Nora Manoukian Forones

DNA methylation as an epigenetic biomarker in colorectal cancer.

Sporadic colorectal cancer (CRC) is a consequence of the accumulation of genetic and epigenetic alterations that result in the transformation of normal colonic epithelial cells to adenocarcinomas. Studies have indicated that a common event in the tumorigenesis of CRC is the association of global hypomethylation with discrete hypermethylation at the promoter regions of specific genes that are involved in cell cycle regulation, DNA repair, apoptosis, angiogenesis, adhesion and invasion. The present study aimed to investigate the epigenetic changes (DNA methylation) in 24 candidate genes in CRC. A total of 10 candidate hypermethylated (HM) and unmethylated (UM) genes were identified that may be useful epigenetic markers for non-invasive CRC screening. The five genes that had the highest average UM percentages in the control group were MLH1 (71.7%), DKK2 (69.6%), CDKN2A (68.4%), APC (67.5%) and hsa-mir-342 (67.4%). RUNX3 (58.9%), PCDH10 (55.5%), SFRP5 (52.1%), IGF2 (50.4%) and Hnf1b (50.0%) were the five genes with the highest average HM percentages in the test group. In summary, the present preliminary study identified the methylation profiles of normal and cancerous colonic epithelial tissues, and provided the groundwork for future large-scale methylation studies.

Depression and Anxiety in Colorectal Cancer Patients

IntroductionCancer has been seen negatively by the people that disclose fear and anxiety face to the disease closely associated with distress, aggressive treatments, and death. Colorectal cancer is one of the most prevalent cancer and few assays were developed studying depression and anxiety in patients after surgical resection of tumor and before adjuvant therapy.AimThis research aims to study the prevalence of depression and anxiety in patients with colorectal cancer before and after adjuvant chemotherapy.Patients and MethodsAfter surgical resection of colorectal cancer, 37 patients were included according to the kind of treatment: chemotherapy group (CHG) and the other one without indication of chemotherapy, the control group (CG). Questionnaires of Depression and Anxiety were done at the beginning and at the end of the treatment in the CHG (n = 19) and at the first and after 6 months of follow-up (n = 18) in the CG.ResultsNo difference on gender, age, or site was observed among the groups. Stage III tumor was more frequent in the CHG group. Mild or moderate depression was diagnosed in 31.6% of the CHG patients in the first evaluation and in 38.6% at the second one. In the CG no depression was observed in both evaluations. About the State-Trait Anxiety Inventory, the results were similar before and after chemotherapy treatment. There was a higher number of patients with moderate state or trait anxiety in the CHG when compared to the CG in both evaluations. No correlation was found about the inventories of anxiety and depression and site of tumor or stage.ConclusionAfter surgical treatment of colorectal cancer, depression and indexes of anxiety were higher in the group of patients treated with chemotherapy when compared to the control group.

Ki67 and p53 in gastrointestinal stromal tumors - GIST

CONTEXT Gastrointestinal stromal tumor (GIST) is the most common mesenchymal tumor. Cellular proliferation and apoptosis is gaining importance for predicting prognosis in several cancers. OBJECTIVE To investigate the Ki67 and p53 immunostaining in GISTs. METHODS Specimens from 40 patients with GIST were assessed for immunohistochemical expression of Ki67 and p53. The tumors were divided according the risk of recurrence in two groups: I with high or intermediate risk and; II with low or very low risk. RESULTS Among the 40 patients, 21 were men, the mean age was 56 years, 16 occurred in the small intestine and 13 in the stomach, 5 in the retroperitonium, 4 in the colon or rectum and 2 in the mesenterium. Thirty two tumors were from group I and 8 from group II. Half of the patients developed recurrence, being 90% of the group I (P = 0.114). The tumor Ki67 labelling index ranged from 0.02 to 0.35 (mean level 0.12). This index was marginally higher in the group I patients with recurrence (P = 0.09) compared to the patients of the same group without recurrence. p53 staining was expressed in 65% of the GISTs. A higher frequency of p53 and Ki67 had been found in the group I tumors when compared to the other group (P = 0.022; OR = 8.00 - IC 95%: 1.32-48.65). CONCLUSION The most common site was the small intestine and 80% had a malignant potential justifying the high recurrence observed. No significant correlation was found between p53 and overall outcome of the patients. In group I patients, the evaluation Ki67LI may be a marker of prognosis. The positivity of both markers is higher among the patients with worst prognosis than in the others.

Immunoexpression of cyclooxygenase-1 and -2 in ulcerative colitis.

Ulcerative colitis (UC) is a disease of the colon and rectum characterized by a nonspecific chronic inflammation mediated by the concerted response of cellular and humoral events. Prostaglandins are synthesized by cyclooxygenase (COX)-1 and -2 and exhibit both pro- and anti-inflammatory activity. To evaluate COX-1 and COX-2 immunoexpression in 42 cases of UC and to correlate it with clinicopathological parameters, COX-1 and COX-2 expression was investigated by the immunohistochemistry method. Only patients with all pertinent clinical and evolutive data as well as with adequate biopsy material were included in the study. Fifteen samples of colorectal adenocarcinoma and 14 of large bowel with no histological changes were used for positive and negative controls, respectively. UC patients showed COX-1 immunoreactivity in epithelial cells in 29% of the cases and in inflammatory cells in 43%. COX-2 positivity in epithelial and inflammatory cells was found in 69% of the samples. The comparison between UC and the control groups revealed that the UC group had significantly more positive cases for COX-1 and COX-2 in inflammatory cells. Immunohistochemistry allowed the identification of COX-1 and COX-2 expression in epithelial and inflammatory cells in UC biopsies. No significant difference between COX-1 and COX-2 immunoreactivity in epithelial and inflammatory cells was observed regarding the clinicopathological parameters. COX-2 presented low expression in normal colon and high expression in colorectal adenocarcinoma. COX-2 might play a role in the pathophysiologic processes of inflammatory bowel disease and the development of neoplasia. Treatment with selective COX-2 inhibitors might be an additional option for therapy.

E-cadherin and metalloproteinase-1 and -7 polymorphisms in colorectal cancer

PURPOSE E-cadherin (CDH1) and metalloproteinase (MMP) polymorphisms could play a crucial role in cancer invasion. Our aim was to investigate the influence of the -160C/A CDH1, -1607ins/delG MMP-1 and -181A/G MMP-7 polymorphisms on the frequency and progression of colorectal cancer (CRC). EXPERIMENTAL DESIGN A total of 130 patients with CRC and 130 noncancer controls were studied. The -160C/A CDH1, -1607ins/delG MMP-1 and -181A/G MMP-7 genotypes were analyzed by polymerase chain reaction-restriction fragment length polymorphism. RESULTS Patients with the 1G allele and a family history of CRC showed a six times higher risk of developing CRC (OR: 6.45, 95% CI: 2.02-20.6, p=0.001). The A/A CDH1 genotype was associated with a higher risk of metastatic disease (OR: 3.43, 95% CI: 1.27-9.27, p=0.023). A higher marginal risk of metastatic disease was observed for MMP-1 genotypes 1G/1G and 1G/2G (OR: 2.97, 95% CI: 0.93-9.47, p=0.098). CONCLUSIONS The -160C/A CDH1, -1607ins/delG MMP-1 and -181A/G MMP-7 single nucleotide polymorphisms did not modify the risk of CRC development. Patients with the 1G/1G or 1G/2G genotype and a family history of CRC presented a higher risk of CRC. The AA CDH1 and 1G/1G and 1G/2G MMP-1 genotypes might be associated with advanced metastatic disease, but are not markers of lymphatic metastasis.

Expression of COX-2 in Stomach Carcinogenesis

BackgroundsGastric cancer is a frequent cause of cancer in Brazil. The understanding of gastric carcinogenesis is not completely known but the progress of the molecular biology has provided that the initiation and progression of gastric cancer process is a consequence of a cumulative series of multiple gene alterations.AimThe aim of the study is to investigate the relationship among cytoplasmatic COX-1 and COX-2, Bcl-2 and nuclear P53 in chronic gastritis, metaplasia, and intestinal and gastric cancer.Patients and MethodsCOX-1, COX-2, P53, and Bcl-2 were evaluated by immunohistochemistry in 34 gastric adenocarcinoma (GA) tissues obtained from gastric resection, 21 tissues of patients with chronic gastritis (CG), and 34 with intestinal metaplasia (IM) obtained from endoscopic biopsies.ResultsCOX-1 and COX-2 were expressed in more than 85% of the tissues. A correlation between COX-1 and COX-2 were observed (r = 0.66). P53 was positive in 29% CG, 20% of IM and in 59 % of GA. Bcl-2 was negative in all the CG, in 88% of IM, and in 85% of GA. P53 staining was expressed more frequently in gastric cancer when compared to CG (p = 0.05) or IM (p = 0.003). The expression of Bcl-2 was also higher in gastric cancer (p = 0.002) and in intestinal metaplasia (p = 0.04) when compared to CG. There were no difference between metaplasia and chronic gastritis for P53 or Bcl-2. The imunoreactivity of COX-2 in gastric cancer was higher in the intestinal type (58%) than in diffuse type. A higher expression of COX-2 was found in advanced gastric cancer (p = 0.019). P53 was also more frequent in node positive cancer (p = 0.04).ConclusionCOX-2 is probably involved in gastric carcinogenesis, being an early alteration in cancer. Although we observed in this study a correlation between COX-2 and depth of cancer, this association as a prognostic marker is not well defined. P53 and Bcl-2 was expressed mainly in gastric cancer, being probably a latest alteration in gastric development.

C-erbB-2 oncoprotein in gastric carcinoma: correlation with clinical stage and prognosis.

The aim of this study was to investigate the expression of the oncogene c-erbB-2 in gastric tumors. Immunohistochemical study of the expression of c-erbB-2 was performed in formalin-fixed, paraffin-embedded sections from 82 gastric adenocarcinomas using polyclonal antibody. c-erbB-2-positive immunostaining was observed in 37 (45%) tumors. Positive staining was detected in 63% of well differentiated, 46% of moderately differentiated and 80% of papillary adenocarcinomas. In poorly differentiated adenocarcinomas, positivity for c-erbB-2 was observed in 21%. According to the Lauren classification, a higher frequency of c-erbB-2 positive staining was observed in intestinal type tumors (70%). During the follow-up period 43% of the patients with c-erbB-2 oncoprotein-negative tumors and 45% of the patients with c-erbB-2 oncoprotein-positive tumors died. There was no significant association between c-erbB-2 staining and sex, age, clinical stage, tumor grade, histological type or survival rates. In conclusion, almost half of the gastric cancers were positive for c-erbB-2. Nonetheless, the expression of c-erbB-2 oncoprotein did not play a role in prognosis.

N-Acetyltransferase 2 genetic polymorphisms and risk of colorectal cancer

AIM To investigate the possible association between meat intake, cigarette smoking and N-acetyltransferase 2 (NAT2) genetic polymorphisms on colorectal cancer (CRC) risk. METHODS Patients with CRC were matched for gender and age to healthy controls. Meat intake and cigarette smoking were assessed using a specific frequency questionnaire. DNA was extracted from peripheral blood and the genotypes of the polymorphism were assessed by polymerase chain reaction-restriction fragment length polymorphism. Five NAT2 alleles were studied (WT, M1, M2, M3 and M4) using specific digestion enzymes. RESULTS A total of 147 patients with colorectal cancer (76 women and 90 men with colon cancer) and 212 controls were studied. The mean age of the two groups was 62 years. More than half the subjects (59.8% in the case group and 51.9% in the control group) were NAT2 slow acetylators. The odds ratio for colorectal cancer was 1.38 (95% CI: 0.90-2.12) in slow acetylators. Although the number of women was small (n = 76 in the case group), the cancer risk was found to be lower in intermediate (W/Mx) acetylators [odds ratio (OR): 0.55, 95% confidence interval (95% CI): 0.29-1.02]. This difference was not observed in men (OR: 0.56, 95% CI: 0.16-2.00). Among NAT2 fast acetylators (W/W or W/Mx), meat consumption more than 3 times a week increased the risk of colorectal cancer (OR: 2.05, 95% CI: 1.01-4.16). In contrast, cigarette smoking increased the risk of CRC among slow acetylators (OR: 1.97, 95% CI: 1.02-3.79). CONCLUSION The risk of CRC was higher among fast acetylators who reported a higher meat intake. Slow NAT2 acetylation was associated with an increased risk of CRC.

Estudo do polimorfismo genético no gene p53 (códon 72) em câncer colorretal

BACKGROUND: Polymorphisms are genetic variations that can occur in sequences of codons, leading to defective proteins. p53 is the most commonly gene affected in human cancer. The polymorphism of this gene occurs by a substitution of a base in codon 72 and may increase the risk of cancer. AIM: To investigate the possible association between p53 arginine/72 proline polymorphism and susceptibility to colorectal cancer. PATIENTS AND METHODS: This polymorphism was studied by polymerization chain reaction using specific primers in 100 patients with colorectal cancer paired by sex and age to 100 patients without cancer. Alcohol and tobacco used by all the patients and clinical aspects as stage, grade of differentiation and recurrence in the case group was compared with the genotype analyzed. RESULTS: The frequency of homozygosis for arginine was 56% in the cancer group and 58% in the control group. No significant difference was observed among both groups. This genotype was more frequent in colorectal cancer patients stage IV than in stage I (80% versus 14%). There was no significant difference between genotypes and alcohol, tobacco, grade of differentiation or recurrence. CONCLUSION: Homozygosity for arginine was the most prevalent genotype in both groups. The frequency of codon 72 proline/arginine p53 gene polymorphism was not correlated with a higher risk of colorectal cancer. Arginine/arginine genotype was more prevalent in advanced cancer patients (stage IV).

Randomized Phase III Trial Exploring the Use of Long-Acting Release Octreotide in the Prevention of Chemotherapy-Induced Diarrhea in Patients With Colorectal Cancer: The LARCID Trial

PURPOSE Chemotherapy-induced diarrhea (CID) is a relatively common adverse event in the treatment of patients with colorectal cancer. The LAR for Chemotherapy-Induced Diarrhea (LARCID) trial evaluated the efficacy and safety of long-acting release octreotide (octreotide LAR) for the prevention of CID in this population. PATIENTS AND METHODS Patients with colorectal cancer starting adjuvant or first-line treatment with a chemotherapy combination containing fluorouracil, capecitabine, and/or irinotecan were randomly assigned to receive octreotide LAR 30 mg intramuscularly every 4 weeks (experimental arm) or the physicians treatment of choice in case of diarrhea (control arm). RESULTS A total of 139 patients were randomly assigned, most of whom received fluorouracil- and oxaliplatin-containing chemotherapy regimens. The rate of diarrhea was 76.1% in the experimental group (n = 68) and 78.9% in the control group (n = 71). Treatment with octreotide LAR did not prevent or reduce the severity of CID. Treatment choices for diarrhea management included loperamide in the majority of patients. No benefit from octreotide LAR was identified in terms of need for diarrhea treatment, opioids, or intravenous hydration or in the rate of hospitalization or quality of life. CONCLUSION This study could not prove the efficacy of octreotide LAR in the prevention of CID.549 Background: Chemotherapy-induced diarrhea (CID) is a relatively common adverse event in the treatment of colorectal cancer patients. The LARCID trial evaluated the efficacy and safety of long-acting release octreotide (octreotide LAR) for the prevention of CID in this population. METHODS Colorectal cancer patients starting adjuvant or first-line treatment with a chemotherapy combination containing fluorouracil (5-FU), capecitabine and/or irinotecan were randomized to receive octreotide LAR, 30 mg intramuscularly every 4 weeks, (experimental arm) or the physicians treatment of choice in case of diarrhea (control arm). RESULTS A total of 139 patients were randomized, most of which received 5-FU- and oxaliplatin-containing chemotherapy regimens. The rate of diarrhea was 76.1% in the experimental group (n=68) and 78.9% in the control group (n=71). Treatment with octreotide LAR did not prevent nor reduced the severity of CID. Treatment choices for diarrhea management included loperamide in the majority of cases. No benefit from octreotide LAR was identified in terms of need for diarrhea treatment, opioids, or intravenous hydration, nor in the rate of hospitalization, or quality-of-life. CONCLUSIONS Octreotide LAR is not indicated for the prevention of CID.