Decision tree learning to predict overweight/obesity based on body mass index and gene polymporphisms.

The new technologies for data analysis, such as decision tree learning, may help to predict the risk of developing diseases. The aim of the present work was to develop a pilot decision tree learning to predict overweight/obesity based on the combination of six single nucleotide polymorphisms (SNP) located in feeding-associated genes. Genotype study was performed in 151 healthy individuals, who were anonymized and randomly selected from the TALAVERA study. The decision tree analysis was performed using the R package rpart. The learning process was stopped when 15 or less observation was found in a node. The participant group consisted of 78 men and 73 women, who 100 individuals showed body mass index (BMI) ≥ 25 kg/m2 and 51 BMI < 25 kg/m2. Chi-square analysis revealed that individuals with BMI ≥ 25 kg/m2 showed higher frequency of the allelic variation Ala67Ala in AgRP rs5030980 with respect to those with BMI <25 kg/m2. However, the variant Thr67Ala in AgRP rs5030980 was the most frequently found in individuals with BMI <25 kg/m2. There were no statistical differences in the other analyzed SNPs. Decision tree learning revealed that carriers of the allelic variants AgRP (rs5030980) Ala67Ala, ADRB2 (rs1042714) Gln27Glu or Glu27Glu, INSIG2 (rs7566605) 73 + 9802 with CC or GG genotypes and PPARG (rs1801282) with the allelic variants of Ala12Ala or Pro12Pro, will most likely develop overweight/obesity (BMI ≥ 25 kg/m2). Moreover, the decision tree learning indicated that age and gender may change the developed three decision learning associated with overweight/obesity development. The present work should be considered as a pilot demonstrative study to reinforce the broad field of application of new data analysis technologies, such as decision tree learning, as useful tools for diseases prediction. This technology may achieve a potential applicability in the design of early strategies to prevent overweight/obesity.

Do MSI-L sporadic colorectal tumors develop through "mild mutator pathway"?

BACKGROUND: The mutator pathway implied in the development of colorectal cancer (CRC) is characterized by microsatellite instability (MSI). MSI tumors can be subdivided according to the level of instability: MSI-H (high), MSI-L (low) or stable MSS. MSI-H CRC displays a well described distinct phenotype, but the true biologic significance of MSI-L is still uncertain. The objective of this study was to further clarify if the MSI-L phenotype could reflect a distinct pathway of tumor development with a different clinical behavior. METHODS: We analyzed the clinicopathological and genetic variables of 156 patients with sporadic CRC in relation with the level of MSI of the tumors. RESULTS: We have found that MSI-L tumors are someway in the middle of MSI-H and MSS CRC, as they share some features with each of the other 2 subgroups: left side location, lower incidence of LOH at MSH2 as MSS and Dukes B (stage II TNM) like MSI-H. Moreover, MSI-L tumors show higher incidence of KRAS mutations. CONCLUSION: We believe that MSI-L tumors could be considered a distinct phenotype that develops through a "mild mutator pathway."

Self-expandable stent before elective surgery vs. emergency surgery for the treatment of malignant colorectal obstructions: comparison of primary anastomosis and morbidity rates.

PURPOSE: At present there are not enough studies that demonstrate the usefulness of self-expandable stents in patients with left-sided malignant colon and rectal obstruction. We evaluated primary anastomosis and morbidity rates obtained with this method in comparison with the results of the emergency surgical treatment. METHODS: From February 1994 to November 1999, 72 consecutive patients with left-sided malignant colorectal obstruction were enrolled. Forty-three patients were assigned to the study group (preoperative stent and elective surgical treatment or palliative stent, depending on the assessment of the stage of the tumor) and 29 to the control group (emergency surgical treatment). The resection was not indicated in 18 cases in the study group (after preoperative staging in 17 and intraoperative staging in 1) and in 3 cases in the control group. RESULTS: In the study group, the obstruction was relieved in 41 cases (95 percent) after the stent placement. Of 26 patients who underwent surgical treatment, a primary anastomosis was possible in 22 (84.6 vs. 41.4 percent in the control group, P = 0.0025), with lower need for a colostomy (15.4 vs. 58.6 percent in the control group). The anastomotic failure rate was similar and the reintervention rate was lower (0 vs. 17 percent, P = 0.014). The total stay (14.23 vs. 18.52 days; P = 0.047), the intensive care unit stay (0.3 vs. 2.9 days; P = 0.015), and the number of patients with severe complications (11.6 vs. 41.2 percent; P = 0.008) were significantly lower in the study group. CONCLUSIONS: In our patients with left-sided malignant colon and rectal obstruction, placement of a preoperative stent prevented 17 (94 percent) of 18 of unnecessary operations and a large number of colostomies after elective surgery. These results were obtained with a lower severe complication rate as well as a shorter hospital stay.