Long-Term Experience with Hyperthermic Chemotherapy (HIVEC) Using Mitomycin-C in Patients with Non-Muscle Invasive Bladder Cancer in Spain.

(1) Background: Intravesical mitomycin-C (MMC) combined with hyperthermia is increasingly used in non-muscle invasive bladder cancer (NMIBC), especially in the context of a relative BCG shortage. We aim to determine real-world data on the long-term treatment outcomes of adjunct hyperthermic intravesical chemotherapy (HIVEC) with MMC and a COMBAT® bladder recirculation system (BRS); (2) Methods: A prospective observational trial was performed on patients with NMIBC treated with HIVEC using BRS in nine academic institutions in Spain between 2012-2020 (HIVEC-E). Treatment effectiveness (recurrence, progression and overall mortality) was evaluated in patients treated with HIVEC MMC 40mg in the adjuvant setting, with baseline data and a clinical follow-up, that comprise the Full Analysis Set (FAS). Safety, according to the number and severity of adverse effects (AEs), was evaluated in the safety (SAF) population, composed by patients with at least one adjunct HIVEC MMC instillation; (3) Results: The FAS population (n = 502) received a median number of 8.78 ± 3.28 (range 1-20) HIVEC MMC instillations. The median follow-up duration was 24.5 ± 16.5 (range 1-81) months. Its distribution, based on EAU risk stratification, was 297 (59.2%) for intermediate and 205 (40.8%) for high-risk. The figures for five-year recurrence-free and progression-free survival were 50.37% (53.3% for intermediate and 47.14% for high-risk) and 89.83% (94.02% for intermediate and 84.23% for high-risk), respectively. A multivariate analysis identified recurrent tumors (HR 1.83), the duration of adjuvant HIVEC therapy <4 months (HR 1.72) and that high-risk group (HR 1.47) were at an increased risk of recurrence. Independent factors of progression were high-risk (HR 3.89), recurrent tumors (HR 3.32) and the induction of HIVEC therapy without maintenance (HR 2.37). The overall survival was determined by patient age at diagnosis (HR 3.36) and the treatment duration (HR 1.82). The SAF population (n = 592) revealed 406 (68.58%) patients without AEs and 186 (31.42%) with at least one AE: 170 (28.72%) of grade 1-2 and 16 (2.7%) of grade 3-4. The most frequent AEs were dysuria (10%), pain (7.1%), urgency (5.7%), skin rash (4.9%), spasms (3.7%) and hematuria (3.6%); (4) Conclusions: HIVEC using BRS is efficacious and well tolerated. A longer treatment duration, its use in naïve patients and the intermediate-risk disease are independent determinants of success. Furthermore, a monthly maintenance of adjunct MMC HIVEC diminishes the progression rate of NMIBC.

High incidence of advanced colorectal neoplasia during endoscopic surveillance in serrated polyposis syndrome.

BACKGROUND: Serrated polyposis syndrome (SPS) has been associated with an increased risk of colorectal cancer (CRC). Accordingly, intensive surveillance with annual colonoscopy is advised. The aim of this multicenter study was to describe the risk of advanced lesions in SPS patients undergoing surveillance, and to identify risk factors that could guide the prevention strategy. METHODS: From March 2013 to April 2015, 296 patients who fulfilled criteria I and/or III for SPS were retrospectively recruited at 18 centers. We selected patients in whom successful clearing colonoscopy had been performed and who underwent subsequent endoscopic surveillance. Advanced neoplasia was defined as CRC, advanced adenoma, or advanced serrated lesion that were ≥ 10 mm and/or with dysplasia. Cumulative incidence of advanced neoplasia was calculated and independent predictors of advanced neoplasia development were identified. RESULTS: In 152 SPS patients a total of 315 surveillance colonoscopies were performed (median 2, range 1 - 7). The 3-year cumulative incidence of CRC and advanced neoplasia were 3.1 % (95 % confidence interval [CI] 0 - 6.9) and 42.0 % (95 %CI 32.4 - 51.7), respectively. Fulfilling both I + III criteria and the presence of advanced serrated lesions at baseline colonoscopy were independent predictors of advanced neoplasia development (odds ratio [OR] 1.85, 95 %CI 1.03 - 3.33, P  = 0.04 and OR 2.62, 95 %CI 1.18 - 5.81, P  = 0.02, respectively). During follow-up, nine patients (5.9 %) were referred for surgery for invasive CRC (n = 4, 2.6 %) or because of polyp burden (n = 5, 3.3 %). After total colectomy, 17.9 % patients developed advanced neoplasia in the retained rectum. CONCLUSIONS: Patients with SPS have a substantial risk of developing advanced neoplasia under endoscopic surveillance, whereas CRC incidence is low. Personalized endoscopic surveillance based on polyp burden and advanced serrated histology could help to optimize prevention in patients with SPS.

POLE and POLD1 screening in 155 patients with multiple polyps and early-onset colorectal cancer.

Germline mutations in POLE and POLD1 have been shown to cause predisposition to colorectal multiple polyposis and a wide range of neoplasms, early-onset colorectal cancer being the most prevalent. In order to find additional mutations affecting the proofreading activity of these polymerases, we sequenced its exonuclease domain in 155 patients with multiple polyps or an early-onset colorectal cancer phenotype without alterations in the known hereditary colorectal cancer genes. Interestingly, none of the previously reported mutations in POLE and POLD1 were found. On the other hand, among the genetic variants detected, only two of them stood out as putative pathogenic in the POLE gene, c.1359 + 46del71 and c.1420G > A (p.Val474Ile). The first variant, detected in two families, was not proven to alter correct RNA splicing. Contrarily, c.1420G > A (p.Val474Ile) was detected in one early-onset colorectal cancer patient and located right next to the exonuclease domain. The pathogenicity of this change was suggested by its rarity and bioinformatics predictions, and it was further indicated by functional assays in Schizosaccharomyces pombe. This is the first study to functionally analyze a POLE genetic variant outside the exonuclease domain and widens the spectrum of genetic changes in this DNA polymerase that could lead to colorectal cancer predisposition.

Low efficacy of metronidazole in the eradication of Blastocystis hominis in symptomatic patients: Case series and systematic literature review. / Escasa eficacia de metronidazol en la erradicación de Blastocystis hominis en pacientes sintomáticos: serie de casos y revisión sistemática de la literatura.

INTRODUCTION: Blastocystis hominis (B. hominis) is a protozoan commonly found in the gastrointestinal tract. There are doubts about its clinical significance. Metronidazole (MTZ) is the recommended first-line treatment. MATERIALS AND METHODS: A retrospective review was carried out between 2011 and 2012. A total of 151 samples were randomly selected from 383 samples positive for B. hominis. Inclusion criteria were: suggestive symptoms, treatment indication and microbiological follow-up. A systematic review was performed of all studies that evaluated the effect of MTZ on B. hominis infection. RESULTS: Forty-six patients met the inclusion criteria (64% women; age, 44.2±2 years). MTZ was used in 39 patients, 31 of whom obtained a clinical response (79.5%) but only 15 a microbiological response (48.4%). No dose-effect relationship was observed. Twenty patients with no initial microbiological response received a second round of treatment (MTZ, cotrimoxazole, paramomycin, others), with a microbiological response in 70%. Overall, B. hominis was cured in 72% (95% CI: 57%-83%). Of 54 treatments associated with a clinical response, a microbiological response occurred in 31 (57%), while in the remaining 12 with no clinical response, microbiological cure was observed in only 2 (17%) (P=.022). The eradication rate in the systematic review varied between 0% and 100%. CONCLUSIONS: There seems to be a relationship between the clinical and microbiological response to B. hominis treatment. The microbiological response to MTZ treatment is insufficient in our geographical setting. The systematic review shows that the response to MTZ is very variable.

Colorectal cancer risk factors in patients with serrated polyposis syndrome: a large multicentre study.

OBJECTIVE: Serrated polyposis syndrome (SPS) is associated with an increased colorectal cancer (CRC) risk, although the magnitude of the risk remains uncertain. Whereas intensive endoscopic surveillance for CRC prevention is advised, predictors that identify patients who have high CRC risk remain unknown. We performed a multicentre nationwide study aimed at describing the CRC risk in patients with SPS and identifying clinicopathological predictors independently associated with CRC. DESIGN: From March 2013 through September 2014, patients with SPS were retrospectively recruited at 18 Spanish centres. Data were collected from medical, endoscopy and histopathology reports. Multivariate logistic regression was performed to identify CRC risk factors. RESULTS: In 296 patients with SPS with a median follow-up time of 45 months (IQR 26-79.7), a median of 26 (IQR 18.2-40.7) serrated polyps and 3 (IQR 1-6) adenomas per patient were detected. Forty-seven patients (15.8%) developed CRC at a mean age of 53.9±12.8, and 4 out of 47 (8.5%) tumours were detected during surveillance (cumulative CRC incidence 1.9%). Patients with >2 sessile serrated adenomas/polyps (SSA/Ps) proximal to splenic flexure and ≥1 proximal SSA/P with high-grade dysplasia were independent CRC risk factors (incremental OR=2, 95% CI 1.22 to 3.24, p=0.006). Patients with no risk factors showed a 55% decrease in CRC risk (OR=0.45, 95% CI 0.24 to 0.86, p=0.01). CONCLUSIONS: Patients with SPS have an increased risk of CRC, although lower than previously published. Close colonoscopy surveillance in experienced centres show a low risk of developing CRC (1.9% in 5 years). Specific polyp features (SSA/P histology, proximal location and presence of high-grade dysplasia) should be used to guide clinical management.

Multiple sporadic colorectal cancers display a unique methylation phenotype.

Epigenetics are thought to play a major role in the carcinogenesis of multiple sporadic colorectal cancers (CRC). Previous studies have suggested concordant DNA hypermethylation between tumor pairs. However, only a few methylation markers have been analyzed. This study was aimed at describing the epigenetic signature of multiple CRC using a genome-scale DNA methylation profiling. We analyzed 12 patients with synchronous CRC and 29 age-, sex-, and tumor location-paired patients with solitary tumors from the EPICOLON II cohort. DNA methylation profiling was performed using the Illumina Infinium HM27 DNA methylation assay. The most significant results were validated by Methylight. Tumors samples were also analyzed for the CpG Island Methylator Phenotype (CIMP); KRAS and BRAF mutations and mismatch repair deficiency status. Functional annotation clustering was performed. We identified 102 CpG sites that showed significant DNA hypermethylation in multiple tumors with respect to the solitary counterparts (difference in ß value ≥0.1). Methylight assays validated the results for 4 selected genes (p = 0.0002). Eight out of 12(66.6%) multiple tumors were classified as CIMP-high, as compared to 5 out of 29(17.2%) solitary tumors (p = 0.004). Interestingly, 76 out of the 102 (74.5%) hypermethylated CpG sites found in multiple tumors were also seen in CIMP-high tumors. Functional analysis of hypermethylated genes found in multiple tumors showed enrichment of genes involved in different tumorigenic functions. In conclusion, multiple CRC are associated with a distinct methylation phenotype, with a close association between tumor multiplicity and CIMP-high. Our results may be important to unravel the underlying mechanism of tumor multiplicity.

Case-control study for colorectal cancer genetic susceptibility in EPICOLON: previously identified variants and mucins.

BACKGROUND: Colorectal cancer (CRC) is the second leading cause of cancer death in developed countries. Familial aggregation in CRC is also important outside syndromic forms and, in this case, a polygenic model with several common low-penetrance alleles contributing to CRC genetic predisposition could be hypothesized. Mucins and GALNTs (N-acetylgalactosaminyltransferase) are interesting candidates for CRC genetic susceptibility and have not been previously evaluated. We present results for ten genetic variants linked to CRC risk in previous studies (previously identified category) and 18 selected variants from the mucin gene family in a case-control association study from the Spanish EPICOLON consortium. METHODS: CRC cases and matched controls were from EPICOLON, a prospective, multicenter, nationwide Spanish initiative, comprised of two independent stages. Stage 1 corresponded to 515 CRC cases and 515 controls, whereas stage 2 consisted of 901 CRC cases and 909 controls. Also, an independent cohort of 549 CRC cases and 599 controls outside EPICOLON was available for additional replication. Genotyping was performed for ten previously identified SNPs in ADH1C, APC, CCDN1, IL6, IL8, IRS1, MTHFR, PPARG, VDR and ARL11, and 18 selected variants in the mucin gene family. RESULTS: None of the 28 SNPs analyzed in our study was found to be associated with CRC risk. Although four SNPs were significant with a P-value < 0.05 in EPICOLON stage 1 [rs698 in ADH1C (OR = 1.63, 95% CI = 1.06-2.50, P-value = 0.02, recessive), rs1800795 in IL6 (OR = 1.62, 95% CI = 1.10-2.37, P-value = 0.01, recessive), rs3803185 in ARL11 (OR = 1.58, 95% CI = 1.17-2.15, P-value = 0.007, codominant), and rs2102302 in GALNTL2 (OR = 1.20, 95% CI = 1.00-1.44, P-value = 0.04, log-additive 0, 1, 2 alleles], only rs3803185 achieved statistical significance in EPICOLON stage 2 (OR = 1.34, 95% CI = 1.06-1.69, P-value = 0.01, recessive). In the joint analysis for both stages, results were only significant for rs3803185 (OR = 1.12, 95% CI = 1.00-1.25, P-value = 0.04, log-additive 0, 1, 2 alleles) and borderline significant for rs698 and rs2102302. The rs3803185 variant was not significantly associated with CRC risk in an external cohort (MCC-Spain), but it still showed some borderline significance in the pooled analysis of both cohorts (OR = 1.08, 95% CI = 0.98-1.18, P-value = 0.09, log-additive 0, 1, 2 alleles). CONCLUSIONS: ARL11, ADH1C, GALNTL2 and IL6 genetic variants may have an effect on CRC risk. Further validation and meta-analyses should be undertaken in larger CRC studies.

MSH6 and MUTYH deficiency is a frequent event in early-onset colorectal cancer.

PURPOSE: Early-onset colorectal cancer (CRC) is suggestive of a hereditary predisposition. Lynch syndrome is the most frequent CRC hereditary cause. The MUTYH gene has also been related to hereditary CRC. A systematic characterization of these two diseases has not been reported previously in this population. EXPERIMENTAL DESIGN: We studied a retrospectively collected series of 140 patients ≤50 years old diagnosed with nonpolyposis CRC. Demographic, clinical, and familial features were obtained. Mismatch repair (MMR) deficiency was determined by microsatellite instability (MSI) analysis, and immunostaining for MLH1, MSH2, MSH6, and PMS2 proteins. Germline MMR mutations were evaluated in all MMR-deficient cases. Tumor samples with loss of MLH1 or MSH2 protein expression were analyzed for somatic methylation. Germline MUTYH mutations were evaluated in all cases. BRAF V600E and KRAS somatic mutational status was also determined. RESULTS: Fifteen tumors (11.4%) were MSI, and 20 (14.3%) showed loss of protein expression (7 for MLH1/PMS2, 2 for isolated MLH1, 3 for MSH2/MSH6, 7 for isolated MSH6, and 1 for MSH6/PMS2). We identified 11 (7.8%) germline MMR mutations, 4 in MLH1, 1 in MSH2, and 6 in MSH6. Methylation analysis revealed one case with somatic MLH1 methylation. Biallelic MUTYH mutations were detected in four (2.8%) cases. KRAS and BRAF V600E mutations were present in 39 (27.9%) and 5 (3.6%) cases, respectively. CONCLUSIONS: Loss of MSH6 expression is the predominant cause of MMR deficiency in early-onset CRC. Our findings prompt the inclusion of MSH6 and MUTYH screening as part of the genetic counseling of these patients and their relatives.

Susceptibility genetic variants associated with colorectal cancer risk correlate with cancer phenotype.

BACKGROUND & AIMS: Ten common low-penetrant genetic variants have been consistently associated with colorectal cancer (CRC) risk; little is known about the correlation between these variants and CRC phenotype. Characterization of such a correlation would improve CRC management and prevention programs. We assessed the association between these genetic variants and CRC phenotype in patients and modeled pairwise combinations to detect epistasis. METHODS: The validation population corresponded to a prospective, multicenter, population-based cohort (EPICOLON I) of 1096 patients with newly diagnosed CRC. The replication set was an independent, prospective, multicenter Spanish cohort (EPICOLON II) of 895 patients with newly diagnosed CRC. For individual single nucleotide polymorphism (SNP) association analyses, a multivariate method using logistic regression was applied in EPICOLON I and subsequently prospectively validated in EPICOLON II. Interactions between SNPs were assessed using the likelihood ratio test. RESULTS: Validated results confirmed that the C allele on 8q23.3 (rs16892766) was significantly associated with advanced-stage tumors (odds ratio [OR], 1.48; 95% confidence interval [CI], 1.15-1.90; P value = 4.9 x 10(-3)). The G allele on 8q24.21 (rs6983267) was more common in patients with a familial history of CRC (OR, 2.02; 95% CI, 1.35-3.03; P value = 3.9 x 10(-4)). The combination of rs6983267 on 8q24.21 and rs9929218 on 16q22.2 was associated with a history of colorectal adenoma (carriers of GG and AA, respectively; OR, 2.28; 95% CI, 1.32-3.93; P = 5.0 x 10(-4)). CONCLUSIONS: CRC susceptibility variants at 8q23.3, 8q24.21, and 16q22.2 appear to be associated with cancer phenotype. These findings might be used to develop screening and surveillance strategies.

Telomerase mRNA expression and immunohistochemical detection as a biomarker of malignant transformation in patients with inflammatory bowel disease.

BACKGROUND: Inflammatory bowel disease is a premalignant condition for developing colorectal cancer. Since a correlation has been suggested between telomere length, chromosomal instability and neoplastic transformation in this setting, we sought to investigate whether telomerase expression in colorectal mucosa may constitute a biomarker for malignant transformation in patients with inflammatory bowel disease. PATIENTS AND METHODS: Forty-seven patients with inflammatory bowel disease with and without cancer or dysplasia were evaluated for human telomerase reverse transcriptase hTERT immunostaining in paraffin-embedded, formalin-fixed colorectal tissues. In addition, hTERT mRNA expression was assessed in fresh frozen specimens from a second set of 35 patients with inflammatory bowel disease at high or low risk for neoplastic transformation. RESULTS: Five out of 10 patients (50%) with colorectal cancer or high-grade dysplasia exhibited hTERT immunochemical detection in adjacent, non-transformed colonic mucosa. However, this phenomenon was also observed in non-affected mucosa of patients with either long-standing (13 out of 19 patients; 68%) or short duration (13 out of 18 patients; 72%) disease without cancer or dysplasia. On the other hand, hTERT mRNA expression in non-affected colorectal mucosa from patients at high risk for neoplastic transformation due to long-standing disease was higher than in those at low risk (7.42+/-6.43 vs. 2.87+/-1.47, respectively; p=0.006). CONCLUSIONS: Whereas hTERT immunostaining provides equivocal results, the observation that patients at high risk for colorectal cancer because of long-standing inflammatory bowel disease overexpress hTERT mRNA in non-affected colorectal mucosa suggests its potential usefulness as a biomarker of the risk of malignant transformation.

Aberrant gene promoter methylation associated with sporadic multiple colorectal cancer.

BACKGROUND: Colorectal cancer (CRC) multiplicity has been mainly related to polyposis and non-polyposis hereditary syndromes. In sporadic CRC, aberrant gene promoter methylation has been shown to play a key role in carcinogenesis, although little is known about its involvement in multiplicity. To assess the effect of methylation in tumor multiplicity in sporadic CRC, hypermethylation of key tumor suppressor genes was evaluated in patients with both multiple and solitary tumors, as a proof-of-concept of an underlying epigenetic defect. METHODOLOGY/PRINCIPAL FINDINGS: We examined a total of 47 synchronous/metachronous primary CRC from 41 patients, and 41 gender, age (5-year intervals) and tumor location-paired patients with solitary tumors. Exclusion criteria were polyposis syndromes, Lynch syndrome and inflammatory bowel disease. DNA methylation at the promoter region of the MGMT, CDKN2A, SFRP1, TMEFF2, HS3ST2 (3OST2), RASSF1A and GATA4 genes was evaluated by quantitative methylation specific PCR in both tumor and corresponding normal appearing colorectal mucosa samples. Overall, patients with multiple lesions exhibited a higher degree of methylation in tumor samples than those with solitary tumors regarding all evaluated genes. After adjusting for age and gender, binomial logistic regression analysis identified methylation of MGMT2 (OR, 1.48; 95% CI, 1.10 to 1.97; p = 0.008) and RASSF1A (OR, 2.04; 95% CI, 1.01 to 4.13; p = 0.047) as variables independently associated with tumor multiplicity, being the risk related to methylation of any of these two genes 4.57 (95% CI, 1.53 to 13.61; p = 0.006). Moreover, in six patients in whom both tumors were available, we found a correlation in the methylation levels of MGMT2 (r = 0.64, p = 0.17), SFRP1 (r = 0.83, 0.06), HPP1 (r = 0.64, p = 0.17), 3OST2 (r = 0.83, p = 0.06) and GATA4 (r = 0.6, p = 0.24). Methylation in normal appearing colorectal mucosa from patients with multiple and solitary CRC showed no relevant difference in any evaluated gene. CONCLUSIONS: These results provide a proof-of-concept that gene promoter methylation is associated with tumor multiplicity. This underlying epigenetic defect may have noteworthy implications in the prevention of patients with sporadic CRC.

Association of MUTYH and MSH6 germline mutations in colorectal cancer patients.

Colorectal cancer (CRC) risk associated with germline monoallelic MUTYH mutations remains controversial, although a slightly increased risk for this disease has been suggested. MUTYH and MSH6 proteins act in cooperation during the DNA repair process. Based on this interaction, it was hypothesized that the combination of heterozygote germline mutations in both genes could result in an increased CRC risk. To further clarify the interaction between MUTYH and MSH6, we analyzed the prevalence of MSH6 mutations in a cohort of CRC patients and controls previously tested for MUTYH mutations: CRC patients with and without a monoallelic MUTYH mutation (group I, n = 26; group II, n = 50, respectively), and healthy carriers with a monoallelic MUTYH mutation (group III, n = 21). In group I, we found three patients (11.5%) with MSH6 mutations, a missense mutation (p.R635G), a change in the 3'UTR region (c.*4098A > C) and a nonsense mutation (p.Q982X). In group II and III, no mutations were detected. In CRC patients, MSH6 mutations were more frequently found in MUTYH mutation carriers than in noncarriers (11.5% vs. 0%, P = 0.037). CRC patients carrying monoallelic MUTYH mutations harbor more frequently concomitant MSH6 mutations than patients without them, thus suggesting that both genes could act cooperatively and confer together an increased CRC risk.

Endoscopic requirements of colorectal cancer screening programs in average-risk population. Estimation according to a Markov model.

BACKGROUND: Although colorectal cancer (CRC) screening strategies are quite common in the United States, their systematic introduction in Europe has been delayed until the year 2008. To estimate endoscopic requirements of four different CRC screening strategies (annual and biennial fecal occult blood testing (FOBT), flexible sigmoidoscopy every 5 years, and colonoscopy every 10 years) in an average-risk population. METHODS: A long-term Markov process model was designed combining three adherence rates for the four above-mentioned screening strategies in individuals aged from 50 to 74. Estimations included endoscopic procedures performed for both screening and surveillance purposes. Models were adjusted for age-related adenoma and CRC incidence rates, life expectancy, and cancer-related survival. RESULTS: The mean number of annual colonoscopies per 100,000 individuals aged 50-74 ranged from 100 to 271 for annual FOBT, from 75 to 203 for biennial FOBT, from 222 to 601 for sigmoidoscopy, and from 903 to 2,449 for colonoscopy-based strategies, depending on the adherence rate. According to these estimations, annual and biennial FOBT strategies would generate a slight decrease of current endoscopic activity (1.4-3.8% and 2.7-7.2%, respectively), whereas sigmoidoscopy and colonoscopy-based strategies would induce a 4.7-12.8% and 32-87% increase, respectively, with respect to a non-screening scenario. The model confirmed a 3-16% mean reduction of CRC incidence depending on the strategy and adherence rate. CONCLUSION: Whereas endoscopic capacity exists for widespread CRC screening with annual or biennial FOBT, implementation of potentially more effective strategies, such as flexible sigmoidoscopy or colonoscopy, would result in a significant increase of current endoscopic resources.

Lynch syndrome in colorectal cancer patients.

Lynch syndrome, also known as hereditary nonpolyposis colorectal cancer, is the most common form of hereditary colorectal cancer. It is characterized by early onset of colorectal cancer and other extracolonic-associated malignancies. This disorder is inherited in an autosomal dominant pattern and is due to a mutation in one of the DNA mismatch repair genes. Although clinical and molecular understanding of the syndrome has progressed dramatically in the last decade, diagnosis of the syndrome is still a clinical challenge. This review summarizes the main features of the syndrome and provides an update of its management.

[Epigenetics of cancer]. / Epigenética del cáncer.

The pathogenesis of cancer includes both genetic and epigenetic mechanisms. The term <> refers to any alteration of gene expression, potentially hereditary, which is not accompanied by a modification in the DNA sequence. The effects of epigenetic changes include alteration of DNA transcription, aberrant activation of specific genes, predisposition of genetic instability through alteration of the control of chromosome replication and silencing of the genes implicated in cancer initiation and progression. Among the various epigenetic alterations that lead to altered gene expression, methylation is the main epigenomic mechanism implicated in cancer, whether through a phenomenon of overall hypomethylation or hypermethylation localized in the promoters of specific genes.