SARS-CoV-2 Neutralizing Antibodies in Mexican Population: A Five Vaccine Comparison.

Neutralizing antibodies (NAs) are key immunological markers and are part of the humoral response of the adaptive immune system. NA assays determine the presence of functional antibodies to prevent SARS-CoV-2 infection. We performed a real-world evidence study to detect NAs that confer protection against SARS-CoV-2 after the application of five vaccines (Pfizer/BioNTech, AstraZeneca, Sinovac, Moderna, and CanSino) in the Mexican population. Side effects of COVID-19 vaccines and clinical and demographic factors associated with low immunogenicity were also evaluated. A total of 242 SARS-CoV-2-vaccinated subjects were recruited. Pfizer/BioNTech and Moderna proved the highest percentage of inhibition in a mono-vaccine scheme. Muscular pain, headache, and fatigue were the most common adverse events. None of the patients reported severe adverse events. We found an estimated contagion-free time of 207 (IQR: 182-231) and 187 (IQR: 184-189) days for Pfizer/BioNTech and CanSino in 12 cases in each group. On the basis of our results, we consider that the emerging vaccination strategy in Mexico is effective and safe.

Identification of Germline Variants in Patients with Hereditary Cancer Syndromes in Northeast Mexico.

Hereditary cancer syndromes (HCS) are genetic diseases with an increased risk of developing cancer. This research describes the implementation of a cancer prevention model, genetic counseling, and germline variants testing in an oncologic center in Mexico. A total of 315 patients received genetic counseling, genetic testing was offered, and 205 individuals were tested for HCS. In 6 years, 131 (63.90%) probands and 74 (36.09%) relatives were tested. Among the probands, we found that 85 (63.9%) had at least one germline variant. We identified founder mutations in BRCA1 and a novel variant in APC that led to the creation of an in-house detection process for the whole family. The most frequent syndrome was hereditary breast and ovarian cancer syndrome (HBOC) (41 cases with BRCA1 germline variants in most of the cases), followed by eight cases of hereditary non-polyposic cancer syndrome (HNPCC or Lynch syndrome) (with MLH1 as the primarily responsible gene), and other high cancer risk syndromes. Genetic counseling in HCS is still a global challenge. Multigene panels are an essential tool to detect the variants frequency. Our program has a high detection rate of probands with HCS and pathogenic variants (40%), compared with other reports that detect 10% in other populations.

Epidemiological Algorithm for Early Detection of COVID-19 Cases in a Mexican Oncologic Center.

An early detection tool for latent COVID-19 infections in oncology staff and patients is essential to prevent outbreaks in a cancer center. (1) Background: In this study, we developed and implemented two early detection tools for the radiotherapy area to identify COVID-19 cases opportunely. (2) Methods: Staff and patients answered a questionnaire (electronic and paper surveys, respectively) with clinical and epidemiological information. The data were collected through two online survey tools: Real-Time Tracking (R-Track) and Summary of Factors (S-Facts). Cut-off values were established according to the algorithm models. SARS-CoV-2 qRT-PCR tests confirmed the positive algorithms individuals. (3) Results: Oncology staff members (n = 142) were tested, and 14% (n = 20) were positives for the R-Track algorithm; 75% (n = 15) were qRT-PCR positive. The S-Facts Algorithm identified 7.75% (n = 11) positive oncology staff members, and 81.82% (n = 9) were qRT-PCR positive. Oncology patients (n = 369) were evaluated, and 1.36% (n = 5) were positive for the Algorithm used. The five patients (100%) were confirmed by qRT-PCR. (4) Conclusions: The proposed early detection tools have proved to be a low-cost and efficient tool in a country where qRT-PCR tests and vaccines are insufficient for the population.

Risk Association of TOX3 and MMP7 Gene Polymorphisms with Sporadic Breast Cancer in Mexican Women.

Breast cancer (BC) has one of the highest incidences and mortality worldwide. Single nucleotide polymorphisms (SNPs) in TOX3 rs3803662 and MMP7 rs1943779 have been associated with susceptibility to BC. In this case-control study, we evaluated the association of rs3803662 (TOX3)/rs1943779 (MMP7) SNPs with clinical features, immunohistochemical reactivity, and risk association with BC in women from northeastern Mexico. We compared 212 BC cases and 212 controls. DNA was isolated from peripheral blood to perform the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) assay. We calculated genotype frequencies, odds ratios, and 95% confidence intervals. We found that CT (Cytocine-Thymine) and TT (Thymine -Thymine) genotypes, and T alleles of TOX3 rs3803662, were associated with BC risk (p = 0.034, p = 0.011, respectively). SNP TOX3 rs3803662 was associated with positive progesterone receptors (PR) and triple-negative BC (TNBC) but not with estrogen receptor (ER) or HER2 reactivity. CT and TT genotypes (p = 0.006) and T alleles (p = 0.002) of SNP MMP7 rs1943779 were associated with risk of BC. We found that T alleles of TOX3 rs3803662 and MMP7 rs1943779 SNPs are associated with BC risk. These findings contribute to personalized medicine in Mexican women.

ADIPOQ single nucleotide polymorphisms and breast cancer in northeastern Mexican women.

BACKGROUND: Adiponectin gene (ADIPOQ) polymorphisms have been shown to affect adiponectin serum concentration and some have been associated with breast cancer (BC) risk. The aims of this study were to describe the frequency of single nucleotide polymorphisms (SNPs) of ADIPOQ in Mexican women with BC and to determine if they show an association with it. METHODS: DNA samples from 397 patients and 355 controls were tested for the ADIPOQ gene SNPs: rs2241766 (GT) and rs1501299 (GT) by TaqMan allelic discrimination assay. Hardy-Weinberg equilibrium (HWE) was tested. Multiple SNP inheritance models adjusted by age and body mass index (BMI) were examined for the SNP rs1501299. RESULTS: We found that in the frequency analysis of rs1501299 without adjusting the BMI and age, the genotype distribution had a statistically significant difference (P = 0.003). The T allele was associated with a BC risk (OR, 1.99; 95% CI 1.13-3.51, TT vs. GG; OR, 1.53; 95% CI 1.12-2.09, GT vs. GG). The SNP rs2241766 was in HW disequilibrium in controls. In conclusion, the rs1501299 polymorphism is associated with a BC risk. CONCLUSIONS: Identification of the genotype of these polymorphisms in patients with BC can contribute to integrate the risk profile in both patients and their relatives as part of a comprehensive approach and increasingly more personalized medicine.

Analysis of the pathogenic variants of BRCA1 and BRCA2 using next-generation sequencing in women with familial breast cancer: a case-control study.

BACKGROUND: Pathogenic variants (PVs) of BRCA genes entail a lifetime risk of developing breast cancer in 50-85% of carriers. Their prevalence in different populations has been previously reported. However, there is scarce information regarding the most common PVs of these genes in Latin-Americans. This study identified BRCA1 and BRCA2 PV frequency in a high-risk female population from Northeastern Mexico and determined the association of these mutations with the patients' clinical and pathological characteristics. METHODS: Women were divided into three groups: aged ≤ 40 years at diagnosis and/or risk factors for hereditary breast cancer (n = 101), aged > 50 years with sporadic breast cancer (n = 22), and healthy women (n = 72). Their DNA was obtained from peripheral blood samples and the variants were examined by next-generation sequencing with Ion AmpliSeq BRCA1 and BRCA2 Panel using next-generation sequencing. RESULTS: PVs were detected in 13.8% group 1 patients (BRCA1, 12 patients; BRCA2, 2 patients). Only two patients in group 2 and none in group 3 exhibited BRCA1 PVs. Variants of uncertain significance were reported in 15.8% patients (n = 16). In group 1, patients with the triple-negative subtype, PV frequency was 40% (12/30). Breast cancer prevalence in young women examined in this study was higher than that reported by the National Cancer Institute Surveillance, Epidemiology (15.5% vs. 5.5%, respectively). CONCLUSIONS: The detected BRCA1 and BRCA2 PV frequency was similar to that reported in other populations. Our results indicate that clinical data should be evaluated before genetic testing and highly recommend genetic testing in patients with the triple-negative subtype and other clinical aspects.

Genetic alterations of triple negative breast cancer (TNBC) in women from Northeastern Mexico.

Triple negative breast cancer (TNBC) is a subtype of breast cancer of heterogeneous nature that is negative for estrogen receptor (ER), progesterone receptor (PR) and growth factor human epidermal 2 (HER2) following immunohistochemical analysis. TNBC is frequently characterized by relapse and reduced survival. To date, there is no targeted therapy for this type of cancer. Chemotherapy, radiotherapy, and surgery remain as the standard treatments options. The lack of a target therapy and the heterogeneity of TNBC highlight the need to seek new therapeutic options. In this study, fresh tissue samples of TNBC were analyzed with a panel of 48 driver genes (212 amplicons) that are likely to be therapeutic targets. We found intron variants, missense, stop gained and splicing variants in TP53, PIK3CA and FLT3 genes. Interestingly, all the analyzed samples had at least two variants in the TP53 gene, one being a drug response variant, rs1042522, found in 94% of our samples. We also found seven additional variants not previously reported in the TP53 gene, to the best of our knowledge, with probable deleterious characteristics of the tumor suppressor gene. We found four genetic variants in the PIK3CA gene, including two missense variants. The rs2491231 variant in the FLT3 gene was identified in 84% (16/19) of the samples, which not yet reported for TNBC, to the best of our knowledge. In conclusion, genetic variants in TP53 were found in all TNBC tumors, with rs1042522 being the most frequent (94% of TNBC biopsies), which had not been previously reported in TNBC. Also, we found two missense variants in the PIK3CA gene. These results justify the validation of these genetic variants in a large cohort, as well as the extensive study of their impact on the prognosis and therapy management of TBNC.

[C677T-SNP of methylenetetrahydrofolate reductase gene and breast cancer in Mexican women]. / SNP C677T del gen metilentetrahidrofolatoreductasa y cáncer de mama en mujeres mexicanas.

BACKGROUND: Low-penetrance susceptibility genes such as 5,10-methylenetetrahydrofolate reductase gene (MTHFR) have been considered in the progression of breast cancer (BC). Cancer is a result of genetic, environmental and epigenetic interactions; therefore, these genes should be studied in environmental context, because the results can vary between populations and even within the same country. The objective was to analyze the allelic and genotypic frequencies of the MTHFR C667T SNP in Mexican Mestizo patients with BC and controls from Northeastern Mexico. METHODS: 243 patients and 118 healthy women were studied. The analysis of the polymorphism was performed with a DNA microarray. Once the frequency of the polymorphism was obtained, Hardy-Weinberg equilibrium test was carried out for the genotypes. Chi square test was used to compare the distribution of frequencies. RESULTS: The allele frequency in patients was: C = 0.5406; T = 0.4594 and in controls C = 0.5678, T = 0.4322. Genotype in BC patients was: C / C = 29.9%, C / T = 48.3% and T / T = 21.8. The distribution in controls was: C / C = 31.4%, C / T = 50.8%, T / T = 17.8% (chi squared 0.77, p = 0.6801). CONCLUSIONS: Northeastern Mexican women in this study showed no association between MTFHR C667T SNP and the risk of BC. It seems that the contribution of this polymorphism to BC in Mexico varies depending on various factors, both genetic and environmental.

INTRODUCCIÓN: existen genes de susceptibilidad de baja penentrancia, como el gen de la 5,10-metilentetrahidrofolato reductasa (MTHFR), que participan en la progresión del cáncer de mama (CM). El cáncer es resultado de interacciones genéticas, ambientales y epigenéticas. Estos genes deben ser estudiados en el contexto del medio ambiente, ya que los resultados pueden variar de una población a otra, incluso dentro del mismo país. El objetivo fue analizar las frecuencias alélicas y genotípicas del polimorfismo C667T del gen de la MTHFR en pacientes mestizos mexicanos con CM y controles del noreste de México. MÉTODOS: se estudiaron 243 pacientes y 118 mujeres sanas. El análisis del polimorfismo se realizó con una microarreglo de ADN. Una vez que se obtuvo la fre cuencia del polimorfismo, la prueba de equilibrio de Hardy-Weinberg se llevó a cabo para los genotipos. Se utilizó chi cuadrada para comparar la distribución de frecuencias. RESULTADOS: la frecuencia de los alelos en los pacientes fue: C = 0.5406, T = 0.4594 y en los controles C = 0.5678, T = 0.4322. El genotipo en pacientes con CM fue: C / C = 29.9%, C / T = 48.3% y T / T = 21.8. La distribución en los controles fue: C / C = 31.4%, C / T = 50.8%, T / T = 17.8% (chi cuadrada 0.77, p = 0.6801). CONCLUSIONES: en este estudio no se observó relación entre el SNP MTFHR C667T y el riesgo de CM. Al parecer la contribución de este polimorfismo al CM en México varía dependiendo de varios factores tanto genéticos como ambientales.

A New Gene Expression Signature for Triple Negative Breast Cancer Using Frozen Fresh Tissue before Neoadjuvant Chemotherapy.

Triple-negative breast cancer (TNBC) is an aggressive subtype of breast cancer tumors. Comparisons between TNBC and non-triple negative breast cancer (nTNBC) may help to differentiate key components involved in TNBC neoplasms. The purpose of the study was to analyze the expression profile of TNBC versus nTNBC tumors in a homogeneous population from northeastern Mexico. A prospective study of 50 patients was conducted (25 TNBC and 25 nTNBC). Clinic parameters were equally distributed for TNBC and nTNBC: age at diagnosis (51 vs 47 years, p=0.1), glucose levels (107 mg/dl vs 104 mg/dl, p=0.64), and body mass index (28 vs 29, p=0.14), respectively. Core biopsies were collected for histopathological diagnosis and gene expression analyses. Total RNA was isolated and expression profiling was performed. 40 genes showed differential expression pattern in TNBC tumors. Among these, 9 over-expressed genes (PRKX/PRKY, UGT8, HMGA1, LPIN1, HAPLN3, and ANKRD11), and one under-expressed (ANX9) gene are involved in general metabolism. Based on this biochemical peculiarity, and the over-expression of BCL11A and FOXC1 (involved in tumor growth and metastasis, respectively) we validated by qPCR the expression profile of 7 genes out of the signature. In this report, a new gene signature for TNBC is proposed. To our knowledge, this is the first TNBC signature which describes genes involved in general metabolism. The findings may be pertinent for Mexican patients and require to be evaluated in further ethnic groups and populations.

Thymidylate synthase polymorphism in Mexican patients with colon cancer treated with 5-fluorouracil.

PURPOSE: We analyzed the genotype and allele frequency of variable number tandem repeats (VNTR)-thymidylate synthase (TS) and its relationship with the disease evolution in colon cancer patients. METHODS: We selected 24 paraffin-embedded colon cancer tissue samples from Mexican patients who received a 5-fluorouracil (5-FU)-based chemotherapy regimen. Tumor tissue was digested with proteinase K and genomic DNA was isolated by the standard method with phenol-chloroform extraction. Polymerase chain reaction (PCR) was performed for TS genotyping of VNTR and the results were evaluated directly in a stained agarose gel. RESULTS: The allele frequency of 2 repeats (2R) was greater (0.66) than 3R (0.34) in metastatic colon cancer (x2=10.24; p=0.001)) however, no difference in allelic distribution between 2R (0.54) and 3R (0.46) in non metastatic patients was observed (x2=0.640; p=0.424). CONCLUSION: Our results suggest that Mexican patients with colon cancer present differences in the allelic distribution, the 2R allele being the most frequent.

Comparative study of polymorphism frequencies of the CYP2D6, CYP3A5, CYP2C8 and IL-10 genes in Mexican and Spanish women with breast cancer.

AIM: Pharmacogenetic studies in breast cancer (BC) may predict the efficacy of tamoxifen and the toxicity of paclitaxel and capecitabine. We determined the frequency of polymorphisms in the CYP2D6 gene associated with activation of tamoxifen, and those of the genes CYP2C8, CYP3A5 and DPYD associated with toxicity of paclitaxel and capecitabine. We also included a IL-10 gene polymorphism associated with advanced tumor stage at diagnosis. PATIENTS & METHODS: Genomic DNAs from 241 BC patients from northeast Mexico were genotyped using DNA microarray technology. RESULTS: For tamoxifen processing, CYP2D6 genotyping predicted that 90.8% of patients were normal metabolizers, 4.2% ultrarapid, 2.1% intermediate and 2.9% poor metabolizers. For paclitaxel and the CYP2C8 gene, 75.3% were normal, 23.4% intermediate and 1.3% poor metabolizers. Regarding the DPYD gene, only one patient was a poor metabolizer. For the IL-10 gene, 47.1% were poor metabolizers. CONCLUSION: These results contribute valuable information towards personalizing BC chemotherapy in Mexican women.

HLA-DRB1 Class II antigen level alleles are associated with persistent HPV infection in Mexican women; a pilot study.

BACKGROUND: Persistent infection with high-risk human papillomavirus (HPV) is a major risk factor for malignant lesions and cervical cancer. A widely studied element in the search for genetic factors influencing risk HPV infection diseases is allelic variation of the human leukocyte antigen (HLA) locus. The study was designed to search for HLA susceptibility alleles contributing to the persistence of HPV infection in Mexican women. METHODS: A total of 172 subjects were divided into three groups: 1) HPV-persistent patients; 2) HPV-cleared; and 3) HPV-reinfected patients. They were screened for HPV types using a polymerase chain reaction (PCR). PCR-sequence specific oligonucleotide probes (PCR-SSOP) was used for HLA DRB1 and DQB1 typing. RESULTS: We observed that HLA-DQB1*0501 allele might be associated with susceptibility of reinfection with HPV (p = 0.01, OR = 4.9, CI 95% = 1.3 -18.7). Allele frequency of HLA-DRB1*14 was particularly reduced in patients with cancer when compared with the HPV-persistent group (p = 0.04), suggesting that this allele is a possible protective factor for the development of cervical cancer (OR = 2.98). HLA-DRB1*07 might be associated with viral clearance (p = 0.04). CONCLUSIONS: Genetic markers for HPV infection susceptibility are different in each population, in Mexicans several HLA-DQB1 alleles might be associated with an enhanced risk for viral persistence. In contrast, DRB1*14, seems to confer protection against cervical cancer.

Analysis of DNA mismatch repair proteins expression and BRAF V600E mutation in a subset of early- and late-onset colorectal carcinoma patients in Mexico.

BACKGROUND AND AIMS: A third of colorectal carcinomas (CRC) affect patients <50 years of age. Fifteen percent of CRC cases with microsatellite instability are due to inherited germ-line mutations in DNA mismatch repair genes. The rest have an epigenetic hypermethylation of the MLH1 promoter in whom the BRAF V600E mutation is a common hallmark. Immunohistochemistry helps to classify colorectal cancers with 100% specificity and 92% sensitivity. We undertook this study to determine if age is a risk factor for defective MMR protein expression and BRAF mutations in our population and to compare these results with the histopathological tumor features. METHODS: Immunohistochemistry for MLH1 and MSH2 and RT-PCR BRAF V600E mutation was performed on tissue specimens from 57 patients <50 years of age. Data on age, gender, tumor location, histology, depth of infiltration, and the presence of metastatic lymph nodes were collected. Forty eight patients >50 years of age were used as a control group. A statistical analysis using ANOVA, χ(2), and Spearman's rho test were performed. RESULTS: Absent MMR protein expression was more prevalent in patients <50 years of age. No BRAF V600E mutations were detected in either group. Medullary and mucinous types were more prevalent among young patients, whereas intestinal type was more frequent in older patients (p = 0.0008). No differences were found regarding clinicopathological stages between groups. CONCLUSIONS: We found an association between young age and defective MMR expression. No V600E BRAF mutations were detected in either group.

[Effectiveness of 5-fluoruracil and vinorelbine in patients who had received multi-treatments for metastatic breast cancer]. / Efectividad de 5-fluoruracilo y vinorelbina en pacientes multitratadas por cáncer de mama metastásico.

PURPOSE: In this study we evaluated the activity and toxicity of a combination of 5-fluorouracil continuous infusion and vinorelbine as second or third line chemotherapy in metastatic breast cancer (MBC). PATIENTS AN METHODS: A total 24 patients who had received doxorrubicin and/or paclitaxel were included in this study. The regimen consisted in 5-fluorouracil 1 gr/m(2) BSA continuous infusion for 3 days and vinorelbine 30 mg/m(2) intravenous (IV) on day 1. The cycles were repeated every 21 days for 6 cycles. RESULTS: Objective responses were recorded in 37.5% (12.5% complete remission). The median disease-free survival was calculated 6.33 +/- 8.12 months (CI 95% of 3.43 months). Toxicity was observed in 12.5% of the patients and no treatment related deaths were recorded. CONCLUSION: The combination of 5-fluorouracil/vinorelbine at the dose administered is an effective regime in patients with MBC, with low toxicity and cost.

Efectividad de 5-fluoruracilo y vinorelbina en pacientes multitratadas por cáncer de mama metastásico / Efectiveness of 5-fluoruracil and vinorelbine in patients who had received multi-treatments for metastatic breast cancer

Objetivo. Evaluar la actividad y toxicidad de fluoruracilo en infusión continua y vinorelbina en segunda o tercera línea de tratamiento del cáncer de mama metastásico (CMM).Método y pacientes. En este estudio fase II se incluyeron 24 pacientes que habían recibido doxorrubicina y/o paclitaxel. Se administró 5-fluoruracilo a 1g/m²/día en infusión continua por 3 días y vinorelbina a 30 mg/m² D1 cada 21 días por 6 ciclos. Resultados. Las respuestas globales observadas fueron del 37,5% (12,5% respuestas completas). El período libre de enfermedad se calculó una media de 6,33 ± 8,12 meses (IC 95% de 3,43 meses). Se observó toxicidad en el 12,5% de las pacientes y no se registró toxicidad grave ni muertes relacionadas a tratamiento. Conclusión. El 5-fluoruracilo/vinorelbina a las dosis administradas es un esquema efectivo en pacientes con CMM multitratadas, con un bajo perfil de toxicidad y costo

Purpose. In this study we evaluated the activity and toxicity of a combination of 5-fluoruracil continuous infusion and vinorelbine as second or third line chemotherapy in metastatic breast cancer (MBC). Patients an methods. A total 24 patients who had received doxorrubicin and/or paclitaxel were included in this study. The regimen consisted in 5-fluoruracil lgr/m² BSA continous infusion for 3 days and vinorelbine 30 mg/m² intravenous (IV) on day 1. The cycles were repeated every 21 days for 6 cycles. Results. Objective responses were recorded in 37.5% (12.5% complete remission). The median desease-free survival was calculated 6.33 ± 8.12 months (CI 95% of 3.43 months). Toxicity was observed in 12.5% of the patients and no treatment related deaths were recorded. Conclusion. The combination of 5-fluoruracil/vinorelbine at the dose administered is an effective regime in patients with MBC, with low toxicity and cost

Risk factors of breast cancer in mexican women

Objetivo. Investigar la asociación entre la historia familiar de neoplasias, factores ginecobstétricos y cáncer mamario (CM) en un estudio de casos y controles. Además, en los casos, estudiar estas variables en relación con inicio temprano del cáncer, forma de detección (autoexamen, exploración individual por dolor o casual), tamaño del tumor. Material y métodos. Entre enero y marzo de 1997 se estudiaron 151 casos prevalentes de CM y 235 controles pareados por edad provenientes del Hospital de Especialidades del Centro Médico del Noreste, Instituto Mexicano del Seguro Social, o del Hospital Universitario de la Universidad Autónoma de Nuevo León, ambos localizados en Monterrey, México. Los factores de riesgo se analizaron con regresión logística múltiple. Resultados. Diez por ciento de casos y 1 por ciento de controles tuvieron historia familiar de primer grado para CM; este antecedente (razón de momios -RM, 11.2; IC 95 por ciento; 2.42-51.92) y el de carcinoma gástrico o pancreático (RM, 17.7; IC 95 por ciento; 2.2-142.6) se asociaron con riesgo de CM. El amamantar a los 25 años o menos fue factor protector (RM, 0.40; IC 95 por ciento; 0.24-0.66). La forma de detección del tumor no influyó en el tamaño del tumor al momento del diagnóstico. Conclusiones. Se mostró que la historia familiar de CM y de carcinoma gástrico o pancreático son factores de riesgo para CM, mientras que la lactancia a los 25 años o antes, es protectora.