IMPACT OF KRAS MUTATIONS IN CLINICAL FEATURES IN COLORECTAL CANCER

Background:

KRAS mutations are important events in colorectal carcinogenesis, as well as negative predictors of response to EGFR inhibitors treatment.

Aim:

To investigate the association of clinical-pathological features with KRAS mutations in colorectal cancer patients treated.

Methods:

Data from 69 patients with colorectal cancer either metastatic at diagnosis or later, were retrospectively analyzed. The direct sequencing and pyrosequencing techniques were related to KRAS exon 2. The mutation diagnosis and its type were determined.

Results:

KRAS mutation was identified in 43.4% of patients. The most common was c.35G>T (p.G12V), c.35G>A (p.G12D) and c.38G>A (p.G13D). No correlation was found between KRAS mutation and age (p=0.646) or gender (p=0.815). However, mutated group had higher CEA levels at admission (p=0.048) and codon 13 mutation was associated with involvement of more than one metastatic site in disease progression (p=0.029). Although there was no association between primary tumor site and mutation diagnosis (p=0.568), primary colon was associated with worse overall survival (p=0.009).

Conclusion:

The KRAS mutation was identified in almost half of patients. Mutated KRAS group had higher levels of CEA at admission and the mutation at codon 13 was associated with involvement of more than one metastatic site in the course of the disease. Colon disease was associated with the worst overall survival.

Genetic variants in gastric cancer: Risks and clinical implications

Cancer is a multifactorial disease that involves many molecular alterations. Gastric cancer (GC) is the third leading cause of cancer death worldwide. GC is a highly heterogeneous disease with different molecular and genetics features. Therefore, this review focuses on an overview of the genetic aspects of gastric cancer by highlighting the important impact and role of deletions and/or duplications of chromosomal segments, genomic variants, H. pylori infection and interleukin variants, as found in gene expression and newly proposed molecular classification studies. The challenge is to better understand the mechanisms and different pathways that lead to the development and progression of GC.

Experimental study of inflammatory response and collagen morphometry with different types of meshes

PURPOSE

To compare an inflammation score and collagen morphometry after incisional hernia repair with four different meshes at two time points.

METHODS

Four types of mesh were used to repair an abdominal wall incisional defect in Wistar rats: high-density polypropylene (HW/PP); low-density polypropylene (LW/PP); polypropylene mesh encapsulated with polydioxanone coated with oxidized cellulose (PP/CE); and expanded polytetrafluoroethylene (ePTFE). An inflammation score based on histological analysis and collagen morphometry was performed after 7 and 28 days after operation (POD).

RESULTS

Compared to LW/PP group at 7 POD, HW/PP group had lower (p = 0.014) and PP/CE group had higher inflammation scores (p = 0.001). At 28 POD, higher scores were seen in all the other groups compared to the LW/PP group (HW/PP, p = 0.046; PP/CE, p < 0.001; ePTFE, p = 0.027). Comparing groups individually at 7 and 28 PODs, all demonstrated lower inflammation score values at 28 POD (HW/PP, p < 0.001; LW/PP, p < 0.001; PP/CE, p = 0.002; ePTFE, p = 0.001). At 7 POD, higher amounts of collagen were detected in ePTFE compared to HW/PP (p < 0.001) and LW/PP (p = 0.004) and in PPCE group compared to HW/PP (p = 0.022). At 28 POD, no statistically significant difference was found. Comparing groups individually at 7 and 28 PODs, HW/PP and LW/PP showed larger amounts of collagen at the 28th POD, without any statistically significant differences for the PP/CE and ePTFE groups.

CONCLUSIONS

Inflammation scores decreased in all groups at 28 POD. Collagen deposition was higher for non-composite meshes at 28 POD.

Duodenum-stomach anastomosis: a new technique for exocrine drainage in pancreas transplantation

INTRODUCTION

Poor vascular access due to previous surgery can be a major obstacle in pancreas transplantation for which new exocrine and vascular outflow techniques might be useful. A 34-year-old female with early onset type 1 diabetes who underwent living donor kidney transplantation 20 years ago and a failed pancreas transplantation 2 years ago presented for pancreas retransplantation.

METHODS

The inferior vena cava was used in the previous deceased donor pancreas transplantation and both iliac arteries had intense perivascular fibrosis, making arterial anastomosis impossible. The only remaining option for the implant was the infrarenal aorta, with venous drainage to the superior mesenteric vein and exocrine drainage to the gastric antrum.

RESULTS

The patient had an uneventful recovery and graft function appeared normal. This report shows that when the recipient's abdominal cavity does not provide clear access for the usual surgical techniques regarding exocrine drainage, the stomach drainage procedure is an option.

CONCLUSION

Duodenum-stomach anastomosis might be an alternative to portal enteric drainage because there is easy access for graft biopsies and even for procedures involving the papilla major.

Relationship between the preoperative body mass index and the resolution of metabolic syndrome following Roux-en-Y gastric bypass

BACKGROUND

The increased prevalence of overweight and obesity has reached alarming proportions worldwide and has serious health implications, including an association with an increase in metabolic syndrome. Among the methods to control metabolic syndrome, bariatric surgery plays an important role and can provide a significant improvement in the components of metabolic syndrome.

OBJECTIVE

The aim of this study was to determine the relationship between the preoperative body mass index (BMI) and the postoperative resolution of metabolic syndrome [using the National Cholesterol Education Program (NCEP ATP III criteria)] in patients undergoing Roux-en-Y gastric bypass (RYGB).

METHODS

Retrospective analysis of a consecutive series of cases, stratified by BMI into three groups (group 1, BMI <40 kg/m(2), group 2, BMI 40-49.9 kg/m(2), and group 3, BMI 50 ≥ kg/m(2)) consisting of both sexes between 20 and 60 years of age. The cohort consisted of 149 patients undergoing RYGB. Anthropometric, biochemical, and clinical evaluations were performed preoperatively and then at 30 and 180 days postoperatively.

RESULTS

The average age was 40 years, and the patients were predominately female (72%). At the end of the study period, all groups showed a significant reduction in metabolic syndrome compared with preoperative levels. Logistic regression showed a higher percentage of metabolic syndrome in patients in group 3 after 180 days.

CONCLUSION

There was significant resolution of metabolic syndrome in all groups, independently of the preoperative BMI. However, in group 3 (BMI ≥ 50 kg/m(2)), 22% of individuals still presented with metabolic syndrome at 180 days postoperatively (P=0.03).

Experimental study comparing meshes made of polypropylene, polypropylene + polyglactin and polypropylene + titanium: inflammatory cytokines, histological changes and morphometric analysis of collagen

PURPOSE

Incisional hernia occurs in approximately 11% of all laparotomies. Changes in collagen have been closely implicated in its pathogenesis. The high recurrence rate (45-54%) after primary suture has stimulated the development of meshes. Currently, meshes are the biomaterials implant group most used in medicine. This study aims to compare the serum and tissue inflammatory responses and collagen deposition caused by meshes made of polypropylene, polypropylene + polyglactin and polypropylene + titanium.

METHODS

Thirty Wistar rats were divided into three groups. In group I, a high-density polypropylene mesh was positioned on the abdominal wall. In groups II and III, low-density meshes were used in associations with polyglactin and titanium, respectively. Immediately before the operation and on the first, third and fortieth postoperative days, pro-inflammatory cytokines were assayed. On the 40th postoperative day, the region of the inserted prosthesis was biopsied. The tissue inflammatory reaction was evaluated using a scale for objective scoring. For collagen, picrosirius was used with data reading using the Image Tool computer software.

RESULTS

Cytokines: there were no statistically significant differences between the groups.

HISTOLOGY

on the 40th postoperative day in group I, there were fewer inflammatory tissue response and greater collagen deposition (P < 0.01). In group II, there were greater inflammatory tissue response and less collagen deposition (P < 0.01). Group III presented intermediate values between groups I and II.

CONCLUSIONS

There were no significant differences in cytokine levels between the groups in the present study. In the animals with the polypropylene + polyglactin mesh implant there was the most intense inflammatory process with lower tissue maturation and collagen deposition on the 40th postoperative day. The polypropylene mesh presented a less severe late inflammatory process, with greater tissue maturation and collagen deposition. The polypropylene + titanium mesh presented intermediate values between the others.