Analysis of gene expression EGFR and KRAS, microRNA-21 and microRNA-203 in patients with colon and rectal cancer and correlation with clinical outcome and prognostic factors

Abstract Purpose: To evaluate the expression of EGFR, KRAS genes, microRNAs-21 and 203 in colon and rectal cancer samples, correlated with their age at diagnosis, histological subtype, value of pretreatment CEA, TNM staging and clinical outcome. Methods: Expression of genes and microRNAs by real time PCR in tumor and non-tumor samples obtained from surgical treatment of 50 patients. Results: An increased expression of microRNAs-21 and 203 in tumor samples in relation to non-tumor samples was found. There was no statistically significant difference between the expression of these genes and microRNAs when compared to age at diagnosis and histological subtype. The EGFR gene showed higher expression in relation to the value of CEA diagnosis. The expression of microRNA-203 was progressively lower in relation to the TNM staging and was higher in the patient group in clinical remission. Conclusions: The therapy of colon and rectum tumors based on microRNAs remains under investigation reserving huge potential for future applications and clinical interventions in conjunction with existing therapies. We expect, based on the exposed data, to stimulate the development of new therapeutic possibilities, making the treatment of these tumors more effective.

Association between apolipoprotein E genotype, serum lipids, and colorectal cancer in Brazilian individuals

We evaluated genetic variants of apolipoprotein E (APOE HhaI) and their association with serum lipids in colorectal cancer (CRC), together with eating habits and personal history. Eight-seven adults with CRC and 73 controls were studied. APOE*2 (rs7412) and APOE*4 (rs429358) were identified by polymerase chain reaction-restriction fragment length polymorphism. APOE gene polymorphisms were similar in both groups, but the å4/å4 genotype (6 percent) was present only in controls. The patients had reduced levels (mean ± SD) of total cholesterol and low-density lipoprotein cholesterol fraction (180.4 ± 49.5 and 116.1 ± 43.1 mg/dL, respectively) compared to controls (204.2 ± 55.6, P = 0.135 and 134.7 ± 50.8 mg/dL; P = 0.330, respectively) indicating that they were not statistically significant after the Bonferroni correction. The APOE*4 allele was associated with lower levels of total cholesterol, low- and high-density lipoprotein cholesterol fraction and increased levels of very low-density lipoprotein cholesterol fraction and triglycerides only among patients (P = 0.014). There was a positive correlation between the altered lipid profile and increased body mass indexes in both groups (P < 0.010). Moreover, a higher rate of hypertension and overweight was observed in controls (P < 0.002). In conclusion, the presence of the å4/å4 genotype only in controls may be due to a protective effect against CRC. Lower lipid profile values among patients, even those on lipid-rich diets associated with the APOE*4 allele, suggest alterations in the lipid synthesis and metabolism pathways in CRC.

Caracterización clínico quirúrgica del cáncer colorrectal en pacientes ingresados / Clinic-surgical characterization of the colorectal cancer in inpatients

El cáncer colorrectal presenta alta incidencia. En Cuba, esta patología ocupa el quinto lugar en ambos sexos entre todas las neoplasias. Con el objetivo de caracterizar dicha afección se realizó un estudio descriptivo transversal en el servicio de Cirugía General del Hospital Militar Docente de Matanzas Dr Mario Muñoz Monroy, en el período de enero del 2001 a enero del 2005, estudiándose edad, sexo, antecedentes oncológicos familiares, forma de presentación, localización y diagnóstico del tumor así como técnica quirúrgica empleada en su tratamiento. Los resultados mostraron predominio del sexo masculino en las edades de 60 a 69 años, síntomas diferentes en dependencia de la localización, predominio del cáncer rectal, entre otros. Se concluyó que existe demora entre el inicio de los síntomas y el diagnóstico, lo que disminuye considerablemente las posibilidades de curación y la sobrevida.

The colorectal cancer presents high incidence. This pathology occupies the fifth place among the neoplasias in both sexes in Cuba. With the objective of characterizing this disease we carried out a descriptive transversal study at the service of General Surgery of the University Military Hospital of Matanzas Dr Mario Muñoz Monroy, in the period from January 2001 to January 2005, studying age, sex, familiar oncological antecedents, presentation form, localization and diagnosis of the tumor, and also the surgical technique used in the treatment. The results showed predominance of the male sex in ages between 60 and 69 years old, different symptoms depending on the localization, predominance of the rectal cancer, and others. It was concluded that there is a delay between the beginning of the symptoms and the diagnosis, considerably diminishing the healing possibilities and survival.

Estudio endoscópico en familiares de primer grado de pacientes operados por cáncer colorrectal / Screening colonoscopy among first degree relatives of patients with colorectal carcinoma

Background: First degree relatives of patients with colorectal carcinoma are at a higher risk of having the disease than the general population. Therefore, they should be subjected to screening colonoscopy. Aim: To assess the effectiveness of colonoscopy among first degree relatives of patients with colorectal carcinoma. Material and methods: A free colonoscopy was offered to first degree relatives of patients operated on for colorectal cancer between 1998 and 2000. As inclusion criteria, subjects had to be asymptomatic, older than 40 years or less than 10 years younger than the index case. Each subject was contacted twice, inviting him/her to have a colonoscopy performed. Results: Two hundred forty three relatives were contacted for the study and in 76, a colonoscopy was performed. Among the latter, a neoplasm was found in 13 (17 percent): One adenocarcinoma and 12 adenomas. Three of these lesions were located in the right colon. The main reason given by the 176 subjects that did not agree to have a colonoscopy was lack of interest. Conclusions: Screening colonoscopy is effective to detect adenoma and adenocarcinomaamong first degree relatives of patients with colorectal carcinoma, however only 31 percent of all potential relatives agreed to undergo a colonoscopy.

Rastreamento do câncer colorretal: artigo de revisäo / Sreening and colorectal cancer: review

Os autores revisam e apresentam os principais métodos de rastreamento populacional para os adenomas colônicos e o câncer colorretal (CCR). A pesquisa de sangue oculto nas fezes pelo método guaiac é um procedimento sensível e específico de rastreamento, principalmente quando é utilizada a reidrataçäo das fezes. É um teste bem estudado em populaçöes assintomáticas, aplicável em nosso meio por ser de fácil utilizaçäo e baixo custo. A retossigmoidoscopia deve ser realizada a cada 3 anos, preferencialmente associada ao teste anual de pesquisa de sangue oculto nas fezes. O exame com aparelho flexível de 60 cm é preferível por ser menos incômodo ao paciente e oferecer alcance diagnóstico a cerca de metade dos CCR. A colonoscopia é um método eficaz e de baixo índice de morbidade, porém tem seu custo elevado, devendo ser indicada apenas em casos selecionados. O grande avanço alcançado nos últimos anos no campo da biologia molecular tornou possível, além do conhecimento do processo de carcinogênese do CCR, a detecçäo de células do epitélio colônico com alteraçöes genéticas descamadas nas fezes. Essas mutaçöes predispöem ao aparecimento do CCR. Os autores também mostram fatores de risco para o desenvolvimento do CCR, como idade acima de 50 anos, retocolite ulcerativa inspecífica, doença de Crohn, antecedentes familiares e pessoais de pólipos e CCR.