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Colorectal cancer (CRC) has a high incidence and mortality worldwide. Microsatellite instability (MSI) is crucial in CRC, with distinct molecular and clinicopathological features in patients. Nowadays, it is a predictive marker for immunotherapy. We proposed to evaluate the 5-year outcome of MSI status in 1002 Brazilian CRC, and associate it with genetic ancestry, molecular and clinicopathological features. MSI evaluation was performed using molecular markers. MSI+ tumors were analyzed for alterations in 23 MSI-targeted genes. Genetic ancestry was evaluated using an Ancestry-Informative markers panel. MSI status was analyzed in relation to CRC specific survival and other clinical and genetic variables. MSI+ status was observed in 10.5% of cases. MSI+ status was significantly associated with the anatomic site right colon, mucinous histological type, clinical stage II, histological grade III/undifferentiated, no recurrence of disease, and live cases without cancer. No association of MSI status with genetic ancestry components was observed. MSI-targeted genes analyses showed the most frequently altered genes: ATM, EGFR, MRE11, ROCK1, and TGFBRII. There was a statistically significant difference in cancer-specific survival between cases according to MSI status. This study constitutes the most comprehensive analyses of the MSI impact on the Brazilian CRC. MSI+ frequency in Brazilian CRC agreed with the literature and was associated with several clinicopathological features related with less aggressive tumors, independently of their genetic ancestry.

The present study compared the accuracy of ColonView (CV) quick test in detecting proximal versus distal colorectal cancer (CRC). A traditional guaiac-based fecal occult blood test (gFOBT) (Hemoccult SENSA) was used as a reference.A cohort of 368 colonoscopy-referral patients were asked to collect 3 consecutive fecal samples, to be analyzed by both assays (CV, SENSA). Receiver operating characteristic (ROC) analysis was used to find the optimal cut-off values for both Hb and Hb/Hp of the CV test. Summary hierarchical ROC (HSROC) curves were used to visualize the pooled overall accuracy of visually analysed (VA) and automatically analyzed (AA) reading modes in proximal and distal CRC detection.The overall specificity (Sp) of the AA reading mode for the proximal CRC and distal CRC endpoint was 73% and 76%, respectively. For proximal CRC, the two most sensitive AA tests showed 90% sensitivity (Se), while for distal CRC, the two most sensitive AA tests showed 100% Se. In the HSROC analysis, the AUC values were as follows: i) VA in proximal CRC: 0.765, ii) AA in proximal CRC: 0.878, iii) VA in distal CRC: 0.955 and iv) AA in distal CRC: 0.961. In roccomp analysis, AUC values were significantly different in: VA vs. AA in proximal CRC p=0.009; VA in proximal vs. VA in distal CRC p0.0001; VA in proximal vs. AA in distal CRC p0.0001; AA in proximal vs. VA in distal CRC p=0.021; AA in proximal CRC vs. AA in distal CRC p=0.006.The applicability of the CV test (a new-generation FIT) in CRC screening was confirmed. The AA reading was superior to VA (or SENSA) in its diagnostic accuracy in detecting proximal CRC patients. Distal CRCs were more accurately detected than proximal CRCs by both reading modes.

AIMS Epigenetic alterations of genes involved in colorectal carcinogenesis are likely to be informative biomarkers for early detection. We assessed the methylation profile of a panel of seven colon cancer-related genes comparing normal colon, colorectal cancer (CRC) precursor lesions and cancer tissues from a Brazilian cohort. METHODS The cohort comprised 114 CRC patients, including 40 matched normal tissue, 47 patients with adenomas, 33 with serrated polyps and 8 with normal colonic biopsy. DNA methylation status of SEPT9, ALX4, NDRG4, BMP3, APC, p16 and MLH1 was determined by pyrosequencing and correlated with clinicopathological features. Sensitivity, specificity, positive predictive value and negative predictive value were calculated for all genes using cancer endpoint. RESULTS The most frequently methylated genes in cancer and in precancer lesions were SEPT9, ALX4, NDRG4, and BMP3, ranging from 55.3 to 95% of the samples. Overall, the frequency of methylation of these four genes in normal colonic tissue was significantly lower as compared to cancer or precursor lesions both in adenoma-carcinoma (p

Background: Colorectal cancer (CRC) is the second leading cause of cancer death worldwide. The development of colorectal cancer is composed of multiple stages, starting with benign polyps in the large intestine and rectum, and gradually progress to carcinomas, providing a window of opportunity for early detection. Early diagnosis increases the survival rate of patients, thus making screening tests for precursor lesions (PL) and early-stage CRC essential for reducing the mortality rate. In this context, the early detection of tumors based on liquid biopsy could provide benefits for improving the survival rate of CRC patients and has emerged as a promising avenue for cancer screening. The aim of the study was to evaluate the presence of variants in plasma cell-free tumor DNA from patients with PL and CCR to identify diagnostic and early screening biomarkers. Material and Methods: The cell-free DNA (cfDNA) samples were obtained from plasma of patients that underwent diagnostic colonoscopy. Eight patients did not have any significant lesions (normal colonoscopy or hyperplastic polyp) and were classified as normal (N), 28 as CRC and 23 as PL - 13 as early adenomas (EA), 9 advanced adenomas (AA), and 1 sessile serrated lesion (SSL). In addition, the genomic DNA samples from 2 FFPE tumor matched pair samples were analyzed. Analysis of variants in 14 CRC associated genes was performed using Oncomine Colon cfDNA Assay and Ion Torrent PGM/S5 sequencer. Results and discussion: All variants were classified as missense or truncating and considered as pathogenic. Forty-seven variants were detected in nine genes (TP53, PIK3CA,FBXW7, APC, BRAF, GNAS, KRAS, MAP2K1, and SMAD4). TP53 gene showed the highest number of variants, comprising 53.19% of all detected variants, followed by KRAS (10.63%) and APC (8.51%). It was possible to detect the presence of at least one variant in ctDNA for 5 PL (5/23 - 21.73%) patients, including variants in 3 patients with early adenoma (3/13 - 23.07%) and 2 with advanced adenomas (2/9 - 22.22%) and fourteen CRC (14/28 - 50%). No variants were detected in patients with normal findings during colonoscopy. Concordance between detected variants in tumor tissue and plasma ctDNA (from matched samples) was observed only for two variants for CRC patients (GNAS and KRAS). Conclusion: The detection of variants in liquid biopsy demonstrates the potential for non-invasive early screening and diagnostic of CRC. Citation Format: Mariana Bisarro Dos Reis, Wellington dos Santos, Ana Carolina de Carvalho, Adhara Brandão, Adhara Brandão, Marcus Matsushita, Rui Manuel Reis, Denise Peixoto Guimarães. Use of liquid biopsy for detection of pathogenic variants in cell-free tumor DNA from patients with precursor lesions and colorectal cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 3380.

Colorectal cancer is the second most common cancer in Brazil. Yet, a nationally organized colorectal screening program is not implemented. Barretos Cancer Hospital (BCH) is one of the largest Brazilian institution that cares for underserved patients. BCH developed a fecal immunochemical test (FIT)-based organized colorectal cancer screening program to improve colorectal cancer outcomes. This study aims to present the quality/performance measures of the first 2 years of the FIT-based colorectal cancer screening program and its impact on the colorectal cancer disease stage. Between 2015 and 2017, a total of 6,737 individuals attending the Outpatient Department of Prevention or the Mobile Unit of BCH, which visits 18 cities of Barretos county, ages 50 to 65 years, were personally invited by a health agent/nurse practitioner. Exclusion criteria were personal history of colorectal cancer, adenomatous polyps, inflammatory bowel disease, and colonoscopy, or flexible sigmoidoscopy performed in the past 5 years. European Union (EU) guidelines for colorectal cancer screening programs were evaluated. Overall, 92.8% returned the FIT, with an inadequate examination rate of 1.5%. Among the 6,253 adequately tested, 12.5% had a positive result. The colonoscopy compliance and completion rates were 84.6 and 98.2%, respectively. The PPVs were 60.0%, 16.5%, and 5.6% for adenoma, advanced adenoma, and cancer, respectively. Stage distribution of screen-detected cancers shows earlier stages than clinically diagnosed colorectal cancer cancers reported at BCH and Brazilian cancer registries. Our colorectal cancer screening program achieved desirable quality metrics, aligned with the EU guidelines. The observed shift toward earlier colorectal cancer stages suggests an exciting opportunity to improve colorectal cancer–related cancers in Brazil.

Colorectal cancer (CRC) is one of the most frequent and deadly neoplasms worldwide. Genetic factors, lifestyle habits, and inflammation are important risk factors associated with CRC development. In recent years, growing evidence has supporting the significant role of the intestinal microbiome in CRC carcinogenesis. Disturbances in the healthy microbial balance, known as dysbiosis, are frequently observed in these patients. Pathogenic microorganisms that induce intestinal dysbiosis have become an important target to determine the role of bacterial infection in tumorigenesis. Interestingly, the presence of different bacterial strains, such as Fusobacterium nucleatum, has been detected in tissue and stool from patients with CRC and associated with substantial clinical and molecular features, as well as with patient therapy response. Therefore, understanding how the presence and levels of F. nucleatumstrains in the gut affect the risk of CRC onset and progression may inform suitable candidates for interventions focused on modulation of this bacteria. Here we review new insights into the role of gut microbiota in CRC carcinogenesis and the clinical utility of using the detection of F. nucleatum in different settings such as screening, prognosis, and microbiota modulation as a means to prevent cancer, augment therapies, and reduce adverse effects of treatment.

Made available in DSpace on 2022-04-29T08:35:38Z (GMT). No. of bitstreams: 0 Previous issue date: 2022-01-01 Background: Chagasic megaesophagus (CM) as well as the presence of human papillomavirus (HPV) has been reported as etiological factors for esophageal squamous cell carcinoma (ESCC). Objective: We assessed the prevalence of HPV DNA in a series of ESCCs associated or not with CM. Data obtained were further correlated to the pathological and clinical data of affected individuals. Methods: A retrospective study was performed on 92 formalin-fixed and paraffin-embedded tissues collected from patients referred to 3 different hospitals in São Paulo, Brazil: Barretos Cancer Hospital, Barretos, São Paulo; Federal University of Triângulo Mineiro, Uberaba, Minas Gerais; and São Paulo State University, Botucatu, São Paulo. Cases were divided into 3 groups: (i) 24 patients with CM associated with ESCC (CM/ESCC); (ii) 37 patients with ESCC without CM (ESCC); and (iii) 31 patients with CM without ESCC (CM). Detection of HPV DNA was assessed in all samples by a genotyping assay combining multiplex polymerase chain reaction and bead-based Luminex technology. Results: We identified a high prevalence of high-risk HPV in patients in the CM group (12/31, 38.8%) and CM/ESCC (8/24, 33.3%), compared to individuals in the ESCC group (6/37, 16.3%). The individuals in the groups with cancer (ESCC and CM/ESCC) had a higher frequency of HPV-16 (4/9, 44.5% and 2/8, 25.0%). The other types of high-risk HPVs detected were HPV-31, 45, 51, 53, 56, 66, and 73. We also observed in some samples HPV coinfection by more than one viral type. Despite the high incidence of HPV, it did not show any association with the patient's clinical-pathological and molecular (TP53 mutation status) characteristics. Conclusion: This is the first report of the presence of HPV DNA in CM associated with ESCC. HPV infection was more presence in megaesophagus lesions. Further studies are needed to confirm and better understand the role of persistent HPV infection in patients with CM. Molecular Oncology Research Center Barretos Cancer Hospital Center for Translational Research in Oncology Instituto Do Cancer Do Estado de Sao Paulo-ICESP, Cerqueira César Department of Digestive Surgery Barretos Cancer Hospital Department of Pathology Diagnosis of Biopsies and Surgical Specimens Barretos Cancer Hospital Department of Digestive Surgery and Pathology Medical School UFTM Federal University of Triangulo Mineiro Departament of Gastroenterology Surgery and Pathology Medical School UNESP São Paulo State University Department of Endoscopy Barretos Cancer Hospital Barretos Life and Health Sciences Research Institute (ICVS) School of Medicine University of Minho ICVS/3B's-PT Government Associate Laboratory, Guimarães Department of Radiology and Oncology Faculdade de Medicina Universidade de Sao Paulo Department of Radiology and Oncology Medical School University of São Paulo, Butanta Medical Laboratory of Medical Investigation (LIM) 14 Department of Pathology Medical School University of São Paulo, Butanta Departament of Gastroenterology Surgery and Pathology Medical School UNESP São Paulo State University

Esophageal cancer is an aggressive tumor that has a high rate of incidence and mortality worldwide. It is the 10th most frequent type in Brazil, being squamous cell carcinoma (ESCC) the predominant subtype. There is currently an incessant search to identify the frequently altered genes associated with esophageal squamous cell carcinoma biology that could be druggable. This study aimed to analyze the somatic mutation profile of a large panel of cancer-related genes in Brazilian ESCC. In a series of 46 ESCC diagnoses at Barretos Cancer Hospital, DNA isolated from paired fresh-frozen and blood tissue, a panel of 150 cancer-related genes was analyzed by next-generation sequencing. The genes with the highest frequency of mutations were TP53 (39/46, 84.8%), followed by NOTCH1 (7/46, 15.2%), NFE2L2 (5/46, 10.8%), RB1 (3/46, 6.5%), PTEN (3/46, 6.5%), CDKN2A (3/46, 6.5%), PTCH1 (2/46, 4.3%) and PIK3CA (2/46, 4.3%). There was no significant association between molecular and patients’ clinicopathological features. Applying an evolutionary action score of p53 (EAp53), we observed that 14 (35.9%) TP53 mutations were classified as high-risk, yet no association with overall survival was observed. Concluding, this the largest mutation profile of Brazilian ESCC patients, which helps in the elucidation of the major cancer-related genes in this population.

Background/aim The present study compared the accuracy of visually analyzed (VA) and automatically analyzed (AA) ColonView (CV) quick test; a new-generation fecal immunochemical test (FIT) for hemoglobin (Hb) and hemoglobin/haptoglobin (Hb/Hp) (Biohit Oyj, Helsinki, Finland) in subjects participating in colorectal neoplasia (CRN) detection in Brazil. A traditional guaiac-based fecal occult blood test (gFOBT) test (HemoccultSENSA) was used as a reference. Patients and methods A cohort of 509 colonoscopy-referral patients were asked to collect three consecutive fecal samples, to be analyzed by both CV and SENSA. Results In ROC analysis for the AA reading, the optimal cut-off value for CV Hb was ≥8.0912 and that for CV Hb/Hp was ≥1.8983. With these cut-offs, the sensitivity (Se), specificity (Sp), and efficiency of CV AA in detecting colorectal adenoma (CRA) were: 64.2%/78.6%, 53.4%/35.3%, and 58.6%/56.5%, for Hb and Hb/Hp, respectively. In the HSROC analysis, the AUC values for i) VA and ii) AA modes were as follows: i) AUC=0.551 (95%CI=0.500-0.602), ii) AUC=0.606 (95%CI=0.550-0.662). The difference between these AUC values was statistically significant (p=0.0160). Conclusion The present study confirms the previous results on the applicability of the ColonView quick test in CRN screening. Of the two optional reading modes, the AA reading showed significantly better diagnostic accuracy as compared to the VA reading (or SENSA), in detecting the CRA endpoint in colonoscopy-referral patients.

Background/aim The present study compared the accuracy of visually analyzed (VA) and automatically analyzed (AA) ColonView (CV) quick test; a new-generation immunochemical test (FIT) for Hb and Hb/Hp (Biohit Oyj, Helsinki, Finland) in subjects participating in colorectal cancer (CRC) detection in Brazil. A traditional gFOBT test (HemoccultSENSA) was used as a reference. Patients and methods A cohort of 368 colonoscopy-referral patients were asked to collect 3 consecutive fecal samples, to be analysed by both assays (CV, SENSA). Results In receiver operating characteristic (ROC) analysis for the AA reading, the optimal cut-off value for CV Hb AA (test AA 3) was ≥117 and that for CV Hb/Hp AA (test AA 4) was ≥48. In the hierarchical summary receiver operating characteristic (HSROC) analysis for pooled accuracy of CV with AA and VA reading, the AUC values for i) VA and ii) AA were as follows: i) AUC=0.859 (95%CI=0.839-0.879), ii) AUC=0.931 (95%CI=0.920-0.942). The difference between these AUC values (Roccomp analysis) was statistically significant (p=0.0024). Conclusion The present study confirms the previous studies on the applicability of the ColonView quick test (a new-generation FIT) in CRC screening.

The molecular basis of colorectal cancer (CRC) can guide patient prognosis and therapy. In Brazil, knowledge on the CRC mutation landscape is limited. Here, we investigated the mutation profile of 150 cancer-related genes by next-generation sequencing and associated with microsatellite instability (MSI) and genetic ancestry in a series of 91 Brazilian CRC patients. Driver mutations were found in the APC (71.4%), TP53 (56.0%), KRAS (52.7%), PIK3CA (15.4%) and FBXW7 (10.9%) genes. Overall, genes in the MAPK/ERK, PIK3/AKT, NOTCH and receptor tyrosine kinase signaling pathways were mutated in 68.0%, 23.1%, 16.5%, and 15.3% of patients, respectively. MSI was found in 13.3% of tumors, most of which were proximal (52.4%, P, We are thankful to Barretos Cancer Hospital. This work was supported by the Brazilian Federal Agency for the Support and Evaluation of Graduate Education (CAPES, Brazil), the National Council for Scientifc and Technological Development (CNPq, Brazil), and the Public Ministry of Labor Campinas (Research, Prevention and Education of Occupational Cancer, Brazil).

Background Most colorectal cancers (CRC) arise from precursor lesions. This study aimed to characterize the mutation profile of colorectal cancer precursor lesions in a Brazilian population. Methods In total, 90 formalin-fixed paraffin-embedded colorectal precursor lesions, including 67 adenomas, 7 sessile serrated lesions, and 16 hyperplastic polyps, were analyzed by next-generation sequencing using a panel of 50 oncogenes and tumor suppressor genes. The genetic ancestry of the patients was estimated. Results Somatic driver mutations were identified in 66.7% of cases, including alterations in APC (32.2%), TP53 (20.0%), KRAS (18.9%), BRAF (13.3%) and EGFR (7.8%). Adenomas displayed a higher number of mutations, mainly in APC, compared to serrated polyps (73.1% vs. 47.8%, p = 0.026). Advanced adenomas had a significantly higher frequency of mutation in KRAS and a high overall mutation rate than early adenomas (92.9% vs. 59%, p = 0.006). A high degree of ancestry admixture was observed in the population studied, with a predominance of European components (mean of 73%) followed by African (mean of 11.3%). No association between genetic ancestry and type of lesions was found. The mutation profile of Brazilian colorectal precursor lesions exhibits alteration in APC, KRAS, TP53, and BRAF at different frequencies according to lesion type. Conclusions These results bestow the knowledge of CRC's biologic history and support the potential of these biomarkers for precursor lesions detection in CRC screening of the Brazilian population.

Colorectal cancer (CRC) is one of the most frequent and deadly neoplasms worldwide. Genetic factors, lifestyle habits, and inflammation are important risk factors associated with CRC development. In recent years, growing evidence has supporting the significant role of the intestinal microbiome in CRC carcinogenesis. Disturbances in the healthy microbial balance, known as dysbiosis, are frequently observed in these patients. Pathogenic microorganisms that induce intestinal dysbiosis have become an important target to determine the role of bacterial infection in tumorigenesis. Interestingly, the presence of different bacterial strains, such as Fusobacterium nucleatum, has been detected in tissue and stool from patients with CRC and associated with substantial clinical and molecular features, as well as with patient therapy response. Therefore, understanding how the presence and levels of F. nucleatumstrains in the gut affect the risk of CRC onset and progression may inform suitable candidates for interventions focused on modulation of this bacteria. Here we review new insights into the role of gut microbiota in CRC carcinogenesis and the clinical utility of using the detection of F. nucleatum in different settings such as screening, prognosis, and microbiota modulation as a means to prevent cancer, augment therapies, and reduce adverse effects of treatment.

Background: Chagasic megaesophagus (clinical manifestation of chagasic disease) has been reported as an etiological factor for squamous cell carcinoma of the esophagus, as well as the presence of human papillomavirus (HPV). Objective: We accessed the prevalence of HPV DNA in a series of squamous cell carcinomas of the esophagus associated or not with the chagasic megaesophagus, and within samples of chagasic megaesophagus without cancer. Data obtained was further correlated to the pathological clinical data of affected individuals. Methods: Retrospective study that used a total 92 samples tissue/biopsy specimens of formalin fixed and paraffin embedded tissues were retrospectively collected from the southeast region of Brazil from patients treated in three hospitals: Barretos Cancer Hospital, Barretos, São Paulo; Federal University of Triângulo Mineiro (UFTM), Uberaba, Minas Gerais; and São Paulo State University (UNESP), Botucatu, São Paulo. Cases were divided in three groups: i) 24 patients with chagasic megaesophagus associated with esophageal ESCC (CM/ESCC); ii) 37 patients with esophageal ESCC without chagasic megaesophagus (ESCC); iii) 31 patients with chagasic megaesophagus without esophageal ESCC (CM). Results: We detected a higher prevalence of high-risk HPVs in patients from both CM (12/31, 38.8%) and CM/ESCC groups (8/24, 33.3%), as compared to individuals of the ESCC group (6/37, 16.3%), although data was not statistically significant. We further observed that HPV-16 was more prevalent in patients of the ESCC (4/9, 44.5%) and CM/ESCC groups (2/8, 25.0%). In addition, some of these samples presented infection by multiple HPV types. High-risk HPVs detected were HPV-31, 45, 51, 53, 56, 66, and 73, of which the majority was identified in patients from the CM group. Furthermore, low-risk HPV-11 and HPV70 were identified in individuals from both ESCC and CM groups. Conclusion: This is the first report regarding the presence of HPV DNA in megaesophagus associated with esophageal squamous cell carcinoma. In the present study, HPV infection appears to be directly related to the development of esophageal squamous cell carcinoma in patients with chagasic megaesophagus. Further studies are warrantee to confirm and better understand the role of oncogenic HPV persistent infection in these patients.

Background Periampullary adenocarcinoma is a major clinical problem in high-risk patients including FAP population. A recent modification for visualizing the ampulla of Vater (AV) involves attaching a cap to the tip of the forward-viewing endoscope. Our aim was to compare the rates of complete visualization of AV using this cap-assisted endoscopy (CAE) approach to standard forward-viewing endoscopy (FVE). We also determined: (i) the rates of complications and additional sedation; (ii) the mean time required for duodenal examination; and (iii) the reproducibility among endoscopists performing this procedure. Methods We performed esophagogastroduodenoscopy for AV visualization in 102 > 18 years old using FVE followed by CAE. Video recordings were blinded and randomly selected for independent expert endoscopic evaluation. Results The complete visualization rate for AV was higher in CAE (97.0%) compared to FVE (51.0%) (p p p = 0.30 and p = 0.14). Three more ampullary adenomas were detected using CAE compared to FVE. Cap displacement occurred in one patient, and there was no observed adverse effect of the additional sedatives used. Kappa values for agreement between endoscopists ranged from 0.60 to 0.85. Conclusions CAE is feasible, reproducible and safe, with a higher success rate for complete visualization compared to FVE. Trial registration: ClinicalTrials.gov, NCT02867826, 16 August 2016.

Background Chagasic megaesophagus (clinical manifestation of chagasic disease) has been reported as an etiological factor for squamous cell carcinoma of the esophagus, as well as the presence of human papillomavirus (HPV). Objective We accessed the prevalence of HPV DNA in a series of squamous cell carcinomas of the esophagus associated or not with the chagasic megaesophagus, and within samples of chagasic megaesophagus without cancer. Data obtained was further correlated to the pathological clinical data of affected individuals. Methods Retrospective study that used a total 92 samples tissue/biopsy specimens of formalin fixed and paraffin embedded tissues were retrospectively collected from the southeast region of Brazil from patients treated in three hospitals: Barretos Cancer Hospital, Barretos, São Paulo; Federal University of Triângulo Mineiro (UFTM), Uberaba, Minas Gerais; and São Paulo State University (UNESP), Botucatu, São Paulo. Cases were divided in three groups: i) 24 patients with chagasic megaesophagus associated with esophageal ESCC (CM/ESCC); ii) 37 patients with esophageal ESCC without chagasic megaesophagus (ESCC); iii) 31 patients with chagasic megaesophagus without esophageal ESCC (CM). Results We detected a higher prevalence of high-risk HPVs in patients from both CM (12/31, 38.8%) and CM/ESCC groups (8/24, 33.3%), as compared to individuals of the ESCC group (6/37, 16.3%), although data was not statistically significant. We further observed that HPV-16 was more prevalent in patients of the ESCC (4/9, 44.5%) and CM/ESCC groups (2/8, 25.0%). In addition, some of these samples presented infection by multiple HPV types. High-risk HPVs detected were HPV-31, 45, 51, 53, 56, 66, and 73, of which the majority was identified in patients from the CM group. Furthermore, low-risk HPV-11 and HPV-70 were identified in individuals from both ESCC and CM groups. Conclusion This is the first report regarding the presence of HPV DNA in megaesophagus associated with esophageal squamous cell carcinoma. In the present study, HPV infection appears to be directly related to the development of esophageal squamous cell carcinoma in patients with chagasic megaesophagus. Further studies are warrantee to confirm and better understand the role of oncogenic HPV persistent infection in these patients.

Colorectal cancer (CRC) is a leading cause of cancer death worldwide. Microsatellite instability (MSI) is a genetic pathway leading to CRC, associated with particular clinicopathological features, and recently a major biomarker of immunotherapy response. There is little information the frequency MSI among Brazilian CRC patients, and it is still debatable the ideal methodology for MSI screening in countries with limited resources. We proposed to evaluate MSI by molecular and immunohistochemistry (IHC) methods, to compare both methodologies and also to assess the inclusion of a novel microsatellite marker, HSP110 (T17). The molecular MSI evaluation was performed using a PCR-multiplex panel in a total of 1013 CRC patients. Mismatch repair (MMR) proteins (MLH1, MSH2, MSH6 and PMS2) expression were evaluated by IHC. HSP110 (T17) marker was analyzed by fragment analysis. Molecularly, 89.5% of cases were MSI-negative and 10.5% were MSI-positive. The IHC showed that 88.9% of cases exhibited MMR-proficient status, 10.2% were MMR-deficient and 0.9% was inconclusive. Genotyping of the HSP110 (T17) in 106 MSI-positive and 215 MSI-negative cases showed its alteration only among the MSI-positive cases. We observed agreement (0.956, Kappa Test) between both molecular and IHC methodologies, with only eight discordant results, and in this subset of cases the HSP110 (T17) corroborate the molecular findings. This study suggests the use of molecular assays over IHC for MSI analysis and proposes the inclusion HSP110 (T17) marker as a complementary analysis in discordant cases., The present study was partially supported by a MCT/FINEP/CT-INFRA- PROINFRA 02/2010 grant., info:eu-repo/semantics/publishedVersion

The microsatellite instability (MSI) phenotype may constitute an important biomarker for patient response to immunotherapy, particularly to anti-programmed death-1 inhibitors. MSI is a type of genomic instability caused by a defect in DNA mismatch repair (MMR) proteins, which is present mainly in colorectal cancer and its hereditary form, hereditary nonpolyposis colorectal cancer. Gastrointestinal stromal tumor (GIST) development is associated with activating mutations of KIT proto-oncogene receptor tyrosine kinase (KIT) or platelet-derived growth factor receptor alpha (PDGFRA), which are oncogenes that predict the response to imatinib mesylate. In addition to KIT/PDGFRA mutations, other molecular alterations are important in GIST development. In GISTs, the characterization of the MSI phenotype is scarce and the results are not consensual. The present study aimed to assess MSI in a series of 79 GISTs. The evaluation of MSI was performed by pentaplex polymerase chain reaction comprising five markers, followed by capillary electrophoresis. The expression of MMR proteins was evaluated by immunohistochemistry. Regarding the KIT/PDGFRA/B-Raf proto-oncogene, serine/threonine kinase molecular profile of the 79 GISTs, 83.6% of the tumors possessed KIT mutations, 10.1% had PDGFRA mutations and 6.3% were triple wild-type. The mutated-PDGFRA cases were associated with gastric location and a lower mitotic index compared with KIT-mutated and wild-types, and these patients were more likely to be alive and without cancer. MSI analysis identified 4 cases with instability in one marker, however, additional evaluation of normal tissue and immunohistochemical staining of MMR proteins confirmed their microsatellite-stable nature. The results of the present study indicated that MSI is not involved in GIST tumorigenesis and, therefore, cannot serve as a biomarker to immunotherapy response in GIST., The present study was supported by The Brazilian National Council for Scientific and Technological Development (grant no. 476192/2013-7) and the São Paulo Research Foundation Doctoral Fellowship (grant no. 2013/25787-3)., info:eu-repo/semantics/publishedVersion

Chaga's disease is an important communicable neglected disease that is gaining wider attention due to its increasing incidence worldwide. Achalasia due to chagasic megaesophagus (CM), a complication of this disease, is a known-yet, poorly understood-etiological factor for esophageal squamous cell carcinoma (ESCC) development. In this study, we aimed to perform the analysis of TP53 mutations in a series of Brazilian patients with ESCC that developed in the context CM (ESCC/CM), and to compare with the TP53 mutation profile of patients with benign CM and patients with nonchagasic ESCC. Additionally, we intended to correlate the TP53 mutation results with patient's clinical pathological features. By polymerase chain reaction (PCR) followed by direct sequencing of the hotspot regions of TP53 (exon 5 to 8), we found that TP53 mutations were present in 40.6% (13/32) of the ESCC/CM group, 45% (18/40) of the nonchagasic ESCC group, and in only 3% (1/33) of the benign CM group. Missense mutations were the most common in the three groups, yet, the type and mutated exon mutation varied significantly among the groups. Clinically, the groups exhibited distinct features, with both cancer groups (ESCC and ESCC/CM) been significantly associated higher consumption of alcohol and tobacco, older age, worse Karnofsky performance status, poor outcome than the patients with benign CM. No significant association was found between TP53 mutation profile and clinical-pathological features in any of the three groups. We describe first the time the analysis of TP53 mutations in ESCC that developed in the context of CM, and the observed high frequency of mutations, suggest that TP53 also plays an important role in the tumorigenic process of this unexplored etiological condition., Supported by Barretos Cancer Hospital internal research funds (PAIP). Rui M Reis is recipient of a CNPq Produtividade em Pesquisa grant, info:eu-repo/semantics/publishedVersion

The diagnostic performance of cytology in esophageal squamous cell carcinoma (ESCC) is meticulously described. bjectives: The diagnostic performance of cytology in esophageal squamous cell carcinoma (ESCC) is meticulously described. Methods: Cytological and biopsy specimens were prospectively taken during esophagogastroduodenoscopy of 123 individuals in 2013 and 2014. Cytology samples were maintained in preservative fluid until processing and biopsies were formalin-fixed and paraffin-embedded. Results: Based on endoscopic biopsy results, 70 cases were positive for ESCC whilst 53 were negative for cancer. In addition, brush cytology showed high sensitivity and specificity (98.57 and 96.23%, respectively) in detecting the disease, and high accuracy (97.5%) comparable to that provided by histopathology which is the accepted gold standard. Conclusion: Brush cytology specimens preserved in liquid medium may be a good alternative for ESCC diagnosis., National Council of Techno-logical and Scientific Development (CNPq) (grant number 482666/2012–9) to A.L.F.

The aim of the present study was to compare fecal immunochemical tests (FITs) for colorectal cancer (CRC) screening with the traditional guaiac-based FOB tests (gFOBT). Background/Aim: The aim of the present study was to compare fecal immunochemical tests (FITs) for colorectal cancer (CRC) screening with the traditional guaiac-based FOB tests (gFOBT). Materials and Methods: A cohort of 368 colonoscopy-referral patients were evaluated by i) the new-generation FIT: ColonView quick test (CV; Biohit Oyj, Finland) and ii) a conventional gFOBT HemoccultSENSA (HS; Beckman Coulter, USA). Three fecal samples were requested for both assays, and all subjects underwent diagnostic colonoscopy with biopsy confirmation. Sensitivity (SE), specificity (SP), positive predictive value (PPV), negative predictive value (NPV) and area under curve (AUC) were calculated for both tests using three endpoints: adenoma (A), advanced adenoma (AA) and adenocarcinoma (AC). Results: Colonoscopy and biopsies disclosed normal mucosa in 90/378 (24.5%) subjects, early A in 108/368 (29.3%) cases, AA in 48/368 (13.0%) and AC in 37/368 (10.1%), and non-neoplastic conditions in the remaining 85 (30.3%). For the AC endpoint, the CV (Hb/Hp) test had 94.6% SE and 65.1% SP (AUC=0.799), while the HS test had SE of 75.7% and SP of 84.3% (AUC=0.800). For the A endpoint, the difference between CV and HS was even more pronounced; SE of 44.2% and 19.2%, respectively (p, The Authors thank Ms. Gabriela de Oliveira for the identification and tracking all the patients included in the study. The Authors would also like to give special thanks to Ms. Thais Thalarico for assisting in data analysis, as well as to Ms. Maraisa Costa and Ms. Adriana Carloni for running the analysis of the gFOBT and FIT tests. This study was supported by Biohit Oyj.

The molecular pathogenesis of esophageal squamous cell carcinoma (ESCC) has been increasingly studied, but there is no report on the role of MSI in ESCC development associated with chagasic megaesophagus (CM).Results/methodology: In four ESCC/CM (4/19) we found microsatellite instability (MSI) alterations (21.1%), being three MSI-L (15.8%) and one MSI-H (5.3%). Four out of 35 ESCC cases showed MSI-L (11.4%) and only one out of 26 CM cases presented MSI-L (3.9%). The MSI-H was observed in an ESCC/CM patient that presents lack of MSH6 immunostaining corroborating deficiency in MMR pathway. Interestingly, the MSI-H ESCC/CM case also presented a deletion the HSP110 poly(T)17 gene., This project was supported by Conselho Nacional de Desenvolvimento Cientifico (CNPq) (476192/2013-7) for RM Reis. NC Campanella was recipient of the Fundacao de Amparo a Pesquisada do Estado de Sao Paulo (FAPESP) Post Doctoral Fellowship (2016/03634-9). The authors have no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript apart from those disclosed., info:eu-repo/semantics/publishedVersion

Hotspot mutations (c.-124bp G > A and c.-146bp G > A) in the promoter region of the TERT gene have been recently described in several types of solid tumors, including glioma, bladder, thyroid, liver and skin neoplasms. However, knowledge with respect to colorectal precursor lesions and cancer is scarce. In the present study we aimed to determine the frequency of hotspot TERT promoter mutations in 145 Brazilian patients, including 103 subjects with precursor lesions and 42 with colorectal carcinomas, and we associated the presence of such mutations with the patients clinical-pathological features. The mutation analysis was conclusive in 123 cases, and none of the precursor and colorectal carcinoma cases showed TERT promoter mutations. We conclude that TERT mutations are not a driving factor in colorectal carcinogenesis., This study was financially partially supported by Barretos Cancer Hospital Internal Research Funds (PAIP) to participating authors, info:eu-repo/semantics/publishedVersion

Background: Esophageal squamous cell carcinoma (ESCC) is a highly lethal malignant tumor. Currently, Human papillomavirus (HPV) is suggested as a potential risk factor for esophageal cancer (EC) in addition to the classic risk factors, alcohol and tobacco, but this hypothesis still remains contradictory. We sought to investigate wether HPV and well-known biomarkers (p16 and p53) and patient-related factors that may have impact on survival of ESCC. Methods: We conducted a prospective cohort study. By using multiplex PCR, we determined the prevalence of high risk HPV in ESCC, and evaluated the immunohistochemical expression of p16 and p53, molecular markers related to esophageal carcinogenesis in order to verify the potential influence of these variables in patients's survival. Survival rates were estimated using Kaplan-Meier methods. A multivariate confirmatory model was performed using Cox proportional hazards regression. Results: Twelve (13.8%) of 87 patients were HPV-DNA positive. Positive reactions of p16 and p53 were 10.7% and 68.6%, respectively. Kaplan-Meier analysis indicated that men (p = 0.025) had poor specific-cancer survival and a shorter progression-free survival (p = 0.050) as compared to women; III or IV clinical stage (p < 0.019) had poor specific-cancer survival and a shorter progression-free survival (p < 0.001) compared to I and II clinical stage; not submitted to surgery (< 0.001) and not submitted to chemoradiotherapy (p = 0.039) had a poor specific-cancer survival, as well. The multivariate analysis showed that HPV, p16 and p53 status are not predictive parameters of progression-free and specific-cancer survival. Conclusion: HPV infection and p53 and p16 expression are not prognostic factors in ESCC., CNPq Universal for providing supplies to the largest study, of which this study is a part of, entitled “The role of human papillomavirus (HPV) as the etiologic agent of esophageal cancer. A cross-sectional study, case-control and longitudinal at Barretos Cancer Hospital”; (Grant number 482666/2012–9 to ALF); INCT HPV [Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) [Grant number 08/57889–1 to LLV]; Conselho Nacional de Desenvolvimento Científico e Tencnológico (CNPq) (Grant number 573799/ 2008–3 to LLV)]., info:eu-repo/semantics/publishedVersion

The first publication that associated Human Papillomavirus (HPV) infection and esophageal cancer was published in 1982. However, data are still contradictory and require further investigation. The aim of this study was to identify high risk HPV DNA in esophageal tissue of patients with and without esophageal squamous cell carcinoma (ESCC) and correlate HPV presence with classical risk factors.Invited patients signed the informed consent form, and interviews were conducted in order to obtain information about sociodemographic and lifestyle behavior. During endoscopy, esophageal biopsies were collected from case and controls. Multiplex polymerase chain reaction genotyping was conducted on endoscopic biopsies to identify HPV types and HPV-16 was further evaluated by specific PCR real time.Among 87 cases, 12 (13.8%) had tumors harboring high risk HPV DNA and among 87 controls, 12 (13.8%) had high risk HPV DNA (OR:1.025 [CI:0.405:2.592]). Variables regarding consumption of alcohol and use of tobacco continued to characterize risk factors even after adjustments by presence or absence of high risk HPV.HPV was demonstrated to be frequently and similarly associated to normal and malignant esophageal tissues, but not as an independent risk factor to esophageal cancer.To contribute to the Brazilian population data on this subject, which is still contradictory.

GOAL: To investigate the HPV prevalence and characterize the expression of potential molecular surrogate markers of HPV infection in esophageal squamous cell carcinoma. MATERIALS AND METHODS: The prevalence of HPV in individuals with and without esophageal cancer (EC) was determined by using multiplex PCR; p16 and p53 protein levels were assessed by immunohistochemistry (IHC). RESULTS: High-risk HPV (hr-HPV) was found in the same frequency (13.8%) in esophageal squamous cell carcinoma (ESCC) and in healthy individuals. The p53 expression was positive in 67.5% of tumor tissue, 20.0% of adjacent non-tumoral tissue and 1.8% of normal esophageal tissue. p16 was positive in 11.6% of esophageal cancer cases and 4.7% of adjacent non-tumoral tissue. p16 was undetectable among control group samples. p53 and p16 levels were not significantly associated with the HPV status. CONCLUSIONS: These results suggest that hr-HPV types are not associated with the development of ESCC and that p53 and p16 protein expression have no relationship with HPV infection in normal or cancerous esophagus., This work was supported by Conselho Nacional de Desenvolvimento Científico e Tencnológico (CNPq) [Grants number 482666/2012-9 to ALF; 573799/2008-3 to LLV]; Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) [Grants numbers 13/15968-0 to PRAP; 08/57889-1 to LLV]. CNPq Universal for promoting supplied to the largest study of which this study is part entitled "The role of human papillomavirus (HPV) as the etiologic agent of esophageal cancer. A cross-sectional study, case-control and longitudinal in Barretos Cancer Hospital" (Grant number 482666/2012-9 to ALF); Fundação de Amparo à Pequisa do Estado de São Paulo (FAPESP) (Grant number 13/15968-0 to PRAP); INCT HPV [Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) [Grant number 08/57889-1 to LLV]; Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) (Grant number 573799/2008-3 to LLV)], info:eu-repo/semantics/publishedVersion

The T-box transcription factor Brachyury was recently reported to be upregulated and associated with prognosis in solid tumors. Here, we proposed to evaluate the potential use of Brachyury protein expression as a new prognostic biomarker in gastrointestinal stromal tumors (GIST). Brachyury protein expression was analyzed by immunohistochemistry in a cohort of 63 bona fide GIST patients. Brachyury expression profiles were correlated with patients' clinicopathological features and prognostic impact. Additionally, an in silico analysis was performed using the Oncomine database to assess Brachyury alterations at DNA and mRNA levels in GISTs. We found that Brachyury was overexpressed in the majority (81.0 %) of primary GISTs. We observed Brachyury staining in the nucleus alone in 4.8 % of cases, 23.8 % depicted only cytoplasm staining, and 52.4 % of cases exhibited both nucleus and cytoplasm immunostaining. The presence of Brachyury was associated with aggressive GIST clinicopathological features. Particularly, Brachyury nuclear (with or without cytoplasm) staining was associated with the presence of metastasis, while cytoplasm sublocalization alone was correlated with poor patient survival. Herein, we demonstrate that Brachyury is overexpressed in GISTs and is associated with worse outcome, constituting a novel prognostic biomarker and a putative target for GIST treatment., This study was partially supported by the ICVS internal research funds of the participating authors and CNPq Universal (476192/2013-7) for RMR. FP received a doctoral fellowship from the FCT (SFRH/BD/81369/2011), and NCC is a recipient of an FAPESP doctoral fellowship (2013/25787-3)., info:eu-repo/semantics/publishedVersion

Introduction: Colorectal cancer is the third most frequent neoplasm in the world population, with a wide geographical heterogeneity, being more frequent in developed countries than in developing countries. In Brazil, this neoplasm also ranks third in incidence, but has been increasing in recent years due to multiple factors such as diet, lifestyle, and aging populations. Most colorectal neoplasms are sporadic (85% of cases); the others are related to inherited susceptibility factors. Surgery is the main treatment modality in the initial stages (stages I to III). In stages IV, treatment will depend on the extent and location of metastases. Among several prognostic factors, the main ones are clinicopathologic, with special emphasis on staging. The ethnic structure of the population has been gaining prominence as another potential prognostic factor, and this becomes more pressing in the Brazilian population due to its great miscegenation. In Brazil, few studies have evaluated and characterized comprehensively the population of patients diagnosed with colorectal cancer. Objectives: In this study we intend to characterize the epidemiologic-clinical-pathologic and therapeutic aspects of a convenience series of about 1013 patients with colorectal cancer treated at the Hospital de Cancer de Barretos. We also intend to determine their genetic ancestry and correlate the ethnic structure of the patients with the remaining epidemiologic and clinical-pathologic data, in order to identify potential ancestral markers with clinical relevance. Materials and Methods: This is a retrospective cohort study of 1013 patients with colorectal cancer, admitted for treatment and follow-up at our institution between 2000 and 2014, where we performed an epidemiologic-clinical-pathologic and therapeutic characterization correlating with supposed prognostic factors such as the location of the primary tumor divided into right and left colon and genetically assessed ancestry. Results: The main characteristics were slightly male predominance, with the age group between 50 and 75 years being more frequent and EC II as the most representative (37.1%); the left/rectum was highlighted with 75% of the cases. No differences were observed in cancer-specific survival between the location of primary tumors. Tumor location on the left side was associated with the following characteristics: male, age less than 50 years, low-grade tumors, T1 and T2 tumors, and absence of synchronous tumors. We found that the main prognostic factors were staging, emergency surgery, angiolymphatic invasion, and primary tumor localization in the left colon. With regard to ancestral diseases, we observed that European ancestry was associated with patients who did not present synchronic tumors, presence of recurrence, while African ancestry was associated with young patients. However, we cannot confirm ancestry as a prognostic factor for cancer-specific survival. Conclusion: We performed one of the most complete characterizations of the main epidemiologic-clinical-pathologic factors and treatment in Brazilian patients with colorectal cancer, correlating with the genetically determined ancestry profile. We concluded that neither the location of the primary tumor nor the genetic ancestry was determinant as to the prognosis of our sample. Citation Format: Ronilson Oliveira Duraes, Rui M. V. Reis, Denise P. Guimaraes, Gustavo N. Berardinelli, Marco A. Oliveira, Cristovam S. Neto. Epidemiologic, clinical-pathologic, and therapeutic characterization and its correlation with ethnic ancestry in patients with colorectal cancer of the Barretos Cancer Hospital [abstract]. In: Proceedings of the AACR International Conference held in cooperation with the Latin American Cooperative Oncology Group (LACOG) on Translational Cancer Medicine; May 4-6, 2017; São Paulo, Brazil. Philadelphia (PA): AACR; Clin Cancer Res 2018;24(1_Suppl):Abstract nr A69.

Colorectal cancer (CRC) is the third most frequent cancer worldwide and the fourth leading cause of death due to cancer. The development of this disease usually occurs due to the progression of precursor lesions in the normal intestinal mucosa to tumor. Environment, age, lifestyle, and genetic background are considered risk factors for the development and progression of CRC. The molecular abnormalities involved in the progression of CRC have been well characterized, including mutations, microsatellite instability, and epigenetic changes. Although the molecular profile of colorectal cancer is well known in developed countries, in the Brazilian population information is still very limited. Therefore, in the present study we intended to characterize the mutation profile of a Brazilian population and associate this with their clinicopathologic features. A total of 61 colorectal cancer cases of different stages were included. DNA was extracted from frozen fresh tumors and sequenced using a panel of 298 genes by next-generation sequencing (NGS). The mean age of patients was 63 years old; 57.4% were male. Three patients had CRC in stage 0, 16 in stage I, 29 in stage II, 10 in stage III, and three in stage IV. Considering only nonsynonymous alterations, we found on average 7.24 mutations per patient. The majority were missense (61.8%), followed by nonsense (15.2%) and frameshift mutations (10.9%). The genes most frequently mutated were APC (78.7%), TP53 (72.1%), KRAS (60.7%), PIK3CA (14.8%), and FBXW7 (14.8%). Alterations in tumor suppressor genes such as APC and TP53 were found throughout the entire gene. On the other hand, oncogenes such as KRAS had alterations in hotspots of the gene. In conclusion, the frequency of alterations in genes sequenced in our population was similar to that found in the international literature for other populations. Citation Format: Wellington Santos, Adriane Feijó Evangelista, Ronilson Durães, Marcus Matsushita, Rui Manuel Reis, Denise Peixoto Guimarães. Somatic mutation profile of a panel of oncogenes and tumor suppressor genes in colorectal cancer in a Brazilian population [abstract]. In: Proceedings of the AACR International Conference held in cooperation with the Latin American Cooperative Oncology Group (LACOG) on Translational Cancer Medicine; May 4-6, 2017; São Paulo, Brazil. Philadelphia (PA): AACR; Clin Cancer Res 2018;24(1_Suppl):Abstract nr A35.

RKIP was described as a metastasis suppressor gene, and it loss was associated with several aggressiveness features, such as with higher stage and/or recurrence, presence of vascular invasion and metastasis, and poor overall survival of cancer patients. RKIP is a member of the phosphatidyl-ethanolamine-binding protein (PEBP) family that negatively regulates not only the MAPK signalling, but also the NF-κ β, GPRC-2, and GSK3β pathway. Gastrointestinal stromal tumors (GIST) are the most common mesenchymal tumor on the gastrointestinal tract characterized by hotspot mutations in KIT and PDGFRA genes, which are predictive of imatinib-based therapy response. In GIST, it is reported that 9% of tumors have loss of expression in RKIP. Our main goal is to investigate the RKIP protein expression in a series of 72 bona-fide GIST and to correlate with patients' clinicopathologic characteristics. Moreover, we intended to assess in vitro role of RKIP gene depletion. We performed immunohistochemistry in 72 primary GIST previously characterized for CD117, S100, Desmin, and CD34 as well as molecularly for KIT (exons 9, 11, 13, 17), PDGFRA (exons 12, 14, 18), and BRAF (V600E). In a second step, we established a RKIP knockout GIST cell line (GIST-T1) by transfection of a pool of 3 different optimized gRNA constructs, targeting RKIP, cloned into the RKIP CRISPR/Cas9 system. The RKIP knockout was verified by Western blotting. The expression profile of RKIP KO cells was assessed using the nanostring Cancer Pathways platform, which contains a set of 800 cancer-related genes. We found that RKIP is absent or expressed at low levels in 16.7% (12/72) of GIST. RKIP reduction was significantly associated with tumor in small intestine, with tumor size increased, and patient death. The overall five-year survival to RKIP-negative cases was 41.7% versus 73.9% in RKIP-positive patients, yet not significant (p=0.07). The in vitro assays showed that RKIP protein levels were depleted in the RKIP KO cells, comparing with the nontransfected cells and with the negative control. The nanostring expression analysis showed 34 genes downregulated and 9 genes upregulated in RKIP-depleted cells. The downregulated genes are especially involved in PI3K-AKT signaling pathway and the upregulated genes in MAPK signaling pathway. In conclusion, we confirm that the lack of RKIP expression occurs in a subset of GISTs and is associated with poor prognosis. We also showed that in GIST loss of RKIP changes important cancer signaling pathways. Citation Format: Nathália Cristina Campanella, Matias Melendez, Lucas Abrahão-Machado, Cristovam Scapulatempo-Neto, Denise Peixoto Guimarães, Rui Reis. Modulation of MAPK and PI3K-AKT signaling pathways and poor prognosis are associated with loss of RKIP [abstract]. In: Proceedings of the AACR International Conference held in cooperation with the Latin American Cooperative Oncology Group (LACOG) on Translational Cancer Medicine; May 4-6, 2017; São Paulo, Brazil. Philadelphia (PA): AACR; Clin Cancer Res 2018;24(1_Suppl):Abstract nr B19.

Background: Colorectal cancer (CRC) is the third most common cancer in Brazil, where it appears as the fifth most deadly cancer. Brazilian National Cancer Institute estimates for the year of 2016 in Brazil 16,660 newly diagnosed cases of CRC in men and 17,620 in women. There is evidence that the incidence and mortality rates can be reduced through the detection of precursor lesions and early cancer in the context of CRC screening. Aberrant hypermethylation of cancer-related genes has emerged as a promising strategy for the molecular CRC screening. However, the methylation profile of colorectal cancer of the Brazilian population has limited information about its characterization and frequency. Objective: To investigate the frequency of DNA methylation in the promoter region of tumor suppressor genes SEPT9, NDRG4, and CDKN2A (p16) in sporadic CRCs of Brazilian patients. Methods: Retrospective molecular analysis included 57 adult patients with CRC in different clinical stages attended at the Barretos Cancer Hospital. Demographic, clinical, and tumor-related characteristics were obtained from medical records. DNA was extracted from fresh-frozen tumor tissues. Levels of DNA methylation were determined by quantitative pyrosequencing. Results: The mean ± SD age of the 57 patients' analysis was 64.40 ±14 years; 56.14% (32/57) were males. Almost all tumors (56/57; 98.24%) were located in the left side of the colon, from descending colon to rectum. Regarding stage, 3/57 (5.26%) were stage 0, 15/57 (26.31 %) stage I, 27/57 (47.36%) stage II, 10/57 (17.54%) stage III, and 2/57 (3.53%) stage IV tumors. Among 57 analyzed, 52/57 (91.22%) were methylated for SEPT9, 42/57 (73.68%) for NDRG4, and 15/57 (26.31%) for CDKN2A. In conclusion, in our Brazilian case series, the gene SEPT9 and NDGR4 showed high frequency of methylation CRC tissues, similar with results found in other populations. Citation Format: Thais Sobanski, Lidia Arantes, Wellington dos Santos, Ronilson Durães, Marcus Matsushita, Rui Manuel Reis, Denise Peixoto Guimaraes. Methylation profile of SEPT9, NDRG4, p16 genes in colorectal cancer [abstract]. In: Proceedings of the AACR International Conference held in cooperation with the Latin American Cooperative Oncology Group (LACOG) on Translational Cancer Medicine; May 4-6, 2017; São Paulo, Brazil. Philadelphia (PA): AACR; Clin Cancer Res 2018;24(1_Suppl):Abstract nr A17.

Os recentes avanços no tratamento dos tumores estromais gastrointestinais (GIST) foram responsáveis pela mudança da história natural da doença. O melhor conhecimento dos mecanismos moleculares foi fundamental para o desenvolvimento de droga alvo-molecular dirigida capaz de obter resultados, até então, não alcançados em nenhum tratamento de tumor sólido. A introdução do imatinibe na prática clínica modificou não só a sobrevida dos portadores de GIST metastático, como também foi responsável por quebras de paradigmas bem estabelecidos; porém, apesar de o tratamento da doença metastática ser baseado na utilização do imatinibe, o papel do cirurgião, nesse contexto, tem sido revisado, havendo alguns indícios de que a cirurgia de resgate na doença metastática possa trazer benefícios a grupos selecionados de pacientes. Dessa forma, um novo conceito se estabelece, o da "cirurgia adjuvante"; ou seja, uma estratégia terapêutica que visa a otimizar os resultados do tratamento do GIST metastático.