Rectal Cancer Tissue Lipidome Differs According to Response to Neoadjuvant Therapy.

Rectal cancer (RC) is a gastrointestinal cancer with a poor prognosis. While some studies have shown metabolic reprogramming to be linked to RC development, it is difficult to define biomolecules, like lipids, that help to understand cancer progression and response to therapy. The present study investigated the relative lipid abundance in tumoral tissue associated with neoadjuvant therapy response using untargeted liquid chromatography-mass spectrometry lipidomics. Locally advanced rectal cancer (LARC) patients (n = 13), clinically staged as T3-4 were biopsied before neoadjuvant chemoradiotherapy (nCRT). Tissue samples collected before nCRT (staging) and afterwards (restaging) were analyzed to discover lipidomic differences in RC cancerous tissue from Responders (n = 7) and Non-responders (n = 6) to nCRT. The limma method was used to test differences between groups and to select relevant feature lipids from tissue samples. Simple glycosphingolipids and differences in some residues of glycerophospholipids were more abundant in the Non-responder group before and after nCRT. Oxidized glycerophospholipids were more abundant in samples of Non-responders, especially those collected after nCRT. This work identified potential lipids in tissue samples that take part in, or may explain, nCRT failure. These results could potentially provide a lipid-based explanation for nCRT response and also help in understanding the molecular basis of RC and nCRT effects on the tissue matrix.

Molecular and Dynamic Evaluation of Proteins Related to Resistance to Neoadjuvant Treatment with Chemoradiotherapy in Circulating Tumor Cells of Patients with Locally Advanced Rectal Cancer.

The heterogeneity of response to neoadjuvant chemoradiotherapy (NCRT) is still a challenge in locally advanced rectal cancer (LARC). The evaluation of thymidylate synthase (TYMS) and RAD23 homolog B (RAD23B) expression in circulating tumor cells (CTCs) provides complementary clinical information. CTCs were prospectively evaluated in 166 blood samples (63 patients) with LARC undergoing NCRT. The primary objective was to verify if the absence of RAD23B/TYMS in CTCs would correlate with pathological complete response (pCR). Secondary objectives were to correlate CTC kinetics before (C1)/after NCRT (C2), in addition to the expression of transforming growth factor-ß receptor I (TGF-ßRI) with survival rates. CTCs were isolated by ISET and evaluated by immunocytochemistry (protein expression). At C1, RAD23B was detected in 54.1% of patients with no pCR and its absence in 91.7% of patients with pCR (p = 0.014); TYMS- was observed in 90% of patients with pCR and TYMS+ in 51.7% without pCR (p = 0.057). Patients with CTC2 > CTC1 had worse disease-free survival (DFS) (p = 0.00025) and overall survival (OS) (p = 0.0036) compared with those with CTC2 ≤ CTC1. TGF-ßRI expression in any time correlated with worse DFS (p = 0.059). To conclude, RAD23B/TYMS and CTC kinetics may facilitate the personalized treatment of LARC.

PET/MRI Characterization of Mucinous Versus Nonmucinous Components of Rectal Adenocarcinoma: A Comparison of Tumor Metabolism and Cellularity.

OBJECTIVE. The purpose of this study was to evaluate whether FDG PET/MRI can be used to differentiate the mucinous from the nonmucinous components of primary rectal tumors and to compare the glycolytic metabolism on PET with tumor cellularity on DWI in both components. SUBJECTS AND METHODS. Ninety-nine patients who underwent FDG PET/MRI for staging of primary rectal cancer were included in this prospective analysis. MRI depicted the mucin component through the tumor volume. Separate volumes of interest were drawn on both mucinous and nonmucinous components and propagated to PET and apparent diffusion coefficient (ADC) mapping. Maximum and mean standardized uptake values (SUVmax, SUVmean) and maximum, mean, and minimum ADC values (ADCmax, ADCmean, ADCmin) were recorded and compared between areas with mucinous and nonmucinous components. Whole-body PET/MRI was also used to evaluate for the presence of distant metastases. Nonparametric testing was used to compare the two groups of patients: those with tumors with a mucinous component and those with tumors without a mucinous component. Logistic regression analysis was performed to calculate the association risk between mucinous component and metastatic disease. RESULTS. Seventeen patients (17.2%) had a mucinous component within the tumor on T2-weighted MRI. Most of these patients had advanced disease, the mucinous component tumors being in significantly higher T categories than the tumors without a mucinous component (88.2% vs 61.0%; p = 0.032). SUVmax (7.4 vs 16.7; p = 0.002) and SUVmean (5.4 vs 13.4; p = 0.001) were significantly lower in tumors with a mucinous component than in those without a mucinous component. Tumor ADC measurements were not different between tumors with and those without a mucinous component (ADCmean, 1.4 vs 1.6; p = 0.361). There was no association between presence of a mucinous component within the primary rectal tumor and presence of synchronous metastases (odds ratio, 1.1 [0.4-3.0]; p = 0.904). Moreover, the occurrence of metastases in patients with mucinous component tumors (7/17 [41.2%]) was not different from that in patients with tumors without a mucinous component (28/82 [34.1%]) (p = 0.887). CONCLUSION. PET/MRI can be used to differentiate the mucinous and nonmucinous components within primary rectal adenocarcinoma on the basis of metabolic status. The FDG uptake is significantly lower in the mucinous component, but tumor cellularity based on MRI and DWI findings is not. Despite being associated with a higher T category in the sample of patients in this study, the presence of a mucinous component seems not to be associated with increased risk of synchronous metastases.

RHBDD2 overexpression promotes a chemoresistant and invasive phenotype to rectal cancer tumors via modulating UPR and focal adhesion genes.

The current standard of care for locally advanced rectal cancer (RC) is neoadjuvant radio-chemotherapy (NRC) with 5-fluorouracil (5Fu) as the main drug, followed by surgery and adjuvant chemotherapy. While a group of patients will achieve a pathological complete response, a significant percentage will not respond to the treatment. The Unfolding Protein Response (UPR) pathway is generally activated in tumors and results in resistance to radio-chemotherapy. We previously showed that RHBDD2 gene is overexpressed in the advanced stages of colorectal cancer (CRC) and that it could modulate the UPR pathway. Moreover, RHBDD2 expression is induced by 5Fu. In this study, we demonstrate that the overexpression of RHBDD2 in CACO2 cell line confers resistance to 5Fu, favors cell migration, adhesion and proliferation and has a profound impact on the expression of both, the UPR genes BiP, PERK and CHOP, and on the cell adhesion genes FAK and PXN. We also determined that RHBDD2 binds to BiP protein, the master UPR regulator. Finally, we confirmed that a high expression of RHBDD2 in RC tumors after NRC treatment is associated with the development of local or distant metastases. The collected evidence positions RHBDD2 as a promising prognostic biomarker to predict the response to neoadjuvant therapy in patients with RC.

Administration of the vasopressin analog desmopressin for the management of bleeding in rectal cancer patients: results of a phase I/II trial.

Purpose The vasopressin analog desmopressin (dDAVP) is known to increase plasma levels of hemostatic factors, and preclinical studies in colorectal cancer models have demonstrated that it hampers tumor vascularization and metastatic progression. We evaluated safety and preliminary efficacy of dDAVP in rectal cancer patients with bleeding, before receiving specific oncologic treatment with surgery, chemotherapy and/or radiotherapy. Methods Patients with rectal cancer having moderate or severe rectal bleeding were enrolled in an open-label, dose-finding trial. Intravenous infusions of dDAVP were administered during two consecutive days in doses from 0.25 to 2.0 µg/kg, using single or twice daily regimen. Bleeding was graded using a score based on the Chutkan scale and tumor perfusion was evaluated by dynamic contrast-enhanced magnetic resonance imaging. Results The trial accrued a total of 32 patients. Dose-limiting toxicity occurred in patients receiving 1 µg/kg or higher. The most prominent treatment-related severe adverse event was hyponatremia. Most patients receiving the maximum tolerated dose of 0.5 µg/kg showed at least a partial hemostatic response and 58% developed a complete response with absence of bleeding at day 4 and/or at the last follow-up at day 14. Tumor perfusion was decreased in two-thirds of patients after dDAVP treatment. Conclusions dDAVP appeared as a promising hemostatic agent in rectal cancer patients with bleeding. Randomized clinical trials to confirm its effectiveness are warranted.Clinical trial registration www.clinicaltrials.gov NCT01623206.

Locally advanced rectal cancer transcriptomic-based secretome analysis reveals novel biomarkers useful to identify patients according to neoadjuvant chemoradiotherapy response.

Most patients with locally advanced rectal cancer (LARC) present incomplete pathological response (pIR) to neoadjuvant chemoradiotherapy (nCRT). Despite the efforts to predict treatment response using tumor-molecular features, as differentially expressed genes, no molecule has proved to be a strong biomarker. The tumor secretome analysis is a promising strategy for biomarkers identification, which can be assessed using transcriptomic data. We performed transcriptomic-based secretome analysis to select potentially secreted proteins using an in silico approach. The tumor expression profile of 28 LARC biopsies collected before nCRT was compared with normal rectal tissues (NT). The expression profile showed no significant differences between complete (pCR) and incomplete responders to nCRT. Genes with increased expression (pCR = 106 and pIR = 357) were used for secretome analysis based on public databases (Vesiclepedia, Human Cancer Secretome, and Plasma Proteome). Seventeen potentially secreted candidates (pCR = 1, pIR = 13 and 3 in both groups) were further investigated in two independent datasets (TCGA and GSE68204) confirming their over-expression in LARC and association with nCRT response (GSE68204). The expression of circulating amphiregulin and cMET proteins was confirmed in serum from 14 LARC patients. Future studies in liquid biopsies could confirm the utility of these proteins for personalized treatment in LARC patients.

Rab5C enhances resistance to ionizing radiation in rectal cancer.

Rectal cancer represents one third of the colorectal cancers that are diagnosed. Neoadjuvant chemoradiation is a well-established protocol for rectal cancer treatment reducing the risk of local recurrence. However, a pathologic complete response is only achieved in 10-40% of cases and the mechanisms associated with resistance are poorly understood. To identify potential targets for preventing therapy resistance, a proteomic analysis of biopsy specimens collected from stage II and III rectal adenocarcinoma patients before neoadjuvant treatment was performed and compared with residual tumor tissues removed by surgery after neoadjuvant therapy. Three proteins, Ku70, Ku80, and Rab5C, exhibited a significant increase in expression after chemoradiation. To better understand the role of these proteins in therapy resistance, a rectal adenocarcinoma cell line was irradiated to generate a radiotherapy-resistant lineage. These cells overexpressed the same three proteins identified in the tissue samples. Furthermore, radiotherapy resistance in this in vitro model was found to involve modulation of epidermal growth factor receptor (EGFR) internalization by Rab5C in response to irradiation, affecting expression of the DNA repair proteins, Ku70 and Ku80, and cell resistance. Taken together, these findings indicate that EGFR and Rab5C are potential targets for the sensitization of rectal cancer cells and they should be further investigated. KEY MESSAGES: • Rab5C orchestrates a mechanism of radioresistance in rectal adenocarcinoma cell. • Rab5C modulates EGFR internalization and its relocalization to the nucleus. • In the nucleus, EGFR can modulate the expression of the DNA repair proteins, Ku70 and Ku80. • Rab5C, Ku70, and Ku80 are overexpressed in tumor tissues that contain tumor cells that are resistant to chemoradiation treatment.

Individualized threshold for tumor segmentation in 18F-FDG PET/CT imaging: The key for response evaluation of neoadjuvant chemoradiation therapy in patients with rectal cancer?

INTRODUCTION: The standard treatment for locally advanced rectal cancer (RC) consists of neoadjuvant chemoradiation followed by radical surgery. Regardless the extensive use of SUVmax in 18F-FDG PET tumor uptake as representation of tumor glycolytic consumption, there is a trend to apply metabolic volume instead. Thus, the aim of the present study was to evaluate a noninvasive method for tumor segmentation using the 18F-FDG PET imaging in order to predict response to neoadjuvant chemoradiation therapy in patients with rectal cancer. METHOD: The sample consisted of stage II and III rectal cancer patients undergoing 18F-FDG PET/CT examination before and eight weeks after neoadjuvant therapy. An individualized tumor segmentation methodology was applied to generate tumor volumes (SUV2SD) and compare with standard SUVmax and fixed threshold (SUV40%, SUV50% and SUV60%) pre- and post-therapy. Therapeutic response was assessed in the resected specimens using Dworak's protocol recommendations. Several variables were generated and compared with the histopathological results. RESULTS: Seventeen (17) patients were included and analyzed. Significant differences were observed between responders (Dworak 3 and 4) and non-responders for SUVmax-2 (p<0.01), SUV2SD-2 (p<0.05), SUV40%-2 (p<0.05), SUV50%-2 (p<0.05) and SUV60%-2 (p<0.05). ROC analyses showed significant areas under the curve (p<0.01) for the proposed methodology with sensitivity and specificity varying from 60% to 83% and 73% to 82%, respectively. CONCLUSION: The present study confirmed the predictive power of the variables using a noninvasive individualized methodology for tumor segmentation based on 18F-FDG PET/CT imaging for response evaluation in patients with rectal cancer after neoadjuvant chemoradiation therapy.

Individualized threshold for tumor segmentation in 18F-FDG PET/CT imaging: The key for response evaluation of neoadjuvant chemoradiation therapy in patients with rectal cancer? / Individualização na segmentação tumoral de imagens de 18F-FDG PET/CT: a chave para avaliação de resposta terapêutica neoadjuvante em pacientes com câncer retal?

Summary Introduction: The standard treatment for locally advanced rectal cancer (RC) consists of neoadjuvant chemoradiation followed by radical surgery. Regardless the extensive use of SUVmax in 18F-FDG PET tumor uptake as representation of tumor glycolytic consumption, there is a trend to apply metabolic volume instead. Thus, the aim of the present study was to evaluate a noninvasive method for tumor segmentation using the 18F-FDG PET imaging in order to predict response to neoadjuvant chemoradiation therapy in patients with rectal cancer. Method: The sample consisted of stage II and III rectal cancer patients undergoing 18F-FDG PET/CT examination before and eight weeks after neoadjuvant therapy. An individualized tumor segmentation methodology was applied to generate tumor volumes (SUV2SD) and compare with standard SUVmax and fixed threshold (SUV40%, SUV50% and SUV60%) pre- and post-therapy. Therapeutic response was assessed in the resected specimens using Dworak's protocol recommendations. Several variables were generated and compared with the histopathological results. Results: Seventeen (17) patients were included and analyzed. Significant differences were observed between responders (Dworak 3 and 4) and non-responders for SUVmax-2 (p<0.01), SUV2SD-2 (p<0.05), SUV40%-2 (p<0.05), SUV50%-2 (p<0.05) and SUV60%-2 (p<0.05). ROC analyses showed significant areas under the curve (p<0.01) for the proposed methodology with sensitivity and specificity varying from 60% to 83% and 73% to 82%, respectively. Conclusion: The present study confirmed the predictive power of the variables using a noninvasive individualized methodology for tumor segmentation based on 18F-FDG PET/CT imaging for response evaluation in patients with rectal cancer after neoadjuvant chemoradiation therapy.

Resumo Introdução: O câncer retal (RC) é uma doença de importância global, e o tratamento padrão para o câncer retal localmente avançado compreende quimiorradiação neoadjuvante seguida de cirurgia radical. Independentemente do uso extensivo da captação tumoral mais intensa do 18F-FDG (conhecida como SUVmax) como representativo do consumo glicolítico do tumor nas imagens de PET, há uma tendência para aplicar volume metabólico. Dessa forma, o objetivo do presente estudo foi avaliar um método não invasivo de segmentação tumoral utilizando a 18F-FDG PET para predizer a resposta à quimiorradioterapia neoadjuvante em pacientes com câncer de reto. Método: A amostra consistiu em pacientes com câncer retal em estádios II e III submetidos ao exame de 18F-FDG PET/CT antes e oito semanas após a terapia neoadjuvante. Foi aplicada uma metodologia de segmentação tumoral individualizada para gerar volumes tumorais (SUV2SD). A resposta terapêutica foi avaliada nos espécimes ressecados utilizando as recomendações do protocolo de Dworak. Várias variáveis foram geradas e comparadas com os resultados histopatológicos. Resultados: Dezessete (17) pacientes foram incluídos e analisados. Foram observadas diferenças significativas entre os respondedores (Dworak 3 e 4) e não respondedores para SUVmax-2 (p<0,01), SUV2SD-2 (p<0,05), SUV40%-2 (p<0,05), SUV50%-2 (p<0,05) e SUV60%-2 (p< 0,05). As análises ROC mostraram áreas significativas sob a curva (p<0,01) para a metodologia proposta, com sensibilidade e especificidade variando de 60% a 83% e 73% a 82%, respectivamente. Conclusão: O presente estudo confirmou o poder preditivo das variáveis utilizando uma metodologia não invasiva individualizada para segmentação tumoral baseada em imagens 18F-FDG PET/CT para avaliação da resposta em pacientes com câncer retal após tratamento com quimiorradiação neoadjuvante.

Effect of Akt activation and experimental pharmacological inhibition on responses to neoadjuvant chemoradiotherapy in rectal cancer.

BACKGROUND: Neoadjuvant chemoradiotherapy (CRT) is one of the preferred initial treatment strategies for locally advanced rectal cancer. Responses are variable, and most patients still require surgery. The aim of this study was to identify molecular mechanisms determining poor response to CRT. METHODS: Global gene expression and pathway enrichment were assessed in pretreatment biopsies from patients with non-metastatic cT2-4 N0-2 rectal cancer within 7 cm of the anal verge. Downstream Akt activation was assessed in an independent set of pretreatment biopsies and in colorectal cancer cell lines using immunohistochemistry and western blot respectively. The radiosensitizing effects of the Akt inhibitor MK2206 were assessed using clonogenic assays and xenografts in immunodeficient mice. RESULTS: A total of 350 differentially expressed genes were identified, of which 123 were upregulated and 199 downregulated in tumours from poor responders. Mitochondrial oxidative phosphorylation (P < 0·001) and phosphatidylinositol signalling pathways (P < 0·050) were identified as significantly enriched pathways among the set of differentially expressed genes. Deregulation of both pathways is known to result in Akt activation, and high immunoexpression of phosphorylated Akt S473 was observed among patients with a poor histological response (tumour regression grade 0-2) to CRT (75 per cent versus 48 per cent in those with a good or complete response; P = 0·016). Akt activation was also confirmed in the radioresistant cell line SW480, and a 50 per cent improvement in sensitivity to CRT was observed in vitro and in vivo when SW480 cells were exposed to the Akt inhibitor MK2206 in combination with radiation and 5-fluorouracil. CONCLUSION: Akt activation is a key event in the response to CRT. Pharmacological inhibition of Akt activation may enhance the effects of CRT. Surgical relevance Organ preservation is an attractive alternative in rectal cancer management following neoadjuvant chemoradiotherapy (CRT) to avoid the morbidity of radical surgery. Molecular steps associated with tumour response to CRT may provide a useful tool for the identification of patients who are candidates for no immediate surgery. In this study, tumours resistant to CRT were more likely to have activation of specific genetic pathways that result in phosphorylated Akt (pAkt) activation. Pretreatment biopsy tissues with high immunoexpression of pAkt were more likely to exhibit a poor histological response to CRT. In addition, the introduction of a pAkt inhibitor to cancer cell lines in vitro and in vivo led to a significant improvement in sensitivity to CRT. Identification of pAkt-activated tumours may thus allow the identification of poor responders to CRT. In addition, the concomitant use of pAkt inhibitors to increase sensitivity to CRT in patients with rectal cancer may constitute an interesting strategy for increasing the chance of a complete response to treatment and organ preservation.

Intratumoral heterogeneity of CD44v6 in rectal cancer.

PURPOSE: CD44v6 plays a controversial role in tumor progression and patient outcome in colorectal cancer by plenty of conflicting reports. The purpose of this study was to profile the intratumoral heterogeneity of CD44v6 in rectal cancer and investigate its role in lymph node metastasis. METHODS: Sixty patients were included in this study. Immunohistochemistry for CD44v6 was performed in normal mucosa, primary tumor, and lymph node metastasis with whole tissue sections. The staining intensity in tumor center and invasive front was separately measured. Sampling bias was evaluated by quantitative real-time PCR with 15 pairs of frozen tissues from different sites of the primary tumor. RESULTS: CD44v6 expression increased from normal mucosa to primary tumor to lymph node metastasis. Multiple intratumoral staining patterns was observed in primary tumor, and CD44v6 expression in invasive front was significantly higher than that in tumor center. In addition, mRNA expression levels differed across different geographical regions of the tumor. No association between CD44v6 expression and lymph node metastasis was revealed. CONCLUSIONS: Substantial intratumoral heterogeneity of CD44v6 exists in rectal cancer that impacts the outcome of individual studies. CD44v6 expression should be assessed in a more precise way with a specified staining pattern and in a designated location.

The Role of EphA4 Signaling in Radiation-Induced EMT-Like Phenotype in Colorectal Cancer Cells.

Radiotherapy is widely used for advanced rectal tumors. However, refractory metastasis has become the major cause of therapy failure in rectal cancer patients. Understanding the molecular mechanism that controls the aggressive cellular response to this treatment is essential for developing new therapeutic applications and improving radiotherapy response in colorectal cancer patients. Using the progeny of cells that were submitted to irradiation, we have demonstrated that the PI3K/AKT, Wnt/ß-catenin signaling pathways as well as ERK1/2 downstream of EPHA4 receptor activation, play an important role in the regulation of events related with the EMT development, which may be associated with the therapeutic failure in rectal cancer after radiotherapy. Here, we further discuss about EphA4 receptor as a potential therapeutic target for the treatment of this cancer type. J. Cell. Biochem. 118: 442-445, 2017. © 2016 Wiley Periodicals, Inc.

Hypoxia facilitates epithelial-mesenchymal transition-mediated rectal cancer progress.

Rectal cancer is a commonly observed tumor in clinics, and epithelial-mesenchymal transition (EMT) is very important for tumor invasion and metastasis. We established a rectal cancer HCT-116 cell hypoxia model and detected cell proliferation, invasion, and EMT-related protein expression in this model, aiming to analyze the effect of hypoxia on rectal cancer cell EMT. Rectal cancer cell line HCT-116 was cultured in normoxic, hypoxic, or anaerobic environment, and hypoxia-inducible factor-1α (HIF-1α) mRNA expression was detected in the cells by real-time PCR. Cell proliferation was tested by MTT assay; cell invasion was determined by transwell assay, and HIF-1α, epithelial-cadherin, and Snail protein levels were evaluated by western blot analysis. HIF-1α mRNA level significantly increased in the anaerobic group compared to that in the normoxic and hypoxic groups (P < 0.05). HCT-116 cell proliferation in the anaerobic group was obviously higher than that in the other two groups, with the hypoxic group showing stronger proliferative ability than the normoxic group (P < 0.05). Compared to the normoxic group, the HCT-116 cells demonstrated enhanced cell invasion and migration in hypoxic and anaerobic groups. HIF-1α and Snail expressions were upregulated, whereas epithelial-cadherin expression had declined in the hypoxic and anaerobic groups, compared to those in the normal control (P < 0.05). Therefore, hypoxia promoted rectal cancer cell progress by increasing HIF-1α to induce EMT.

The destruction complex of beta-catenin in colorectal carcinoma and colonic adenoma.

OBJECTIVE: To evaluate the destruction complex of beta-catenin by the expression of the proteins beta-catetenin, adenomatous polyposis coli, GSK3ß, axin and ubiquitin in colorectal carcinoma and colonic adenoma. METHODS: Tissue samples from 64 patients with colorectal carcinoma and 53 patients with colonic adenoma were analyzed. Tissue microarray blocks and slides were prepared and subjected to immunohistochemistry with polyclonal antibodies in carcinoma, adjacent non-neoplastic mucosa, and adenoma tissues. The immunoreactivity was evaluated by the percentage of positive stained cells and by the intensity assessed through of the stained grade of proteins in the cytoplasm and nucleus of cells. In the statistical analysis, the Spearman correlation coefficient, Student's t, χ2, Mann-Whitney, and McNemar tests, and univariate logistic regression analysis were used. RESULTS: In colorectal carcinoma, the expressions of beta-catenin and adenomatous polyposis coli proteins were significantly higher than in colonic adenomas (p<0.001 and p<0.0001, respectively). The immunoreactivity of GSK3ß, axin 1 and ubiquitin proteins was significantly higher (p=0.03, p=0.039 and p=0.03, respectively) in colorectal carcinoma than in the colonic adenoma and adjacent non-neoplastic mucosa. The immunohistochemistry staining of these proteins did not show significant differences with the clinical and pathological characteristics of colorectal cancer and colonic adenoma. CONCLUSIONS: These results suggest that, in adenomas, the lower expression of the beta-catenin, axin 1 and GSK3ß proteins indicated that the destruction complex of beta-catenin was maintained, while in colorectal carcinoma, the increased expression of beta-catenin, GSK3ß, axin 1, and ubiquitin proteins indicated that the destruction complex of beta-catenin was disrupted. OBJETIVO: Avaliar o complexo de destruição da betacatenina no carcinoma colorretal e no adenoma do colo pela expressão das proteínas betacatenina, adenomatous polyposis coli, GSK3ß, axina e ubiquitina. MÉTODOS: Amostras de tecidos de 64 doentes com carcinoma colorretal e de 53 pacientes com adenoma do colo foram analisadas. Blocos de tecidos foram submetidos ao estudo imuno-histoquímico com anticorpos policlonais nos tecidos do carcinoma, mucosa não neoplásica adjacente e adenoma. A imunorreatividade foi avaliada pela porcentagem de positividade de células coradas e pela intensidade do grau de coloração das proteínas no citoplasma e no núcleo das células. Na análise estatística, foram utilizados o coeficiente de correlação de Spearman, os testes t de Student, χ2, Mann-Whitney e de McNemar, e a análise de regressão logística univariada. RESULTADOS: No carcinoma colorretal, as expressões da betacatenina e da adenomatous polyposis coli foram significativamente maiores do que em adenomas do colo (p<0,001 e p<0,0001, respectivamente). A imunorreatividade das proteínas GSK3ß, axina 1 e ubiquitina foi significativamente maior (p=0,03, p=0,039 e p=0,03, respectivamente) no carcinoma colorretal do que no adenoma e na mucosa não neoplásica adjacente. A coloração imuno-histoquímica dessas proteínas não apresentou diferenças significantes em relação às características clinicopatológicas do câncer colorretal e do adenoma. CONCLUSÕES: Em adenomas, as menores expressões de betacatenina, axina 1 e GSK3ß indicaram que o complexo de destruição da betacatenina estava conservado, enquanto que, no carcinoma colorretal, o aumento das expressões da betacatenina, GSK3ß, 1 axina, e ubiquitina indicaram que o complexo de destruição de betacatenina estava alterado.

(18)F-FDG uptake by rectal cancer is similar in mucinous and nonmucinous histological subtypes.

PURPOSE: PET/CT has been considered limited for the evaluation of mucinous colorectal tumors due to low (18)F-FDG uptake. The aim of our study was to compare PET/CT variables in mucinous (MC) and nonmucinous (NMC) rectal adenocarcinomas. METHODS: Consecutive patients with cT2-4N0-2M0 rectal cancer included in a prospective clinical trial were reviewed. PET/CT was performed for primary baseline staging. Visual and quantitative analysis included SUVmax and SUVmean, metabolic tumor volume (MTV) and total lesion glycolysis (TLG). PET/CT parameters were compared according to histological subtypes. RESULTS: Overall, 73 patients were included (18 mucinous and 55 nonmucinous). SUVmax values were similar between MC and NMC (19.7 vs. 16.6; p = 0.5). MTV and TLG values were greater in the MC group (103.9 vs. 54.1; p = 0.007 and 892.5 vs. 358.8; p = 0.020) due to larger tumor volumes of MC. CONCLUSIONS: Metabolic parameters at baseline PET/CT for patients with rectal cancer are similar in mucinous and nonmucinous histological subtypes.

The destruction complex of beta-catenin in colorectal carcinoma and colonic adenoma / O complexo destruidor de betacatenina no carcinoma colorretal e no adenoma cólico

ABSTRACT Objective To evaluate the destruction complex of beta-catenin by the expression of the proteins beta-catetenin, adenomatous polyposis coli, GSK3β, axin and ubiquitin in colorectal carcinoma and colonic adenoma. Methods Tissue samples from 64 patients with colorectal carcinoma and 53 patients with colonic adenoma were analyzed. Tissue microarray blocks and slides were prepared and subjected to immunohistochemistry with polyclonal antibodies in carcinoma, adjacent non-neoplastic mucosa, and adenoma tissues. The immunoreactivity was evaluated by the percentage of positive stained cells and by the intensity assessed through of the stained grade of proteins in the cytoplasm and nucleus of cells. In the statistical analysis, the Spearman correlation coefficient, Student’s t, χ2, Mann-Whitney, and McNemar tests, and univariate logistic regression analysis were used. Results In colorectal carcinoma, the expressions of beta-catenin and adenomatous polyposis coli proteins were significantly higher than in colonic adenomas (p<0.001 and p<0.0001, respectively). The immunoreactivity of GSK3β, axin 1 and ubiquitin proteins was significantly higher (p=0.03, p=0.039 and p=0.03, respectively) in colorectal carcinoma than in the colonic adenoma and adjacent non-neoplastic mucosa. The immunohistochemistry staining of these proteins did not show significant differences with the clinical and pathological characteristics of colorectal cancer and colonic adenoma. Conclusions These results suggest that, in adenomas, the lower expression of the beta-catenin, axin 1 and GSK3β proteins indicated that the destruction complex of beta-catenin was maintained, while in colorectal carcinoma, the increased expression of beta-catenin, GSK3β, axin 1, and ubiquitin proteins indicated that the destruction complex of beta-catenin was disrupted.

RESUMO Objetivo Avaliar o complexo de destruição da betacatenina no carcinoma colorretal e no adenoma do colo pela expressão das proteínas betacatenina, adenomatous polyposis coli, GSK3β, axina e ubiquitina. Métodos Amostras de tecidos de 64 doentes com carcinoma colorretal e de 53 pacientes com adenoma do colo foram analisadas. Blocos de tecidos foram submetidos ao estudo imuno-histoquímico com anticorpos policlonais nos tecidos do carcinoma, mucosa não neoplásica adjacente e adenoma. A imunorreatividade foi avaliada pela porcentagem de positividade de células coradas e pela intensidade do grau de coloração das proteínas no citoplasma e no núcleo das células. Na análise estatística, foram utilizados o coeficiente de correlação de Spearman, os testes t de Student, χ2, Mann-Whitney e de McNemar, e a análise de regressão logística univariada. Resultados No carcinoma colorretal, as expressões da betacatenina e da adenomatous polyposis coli foram significativamente maiores do que em adenomas do colo (p<0,001 e p<0,0001, respectivamente). A imunorreatividade das proteínas GSK3β, axina 1 e ubiquitina foi significativamente maior (p=0,03, p=0,039 e p=0,03, respectivamente) no carcinoma colorretal do que no adenoma e na mucosa não neoplásica adjacente. A coloração imuno-histoquímica dessas proteínas não apresentou diferenças significantes em relação às características clinicopatológicas do câncer colorretal e do adenoma. Conclusões Em adenomas, as menores expressões de betacatenina, axina 1 e GSK3β indicaram que o complexo de destruição da betacatenina estava conservado, enquanto que, no carcinoma colorretal, o aumento das expressões da betacatenina, GSK3β, 1 axina, e ubiquitina indicaram que o complexo de destruição de betacatenina estava alterado.

Metabolic and molecular relative percentage coreduction in patients with locally advanced rectal cancer treated with neoadjuvant therapy.

PURPOSE: Vascular endothelial growth factor receptor-2 (VEGFR-2), epidermal growth factor receptor-1 (EGFR) and cyclooxygenase-2 (COX-2) stimulate key processes involved in tumour progression and are important targets for cancer therapeutics. (18)F-FDG maximum standardized uptake value (SUVmax) on PET/CT is a marker of tumour metabolic activity. The purpose of this study was to measure percentage reductions in SUVmax (∆SUVmax%), VEGFR-2 (∆VEGFR-2%), EGFR (∆EGFR%) and COX-2 (∆COX-2%) in patients with locally advanced rectal cancer (LARC) after preoperative treatment, and to correlate the changes in these markers of response with pathological response in terms of tumour regression grade (TRG) using Rödel's scale and long-term clinical outcome. METHODS: VEGFR-2, EGFR and COX-2 were measured using a quantitative and qualitative compound immunohistochemistry analysis (immunoreactive score) of the pretreatment endoscopic biopsy and definitive surgical specimens. Composite indexes using ∆SUVmax% and the three molecules were developed to differentiate patients with metabolic and molecular responses from nonresponders. Cox proportional hazards model was used to explore associations between the tumour markers, disease-free survival (DFS) and overall survival (OS). RESULTS: The analysis included 38 patients with a median follow-up of 86 months (range 5 - 113 months). The ∆VEGFR-2%/∆SUVmax% index correctly identified 13 of 19 pathological responders (TRG 3 and 4) and 17 of 19 nonresponders (TRG 0 - 2) (sensitivity 68 %, specificity 89 %, accuracy 79 %, positive predictive value 87 %, negative predictive value 74 %). In multivariate analysis, only the ∆VEGFR-2%/∆SUVmax% index was associated with DFS (HR 0.11, p = 0.001) and OS (HR 0.15, p = 0.02). CONCLUSION: In patients with LARC the ∆VEGFR-2%/∆SUVmax% response index is associated with outcome. Determination of the optimal diagnostic cut-off level for this novel biomarker association should be explored. Evaluation in a clinical trial is required to determine whether selected patients could benefit from treatment with a VEGFR-targeted therapeutic agent.

Overexpression of nuclear ß-catenin at invasive front in rectal carcinoma is associated with lymph node metastasis and poor prognosis.

BACKGROUND: This study aims to investigate whether nuclear ß-catenin overexpression at invasive front in rectal carcinoma is associated with lymph node metastasis and prognosis. METHODS: Immunohistochemistry was adopted to detect the expression of ß-catenin in rectal carcinoma and lymph node metastatic lesions. Spearman's rank correlation analysis and Tukey's test were used to evaluate the association between nuclear ß-catenin expression at invasive front in rectal carcinoma and lymph node metastasis. Kaplan-Meier method and multivariate Cox regression model were used to evaluate the prognostic value of nuclear ß-catenin overexpression at invasive front in rectal carcinoma for disease-free survival (DFS) and overall survival (OS). RESULTS: Overexpression of nuclear ß-catenin at the invasive front in rectal carcinoma in stage III-N2 was significantly higher than that in stage III-N1 (73.4 vs. 40.4 %, P < 0.001). Nuclear ß-catenin expression at the invasive front in rectal carcinoma was associated with the expression of nuclear ß-catenin in corresponding lymph node metastatic lesions (r = 0.297, P < 0.001). Overexpression of nuclear ß-catenin at the invasive front in rectal carcinoma was correlated with the number of metastatic lymph nodes (P < 0.001). Patients with nuclear ß-catenin overexpression at the invasive front in rectal carcinoma had poor DFS (P = 0.002) and OS (P = 0.003). Moreover, overexpression of nuclear ß-catenin at the invasive front was an independent prognosticator for unfavorable DFS and OS (P = 0.002 and 0.001). CONCLUSIONS: Our findings suggest that overexpression of nuclear ß-catenin at the invasive front in rectal carcinoma may be a useful marker to evaluate lymph node metastasis, as well as a promising predictor of poor prognosis.

[Rectal cancer and Trousseau syndrome. Case report]. / Síndrome de Trousseau y cáncer de recto. Informe de un caso.

BACKGROUND: The Trousseau syndrome, first described in 1865, is the relationship of venous thromboembolisms and cancer. We present a case with rectal cancer and Trousseau syndrome. CLINICAL CASE: Female 40 years old, went to the Coloproctology Service for painless bleeding. A computed tomography report showed a tumor of 5 by 6 cm up 5 cm from the anal margin. Ultra-low anterior resection with colonic reservoir and loop ileostomy surgery was performed. The pathology report showed a semidiferenciate adenocarcinoma of the rectum and we established the stage as T3N0M0. Within 72 hours of her operation, she experienced sudden hypotension and painful abdominal distention. A second surgery was done finding necrosis of the colon from the splenic angle until the colonic reservoir with thrombi in the left colic artery, ischemic signs of bilateral fallopian tubes, ovaries, uterus, pelvic floor and the small intestine, 40 cm before ileostomy and ileon. Left hemicolectomy and colostomy was done. She was taken to intensive care where continuous administration of heparin was given; she died within 5 days because of multiorgan failure. CONCLUSIONS: The mechanism for this syndrome was unknown but there are several hypotheses, suggesting that hematological cancer patients are at an increased risk of deep vein thrombosis. Pancreatic cancer is the most common presentation with this syndrome (in 50% of cases). We suggested continuing with the standards of prevention of thromboembolism.

antecedentes: el síndrome de Trousseau se describió por primera vez en 1865; es la relación entre tromboembolismo venoso y cáncer. Objetivo: informar el caso de una paciente con cáncer de recto y síndrome de Trousseau. Caso clínico: paciente femenina de 40 años de edad que acudió al servicio de Coloproctología por rectorragia indolora. La TAC reportó un tumor de 5 por 6cm y del margen anal a 5cm. Se efectuó resección anterior ultrabaja, con reservorio colónico e ileostomía de protección. El reporte de patología fue de: adenocarcinoma semidiferenciado del recto, con clasificación T3N0M0. A las 72 horas del postoperatorio tuvo hipotensión arterial súbita y distensión abdominal dolorosa. En la reintervención quirúrgica se encontró: necrosis del colon desde el ángulo esplénico hasta el reservorio colónico, con trombos en meso, signos de isquemia en el útero, trompa de Falopio y ovarios, piso pélvico y 40 cm de intestino delgado, antes de la ileostomía e íleon. Se realizó hemicolectomía izquierda y colostomía. Se trasladó a la unidad de terapia intensiva donde continuó con la administración de heparina; falleció a los cinco días por insuficiencia multiorgánica. Conclusiones: el mecanismo de este síndrome se desconoce pero existen varias hipótesis: se ha sugerido que los cánceres hematológicos son los que tienen mayor riesgo de trombosis venosa profunda. El cáncer de páncreas se relaciona con este síndrome en 50% de los casos. Se sugiere continuar con las normas de prevención del tromboembolismo.

Early changes in carcinogenesis of colorectal adenomas.

OBJECTIVES: Adenocarcinoma of the colon and rectum is the third most common cause of cancer deaths and the sixth most common cancer in the world. Adenomas are benign neoplastic lesions which can be transformed into carcinomas, but this is usually not the case. There should be some risk factors which lead to the development of carcinomas into adenomas. The aim of this study is to find out the early changes and high risk factors related to carcinogenesis in colonic polyps. METHODS: In this study, we reviewed nearly 1000 colonoscopic biopsies and chose 72 biopsies. We developed three groups (tubular adenomas group 1, villous adenomas group 2, normal mucosa group 3); each group had 24 different biopsies. P53, Ki-67, bcl-2, cyclin D1, E-cadherin, c-erb B2 immunohistochemistry and human papillomavirus (HPV) in-situ hybridization were used for analysis. RESULTS: Five of the seventy-two cases were positive in HPV in-situ analysis. Four of them were villous adenomas and one was a tubular adenoma. Ki-67 expression was limited only to crypts in group 3 but in groups 1 and 2, Ki-67 expression was seen both in crypt epithelium and surface epithelium. Cyclin D1, c-erb B2, bcl-2 expression was significantly increased in neoplastic polyps. CONCLUSION: Ki-67 expression, both in the crypt and surface epithelium, and cyclin D1, c-erb B2, bcl-2 over-expression may be a clue of dysplastic epithelium and if the role of HPV is elucidated and shown to be important in colonic carcinogenesis, then vaccination might prevent carcinogenesis caused by HPV.