Retrospective cohort of pancreatic and Vater ampullary adenocarcinoma from a reference center in Mexico.

INTRODUCTION: Pancreatic ductal adenocarcinoma (PDAC) and ampulla of Vater adenocarcinomas (AVAC) are periampullary tumors. These tumors have overlapping symptoms and a common treatment, but present differences in their survival and biology. No recent studies in Mexico have been published that describe the clinicopathological characteristics of these tumors. Therefore, the aim of this study was to describe the clinicopathological characteristics of PDAC and AVAC in patients at a reference center in Mexico. METHODS: A retrospective cohort of patients with PDAC or AVAC was analyzed at our institution (July 2007 to June 2016). Inferential analysis of the clinical data was performed with Student's t-test or a χ2 test with odds ratios (OR) and confidence intervals (CI), depending on the variables. Overall survival was compared using Kaplan-Meier curves with log-rank p values. RESULTS: Forty patients with PDAC and 76 with AVAC were analyzed, including 77 females and 39 males with a mean age of 60.6 years and a mean evolution time of 5.7 months. PDAC patients had more abdominal pain, a larger tumor size and more advanced stages than AVAC patients. In contrast, AVAC patients had more jaundice, a higher percentage of complete resections and higher overall survival. Up to 70% of patients were overweight. PDAC cohort included a higher proportion of smokers. CONCLUSIONS: Our cohort was slightly younger, had a larger percentage of females, and a greater percentage of obese patients than those in many international reports. A high proportion of PDAC patients are diagnosed in advanced stages and have a low likelihood of resectability.

Treatment of non-resectable and metastatic gastrointestinal stromal tumors: experience with the use of tyrosine kinase inhibitors in a third level hospital in Mexico.

BACKGROUND: Stromal tumors of the digestive tract are uncommon malignant diseases, are subclassified as leiomyosarcomas and Gastrointestinal Stromal Tumors (GIST) depending on the molecular expression of tyrosine kinase receptor KIT (CD117). GISTs represent 1% of malignant tumors affecting this anatomical site. Localized tumours diseases are reasonably well controlled by surgical resection and several criteria define the need for adjuvant therapy. In the case of metastatic disease a poor prognosis has been reported with systemic treatment based on chemotherapy. Recently, significant advances have been shown since tyrosine kinase inhibitors (TKIs) were introduced, with median overall survival close to 5 years. Unfortunately in Mexico, even though the therapy has been long used there are no published data of the experience in the treatment of these tumors. METHODS: We used an electronic data base to obtain clinical, radiological and histological data of patients diagnosed with GIST and treated in the oncological center of the Mexican Institute of Social Security, patients were subclassified by stage, symptoms at diagnosis as well as the initial and subsequent systemic treatment. Finally we made an analysis for progression free survival and overall survival identifying prognostic factors. RESULTS: We obtained information of 71 patients with metastatic, non-resectable or recurrent GIST, treated with a TKI, we observed a predominant relation for women (60.4%) with median age of 58 years. Stage at diagnosis was predominantly metastatic (46.5%), most frequently affected sites were lung, liver and retroperitoneum. Median progression free survival was 30.6 months and overall survival was 81.3 months. All patients were initially treated with imatinib at a dose of 400 mg per day. Treatment was well-tolerated in most cases. CONCLUSIONS: Metastatic GIST evaluated in our center shows a different affection in gender and age, and our population shows a different response to TKIs, compared to those reported in other series with superior overall survival. Poor prognosis is associated with lung affection. Biological studies will be started for the molecular evaluation of these tumors.

Systemic treatment with capecitabine as maintenance therapy in patients with recurring or metastatic breast cancer: experience in the Oncology Hospital, National Medical Center Siglo XXI, Mexican Social Security Institute.

Metastatic breast cancer as initial onset represents between 20 and 30 % of cases and is considered an incurable disease. The goal of its treatment is palliative, looking for increasing the survival while reducing the symptoms. Maintenance chemotherapy studies for metastatic breast cancer have demonstrated to prolong the progression-free survival, with unclear results in terms of overall survival. The main objectives of our study were the progression-free survival and overall survival in patients with recurring or metastatic breast cancer treated with capecitabine in the maintenance chemotherapy setting compared with patients not receiving maintenance chemotherapy. As secondary objectives, the frequency of dose-limiting toxicities and response rate were determined. A non-probabilistic sampling was used, through expert selection of patients from the recurring/metastatic breast cancer survey cared within the period from January 1, 2007, to December 21, 2012. A total of 77 patients were included. Clinical data of advanced/recurrent breast cancer patients that were treated with capecitabine were recorded. The study achieved its primary objective, since the progression-free survival was prolonged for the maintenance therapy group: 6.6 versus 18.1 months, p < 0.001. The absolute benefit was 11.5 months. Likewise, there was a benefit in the overall survival of 21.03 versus 29 months, p = 0.015, with an absolute benefit of 7.97 months. The toxicity profile was favorable in the maintenance group. The maintenance chemotherapy with capecitabine in patients treated at the National Medical Center Siglo XXI Oncology Hospital extends the overall survival and progression-free survival with a good toxicity profile.

Increased erythrocytes by-products of arginine catabolism are associated with hyperglycemia and could be involved in the pathogenesis of type 2 diabetes mellitus.

Diabetes mellitus (DM) is a worldwide disease characterized by metabolic disturbances, frequently associated with high risk of atherosclerosis and renal and nervous system damage. Here, we assessed whether metabolites reflecting oxidative redox state, arginine and nitric oxide metabolism, are differentially distributed between serum and red blood cells (RBC), and whether significant metabolism of arginine exists in RBC. In 90 patients with type 2 DM without regular treatment for diabetes and 90 healthy controls, paired by age and gender, we measured serum and RBC levels of malondialdehyde (MDA), nitrites, ornithine, citrulline, and urea. In isolated RBC, metabolism of L-[(14)C]-arginine was also determined. In both groups, nitrites were equally distributed in serum and RBC; citrulline predominated in serum, whereas urea, arginine, and ornithine were found mainly in RBC. DM patients showed hyperglycemia and increased blood HbA1C, and increased levels of these metabolites, except for arginine, significantly correlating with blood glucose levels. RBC were observed to be capable of catabolizing arginine to ornithine, citrulline and urea, which was increased in RBC from DM patients, and correlated with an increased affinity for arginine in the activities of putative RBC arginase (Km = 0.23±0.06 vs. 0.50±0.13 mM, in controls) and nitric oxide synthase (Km = 0.28±0.06 vs. 0.43±0.09 mM, in controls). In conclusion, our results suggest that DM alters metabolite distribution between serum and RBC, demonstrating that RBC regulate serum levels of metabolites which affect nitrogen metabolism, not only by transporting them but also by metabolizing amino acids such as arginine. Moreover, we confirmed that urea can be produced also by human RBC besides hepatocytes, being much more evident in RBC from patients with type 2 DM. These events are probably involved in the specific physiopathology of this disease, i.e., endothelial damage and dysfunction.