Mutational Signatures Driven by Epigenetic Determinants Enable the Stratification of Patients with Gastric Cancer for Therapeutic Intervention.

DNA mismatch repair deficiency (dMMR) is associated with the microsatellite instability (MSI) phenotype and leads to increased mutation load, which in turn may impact anti-tumor immune responses and treatment effectiveness. Various mutational signatures directly linked to dMMR have been described for primary cancers. To investigate which mutational signatures are associated with prognosis in gastric cancer, we performed a de novo extraction of mutational signatures in a cohort of 787 patients. We detected three dMMR-related signatures, one of which clearly discriminates tumors with MLH1 gene silencing caused by promoter hypermethylation (area under the curve = 98%). We then demonstrated that samples with the highest exposure of this signature share features related to better prognosis, encompassing clinical and molecular aspects and altered immune infiltrate composition. Overall, the assessment of the prognostic value and of the impact of modifications in MMR-related genes on shaping specific dMMR mutational signatures provides evidence that classification based on mutational signature exposure enables prognosis stratification.

The diffuse-type gastric cancer epidemiology enigma.

BACKGROUND: Intestinal and diffuse gastric adenocarcinomas differ in clinical, epidemiological and molecular features. However, most of the concepts related to the intestinal-type are translated to gastric adenocarcinoma in general; thus, the peculiarities of the diffuse-type are underappreciated. RESULTS: Besides its growing importance, there are many gaps about the diffuse-type carcinogenesis and, as a result, its epidemiologic and pathogenetic features remain poorly understood. CONCLUSIONS: Alternative hypotheses to explain these features are discussed, including the role of the gastric microbiota, medical therapies, and modifications in the stomach's microenvironment.

Identification of DNA mutations in gastric washes from gastric adenocarcinoma patients: Possible implications for liquid biopsies and patient follow-up.

Whereas cancer patients have benefited from liquid biopsies, the scenario for gastric adenocarcinoma (GAC) is still dismal. We used next-generation deep sequencing of TP53-a highly mutated and informative gene in GAC-to assess mutations in tumor biopsies, plasma (PL) and stomach fluids (gastric wash-GW). We evaluated their potential to reveal tumor-derived mutations, useful for monitoring mutational dynamics at diagnosis, progression and treatment. Exon-capture libraries were constructed from 46 patients including tumor biopsies, GW and PL pre and post-treatment (196 samples), with high vertical coverage >8,000×. At diagnosis, we detected TP53 mutations in 15/46 biopsies (32.6%), 7/46 GW- (15.2%) and 6/46 PL-samples (13%). Biopsies and GW were concordant in 38/46 cases (82.6%) for the presence/absence of mutations and, furthermore, four GW-exclusive mutations were identified, suggesting tumor heterogeneity. Considering the combined analysis of GW and PL, TP53 mutations found in biopsies were also identified in 9/15 (60%) of cases, the highest detection level reported for GAC. Our study indicates that GW could be useful to track DNA alterations, especially if anchored to a comprehensive gene-panel designed for this malignancy.

Avaliação do perfil de mutações somáticas em uma coorte de pacientes com adenocarcinoma gástrico / Tumor molecular profiling in a Brazilian cohort of gastric adenocarcinoma patients

INTRODUÇÃO: O adenocarcinoma gástrico (AdG) é responsável por 5,7% de todos os casos novos e por 8,2% das mortes relacionadas a câncer no mundo. A literatura sobre AdG tem enriquecido com a publicação de amplas análises moleculares nos últimos anos, mas boa parte delas carece de dados de sobrevida e do impacto prognóstico das alterações descritas OBJETIVOS: 1) Descrever o perfil mutacional e avaliar o impacto prognóstico das mutações mais relevantes de AdGs em uma coorte de 112 pacientes tratados no A.C. Camargo Cancer Center; 2) Determinar a ancestralidade genômica e seu impacto prognóstico nesta coorte; 3) Investigar o impacto da carga mutacional global do tumor sobre o prognóstico; 4) Buscar novos marcadores moleculares prognósticos através do sequenciamento comparativo do exoma tumoral completo de 24 pacientes da mesma coorte. MÉTODOS: Este é um estudo longitudinal, retrospectivo, com amostragem não-aleatória e consecutiva de 112 pacientes com AdG, independente de estádio clínico, com amostras disponíveis no biobanco institucional e diagnóstico entre 2007 e 2013. O DNA tumoral foi sequenciado com um painel de captura incluindo 99 genes e 24 amostras também tiveram o exoma tumoral completo sequenciado. Utilizamos um pool de 1600 marcadores informativos de ancestralidade para determinar a ancestralidade genômica dos casos. RESULTADOS: Os dez genes mais frequentemente mutados em nossa coorte foram TP53 (30%), LAMA1 (21%), ARID1A (19%), CIC (19%), FAT4 (17%), PKHD1 (16%), KMT2C (15%), MACF1 (15%), PKHDL1 (15%) e BRCA2 (14%). Demonstramos que em uma população etnicamente miscigenada como a brasileira, a ancestralidade genômica asiática per se não representa um fator prognóstico independente e levantamos a hipótese de que em nossa população, a ancestralidade predominante africana talvez esteja associada a um prognóstico adverso. Identificamos a presença de mutações em RHOA como um possível fator associado a prognóstico favorável, dado que ainda carece de validação. Demonstramos que FAT4, ARID1A e BRCA2 são genes frequentemente mutados em nossa coorte e, ao contrário de relatos prévios, não estiveram associados ao prognóstico de pacientes com AdG

INTRODUCTION: Gastric adenocarcinoma (AdG) accounts for 5.7% of all tumors and 8.2% of cancer related deaths worldwide. Comprehensive reports have recently contributed to the molecular characterization of AdG, but most of them have not investigated the possible prognostic impact of the described mutations. OBJECTIVES: 1) To identify molecular alterations and to assess the prognostic impact of the most relevant mutations found in a cohort of 112 AdG patients treated at A.C. Camargo Cancer Center; 2) To determine the genomic ancestry, for the same cohort, and it's prognostic impact; 3) To assess the global tumor mutational burden and it's prognostic impact 4) To screen potential new prognostic molecular alterations through whole exome sequencing (WES) of tumors from 24 patients. METHODS: This is a retrospective longitudinal analysis that recruited 112 AdG patients, all stages, diagnosed between 2007 and 2013, with available tissue at the A.C. Camargo Cancer Center biobank. DNA extracted from tumor samples was sequenced by a targeted gene panel including 99 genes. Twenty-four tumors were also assessed by WES. We used a pool of 1600 ancestry informative markers to infer each individual genomic ancestry. RESULTS: The top 10 mutated genes in our cohort were: TP53 (30%), LAMA1 (21%), ARID1A (19%), CIC (19%), FAT4 (17%), PKHD1 (16%), KMT2C (15%), MACF1 (15%), PKHDL1 (15%) e BRCA2 (14%). Different from other studies, Asian ancestry was not an independent prognostic factor in our ethnically highly-admixed population, but we found worse prognosis in African ancestry. Mutations in RHOA were associated with good prognosis in this cohort, and we also demonstrated that, besides being common among Brazilian AdG patients, mutations in FAT4, ARID1A and BRCA2 had no prognostic impact

BRAZILIAN CONSENSUS FOR MULTIMODAL TREATMENT OF COLORECTAL LIVER METASTASES. MODULE 3: CONTROVERSIES AND UNRESECTABLE METASTASES.

In the last module of this consensus, controversial topics were discussed. Management of the disease after progression during first line chemotherapy was the first discussion. Next, the benefits of liver resection in the presence of extra-hepatic disease were debated, as soon as, the best sequence of treatment. Conversion chemotherapy in the presence of unresectable liver disease was also discussed in this module. Lastly, the approach to the unresectable disease was also discussed, focusing in the best chemotherapy regimens and hole of chemo-embolization.

Neste último módulo do consenso, abordou-se alguns temas controversos. O primeiro tópico discutido foi o manejo da doença após progressão na primeira linha de quimioterapia, com foco em se ainda haveria indicação cirúrgica neste cenário. A seguir, o painel debruçou-se sobre as situações de ressecção da doença hepática na presença de doença extra-hepática, assim como, qual a melhor sequência de tratamento. O tratamento de conversão para doença inicialmente irressecável também foi abordado neste módulo, incluindo as importantes definições de quando se pode esperar que a doença se torne ressecável e quais esquemas terapêuticos seriam mais efetivos à luz dos conhecimentos atuais sobre a biologia tumoral e taxas de resposta objetiva. Por último, o tratamento da doença não passível de ressecção foi discutida, focando-se nos melhores esquemas a serem empregados e seu sequenciamento, bem como o papel da quimioembolização no manejo destes pacientes.

Brazilian consensus for multimodal treatment of colorectal liver metastases. module 3: controversies and unresectable metastases / Consenso brasileiro de tratamento multidisciplinar de metástase hepática de origem colorretal módulo 3: controvérsias e metástases irressecáveis

ABSTRACT In the last module of this consensus, controversial topics were discussed. Management of the disease after progression during first line chemotherapy was the first discussion. Next, the benefits of liver resection in the presence of extra-hepatic disease were debated, as soon as, the best sequence of treatment. Conversion chemotherapy in the presence of unresectable liver disease was also discussed in this module. Lastly, the approach to the unresectable disease was also discussed, focusing in the best chemotherapy regimens and hole of chemo-embolization.

RESUMO Neste último módulo do consenso, abordou-se alguns temas controversos. O primeiro tópico discutido foi o manejo da doença após progressão na primeira linha de quimioterapia, com foco em se ainda haveria indicação cirúrgica neste cenário. A seguir, o painel debruçou-se sobre as situações de ressecção da doença hepática na presença de doença extra-hepática, assim como, qual a melhor sequência de tratamento. O tratamento de conversão para doença inicialmente irressecável também foi abordado neste módulo, incluindo as importantes definições de quando se pode esperar que a doença se torne ressecável e quais esquemas terapêuticos seriam mais efetivos à luz dos conhecimentos atuais sobre a biologia tumoral e taxas de resposta objetiva. Por último, o tratamento da doença não passível de ressecção foi discutida, focando-se nos melhores esquemas a serem empregados e seu sequenciamento, bem como o papel da quimioembolização no manejo destes pacientes.

Interleukin-4 modulates the inflammatory response in ifosfamide-induced hemorrhagic cystitis.

We investigated whether interleukin-4 (IL-4) is present and capable of reducing inflammatory changes seen in ifosfamide-induced hemorrhagic cystitis. Male Swiss mice were treated with saline or ifosfamide alone or ifosfamide with the classical protocol with mesna and analyzed by changes in bladder wet weight (BWW), macroscopic and microscopic parameters, exudate, and hemoglobin quantification. In other groups, IL-4 was administered intraperitoneally 1 h before ifosfamide. In other experimental groups, C57BL/6 WT (wild type) and C57BL/6 WT IL-4 (-/-) knockout animals were treated with ifosfamide and analyzed for changes in BWW. Quantification of bladder IL-4 protein by ELISA in control, ifosfamide-, and mesna-treated groups was performed. Immunohistochemistry to tumor necrosis factor-alpha (TNF-α) and interleukin-1 beta (IL-1ß) as well as protein identification by Western blot assay for inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) was carried out on ifosfamide- and IL-4-treated animals. In other experimental groups, antiserum against IL-4 was given 30 min before ifosfamide. In IL-4-treated animals, the severity of hemorrhagic cystitis was significantly milder than in animals treated with ifosfamide only, an effect that was reverted with serum anti-IL-4. Moreover, knockout animals for IL-4 (-/-) exhibit a worse degree of inflammation when compared to C57BL/6 wild type. Exogenous IL-4 also attenuated TNF-α, IL-1ß, iNOS, and COX-2 expressions in ifosfamide-treated bladders. IL-4, an anti-inflammatory cytokine, attenuates the inflammation seen in ifosfamide-induced hemorrhagic cystitis.

Inhibition of angiotensin II receptor 1 limits tumor-associated angiogenesis and attenuates growth of murine melanoma.

PURPOSE: We evaluated the involvement of angiotensin II (AngII)-dependent pathways in melanoma growth, through the pharmacological blockage of AT1 receptor by the anti-hypertensive drug losartan (LOS). RESULTS: We showed immunolabeling for both AngII and the AT1 receptor within the human melanoma microenvironment. Like human melanomas, we showed that murine melanomas also express the AT1 receptor. Growth of murine melanoma, both locally and at distant sites, was limited in mice treated with LOS. The reduction in tumor growth was accompanied by a twofold decrease in tumor-associated microvessel density and by a decrease in CD31 mRNA levels. While no differences were found in the VEGF expression levels in tumors from treated animals, reduction in the expression of the VEGFR1 (Flt-1) at the mRNA and protein levels was observed. We also showed downregulation of mRNA levels of both Flt-4 and its ligand, VEGF-C. CONCLUSIONS: Together, these results show that blockage of AT1 receptor signaling may be a promising anti-tumor strategy, interfering with angiogenesis by decreasing the expression of angiogenic factor receptors.

Hormone replacement therapy and the risk of breast cancer: assessment of therapy acceptance in a cohort of previously treated breast cancer patients.

INTRODUCTION: In the postmenopausal period, an average of 25% of women will present symptomatic ovarian failure requiring hormonal replacement therapy. Estrogen can relieve vasomotor symptoms. Hormonal replacement therapy is generally not recommended for breast cancer patients due to the potential risk of tumor recurrence. To answer the questions about the safety of hormonal replacement therapy in this subgroup of women, it is necessary to establish the acceptance of treatment. METHODS: Between September 1998 and February 2001, a cohort of 216 breast cancer patients were asked to complete a questionnaire. All patients had completed their treatment and were informed about survival rates after breast cancer and hormonal replacement therapy. RESULTS: Among the 216 patients, 134 (62%) would refuse hormonal replacement therapy. A hundred patients were afraid of relapse (74.6%). Adjuvant tamoxifen therapy was the only statistically significant variable (70.3% versus 29.7% p=0.003). Understanding clinical stage (p= 0.045) and type of medical assistance (private versus public, p=0.033) also seemed to influence the decision. Early stage disease (p= 0.22), type of surgical procedure (radical versus conservative, p=0.67), adjuvant chemotherapy (p=0.082) or marital status (p=0.98 ) were not statistically significant in decision making. Several patients submitted to adjuvant chemotherapy (41.6%) would accept hormonal replacement therapy under medical supervision, as did most of advanced clinical stage patients (58.3%; p=0.022). CONCLUSION: There is a high level of rejection for hormonal replacement therapy among breast cancer patients when current data on tumor cure rates, and potential risks of estrogen use is available. Adverse effects of tamoxifen in the adjuvant setting may be the reason for refusal of hormonal replacement therapy.

Hormone replacement therapy and the risk of breast cancer: assessment of therapy acceptance in a cohort of previously treated breast cancer patients

INTRODUCTION: In the postmenopausal period, an average of 25 percent of women will present symptomatic ovarian failure requiring hormonal replacement therapy. Estrogen can relieve vasomotor symptoms. Hormonal replacement therapy is generally not recommended for breast cancer patients due to the potential risk of tumor recurrence. To answer the questions about the safety of hormonal replacement therapy in this subgroup of women, it is necessary to establish the acceptance of treatment. METHODS: Between September 1998 and February 2001, a cohort of 216 breast cancer patients were asked to complete a questionnaire. All patients had completed their treatment and were informed about survival rates after breast cancer and hormonal replacement therapy. RESULTS: Among the 216 patients, 134 (62 percent) would refuse hormonal replacement therapy. A hundred patients were afraid of relapse (74.6 percent). Adjuvant tamoxifen therapy was the only statistically significant variable (70.3 percent versus 29.7 percent p=0.003). Understanding clinical stage (p= 0.045) and type of medical assistance (private versus public , p=0.033) also seemed to influence the decision. Early stage disease (p= 0.22), type of surgical procedure (radical versus conservative, p=0.67), adjuvant chemotherapy (p=0.082) or marital status (p=0.98 ) were not statistically significant in decision making. Several patients submitted to adjuvant chemotherapy (41.6 percent) would accept hormonal replacement therapy under medical supervision, as did most of advanced clinical stage patients (58.3 percent; p=0.022). CONCLUSION: There is a high level of rejection for hormonal replacement therapy among breast cancer patients when current data on tumor cure rates, and potential risks of estrogen use is available. Adverse effects of tamoxifen in the adjuvant setting may be the reason for refusal of hormonal replacement therapy