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John L Cameron

Publications and source records attributed to John L Cameron.

83 records · Page 5Linked to original sources
PubMed2002

MUC4 expression increases progressively in pancreatic intraepithelial neoplasia.

Pancreatic adenocarcinoma is believed to develop from histologically identifiable intraductal lesions known as pancreatic intraepithelial neoplasias (PanINs) that undergo a series of architectural, cytologic, and genetic changes, a progression model similar to the adenoma-carcinoma sequence in the colon. The apomucin MUC4 has been implicated in invasive pancreatic adenocarcinoma. MUC4 expression is not detectable at the RNA level in normal pancreas but is detectable at high levels in invasive pancreatic adenocarcinoma. We documented the pattern of expression of MUC4 in PanINs by studying a series of 71 PanIN lesions immunohistochemically using a new monoclonal antibody to MUC4. Five (17%) of 30 PanIN-1 lesions, 10 (36%) of 28 PanIN-2 lesions, 11 (85%) of 13 PanIN-3 lesions, and 25 (89%) of 28 invasive adenocarcinomas labeled with the MUC4 antibody used in the study. In addition, afew nonneoplastic lesions labeled with the MUC4 antibody, including reactive ducts in chronic pancreatitis, atrophic ducts filled with inspissated secretions, and ducts showing squamous metaplasia. Our data help establish the patterns of MUC4 expression in neoplastic precursors in the pancreas and add further support to the progression model for pancreatic adenocarcinoma.

Biomarkers, Tumor↗
PubMed2002

Tissue protection immunohistochemistry: a useful adjunct in the interpretation of prostate biopsy specimens and other selected cases in which immunostains are needed on minute lesions.

Performing immunohistochemical analysis on minute lesions is a challenging task, primarily because they frequently disappear when the paraffin block is recutfor immunostaining purposes. This is a particularly common occurrence with prostate biopsy specimens, in which immunostains for high-molecular-weight cytokeratin commonly are used as an adjunct to H&E examination for aiding in the interpretation of minute "suspicious" lesions. We describe an original method designated tissue protection immunohistochemistry, that allows the performance of high-molecular-weight cytokeratin immunostains (or other immunostains) on previously stained H&E slides. The method described does not require destaining of H&E-stained sections, and it allows the preservation of the H&E stain on adjacent levels that may be present on the same slide. The method described requires that the original H&E-stained sections be placed on adhesive slides, but it has the advantages of eliminating the requirement of a paraffin block for immunostaining and eliminating the need for saving intervening unstained sections for possible immunohistochemical analysis.

Biopsy, Needle↗
PubMedDate not supplied

Predicting resectability of periampullary cancer with three-dimensional computed tomography.

The radiographic assessment of extent of tumor burden and local vascular invasion appears to be enhanced with three-dimensional computed tomography (3D-CT). The purpose of this study was to evaluate the impact of preoperative 3D-CT in determining the resectability of patients with periampullary tumors. Intraoperative findings from exploratory laparotomy were gathered prospectively from 140 patients who were thought to have periampullary tumors and were deemed resectable after undergoing preoperative 3D-CT imaging. CT findings were compared to intraoperative findings, and the accuracy of 3D-CT in predicting tumor resectability and, ultimately, the likelihood of obtaining a margin-negative resection were assessed. Of the 140 patients who were thought to have resectable periampullary tumors after preoperative 3D-CT, 115 (82%) were subsequently determined to have periampullary cancer. The remaining 25 patients had benign disease. Among the patients with periampullary cancer, the extent of local tumor burden involving the pancreas and peripancreatic tissues was accurately depicted by 3D-CT in 93% of the patients. 3D-CT was 95% accurate in determining cancer invasion of the superior mesenteric vessels. Preoperative 3D-CT accurately predicted periampullary cancer resectability and a margin-negative resection in 98% and 86% of patients, respectively. For patients with pancreatic adenocarcinoma (n=85), preoperative 3D-CT resulted in a resectability rate and a margin-negative resection rate of 79% and 73%, respectively. The ability of 3D-CT to predict a margin-negative resection for periampullary cancer, including pancreatic adenocarcinoma, relies on its enhanced assessment of the extent of local tumor burden and involvement of the mesenteric vascular anatomy.

Adenocarcinoma↗
PubMedDate not supplied

Central pancreatectomy with pancreaticogastrostomy for benign pancreatic pathology.

Benign lesions of the neck and proximal body of the pancreas pose an interesting surgical challenge. If the lesions are not amenable to simple enucleation, surgeons may be faced with the choice of performing a right-sided resection (pancreaticoduodenectomy) or a left-sided resection (distal pancreatectomy) to include the lesion, resulting in resection of a substantial amount of normal pancreatic parenchyma. Central pancreatic resection has been reported with Roux-en-Y pancreaticojejunostomy reconstruction; however, this interrupts small bowel continuity and obligates an additional anastomosis. We have reviewed our experience with central pancreatectomy with pancreaticogastrostomy (PG) for benign central pancreatic pathology. Between January 1999 and December 2002, 14 central pancreatectomies were performed with PG reconstruction. There were 7 women and 7 men with a mean age of 60.9 years. Five resections were performed for islet cell tumors, three were performed for noninvasive intraductal papillary mucinous neoplasms, two were performed for serous cystadenoma, and one each was performed for a simple cyst, pseudocyst, mucinous metaplasia, and focal chronic pancreatitis. Seven out of 14 patients experienced a total of 10 complications. Pancreatic fistulae manifested by drainage of amylase-rich fluid from the operatively placed drains developed in 5 patients (36%). Reoperation or interventional radiologic procedures were not required in any patient with a fistula. Postoperative follow-up demonstrated 13 out of 14 patients to be alive and well without evidence of pancreatic insufficiency. One patient died at home on postoperative day 57 of cardiac pathology. Central pancreatectomy with PG is a safe and effective procedure that allows for preservation of pancreatic endocrine and exocrine function without disruption of enteric continuity. The complication of pancreatic fistula was managed conservatively via maintenance of operatively placed drains.

Adult↗
PubMedDate not supplied

Survival after gastric adenocarcinoma resection: eighteen-year experience at a single institution.

Gastric adenocarcinoma is the second leading cause of cancer death worldwide. In Western series, survival rates vary widely and are generally lower than those reported from Eastern series. We performed a retrospective analysis of cases operated on at the Johns Hopkins Hospital over the past 18 years and collected data on demographics, tumor characteristics, pathologic stage, treatment methods, complications, survival time, and other relevant factors. Survival according to stage of disease, Lauren tumor type, tumor location, time period, and administration of adjuvant therapy was analyzed, and results were compared with those of other Western series. During this period, 436 patients with gastric adenocarcinoma underwent resection. We have shown a statistically significant association between survival and margin status, stage of disease, and Lauren tumor type. Overall 5-year survival was 26%, and 5-year survival after R0 resection was 33%. No significant difference was detected between survival and tumor location, time period of treatment, or administration of adjuvant therapy. Analysis of various Western series reveals major differences between the cohorts under study, such as stage of disease, extent of resection, tumor type, and tumor location. Many of the reported differences among Western series may be due to cohort differences, such as stage of disease, extent of resection, tumor type, and tumor location.

Adenocarcinoma↗
PubMedDate not supplied

Retroperitoneal paraganglioma: single-institution experience and review of the literature.

Paragangliomas are rare tumors arising from extra-adrenal chromaffin cells. We examined the clinical characteristics of all patients at our institution having paragangliomas resected from 1984 through 2005. Of 253 resections, 22 (9%) were retroperitoneal and were selected for further study. The ratio of males to females was 1.3:1, and the median age was 39 years. The average size, rate of metastasis (i.e., malignancy), and rate of function was 7.4 cm, 9.5%, and 57.1%, respectively. Tumors larger than 7 cm were more likely to require adjacent organ resection (P = 0.01). The overall 5-year survival was 73%. Survival was significantly worse after metastasis (P = 0.0023) but did not depend on the tumor diameter, the secreting function of the tumor, the status of surgical margins of resection, or status of the resected lymph nodes.

Digestive System Surgical Procedures↗
PubMedDate not supplied

Diagnostic laparoscopy for periampullary and pancreatic cancer: what is the true benefit?

The role of diagnostic laparoscopy in patients with periampullary and pancreatic malignancies is controversial. A retrospective review was performed including all patients (n = 188) with a periampullary or pancreatic malignancy who underwent both CT and laparotomy at our institution between January 1997 and December 1999. The overall resectability rate for all periampullary cancers was 67.3% (115 of 171 patients). This compared favorably with the resectability rate for cancers of the pancreatic body and tail (3 of 17 patients, 17.6%; P < 0.01 vs. periampullary cancers). Fifty percent of patients with periampullary cancers were unresectable because of metastatic disease, whereas metastatic disease precluded resection in 64.3% of patients with cancers of the pancreatic body and tail. After patients undergoing operative palliation were eliminated, a nontherapeutic laparotomy would have been precluded by the use of diagnostic laparoscopy in only 2.3% of patients with periampullary cancers (4 of 171 patients). In contrast, 6 (35.3%) of 17 patients with cancers of the pancreatic body and tail underwent a nontherapeutic laparotomy (P < 0.01 vs. periampullary cancers). One hundred fifty-eight (84%) of the 188 CT reports reviewed could be definitively categorized as either "likely to be resectable" or "likely to be unresectable." The remaining 16% were equivocal. Of the 107 patients categorized as likely to be resectable, 89 were actually resected (83.2%). In contrast, only 10 of the 51 patients categorized as likely to be unresectable could be resected (19.6%).

Aged↗
PubMedDate not supplied

Cholecystectomy, liver resection, and pylorus-preserving pancreaticoduodenectomy for gallbladder cancer: report of five cases.

Carcinoma of the gallbladder is an uncommon yet highly malignant disease with a poor overall prognosis. Surgical resection offers the only hope for cure in patients with this type of cancer, but resection is often impossible because of advanced disease at the time of presentation. Patients with locally advanced gallbladder cancer, however, may occasionally be amenable to management by adding pancreaticoduodenectomy to cholecystectomy and liver resection. A retrospective review of patient records at the Johns Hopkins Hospital identified five patients with gallbladder cancer with peripancreatic lymph node involvement, who were treated by surgical resection including pancreaticoduodenectomy. The preoperative evaluation, operative technique, pathologic findings, and outcome were reviewed for each patient. Follow-up was obtained via clinic visit or telephone contact. All five patients underwent resection of the gallbladder cancer with an operation that included pylorus-preserving pancreaticoduodenectomy to remove the peripancreatic lymph nodes. In addition, four of the five patients underwent a nonanatomic liver resection. There were no in-hospital deaths. Two patients had postoperative complications; one had persistent drainage from a T-tube site and one had an anastomotic leak from the hepaticojejunostomy. Four patients have died of recurrent tumor during follow-up at intervals ranging from 11 months to 23 months. The fifth patient is alive and free of clinical disease at 42 months after operation. Carcinoma of the gallbladder is a highly malignant disease that is often not amenable to surgical cure. There is a select group of patients, however, in whom adding a pylorus-preserving pancreaticoduodenectomy can result in a potentially curative operation by removing extensive regional spread to the peripancreatic lymph nodes.

Adenocarcinoma↗
PubMedDate not supplied

Diagnosing pancreatic cancer using methylation specific PCR analysis of pancreatic juice.

The aim of this study was to determine the utility of detecting methylated ppENK and pi6 in pancreatic juice by methylation specific PCR as a marker of pancreatic adeno-carcinoma. Pancreatic juice samples were collected either intraoperatively, from 92 patients undergoing pancreaticoduodenectomy for benign (n=20) and malignant periampullary disease (n = 72) or endoscopically (by duodenal aspiration after secretin infusion), from 13 patients undergoing investigation for pancreatic disease. Methylated ppENK was detected in the pancreatic juice of 30 (66.7%) of 45 patients with pancreatic ductal adenocarcinoma, in 4 (44.4%) of 9 patients with intraductal papillary-mucinous adenocarcinoma, and in 7 (41.2%) of 17 patients with other periampullary carcinomas, using methylation specific PCR. Methylated pi6 was detected in a lower percentage of these patients (11.1%, 11.1% and 23.5%, respectively). In contrast, methylated ppENK and pi6 were not detected in 20 patients with non-malignant periampullary disease including 12 patients with chronic pancreatitis. Methylated ppENK was detected in 30 of 33 (90.9%) primary pancreatic adenocarcinoma and methylated pi6 was in 6/33 (1 8.2%). Despite the absence of ppENKand pi6 methylation in normal pancreas, methylated ppENK and pi6 was present in the duodenum of 90.5% and 28.6%, respectively of patients without cancer. Further, methylated ppENK and pi6 was seen in 88.9% and 11.1%, respectively of pancreatic juice samples obtained by duodenal aspiration from patients without cancer. We conclude that since ppENK and pi6 are not normally methylated in pancreatic secretions, detection of methylated ppENK and pi6 in pure pancreatic juice obtained by direct cannulation of the pancreatic duct to avoid duodenal secretions may suggest the presence of pancreatic adenocarcinoma

Adenocarcinoma, Mucinous↗