The impact of cancer metastases on COVID-19 outcomes: A COVID-19 and Cancer Consortium registry-based retrospective cohort study.

BACKGROUND: COVID-19 can have a particularly detrimental effect on patients with cancer, but no studies to date have examined if the presence, or site, of metastatic cancer is related to COVID-19 outcomes. METHODS: Using the COVID-19 and Cancer Consortium (CCC19) registry, the authors identified 10,065 patients with COVID-19 and cancer (2325 with and 7740 without metastasis at the time of COVID-19 diagnosis). The primary ordinal outcome was COVID-19 severity: not hospitalized, hospitalized but did not receive supplemental O2, hospitalized and received supplemental O2, admitted to an intensive care unit, received mechanical ventilation, or died from any cause. The authors used ordinal logistic regression models to compare COVID-19 severity by presence and specific site of metastatic cancer. They used logistic regression models to assess 30-day all-cause mortality. RESULTS: Compared to patients without metastasis, patients with metastases have increased hospitalization rates (59% vs. 49%) and higher 30 day mortality (18% vs. 9%). Patients with metastasis to bone, lung, liver, lymph nodes, and brain have significantly higher COVID-19 severity (adjusted odds ratios [ORs], 1.38, 1.59, 1.38, 1.00, and 2.21) compared to patients without metastases at those sites. Patients with metastasis to the lung have significantly higher odds of 30-day mortality (adjusted OR, 1.53; 95% confidence interval, 1.17-2.00) when adjusting for COVID-19 severity. CONCLUSIONS: Patients with metastatic cancer, especially with metastasis to the brain, are more likely to have severe outcomes after COVID-19 whereas patients with metastasis to the lung, compared to patients with cancer metastasis to other sites, have the highest 30-day mortality after COVID-19.

Evidence of SARS-CoV-2 infection in companion animals from owners who tested positive for COVID-19 in the Valley of Mexico.

BACKGROUND: Little is known about the companion animals which tested positive in Mexico for Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) infection. Due to this, it is that we have documented the infection of companion animals, via an exploratory approach in two localities of the Valley of Mexico, in which the companion animal owners tested positive for COVID-19. METHODS: Oropharyngeal and nasopharyngeal swabs were collected from 21 companion animals. Also, a Reverse-Transcription Quantitative Polymerase Chain Reaction was used to test five probes in three SARS-CoV-2 genes. More than one-third (5/14) of these samples were positive for SARS CoV-2 corresponding to dogs. RESULTS: This research translates into the first available report on companion animals with SARS-CoV-2 infection in the most populated area of Mexico. Samples were added chronologically to previous reports prepared in other areas of the country, from February through November 2022. CONCLUSION: Although SARS-CoV-2 infection in dogs is not as common as in other animals, our results suggest that it can be transmitted to dogs by their owners to a greater extent than previously reported.

Validation of the Mexican version of the EORTC QLQ-CR29 in patients with colorectal cancer.

BACKGROUND: The evaluation of the quality of life (QoL) of patients with colorectal cancer (CRC) is an essential measure to measure the impact of the disease and treatments on the lives of patients. However, in Latin America there is no validated and reliable instrument to assess this construct. OBJECTIVES: This study aims to validate the EORTC QLQ-CR29 instrument in the Mexican population with CRC. METHODS: This study aims to validate the EORTC QLQ-CR29 instrument in the Mexican population with CRC. The study used an instrumental design and a nonprobabilistic sample due to availability, made up of 251 patients with CRC, with an average age of 54.7 ± 12.28 years. Exploratory and confirmatory factor analyses were performed, as well as concurrent validity tests. RESULTS: The exploratory factorial analysis yielded 4 factors that explained 51.64% of the variance, with a Cronbach reliability coefficient of .766 and an Omega index of .725. The confirmatory factor analysis indicated that the proposed theoretical model fits the data almost perfectly, with an error close to 0, which shows that it is a balanced and parsimonious instrument to measure the QoL of the patients with CRC. SIGNIFICANCE OF RESULTS: The EORTC QLQ-CR29 instrument proved to be a valid and reliable instrument for use in clinical care and research directed at patients with CRC in Mexico. Its use is recommended by multidisciplinary health teams in oncology in Mexico, since it allows knowing the patient's perspective on the impact of CRC on their life, guiding therapeutic decision-making and being a primary outcome measure.

Persistent high levels of carcinoembryonic antigen after tumor resection are associated with poorer survival outcomes in patients with resected colon cancer.

BACKGROUND: Interindividual survival and recurrence rates in cases of locoregional colon cancer following surgical resection are highly variable. The aim of the present study was to determine whether elevated pre-operative and post-operative CEA values are useful prognostic biomarkers for patients with stage I-III colon cancer who underwent surgery with curative intent. METHODS: We conducted a retrospective study in patients with histologically confirmed stage I-III primary colonic adenocarcinoma who underwent radical surgical resection at Mexico's National Cancer Institute, between January 2008 and January 2020. We determined pre-operative and post-operative CEA and analyzed the association of scores with poorer survival outcomes in patients with resected colon cancer, considering overall survival (OS) and disease-free survival (DFS). RESULTS: We included 640 patients with stage I-III colon cancer. Pre-operative CEA levels were in the normal range in 460 patients (group A) and above the reference value in the other 180. Of the latter, 134 presented normalized CEA levels after surgery, but 46 (group C) continued to show CEA levels above the reference values after surgery. Therefore, propensity score matching (PSM) was carried out to reduce the bias. Patients were adjusted at a 1:1:1 ratio with 46 in each group, to match the number in the smallest group. Median follow- up was 46.4 months (range, 4.9-147.4 months). Median DFS was significantly shorter in Group C: 55.5 months (95% CI 39.6-71.3) than in the other two groups [Group A: 77.1 months (95% CI 72.6-81.6). Group B: 75.7 months (95% CI 66.8-84.5) (p-value < 0.001)]. Overall survival was also significantly worse in group C [57.1 (95% CI 37.8-76.3) months] than in group A [82.8 (95% CI 78.6-86.9 months] and group B [87.1 (95% CI 79.6-94.5 months] (p-value = 0.002). To identify whether change in CEA levels operative and post-surgery was an independent prognostic factor for survival outcomes, a Cox proportional hazard model was applied. In multivariate analysis, change in CEA level was a statistically significant, independent prognostic factor for overall survival (p-value = 0.031). CONCLUSIONS: When assessed collectively, pre-operative and post-operative CEA values are useful biomarkers for predicting survival outcomes in patients with resected colon cancer. Prognoses are worse for patients with elevated pre-operative and post-surgical CEA values, but similar in patients with normal post-surgical values, regardless of their pre-surgery values.

Multivariate Prognostic Models for Patients with Stages I and Ii Colon Carcinoma: a Strobe-Compliant Retrospective Cohort Study.

Background: Colorectal cancer is the most frequent gastrointestinal malignancy worldwide. The value of adjuvant treatment is controversial in Stages I and II. Objective: The aim of this study was to construct post-operative prognostic models applicable to patients with stages I-II colon carcinoma (CC). Methods: This is a retrospective cohort study of patients with Stage I-II CC treated over a 25-year period. Exposure was defined as clinical, histopathological, and immunohistochemical factors (including CDX2 and MUC2 expression). Patients were randomly allocated to either a "modeling set" or a "validation set". Factors associated with recurrence, disease-free survival (DFS), and overall survival (OS) were defined in the "modeling set". Their performances were tested in the "validation set". Results: From a total of 556 recruited patients, 339 (61%) were allocated to the "modeling set" and 217 (39%) to the "validation set". Three models explaining recurrence, DFS, and OS were described. Tumor location in the left colon (Hazards ratio [HR] = 1.57; 95% Confidence interval [CI] 0.99-2.48), lymphocyte (HR = 0.46; 96% CI 0.27-0.88) and monocyte (HR = 0.99; 95% CI 0.99-1) counts, neutrophil/platelet ratio (HR = 1.3; 95% CI 0.74-2.3, and HR = 2.3; 95% CI 1.3-4.1; for second and third category, respectively), albumin/monocyte ratio (HR = 0.43; 95% CI 0.21-0.87), and microscopic residual disease after surgery (HR = 8.7; 95% CI 3.1-24) were independently associated with OS. T classification and expression of CDX2 and/or MUC2 were not independently associated with recurrence or prognosis. Conclusion: These models are simple and readily available, and distinguish the risk and prognosis in patients with CC stages I and II; these models require cheaper processes than the use of more sophisticated molecular biology techniques. They may guide either the need for adjuvant therapy versus post-operative surveillance only, as well as aid in the design of clinical trials.

CD117 immunoexpression in oral and sinonasal mucosal melanoma does not correlate with somatic driver mutations in the MAPK pathway.

BACKGROUND: Mutations on KIT and downstream genes of MAPK pathway that overstimulate cellular proliferation have been associated with primary oral and sinonasal melanomas (POSNM), but there is limited information that allows the use of personalized therapy. Thus, the aim of the present study was to determine a possible association between the C-KIT immunohistochemical expression with the presence of somatic driver mutations in NRAS, BRAF, KIT, MITF and PTEN on POSNM. METHODS: A retrospective study included 62 tumour samples of an oncological reference centre in Mexico City (17-year period). Immunohistochemistry stain of C-KIT was carried out. Genomic DNA was obtained and used to assess hotspot mutations of KIT, NRAS, BRAF, MITF and PTEN through qPCR. Chi-square, Fisher's exact and the Mann-Whitney U tests were applied when necessary. The significance was set at P < 0.05. RESULTS: Sixty-two cases were included, 74% were positive for C-KIT immunoexpression, all exhibited moderate/strong intensity. Ten (16.1%) samples harboured at least one mutation, 6.4% and 6.6% for NRASQ 61R and BRAFV 600E , respectively, followed by KITK624E (3.2%). No KITL 576P , MITF or PTEN mutations were identified. No significant correlation was observed between mutations and immunostaining (rs = -0.057, P = 0.765). CONCLUSIONS: Regardless of the high immunoexpression of C-KIT, there was no association with the MAPK mutations among POSNM samples. Thus, C-KIT immunohistochemistry is not a reliable tool to detect POSNM candidates for biological therapy.

Immuno-Oncology in the Era of Personalized Medicine.

Personalized medicine in oncology utilizes evidence derived from genetic, immune, and proteomic profiling to inform therapeutic options as well as provide prognostic information for each unique individual and their tumor. Our ability to biologically and immunologically define each patient's tumor has been driven by the development of assays characterizing the genomic and proteomic profiles of tumors that in turn have led to the development of large biologic databases and computational tools for the analysis of these large data sets. In Immuno-oncology, the introduction of checkpoint inhibitors and their approval across multiple tumor types has led to the recognition that the majority of patients will not clinically respond to these therapies but will remain at risk for the development of significant immunologic side effects. This challenge highlights the need for the development and validation of both predictive biomarkers for response to such therapies as well as biomarkers prognostic of disease course. Despite extensive investigation into predictive biomarkers using these biologic databases and computational methods, only recently has progress been made in this area. This progress is the first step allowing us to identify patients likely to benefit from these therapies and moving our field closer to a truly personalized approach to the use of immune therapies in oncology.

Addition of analysis of KRAS mutation or immunohistochemistry with MUC1 and carcinoembryonic antigen improves the diagnostic performance of fine needle aspiration cytology for the diagnosis of pancreatic carcinoma.

BACKGROUND: Pancreatic adenocarcinoma (PAC) is a health problem because of high lethality, increasing incidence and the absence of an early diagnosis. Biopsy by fine needle aspiration guided by endoscopic ultrasound has allowed obtaining tissue for cytopathological analysis, but there are several problems with their interpretation. We aimed to compare the diagnostic performance of the cytopathological analysis with the addition of either an immunohistochemical (IHC) panel or the KRAS mutation for the diagnosis of PAC. METHODS: We evaluated 62 pancreatic lesions by fine needle aspiration guided by endoscopic ultrasound, applying an IHC panel with mucin (MUC)-1, MUC4, carcinoembryonic antigen (CEA) and p53. All cases also had a KRAS mutation determination. Three cytopathologists blinded to clinical data and the KRAS status reviewed the cytology independently. We calculated diagnostic performances for the cytology alone, cytology+IHC and cytology+KRAS to show the best method to diagnose PAC. RESULTS: From 62 samples, 50 (80.6%) were PAC and 12 benign lesions. The cytopathological analysis correctly interpreted 26 malignant and 12 non-neoplastic cases (sensitivity 52%, specificity 100% and diagnostic accuracy 61.3%). The KRAS mutation was present in 88% of PAC. The cytology+ KRAS mutation increased the sensitivity by 10% and the diagnostic accuracy by 8%. The sensitivity increased by 2% adding either MUC1 or CEA to the cytology, and the diagnostic accuracy by 10 or 18%, respectively. CONCLUSION: The addition of IHC either with CEA or MUC1 improved the diagnostic performance of the cytology alone to diagnose PAC. The cytology + IHC evaluation was superior to the cytology + KRAS mutation to diagnose PAC.

Gastric cancer in Latin America.

Every year, cancer affects more than one million Latin Americans. The increasing incidence of cancer could be secondary to an aging population, westernization of life style, and urbanization. LA has among the highest incidence rates of gastric cancer, compared to other countries. In this review, different studies on gastric cancer and its relation with risks factors, such as infections, diet and life styles typical of LA, besides the different molecular alterations of that specific population (mainly at a genetic polymorphism level) are analyzed. An exhaustive research was made in PubMed, MEDLINE and Embase of the most relevant studies conducted in the last 27 years (1990-2017) in LA.

A microRNA signature associated with pathological complete response to novel neoadjuvant therapy regimen in triple-negative breast cancer.

Neoadjuvant chemotherapy aims to improve the outcome of breast cancer patients, but only few would benefit from this treatment. Pathological complete response has been proposed as a surrogate marker for the prediction of long-term clinical benefits; however, 50%-85% patients have an unfavorable pathological complete response to chemotherapy. MicroRNAs are known biomarkers of breast cancer progression; nevertheless, their potential to identify patients with pathological complete response remains poorly understood. Here, we investigated whether a microRNA profile could be associated with pathological complete response in triple-negative breast cancer patients receiving 5-fluorouracil, adriamycin, cyclophosphamide-cisplatin/paclitaxel as a novel neoadjuvant chemotherapy. In the discovery cohort, the expression of 754 microRNAs was examined in tumors from 10 triple-negative breast cancer patients who achieved pathological complete response and 8 without pathological complete response using TaqMan Low-Density Arrays. Unsupervised hierarchical cluster analysis identified 11 microRNAs with significant differences between responder and no-responder patients (fold change ≥ 1.5; p < 0.05). The differential expression of miR-30a, miR-9-3p, miR-770, and miR-143-5p was validated in an independent group of 17 patients with or without pathological complete response. Moreover, Kaplan-Meier analysis showed that expression of these four microRNAs was associated with an increased disease-free survival. Gene ontology classification of predicted microRNA targets indicated that numerous genes are involved in pathways related to chemoresistance, such as vascular endothelial growth factor, focal adhesion kinase, WNT, ERbB, phosphoinositide 3-kinase, and AKT signaling. In summary, we identified a novel microRNA expression signature associated with pathological complete response in breast cancer. We propose that the four validated microRNAs could be used as molecular biomarkers of clinical response in triple-negative breast cancer patients with pathological complete response to neoadjuvant therapy.

Suppression of cell migration is promoted by miR-944 through targeting of SIAH1 and PTP4A1 in breast cancer cells.

BACKGROUND: Aberrant expression of microRNAs has been associated with migration of tumor cells. In this study, we aimed to investigate the biological significance of miR-944 whose function is unknown in breast cancer. METHODS: MiR-944 expression in breast cancer cells and tumors was evaluated by Taqman qRT-PCR assays. Transcriptional profiling of MDA-MB-231 cells expressing miR-944 was performed using DNA microarrays. Cell viability, migration and invasion were assessed by MTT, scratch/wound-healing and transwell chamber assays, respectively. The luciferase reporter assay was used to evaluate targeting of SIAH1, PTP4A1 and PRKCA genes by miR-944. SIAH1 protein levels were measured by Western blot. Silencing of SIAH1 gene was performed by RNA interference using shRNAs. RESULTS: Our data showed that miR-944 expression was severely repressed in clinical specimens and breast cancer cell lines. Suppression of miR-944 levels was independent of hormonal status and metastatic potential of breast cancer cells. Gain-of-function analysis indicated that miR-944 altered the actin cytoskeleton dynamics and impaired cell migration and invasion. Genome-wide transcriptional profiling of MDA-MB-231 cells that ectopically express miR-944 showed that 15 genes involved in migration were significantly repressed. Notably, luciferase reporter assays confirmed the ability of miR-944 to bind the 3´UTR of SIAH1 and PTP4A1 genes, but not PRKCA gene. Congruently, an inverse correlation between miR-944 and SIAH1 protein expression was found in breast cancer cells. Moreover, SIAH1 was upregulated in 75 % of miR-944-deficient breast tumors. Finally, SIAH1 gene silencing by RNA interference significantly impaired cell migration of breast cancer cells. CONCLUSIONS: Our results pointed out that miR-944 is a novel upstream negative regulator of SIAH1 and PTP4A1 genes and provided for the first time evidence for its functional role in migration and invasion of breast cancer cells. They also suggest that miR-944 restoration may represent a potential strategy for breast cancer therapy.

Pre-operative Neutrophils/Lymphocyte Ratio in Rectal Cancer Patients with Preoperative Chemoradiotherapy.

BACKGROUND: Several studies have reported that an elevation in neutrophils/lymphocyte ratio (NLR) is correlated with poor survival in patients with colorectal cancer, but in rectal cancer (RC), it has been reported only in a few studies. It is necessary to separate colon cancer and rectal cancer to clarify the prognostic significance of NLR, especially in patients who received chemoradiotherapy. METHODS: It is a comparative, observational retrospective study of a cohort of 175 patients. We grouped the patients into two based on their NLR (0-3 vs. > 3) to correlate with disease-specific survival (DSS) and pathologic complete response (pCR). RESULTS: The average NLR was 2.65 + 1.32 (range 0.58-6.89), and 144 (82.3%) patients had an NLR of 0-3. The median follow-up was 33.53 months. There were no differences in pCR between the two groups. The 5-year DSS was 78.8%. NLR did not correlate with survival. Mesorectal quality, pT3-4 tumors, lymph node metastasis, lymphovascular invasion, perineural invasion, positive margins and recurrence were statistically significant predictors of increased mortality in univariate analysis. In multivariate analysis, only overall recurrence correlated with poor survival. The analysis of the association of NLR with outcomes with different cut points (2.0, 2.5, 4 and 5) did not show differences in DSS and pCR. CONCLUSION: In our cohort, the NLR did not serve as a prognostic marker in patients with locally advanced rectal cancer and who received chemoradiotherapy and did not correlate with pCR as well.

Mesorectal pathologic assessment in two grades predicts accurately recurrence, positive circumferential margin, and correlates with survival.

BACKGROUND AND OBJECTIVES: We aimed to determine the prognostic value of the mesorectum quality assessed in a two-grade system compared with a classic system. METHODS: Consecutive patients undergoing surgery for rectal cancer were included (n = 103). Mesorectum was assessed into three grades (classic system: complete, nearly complete, incomplete) and compared with a two-grade system (adequate, inadequate). RESULTS: Mesorectum was complete in 62 (60.25%) patients, nearly complete in 21, and incomplete in 20. Reassessment showed adequate mesorectum in 83 (80.5%) patients and inadequate in 20. A R0 resection was achieved in 90.4% of adequate mesorectum and in 65% of inadequate mesorectum (P = 0.006). Recurrence was present in 18% of adequate mesorectum patients as compared with 50% of inadequate mesorectum (P = 0.003). The classic system failed to accurately predict the 5-year survival rate between complete (78.9%) and nearly complete (86.2%) categories (P = 0.235); whereas a two grading system showed a 5-year survival rate of 80.8% for adequate versus 39.3% for inadequate (P = 0.034). CONCLUSION: High recurrence occurred in inadecuate mesorectum patients and was correlated with R1/R2 resections, positive margins, and decreased survival. We propose a simplified classification of mesorectum that correlates with survival and overall recurrence.

Somatic Mutations in Latin American Breast Cancer Patients: A Systematic Review and Meta-Analysis.

(1) Background: Somatic mutations may be connected to the exposome, potentially playing a role in breast cancer's development and clinical outcomes. There needs to be information regarding Latin American women specifically, as they are underrepresented in clinical trials and have limited access to somatic analysis in their countries. This study aims to systematically investigate somatic mutations in breast cancer patients from Latin America to gain a better understanding of tumor biology in the region. (2) Methods: We realize a systematic review of studies on breast cancer in 21 Latin American countries using various databases such as PubMed, Google Scholar, Web of Science, RedAlyc, Dianlet, and Biblioteca Virtual en Salud. Of 392 articles that fit the criteria, 10 studies have clinical data which can be used to create a database containing clinical and genetic information. We compared mutation frequencies across different breast cancer subtypes using statistical analyses and meta-analyses of proportions. Furthermore, we identified overexpressed biological processes and canonical pathways through functional enrichment analysis. (3) Results: 342 mutations were found in six Latin American countries, with the TP53 and PIK3CA genes being the most studied mutations. The most common PIK3CA mutation was H1047R. Functional analysis provided insights into tumor biology and potential therapies. (4) Conclusion: evaluating specific somatic mutations in the Latin American population is crucial for understanding tumor biology and determining appropriate treatment options. Combining targeted therapies may improve clinical outcomes in breast cancer. Moreover, implementing healthy lifestyle strategies in Latin America could enhance therapy effectiveness and clinical outcomes.

Examining the Role of Histaminergic, Orexinergic, and Cannabinergic Systems in Redox Regulation in Gastric Adenocarcinoma.

Histaminergic, orexinergic, and cannabinoid systems play a role in both physiologic and oncogenic mechanisms in digestive tissues. These three systems are important mediators of tumor transformation, as they are associated with redox alterations, which are key aspects in oncological disorders. The three systems are known to promote alterations in the gastric epithelium through intracellular signaling pathways, such as oxidative phosphorylation, mitochondrial dysfunction, and increased Akt, which might promote tumorigenesis. Histamine promotes cell transformation through redox-mediated alterations in the cell cycle, DNA repair, and immunological response. The increase in histamine and oxidative stress generates angiogenic and metastatic signals through the VEGF receptor and H2R-cAMP-PKA pathway. Immunosuppression in the presence of histamine and ROS is linked to a decrease in dendritic and myeloid cells in gastric tissue. These effects are counteracted by histamine receptor antagonists, such as cimetidine. Regarding orexins, overexpression of the Orexin 1 Receptor (OX1R) induces tumor regression through the activation of MAPK-dependent caspases and src-tyrosine. OX1R agonists are candidates for the treatment of gastric cancer by stimulating apoptosis and adhesive interactions. Lastly, cannabinoid type 2 (CB2) receptor agonists increase ROS, leading to the activation of apoptotic pathways. In contrast, cannabinoid type 1 (CB1) receptor agonists decrease ROS formation and inflammation in gastric tumors exposed to cisplatin. Overall, the repercussion of ROS modulation through these three systems on tumor activity in gastric cancer depends on intracellular and/or nuclear signals associated with proliferation, metastasis, angiogenesis, and cell death. Here, we review the role of these modulatory systems and redox alterations in gastric cancer.

Latin American young patients with gastric adenocarcinoma: worst prognosis and outcomes.

Background: Incidence of young patients (aged 40 years or younger) diagnosed with gastric carcinoma has increased worldwide. Young GC diagnosis, have clinicopathological features that differ from elderly, and is correlated with bad prognosis factors. The purpose of this work is to describe the prevalence, clinic-pathological features, and prognosis of overall survival (OS) of young Latin-American patients with GC. Methods: Retrospective, observational study. Included patients treated at the National Cancer Institute [2004-2020]. Statistical analysis: χ2 and t-test, Kaplan-Meier, Log-Rank and Cox-Regression. Statistical significance differences were assessed when P was bilaterally <0.05. Results: A total of 2,543 patients fulfilled the inclusion criteria. Young-patients were predominantly female (54%), with diffuse-type adenocarcinoma (68%), signet-ring-cell (72%), poor-differentiation (90%), and metastatic (79%). In OS analysis, patients with metastatic disease, showed differences regarding age, young patients reported a median-OS of 8 versus 13 months for elderly patients (P=0.001). Among young patients, differences were also observed regarding gender, young-female patients had a median-OS of 5 versus 11 months for young-man (P=0.001). Conclusions: This is one of the pioneer studies correlating age with gender and the prognostic features of bad prognosis in Latin-American population. Besides, supports the idea that a global effort is required to improve awareness, prevention, and early diagnosis of GC.

Influence of proton pump inhibitors on the pathological response of rectal cancer: a multicentre study.

Background: The standard neoadjuvant therapy for rectal cancer involves fluoropyrimidines and radiotherapy and, most recently, total neoadjuvant therapy (TNT). A drug-drug interaction between fluoropyrimidines and proton-pump inhibitors (PPI) was suggested, with a negative impact on oncological outcomes in breast, colon and gastric cancers. Little is known about such an effect on rectal tumours. We aimed to evaluate the impact of PPI utilisation on the pathological response after chemoradiation for rectal cancer. Materials and methods: Retrospective multicentre study of rectal cancer patients treated with neoadjuvant chemoradiotherapy with capecitabine (cohort 1) or 5-fluororuracil (5-FU) (cohort 2); TNT with oxaliplatin-based regimens was allowed. The pathological response was considered a complete (ypCR) or complete + partial (ypCR + ypPR) according to American Joint Committee on Cancer. PPI use was considered at any time during the neoadjuvant period if concomitant to fluoropyrimidines. Results: From January 2007 to November 2020, 251 patients received capecitabine and 196 5-FU. The rates of PPI use in cohorts 1 and 2 were 20.3% and 26.5%, respectively. TNT was offered to 18.3% in cohort 1. PPI use did not influence ypCR in cohort 1 (yes versus no: 29.4% versus 19.5%; p = 0.13) or 2 (yes versus no: 25.0% versus 26.4%; p = 1.0). Similar ypCR + ypPR were observed in both cohorts 1 (76.5% versus 72.0%; p = 0.60) and 2 (86.5% versus 76.4%; p = 0.16). PPI use was not associated with pathological response in multivariable analysis. PPI users experienced more grade 3 or higher diarrhoea and infections. Conclusion: PPI concomitant to capecitabine/5-FU chemoradiation did not influence the pathological response in rectal cancer but was associated with more treatment-related adverse events.

Pathogenic variant profile in DNA damage response genes correlates with metastatic breast cancer progression-free survival in a Mexican-mestizo population.

Introduction: Metastatic breast cancer causes the most breast cancer-related deaths around the world, especially in countries where breast cancer is detected late into its development. Genetic testing for cancer susceptibility started with the BRCA 1 and 2 genes. Still, recent research has shown that variations in other members of the DNA damage response (DDR) are also associated with elevated cancer risk, opening new opportunities for enhanced genetic testing strategies. Methods: We sequenced BRCA1/2 and twelve other DDR genes from a Mexican-mestizo population of 40 metastatic breast cancer patients through semiconductor sequencing. Results: Overall, we found 22 variants -9 of them reported for the first time- and a strikingly high proportion of variations in ARID1A. The presence of at least one variant in the ARID1A, BRCA1, BRCA2, or FANCA genes was associated with worse progression-free survival and overall survival in our patient cohort. Discussion: Our results reflected the unique characteristics of the Mexican-mestizo population as the proportion of variants we found differed from that of other global populations. Based on these findings, we suggest routine screening for variants in ARID1A along with BRCA1/2 in breast cancer patients from the Mexican-mestizo population.