Search Results Heading

MBRLSearchResults

mbrl.module.common.modules.added.book.to.shelf
Title added to your shelf!
View what I already have on My Shelf.
Oops! Something went wrong.
Oops! Something went wrong.
While trying to add the title to your shelf something went wrong :( Kindly try again later!
Are you sure you want to remove the book from the shelf?
Oops! Something went wrong.
Oops! Something went wrong.
While trying to remove the title from your shelf something went wrong :( Kindly try again later!
    Done
    Filters
    Reset
  • Discipline
      Discipline
      Clear All
      Discipline
  • Is Peer Reviewed
      Is Peer Reviewed
      Clear All
      Is Peer Reviewed
  • Item Type
      Item Type
      Clear All
      Item Type
  • Subject
      Subject
      Clear All
      Subject
  • Year
      Year
      Clear All
      From:
      -
      To:
  • More Filters
      More Filters
      Clear All
      More Filters
      Source
    • Language
115 result(s) for "Calvo, Benjamin"
Sort by:
A Six-Gene Signature Predicts Survival of Patients with Localized Pancreatic Ductal Adenocarcinoma
Pancreatic ductal adenocarcinoma (PDAC) remains a lethal disease. For patients with localized PDAC, surgery is the best option, but with a median survival of less than 2 years and a difficult and prolonged postoperative course for most, there is an urgent need to better identify patients who have the most aggressive disease. We analyzed the gene expression profiles of primary tumors from patients with localized compared to metastatic disease and identified a six-gene signature associated with metastatic disease. We evaluated the prognostic potential of this signature in a training set of 34 patients with localized and resected PDAC and selected a cut-point associated with outcome using X-tile. We then applied this cut-point to an independent test set of 67 patients with localized and resected PDAC and found that our signature was independently predictive of survival and superior to established clinical prognostic factors such as grade, tumor size, and nodal status, with a hazard ratio of 4.1 (95% confidence interval [CI] 1.7-10.0). Patients defined to be high-risk patients by the six-gene signature had a 1-year survival rate of 55% compared to 91% in the low-risk group. Our six-gene signature may be used to better stage PDAC patients and assist in the difficult treatment decisions of surgery and to select patients whose tumor biology may benefit most from neoadjuvant therapy. The use of this six-gene signature should be investigated in prospective patient cohorts, and if confirmed, in future PDAC clinical trials, its potential as a biomarker should be investigated. Genes in this signature, or the pathways that they fall into, may represent new therapeutic targets. Please see later in the article for the Editors' Summary.
Outcomes of surgical resection and intraoperative electron radiotherapy for patients with para-aortic recurrences of gastrointestinal and gynecologic malignancies
Background Para-aortic lymph node (PALN) metastases from primary pelvic malignancies are often treated with resection, but recurrence is common. We report toxicity and oncologic outcomes for patients with PALN metastases from gastrointestinal and gynecologic malignancies treated with resection and intraoperative electron radiotherapy (IORT). Methods We retrospectively identified patients with recurrent PALN metastases who underwent resection with IORT. All patients were included in the local recurrence (LR) and toxicity analyses. Only patients with primary colorectal tumors were included in the survival analysis. Results There were 26 patients with a median follow up of 10.4 months. The rate of para-aortic local control (LC) was 77% (20/26 patients) and the rate of any cancer recurrence was 58% (15/26 patients). Median time from surgery and IORT to any recurrence was 7 months. The LR rate for those with positive/close margins was 58% (7/12 patients) versus 7% (1/14 patients) for those with negative margins (p = 0.009). 15% (4/26 patients) developed surgical wound and/or infectious complications, 8% (2/26 patients) developed lower extremity edema, 8% (2/26 patients) experienced diarrhea, and 19% (5/26 patients) developed an acute kidney injury. There were no reported nerve injuries, bowel perforations, or bowel obstructions. For patients with primary colorectal tumors (n = 19), the median survival (OS) was 23 months. Conclusions We report favorable LC and acceptable toxicity for patients receiving surgical resection and IORT for a population that has historically poor outcomes. Our data show disease control rates similar to literature comparisons for patients with strong risk factors for LR, such as positive/close margins.
Utilization and Morbidity Associated with Placement of a Feeding Jejunostomy at the Time of Gastroesophageal Resection
Background The purpose of the study was to evaluate the utilization and morbidity associated with feeding jejunostomy tubes (JT) placed at the time of gastroesophageal resection (GER). Methods Under institutional review board approval, a prospective database of patients undergoing GER from January 2004 to September 2010 was reviewed. Data analyzed included patient demographics, postoperative complications, JT use, and JT specific complications. Fisher’s exact tests explored associations with utilization of a JT following resection. Results Seventy-three patients (51 men, 22 women, median age of 59) underwent placement of a JT at the time of GER (total gastrectomy = 28, Ivor–Lewis = 28, subtotal gastrectomy = 8, proximal gastrectomy = 6, and transhiatal esophagectomy = 3) of both malignant (97%) and benign (3%) disease processes. Twenty-one JT specific complications (11 minor and 10 major) were identified. Reoperation was required in the management of two complications (small bowel obstructions), while all other complications were easily managed by an interventional radiologist ( n  = 8), bedside procedure ( n  = 5), or did not require intervention ( n  = 6). Eighty-six percent of patients were discharged tolerating a postgastrectomy diet, 10% nothing per orem, and 4% a liquid diet. Inpatient enteral nutrition (EN) was initiated in 68%, but continued on discharge in only 54% secondary to failure to thrive (54%), dysphagia (21%), anastomic leak (15%), chyle leak (3%), esophagostomy (3%), and duodenal stump leak (3%). The mean time to discontinuance of EN and removal of the JT was 44 days (range, 4–203) and 71 days (range, 15–337) respectively. Although only 13% ( n  = 5) of patients requiring adjuvant therapy were utilizing their JT at the commencement of therapy, 75% ( n  = 21) required EN during its course. The median time to adjuvant therapy was found to be slightly longer in those who required outpatient EN versus those who did not (61 vs. 90 days, p  = 0.08). However, the median time to adjuvant therapy did not differ between those who were and were not receiving EN at the time of adjuvant therapy commencement (80 vs. 92 days, p  = 0.2). Age ( p  = 0.4), number of co-morbidities ( p  = 0.2), preoperative percent body weight loss ( p  = 0.9), and clinical stage ( p  = 0.8) were not significantly associated with outpatient JT use. Patients who suffered a postoperative complication were most likely to require EN ( p  = 0.002), an association that strengthened as the number of complications increased ( p  = 0.0008). Although not statistically significant, a trend towards increased outpatient EN was noted in patients who underwent transhiatal esophagectomy and total gastrectomy ( p  = 0.06). Conclusions JT placement carries a considerable morbidity in patients undergoing GER. However, because it is difficult to preoperatively ascertain who will need prolonged EN, the routine placement of a JT is recommended, particularly in those who will likely require adjuvant therapy or are at high risk for postoperative complications. Despite patient desires for early removal of an unused JT, caution should be taken if adjuvant therapy is being considered.
Size of Residual Lymph Node Metastasis After Neoadjuvant Chemotherapy in Locally Advanced Breast Cancer Patients Is Prognostic
The prognostic significance of micrometastasis after neoadjuvant chemotherapy for locally advanced breast cancer is unknown. We examined the residual lymph node metastasis size in patients after treatment with neoadjuvant chemotherapy to determine the relevance of metastasis size on outcome. Stage II/III breast cancer patients treated with neoadjuvant chemotherapy at our institution from 1991 to 2002 were included. We examined the relationship of postneoadjuvant chemotherapy lymph node metastasis size and number with distant disease-free survival (DDFS) and overall survival (OS). In 122 patients with a median follow-up of 5.4 years, we found not only that patients with an increasing number of residual positive nodes had progressively worse DDFS and OS (P < .0001 for both) compared with patients with negative nodes, but also that the size of the largest lymph node metastasis was associated with worse DDFS and OS (P < .0001 for both) in both univariate and multivariate analysis. Compared with negative nodes, even lymph node micrometastasis (<2 mm) was associated with worsened DDFS and OS (adjusted P = .02 and P = .005, respectively). Residual micrometastatic disease in the axillary lymph nodes after neoadjuvant chemotherapy is predictive of worse prognosis than negative nodes. In this study, the lymph node metastasis size and the number of involved lymph nodes were independent powerful predictors of DDFS and OS.
Phospho-ERK and AKT status, but not KRAS mutation status, are associated with outcomes in rectal cancer treated with chemoradiotherapy
Background KRAS mutations may predict poor response to radiotherapy. Downstream events from KRAS , such as activation of BRAF , AKT and ERK, may also confer prognostic information but have not been tested in rectal cancer (RC). Our objective was to explore the relationships of KRAS and BRAF mutation status with p-AKT and p-ERK and outcomes in RC. Methods Pre-radiotherapy RC tumor biopsies were evaluated. KRAS and BRAF mutations were assessed by pyrosequencing; p-AKT and p-ERK expression by immunohistochemistry. Results Of 70 patients, mean age was 58; 36% stage II, 56% stage III, and 9% stage IV. Responses to neoadjuvant chemoradiotherapy: 64% limited, 19% major, and 17% pathologic complete response. 64% were KRAS WT, 95% were BRAF WT. High p-ERK levels were associated with improved OS but not for p-AKT. High levels of p-AKT and p-ERK expression were associated with better responses. KRAS WT correlated with lower p-AKT expression but not p-ERK expression. No differences in OS, residual disease, or tumor downstaging were detected by KRAS status. Conclusions KRAS mutation was not associated with lesser response to chemoradiotherapy or worse OS. High p-ERK expression was associated with better OS and response. Higher p-AKT expression was correlated with better response but not OS.
Exploration of Natural Aggregates for a Sustainable Construction Industry in Western Colombia
The sources of aggregates for construction materials in the area surrounding Medellín, Western Colombia, are experiencing a significant decrease due to the depletion of their resources and reserves and the policies of land use in territorial planning. The objective of this study is to identify and assess the potential sources of aggregates for the construction industry in Medellín. A lithological characterization is made in the field and laboratory tests are performed to determine the physical and chemical behaviour of the rocks in the lithostratigraphic units. The study allowed us to define the properties and quality of rocks and to map sand and gravel in unconsolidated deposits in the weathering zone of granitic rocks and in stratified rocks. The results allowed us to define the preliminary physical and chemical quality of these rocks and assess their potential as raw material for use in the construction industry. This work constitutes a tool for civil and mining authorities in making decisions on land-use policies and the proper use of resources in the face of the growth and demand requirements of these materials.
Successful minimally invasive parathyroidectomy for primary hyperparathyroidism without using intraoperative parathyroid hormone assays
The need for intraoperative parathyroid hormone (iPTH) assays in minimally invasive parathyroidectomy (MIP) remains controversial. We report the results of MIP performed without the use of iPTH assays. This was a single-institution retrospective review of patients with primary hyperparathyroidism treated with MIP between October 1, 1998, and December 31, 2002. Seventy-seven patients were studied. The mean preoperative calcium level was 11.4 mg/dL. All patients had a normal calcium level postoperatively (range, 7.4–10.2 mg/dL, mean, 9.1 mg/dL). Three patients (4%) required re-exploration for various reasons including the development of a second adenoma, secondary hyperparathyroidism, and discordant pathology. All 3 patients initially were eucalcemic. Our success rate of 96% using a combination of preoperative sestamibi scans, intraoperative gamma probe localization, and selective frozen pathology is consistent with the published success rates using iPTH assays of 95% to 100%. We conclude that MIP can be performed successfully without using iPTH assays.
Axillary lymph node count is lower after neoadjuvant chemotherapy
Retrieval of fewer than 10 lymph nodes at axillary dissection (ALND) for breast cancer can represent anatomic variation or inadequate dissection. We postulated that despite aggressive ALND, a lower lymph node count is more frequent after neoadjuvant chemotherapy. Patients who received neoadjuvant chemotherapy followed by ALND were compared with patients who received surgery first. All patients received a level I and II ALND at a single institution by one of the breast surgeons. The number of nodes retrieved at ALND was dichotomized into categories (<10 and ≥10), and compared using Fisher exact test. A total of 143 neoadjuvant and 170 surgery-first patients were studied. Patients treated with neoadjuvant chemotherapy were significantly more likely to have fewer than 10 lymph nodes retrieved at ALND than were the surgery-first patients (19/143 or 13% vs. 6/170 or 4%, P = .003). A low lymph node count is more common in patients after treatment with neoadjuvant chemotherapy and should not be assumed to represent an incomplete ALND.
Complications Associated with Neoadjuvant Radiotherapy in the Multidisciplinary Treatment of Retroperitoneal Sarcomas
Retroperitoneal sarcomas (RPS) remain a therapeutic challenge due to high local recurrence rates. Preoperative RT offers theoretical advantages in the multidisciplinary care of RPS. The purpose of our study was to evaluate our experience using preoperative radiotherapy (PRT) in the treatment of RPS. This is a single-institution review of patients with RPS treated with PRT from 1994 until 2004. Three radiation oncologists and four surgical oncologists were involved. Medical records, tumor registries, and death records were reviewed. Fourteen patients were included; nine were treated for primary presentation and five for recurrent disease. Histologic grade was grade I (n = 3), grade II (n = 3), and grade III (n = 8). Five patients received additional IORT. Radiotherapy complications were generally mild, including nausea (n = 3), diarrhea (n = 1), dehydration (n = 1), anemia (n = 1), and skin changes (n = 1); one required early cessation due to nausea. Thirteen patients had gross negative margins; while 7/13 had negative microscopic margins. Operative complications included anastomotic bleeding (n = 1), fluid collections (n = 2), ileus (n = 3), ascites (n = 2), temporary leg weakness (n = 1), and uncomplicated wound infections (n = 2). In patients with R0 or R1 resections, one and two year local control rates were 64 and 50%. Overall survival for all patients was 90% at 1 year and 74% at 2 years with median survival of 21 months. PRT and IORT can be administered effectively in carefully selected patients with resectable RPS. Larger multi-center studies are needed to delineate the role of PRT and IORT to improve local recurrence and survival rates in the treatment of RPS.
Postoperative Hypocalcemia after Parathyroidectomy for Renal Hyperparathyroidism in the Era of Cinacalcet
Chronic kidney disease is often accompanied by hyperparathyroidism. Cinacalcet, a recent addition to the medical armamentarium, has proven efficacious. It is unclear whether cinacalcet use has any impact on the postoperative course in patients progressing to surgery. The records of 77 patients operated on for renal hyperparathyroidism were reviewed. Sixty-three were treated before the use of cinacalcet and 14 after. Ten subtotal and 67 total parathyroidectomies were performed. Mean nadir serum calcium was similar (6.6 ± 1.3 vs 6.2 ± 1.4 mg/dL). More patients taking cinacalcet preoperatively required intravenous calcium postoperatively (62%) than those treated before its use (41%), although this did not reach statistical significance ( P = 0.09). In those undergoing total parathyroidectomy, cinacalcet use preoperatively (n = 11) led to a lower postoperative nadir calcium (5.8 ± 1.7 vs 6.6 ± 1.3 mg/dL) as compared with those who did not receive it (n = 56) ( P = 0.05). This translated to a greater need for intravenous calcium infusion postoperatively (72 vs 38%) ( P = 0.03). These data suggest a somewhat more aggressive postoperative course in patients who fail calcimimetic and require surgery. This may be useful to inform physicians and patients of expectations postoperatively, although it is not likely to alter management.