Clinicopathological differences between familial colorectal cancer type X and sporadic cancer in an isolated area of spain.

AIM: Very few studies have compared the epidemiological characteristics of patients with familial colorectal cancer Type X (FCCTX) with those of sporadic colorectal cancer (S-CRC). The aim of this study was to compare clinicopathological characteristics and survival between FCCTX and S-CRC in patients from a historically isolated geographical region. METHOD: A retrospective study was carried out of patients with S-CRC and FCCTX treated in the Canary Islands. Family and personal history of colorectal cancer (CRC) were recorded, together with genetic (microsatellite instability), immunohistochemical and clinical variables. RESULTS: Forty-eight (10.6%) of 451 patients were classified as FCCTX and the remaining 403 (89.4%) as S-CRC. Age at the diagnosis of tumour was significantly lower in FCCTX than in S-CRC (64.06 ± 12.65 years vs 69.13 ± 10.80 years; P = 0.01; Z = -2.48). Patients with FCCTX had a larger number of synchronous tumours (P = 0.09). Recurrence was significantly higher in FCCTX than in S-CRC (18.7% vs 8.6%; P = 0.01). Survival correlated significantly with the number of first-degree and second-degree relatives with CRC (P = 0.04; OR: 1.368, 95% CI: 1.01-1.84, and P = 0.04; OR: 1.363, 95% CI: 1.08-1.65) and with the total number of cases of CRC in the immediate family (P < 0.01; OR: 1.377, 95% CI: 1.17-1.61). Recurrence-free time was significantly lower in patients with FCCTX (log-rank = 0.01). CONCLUSION: Significant differences were found in several demographic and clinicopathological variables between patients with FCCTX and patients with S-CRC. These included increased tumour presentation under the age of 50 years and a higher recurrence rate in patients with FCCTX, suggesting an increased risk of CRC in this group.

Adrenocortical carcinoma, an unusual extracolonic tumor associated with Lynch II syndrome.

Lynch syndrome (LS) is an autosomal dominant condition that predisposes to colorectal cancer and specific other tumors. Extracolonic tumors occur mainly in the endometrium, stomach, ovary, small intestine and urinary tract. The presence of rare tumors in patients belonging to families who have Lynch syndrome is always interesting, because the question arises whether these tumors should be considered as a coincidence or are related with the syndrome. In this last case, they are also the result of the defect in the mismatch repair system, opening the possibility of extending the tumor spectrum associated with the syndrome. Here we describe a patient from a Lynch syndrome family with a germline mutation c.2063T>G (p.M688R) in the MSH2 gene, who developed an adrenal cortical carcinoma, a tumor not usually associated with LS. We analyzed the adrenocortical tumour for microsatellite instability (MSI), LOH and the presence of the germline c.2063T>G (M688R) mutation. The adrenal cortical carcinoma showed the MSH2 mutation, loss of heterozygosity of the normal allele in the MSH2 gene and loss of immunohistochemical expression for MSH2 protein, but no microsatellite instability. Additionally, the adrenal cortical carcinoma did not harbour a TP53 mutation. The molecular study indicates that this adrenal cortical cancer is probably due to the mismatch repair defect.

Tumour spectrum of non-polyposis colorectal cancer (Lynch syndrome) on the island of Tenerife and influence of insularity on the clinical manifestations.

Colorectal cancer is a complex disease from a genetic point of view because both genetic and environmental factors interact in its development. Only familial adenomatous polyposis (FAP) follows mendelian genetics, in that mutations of the APC gene lead to development of the tumours. Lynch syndrome is the most frequent form of hereditary colorectal cancer and appears to be associated with other types of extracolonic cancers. The genetic basis has been established as a defect in DNA mismatch repair genes, and there is genetic heterogeneity due to the involvement of several genes in this system. Germinal mutations in these genes predispose to appearance of the syndrome. The aim of this study is to describe the tumoral spectrum of 10 families, comprising a total of 488 individuals, from the island of Tenerife (Canary Islands) and to assess whether the geographical isolation of this population has changed any features of the tumoral spectrum of the syndrome in comparison with studies that cover larger geographical areas with more genetic exchange. From our results we can conclude that the genetic drift and consanguinity in this population with a demographic history of isolation did not significantly alter the tumoral spectrum of the syndrome. Our data confirm that families affected by Lynch syndrome are a high-risk population and should be closely monitored, since their careful supervision has been shown to be useful in preventing cancer. We also emphasize the importance of developing a complete family history that permits these families to be identified together with a mutational screening of DNA mismatch repair genes (mainly MLH1 and MSH2 genes) with the aim of a possible identification of members of a family that should be carefully monitored (the carriers of germline mutations in these genes), whereas the remaining members, originally, are no more at risk than the general population.

[Cytometric study of colonic tumors in a model of experimental colonic cancer. Impact of the diet]. / Estudio citométrico de tumores colónicos en un modelo de cáncer de colon experimental. Influencia de la dieta.

Butyrate is a short chain fatty acid, made up of four carbon atoms. Along with acetate and propionate, they are the main volatile fatty acids formed by the microbial fermentation of the carbohydrates of dietary fibre in the colon, mainly in the caecum. Additionally, they acidify the intracolonic pH, and they play an important role in the regulation of the absorption of water and sodium. On the other hand, they are, especially butyrate, preferred by the colon cell, as sources of energy alternative to glucose. Besides this, butyrate, in cellular cultures, is a known antineoplasic agent which is characterized by doubling the cellular duplication time for cells in the G1 phase, it increases the activity of certain enzymes, it stimulates the effects of interferon, it modifies the morphology of the cells, which in some cases leads to the reversion of the characteristic transformations of the cancerous cells, and it produces alterations in the chromatin, the nucleoli, elements of the cytoskeleton and the Golgi apparatus. Even though it is not known how it causes these actions, it is thought that the acetylization of histones which it produces, may be an important mechanism. We analyzed the effect of this substance in a colonic carcinogenesis model in Sprague-Dawley rats, in which the tumors were induced with the alkylating agent 1,2-dimethylhydrazide, observing the cytometric pattern of the tumors, and the possible differences between both groups. In one of them, sodium butyrate was continuously infused by means of a intrathecal catheter at a rhythm of 1.5 ml/hour during the tumoral induction which lasted four weeks.(ABSTRACT TRUNCATED AT 250 WORDS)