Increased c-myb mRNA expression in Barrett's esophagus and Barrett's-associated adenocarcinoma

BACKGROUND

Esophageal adenocarcinoma develops through a multistage process which is characterized histopathologically by progression from Barrett's intestinal metaplasia to Barrett's esophagus with dysplasia and ultimately to adenocarcinoma. The genetic basis of this process is increasingly well understood, but no studies have examined the role of the transcription factor c-myb in this disease.

MATERIALS AND METHODS

c-myb mRNA expression levels were measured using a quantitative reverse transcription-polymerase chain reaction (RT-PCR) method in specimens of Barrett's intestinal metaplasia (n = 16), adenocarcinoma (n = 22), matching normal squamous esophagus tissues (n = 38), and normal squamous esophagus tissues from patients without Barrett's esophagus or chronic gastroesophageal reflux disease (n = 10).

RESULTS

The median c-myb mRNA expression levels were significantly increased in Barrett's intestinal metaplasia tissues compared to normal esophagus tissues (P = 0.013) and in Barrett's-associated adenocarcinoma tissues compared to normal squamous esophagus tissues (P = 0.001). The c-myb expression levels increased progressively and significantly in histopathologically worse tissue types, with an increase from normal squamous esophagus mucosa to Barrett's intestinal metaplasia, and from Barrett's intestinal metaplasia to adenocarcinoma of the esophagus (P = 0.002). Median c-myb expression levels were also significantly higher in histologically normal squamous esophagus tissues from cancer patients compared to normal esophagus tissues from patients without cancer (P < 0.001) and a control group without evidence of Barrett's esophagus or gastroesophageal reflux disease (P = 0.003). Very high c-myb mRNA expression levels were found only in patients with cancer.

CONCLUSION

These findings suggest that upregulation of c-myb mRNA expression is an early event in the development of Barrett's esophagus and associated adenocarcinoma, that high c-myb mRNA expression levels may be a clinically useful biomarker for the detection of occult adenocarcinoma, and that a widespread cancer "field" effect is present in the esophagus of patients with Barrett's-associated adenocarcinoma.

Risk factors and the prevalence of trocar site herniation after laparoscopic fundoplication

BACKGROUND

Although there have been case reports describing trocar site herniation after laparoscopic fundoplication, its overall prevalence and the risk factors for its development are unclear.

METHODS

The records of 320 patients undergoing primary laparoscopic fundoplication as treatment for gastroesophageal reflex disease (GERD) or hiatal hernia between 1991 and 1999 were reviewed retrospectively. Placement of the initial supraumbilical trocar was by the open Hassan technique in all patients.

RESULTS

Nine patients (five male) with a mean age 54 years (range, 37-75) developed trocar site herniation, for an overall prevalence of 3%. The mean interval between surgery and diagnosis was 12 months (range, 4-21). In all patients, the hernia occurred at the supraumbilical camera port site. Patients with trocar hernias tended to have a higher body mass index (BMI) than those without hernias (mean BMI, 29.4 kg/m2 vs 27.2 kg/m2, p = 0.13). None of the patients developed intestinal obstruction as a consequence of herniation. To date, all but one of the hernias have been repaired. Six of them required the insertion of a prosthetic mesh.

CONCLUSIONS

The prevalence of trocar site herniation after laparoscopic fundoplication was minimal at 3%. All hernias occurred at the midline supraumbilical port, the only site where open trocar insertion was employed. As a consequence of these observations, we have developed a new method of open trocar placement. This method utilizes a paramedian skin incision and separate fascial incisions through anterior and posterior rectus sheathes, with retraction of the rectus abdominis muscle laterally.

Adenomatous polyposis coli gene promoter hypermethylation in non-small cell lung cancer is associated with survival

Methylation of 5' CpG islands in promoter and upstream coding regions has been identified as a mechanism for transcriptional inactivation of tumor suppressor genes. The purpose of this study was to determine whether hypermethylation of the adenomatous polyposis coli (APC) gene promoter occurs in primary non-small cell lung cancer (NSCLC), and whether hypermethylated APC has any relationship with survival. APC promoter 1A methylation was determined in normal and corresponding tumor tissue from 91 NSCLC patients and in a control group of 10 patients without cancer, using a quantitative fluorogenic real-time PCR (Taqman) system. APC promoter methylation was detectable in 86 (95%) of 91 tumor samples, but also in 80 (88%) of 91 normal samples of NSCLC patients, and in only two (20%) of 10 normal lung tissues of the control group. The median level of APC promoter methylation was 4.75 in tumor compared to 1.57 in normal lung tissue (P<0.001). Patients with low methylation status showed significantly longer survival than did patients with high methylation status (P=0.041). In a multivariate analysis of prognostic factors, APC methylation was a significant independent prognostic factor (P=0.044), as were pT (P=0.050) and pN (P<0.001) classifications. This investigation shows that APC gene promoter methylation occurs in the majority of primary NSCLCs. High APC promoter methylation is significantly associated with inferior survival, showing promise as a biomarker of biologically aggressive disease in NSCLC.

Epigenetic patterns in the progression of esophageal adenocarcinoma

Esophageal adenocarcinoma (EAC) arises after normal squamous mucosa undergoes metaplasia to specialized columnar epithelium (intestinal metaplasia or Barrett's esophagus), which can then ultimately progress to dysplasia and subsequent malignancy. Epigenetic studies of this model have thus far been limited to the DNA methylation analysis of a few genes. In this study, we analyzed a panel of 20 genes using a quantitative, high-throughput methylation assay, METHYLIGHT: We used this broader approach to gain insight into concordant methylation behavior between genes and to generate epigenomic fingerprints for the different histological stages of EAC. Our study included a total of 104 tissue specimens from 51 patients with different stages of Barrett's esophagus and/or associated adenocarcinoma. We screened 84 of these samples with the full panel of 20 genes and found distinct classes of methylation patterns in the different types of tissue. The most informative genes were those with an intermediate frequency of significant hypermethylation [ranging from 15% (CDKN2A) to 60% (MGMT) of the samples]. This group could be further subdivided into three classes, according to the absence (CDKN2A, ESR1, and MYOD1) or presence (CALCA, MGMT, and TIMP3) of methylation in normal esophageal mucosa and stomach, or the infrequent methylation of normal esophageal mucosa accompanied by methylation in all normal stomach samples (APC). The other genes were less informative, because the frequency of hypermethylation was below 5% (ARF, CDH1, CDKN2B, GSTP1, MLH1, PTGS2, and THBS1), completely absent (CTNNB1, RB1, TGFBR2, and TYMS1), or ubiquitous (HIC1 and MTHFR), regardless of tissue type. Each class undergoes unique epigenetic changes at different steps of disease progression of EAC, suggesting a step-wise loss of multiple protective barriers against CpG island hypermethylation. The aberrant hypermethylation occurs at many different loci in the same tissues, suggestive of an overall deregulation of methylation control in EAC tumorigenesis. However, we did not find evidence for a distinct group of tumors with a CpG island methylator phenotype. Finally, we found that normal and metaplastic tissues from patients with evidence of associated dysplasia or cancer had a significantly higher incidence of hypermethylation than similar tissues from patients with no further progression of their disease. The fact that the samples from these two groups of patients were histologically indistinguishable, yet molecularly distinct, suggests that the occurrence of such hypermethylation may provide a clinical tool to identify patients with premalignant Barrett's who are at risk for further progression.

Upregulation of ornithine decarboxylase mRNA expression in Barrett's esophagus and Barrett's-associated adenocarcinoma

The Barrett's multistage process is characterized histopathologically by progression from Barrett's intestinal metaplasia to Barrett's esophagus with dysplasia and ultimately adenocarcinoma. Understanding the cellular and molecular events in this multistage process may contribute to improved diagnosis and treatment. Ornithine decarboxylase (ODC) is the first enzyme in the biosynthesis of polyamines. Elevated ODC activity has been found to be associated with progression during Barrett's esophagus, but the regulation of ODC gene expression in the development of Barrett's-associated adenocarcinoma has not been reported. The aim of this study was to assess the prevalence and timing of ODC mRNA expression in the Barrett's metaplasia-dysplasia-adenocarcinoma sequence. ODC mRNA expression levels, relative to the stably expressed internal reference gene beta-actin, were measured using a quantitative reverse transcription-polymerase chain reaction (RT-PCR) method (ABI 7700 Sequence Detector System) in 104 specimens from 19 patients with Barrett's esophagus without carcinoma and 22 patients with Barrett's-associated adenocarcinoma. The median ODC mRNA expression levels were significantly increased in Barrett's esophagus tissues compared to matched normal tissues in patients without adenocarcinoma of the esophagus (P = 0.002; Wilcoxon test). A significant progressive increase in ODC mRNA expression was detectable through the stages of the metaplasia-dysplasia-carcinoma sequence in patients with Barrett's-associated adenocarcinoma (r = 0.719; P < or = 0.001; Spearman's rho test). These findings show that upregulation of ODC mRNA expression is an early event in the development and progression of Barrett's-associated adenocarcinoma of the esophagus, and they suggest that high ODC mRNA expression levels may be a clinically useful biomarker for the detection of occult adenocarcinoma

Retinoic acid receptor-alpha messenger RNA expression is increased and retinoic acid receptor-gamma expression is decreased in Barrett's intestinal metaplasia, dysplasia, adenocarcinoma sequence

BACKGROUND

Expression levels of the retinoic acid receptors (RAR-alpha, RAR-beta, and RAR-gamma) are significantly different in neoplastic tissues compared with non-neoplastic tissues for some tumors. This study investigated whether retinoic acid receptor messenger RNA (mRNA) expression levels are altered in Barrett's esophagus and Barrett's adenocarcinoma tissues.

METHODS

Relative mRNA expression levels of the RARs were quantified by using the ABI 7700 Sequence Detector (Taqman) system in Barrett's intestinal metaplasia (n = 15), dysplasia (n = 6), adenocarcinoma (n = 17), and matching normal esophagus tissues (n = 36).

RESULTS

RAR-alpha expression was significantly increased, and RAR-gamma expression was significantly decreased, at higher stages in the Barrett's sequence. There was almost complete loss of RAR-gamma expression (relative expression level < or = 1) in a majority (70%) of the dysplasia and adenocarcinoma tissues. There were significant differences in RAR-alpha and RAR-gamma expression in histopathologically normal tissues in patients with cancer versus patients without cancer. RAR-beta expression levels were significantly elevated in adenocarcinoma versus normal esophagus tissues. The RAR expression profile was similar for cancers arising within the esophagus and for cancers arising at the gastroesophageal junction.

CONCLUSIONS

RAR mRNA expression levels are significantly different in Barrett's tissues compared with normal esophagus tissues, and these levels are significantly different in Barrett's dysplasia and adenocarcinoma tissues compared with nondysplastic tissues. These results suggest that RAR mRNA levels may be useful biomarkers for this disease and that gastroesophageal junction adenocarcinomas are genetically similar to esophageal adenocarcinomas. These results also suggest that a cancer field is present in the esophagus in patients with cancer and that genetic alterations can precede histopathologic alterations in this disease.

Predictors of response after laparoscopic splenectomy for immune thrombocytopenic purpura

BACKGROUND

Splenectomy has been shown to produce long term remission in patients with immune thrombocytopenic purpura (ITP). With the development of laparoscopic splenectomy, there is renewed interest in the surgical treatment of ITP. The aim of this study was to identify factors that are predictive of outcome after laparoscopic splenectomy for ITP.

METHODS

A case series of 67 consecutive patients with ITP undergoing laparoscopic splenectomy was reviewed. A positive response was defined as a postoperative platelet count greater than 150,000/ml requiring no maintenance medical therapy on follow-up evaluation. A chi-square test and a stepwise logistic regression analysis were performed for the following variables: age, gender, preoperative response to steroids, duration of disease, severity of preoperative bleeding, accessory spleens, and thrombocytosis on discharge.

RESULTS

At a median follow-up period of 38 months (range, 2-56 months), 52 patients (78%) had a positive response to laparoscopic splenectomy. Of the 15 patients (22%) who did not have a positive response, 11 were refractory and 4 relapsed. All relapses occurred in patients with a platelet count less than 150,000/microl at discharge. Patient age was the most significant predictive factor for success or failure of the operation. The median age of the responders (31 years; range, 19-71 years) was significantly lower than the median age of the nonresponders (49 years; range, 24-62; p < 0.001). Only 5.6% of those younger than 40 years did not have a positive response, compared with 42% of patients older than 40 years (p < 0.05). Patient age was significantly associated with outcome on univariable chi-square analysis (p = 0.001), and was the only significant factor on multivariable analysis (odds ratio, 2.65; 95% confidence interval, 1.71-4.1). Other significant predictors of outcome on univariable analysis were preoperative response to corticosteroids and platelet count on discharge.

CONCLUSIONS

A long-lasting response after splenectomy for ITP is more likely to occur in patients younger than 40 years of age. To avoid the long-term side effects of corticosteroid use, early surgical referral of younger patients with ITP should be considered.

Carditis: a manifestation of gastroesophageal reflux disease

This series consists of 141 patients in whom cardiac mucosa (CM) was present in biopsy samples from the gastroesophageal junctional region. Inflammation of CM, irrespective of its exact anatomic location, was defined as carditis and classified as acute or chronic based on the number of inflammatory cells present. In all cases, CM showed significant chronic inflammation. One hundred and eleven (79%) of the 141 patients with carditis showed no evidence of gastritis in biopsy samples from the gastric antrum and body. Helicobacter pylori was present in 20 of 141 (14%) patients; of these, 17 had evidence of a pangastritis, with 15 of these patients also showing H. pylori in CM. Patients with severe chronic inflammation in CM had a significantly higher acid exposure of the lower esophagus as quantitated by a 24-hour pH test than those with mild chronic inflammation in CM. Acute inflammation was uncommon in CM; it was present in only 26 of 141 (18.4%) patients. There was no significant difference in acid exposure of the lower esophagus between patients with and without acute inflammation in CM. The presence of acute inflammation in CM was significantly associated with distal gastritis and H. pylori infection. Men with carditis had quantitatively higher acid exposure of the lower esophagus than did women with this disorder. This difference was greatest in men with severe inflammation in CM who had no evidence of distal gastritis. These findings provide evidence that chronic inflammation in CM is strongly associated with acid reflux and that H. pylori is not a significant etiologic factor in carditis. They also show that in patients with CM in whom H. pylori gastritis develops, the infection frequently spreads to involve CM, resulting in acute inflammation with neutrophils that is superimposed on the chronic inflammation already present.

Hypermethylated APC DNA in plasma and prognosis of patients with esophageal adenocarcinoma

BACKGROUND

The adenomatous polyposis coli (APC) locus on chromosome 5q21-22 shows frequent loss of heterozygosity (LOH) in esophageal carcinomas. However, the prevalence of truncating mutations in the APC gene in esophageal carcinomas is low. Because hypermethylation of promoter regions is known to affect several other tumor suppressor genes, we investigated whether the APC promoter region is hypermethylated in esophageal cancer patients and whether this abnormality could serve as a prognostic plasma biomarker.

METHODS

We assayed DNA from tumor tissue and matched plasma from esophageal cancer patients for hypermethylation of the promoter region of the APC gene. We used the maximal chi-square statistic to identify a discriminatory cutoff value for hypermethylated APC DNA levels in plasma and used bootstrap-like simulations to determine the P: value to test for the strength of this association. This cutoff value was used to generate Kaplan-Meier survival curves. All P values were based on two-sided tests.

RESULTS

Hypermethylation of the promoter region of the APC gene occurred in abnormal esophageal tissue in 48 (92%) of 52 patients with esophageal adenocarcinoma, in 16 (50%) of 32 patients with esophageal squamous cell carcinoma, and in 17 (39.5%) of 43 patients with Barrett's metaplasia but not in matching normal esophageal tissues. Hypermethylated APC DNA was observed in the plasma of 13 (25%) of 52 adenocarcinoma patients and in two (6.3%) of 32 squamous carcinoma patients. High plasma levels of methylated APC DNA were statistically significantly associated with reduced patient survival (P =.016).

CONCLUSION

The APC promoter region was hypermethylated in tumors of the majority of patients with primary esophageal adenocarcinomas. Levels of hypermethylated APC gene DNA in the plasma may be a useful biomarker of biologically aggressive disease in esophageal adenocarcinoma patients and should be evaluated as a potential biomarker in additional tumor types.

Fields of aberrant CpG island hypermethylation in Barrett's esophagus and associated adenocarcinoma

Esophageal adenocarcinoma (EAC) is thought to develop through a multistage process in which Barrett's metaplasia progresses through low- and high-grade dysplasia to invasive cancer. Transcriptional silencing of tumor suppressor genes by promoter CpG island hypermethylation has been observed in many types of human cancer. Analysis of CpG island hypermethylation in EAC has thus far been limited to the CDKN2A (p16) gene. In this study, we extend the methylation analysis of EAC to include three other genes, APC, CDH1 (E-cadherin), and ESR1 (ER, estrogen receptor alpha), in addition to CDKN2A. Molecular analysis can provide insight into the complex relationships between tissues with different histologies in Barrett's esophagus and associated adenocarcinoma. Therefore, we have mapped the spatial distribution of methylation patterns in six esophagectomy cases in detail. Hypermethylation of the four CpG islands was analyzed by the MethyLight technique in 107 biopsies derived from these six patients for a total of 428 methylation analyses. Our results show that normal esophageal squamous epithelium is unmethylated at all four CpG islands. CDH1 is unmethylated in most other tissue types as well. Hypermethylation of ESR1 is seen at high frequency in inflammatory reflux esophagitis and at all subsequent stages, whereas APC and CDKN2A hypermethylation is found in Barrett's metaplasia, dysplasia, and EAC. When it occurs, hypermethylation of APC, CDKN2A, and ESR1 is usually found in a large contiguous field, suggesting either a concerted methylation change associated with metaplasia or a clonal expansion of cells with abnormal hypermethylation.

K-ras codon 12 mutations in Barrett's oesophagus and adenocarcinomas of the oesophagus and oesophagogastric junction

BACKGROUND

Activation of the ras oncogene is commonly found in gastrointestinal tract cancers, but the role of ras in the development and progression of Barrett's oesophagus and associated cancers is uncertain.

METHODS

The frequency of K-ras codon 12 point mutations was assessed in 52 paraffin-embedded tissues from 44 patients with oesophageal pathology. The specimens were classified pathologically as follows: adenocarcinoma of the oesophagus or oesophagogastric junction (n = 23), Barrett's high-grade dysplasia (n = 5), low-grade dysplasia (n = 14), intestinal metaplasia (n = 4), normal oesophagus (n = 5) or normal stomach (n = 1). DNA was extracted from three consecutive sections of each paraffin block and mutations at bases 1 and 2 of K-ras codon 12 were identified using a novel restriction endonuclease-mediated selective polymerase chain reaction method.

RESULTS

Mutations were found in 7 of 23 (30.4%) adenocarcinomas and in 2 of 5 (40%) high-grade dysplasia specimens. No mutations were found in specimens of low-grade dysplasia, intestinal metaplasia without dysplasia, or normal oesophagus and stomach. There were no significant associations between the presence of mutations and clinicopathologic features in the patients with cancer. One patient who progressed from low-grade to high-grade dysplasia was found to have developed mutant K-ras in the course of this transformation.

CONCLUSION

These results suggest that K-ras codon 12 mutations may occur frequently in patients with Barrett's oesophagus with high-grade dysplasia or adenocarcinoma of the oesophagus or oesophagogastric junction. K-ras mutation may be a late event in the Barrett's metaplasia-dysplasia-adenocarcinoma sequence.

Is adenocarcinoma following esophagoduodenostomy without carcinogen in the rat reflux-induced?

BACKGROUND

A widely used rat model for reflux-induced esophageal adenocarcinoma in the absence of carcinogens involves induction of duodenoesophageal reflux by performance of esophagoduodenostomy. The aim of this study was to test the hypothesis that acid reflux reduces the incidence of adenocarcinoma in this animal model.

METHODS

One hundred ninety 8-week-old male Sprague-Dawley rats were studied. The animals were randomly divided into four groups with a different type of reflux established in each group. Group 1 had an esophagoduodenostomy for duodenogastroesophageal reflux (n = 59), group 2 had an esophagoduodenostomy and a total gastrectomy for duodenoesophageal reflux (n = 54), group 3 had an esophagoduodenostomy and a total gastrectomy with acid supplementation with acidified water to control for the effect of the gastrectomy (n = 50), and group 4 had a total gastrectomy with Roux-en-Y reconstruction to eliminate all reflux (n = 25). One hundred eighty-eight surviving animals were sacrificed at 36 weeks of age and the resected esophagi were examined.

RESULTS

All animals except the no reflux control group had severe reflux esophagitis. The frequency of tumor development was similar in all study groups. All of the tumors were well-differentiated adenocarcinomas that were located on the external surface of the bowel either at or immediately distal to the esophagoenteric anastomosis. The tumors appeared to arise from the submucosa and did not involve the overlying mucosa. There was no definite evidence of columnar lining of the esophagus but an admixture of squamous and columnar epithelium was found microscopically in all groups. This finding was unrelated to the presence and composition of reflux.

CONCLUSIONS

Adenocarcinomas in this animal model are not reflux-induced and do not arise from the mucosa. Despite previous reports to the contrary, we suggest that this model may not be valid for the study of reflux-induced esophageal adenocarcinoma.

Determinants of intestinal metaplasia within the columnar-lined esophagus

HYPOTHESIS

The clinical and physiological features of patients with short segments of columnar-lined esophagus (CLE) with and without intestinal metaplasia (IM) are distinct.

DESIGN

Retrospective case series.

SETTING

University tertiary referral center.

PATIENTS

Sixty-five consecutive patients with a 2-cm or shorter length of endoscopically visible CLE.

INTERVENTIONS

The type of CLE and the presence of Helicobacter pylori were determined by histopathologic examination of esophageal and gastric antrum biopsy specimens. All patients underwent esophageal manometry and simultaneous 24-hour pH and bilirubin monitoring.

MAIN OUTCOME MEASURES

Clinical and physiological data were compared in patients with and without IM.

RESULTS

Thirty-six patients had IM and 29 had cardiac-type mucosa without IM in biopsy specimens from the CLE. There was no significant difference in age or sex distribution, but the duration of symptoms was significantly longer in patients with IM (10 vs 5 years; P = .03). Abnormal esophageal acid exposure was found in 30 (83%) of 36 patients with IM and 23 (79%) of 29 patients without IM. The prevalence of abnormal bilirubin exposure was significantly higher in patients with IM (75% [27/36]) than in those without IM (41% [12/29]; P = .01). There was no significant difference in the prevalence of H pylori infection between the 2 groups (8% vs 10%; P >.99).

CONCLUSIONS

Patients with short segments of CLE and IM have similar esophageal acid exposure but significantly higher frequency of abnormal bilirubin exposure and longer median duration of reflux symptoms than patients without IM. Therefore, CLE, regardless of histological type, is a manifestation of gastroesophageal reflux disease. The presence of duodenoesophageal reflux and the duration of reflux seem to be important in the pathogenesis of IM.

Telomerase reverse transcriptase expression is increased early in the Barrett's metaplasia, dysplasia, adenocarcinoma sequence

Barrett's esophagus is a multistage polyclonal disease that is associated with the development of adenocarcinoma of the esophagus and esophagogastric junction. Telomerase activation is associated with cellular immortality and carcinogenesis, and increased expression of the telomerase reverse transcriptase catalytic subunit (hTERT) has been used for the early detection of malignant diseases. To identify biomarkers associated with each stage of the Barrett's process, relative mRNA expression levels of hTERT were measured using a quantitative reverse transcription-polymerase chain reaction method (ABI 7700 Sequence Detector (TaqMan system) in Barrett's intestinal metaplasia (n = 14), Barrett's dysplasia (n = 10), Barrett's adenocarcinoma (n = 14), and matching normal squamous esophagus tissues (n = 32). hTERT expression was significantly increased at all stages of Barrett's esophagus, including the intestinal metaplasia stage, compared to normal tissues from patients without cancer (intestinal metaplasia vs. normal esophagus, P <0.0001; dysplasia, P = 0.001; adenocarcinoma, P = 0.007; all Mann-Whitney U test ). hTERT expression levels were significantly higher in adenocarcinoma tissues than in intestinal metaplasia tissues (P = 0.003), and were higher in dysplasia compared with intestinal metaplasia tissues (P = 0.056). hTERT levels were also significantly higher in histologically normal squamous esophagus tissues from cancer patients than in normal esophagus tissues from patients with no cancer (P = 0.013). Very high expression levels ([hTERT x 100: beta-actin] >20) were found only in patients with cancer. These findings suggest that telomerase activation is an important early event in the development of Barrett's esophagus and esophageal adenocarcinoma, that very high telomerase levels may be a clinically useful biomarker for the detection of occult adenocarcinoma, and that a widespread cancer "field" effect is present in the esophagus of patients with Barrett's cancer.

Clinical significance of p53 mutations in adenocarcinoma of the esophagus and cardia

OBJECTIVE

To compare the frequency and spectrum of p53 gene mutations in adenocarcinomas of the esophagus and cardia and to compare clinical and pathologic features in patients with p53 mutant and nonmutant cancers.

SUMMARY BACKGROUND DATA

The p53 gene is commonly mutated in human cancers, and a p53 mutation is reported to be present in more than 50% of esophageal adenocarcinomas. Although many studies have investigated the frequency of p53 protein overexpression in adenocarcinomas of the esophagus or esophagogastric junction, few studies have assessed the frequency and clinical significance of p53 mutations in these tumors. In particular, the prognostic importance of p53 mutation is uncertain. Adenocarcinomas of the esophagus and cardia share many epidemiologic and pathologic features, but it is controversial whether they represent the same tumor. A comparison of the frequency and spectrum of mutations in adenocarcinomas of the esophagus and cardia would test whether these tumors are also similar at the molecular level.

METHODS

DNA was isolated from microdissected paraffin-embedded tumor tissues of patients who underwent esophagogastrectomy for adenocarcinoma of the esophagus (n = 19), cardia (esophagogastric junction, n = 12), or subcardia (n = 6). Exons 5 to 8 of the p53 gene were analyzed for the presence of mutations using the polymerase chain reaction with single-strand conformation polymorphism and DNA sequencing of bands showing abnormal mobility. The presence of mutation was confirmed by selective hybridization of a mutant-specific oligonucleotide to DNA isolated from the tumor.

RESULTS

p53 mutations were identified in 18 of 37 (48.6%) tumors. Patients with p53 mutant tumors were significantly younger and had a significantly poorer prognosis. There was a similar prevalence of p53 mutations in adenocarcinomas of the esophagus (53%) and cardia (58%). In contrast, mutations were relatively uncommon in subcardia adenocarcinomas (one mutant tumor [17%]). The types of mutations found in the esophageal and the cardia cancers were also similar.

CONCLUSIONS

Adenocarcinomas of the esophagus and cardia have a similar frequency and spectrum of p53 gene mutations, suggesting that these tumors have a common pathogenesis. Patients with mutations are younger, have signs of more advanced disease, and have a poorer prognosis than patients without mutations.

Optimal treatment for localized esophageal cancer still uncertain

These articles both report the results of multi-institutional, randomized, phase 3 trials for the treatment of patients with localized (T1-3 N0-1 M0) esophageal squamous cell carcinoma (SCC) or esophageal adenocarcinoma. Both studies were initiated and coordinated by the Radiation Therapy Oncology Group (RTOG) but included patients enrolled by other study groups as well. Cooper et al. report late follow-up results for the RTOG 85-01 trial that was conducted between 1986 and 1990. This trial randomized patients to either radiation therapy (RT) alone (RT, 64 Gy in 32 fractions over 6.4 wk, n = 62) or combined RT and chemotherapy (50 Gy in 25 fractions over 5 wk, plus cisplatin 75 mg/m2 i.v. on first day of wk 1, 5, 8, and 11, and continuous infusion fluorouracil (5FU) 1 g/m2 per day on the first 4 days of the same weeks, n = 61). Most (82%) of the patients had SCC. Eight percent of the cohort randomly assigned to combined modality therapy experienced acute life-threatening toxic effects, and an additional 2% died as a direct consequence of treatment. The randomized trial was halted in 1990 when an interim analysis found a highly significant difference in survival favoring the combined therapy group, after which 73 consecutive patients were enrolled into a nonrandomized study offering only the combined therapy regimen. At 5-yr of follow-up, the overall survival rate for the combined therapy group in the randomized study was 26% (95% CI, 15-37%) compared with 0% for RT alone. In the nonrandomized study, the 5-yr overall survival rate was 14% (95% CI, 6-23%). The histopathological type of tumor did not significantly influence survival. Cooper et al. now report that 22% of the randomized combined modality group survived at least 8 yr after treatment, and that there were no deaths caused by esophageal cancer after 5 yr post-treatment. The study reported by Kelsen et al. included 440 patients with esophageal adenocarcinoma (n = 236) or SCC (n = 204) randomized to either preoperative chemotherapy plus esophagectomy or to esophagectomy alone. The chemotherapy regimen consisted of three cycles of preoperative cisplatin and 5FU and two cycles after operation for responding patients. Doses were higher than those used in the RTOG 85-01 trial. Although radiation therapy was not part of the treatment plan, it could be given in some circumstances. There was no significant difference in median survival (14.9 months for chemotherapy plus surgery compared with 16.1 months for surgery alone), and there were also no significant differences in 1-yr, 2-yr, 3-yr, or disease-free survival rates. There were no significant differences in survival between patients with adenocarcinoma and those with SCC. A clinical response to chemotherapy, as assessed by barium contrast radiography, was found in 19% of patients who received chemotherapy. A complete pathological response was found in 2.5% of patients. There was no significant increase in operative complications in the chemotherapy treated group.

Prevalence of Helicobacter pylori infection in 160 patients with Barrett's oesophagus or Barrett's adenocarcinoma

BACKGROUND

The role of Helicobacter pylori infection in the development of Barrett's oesophagus and its complications is uncertain. The aim of the present study was to determine the importance of H. pylori infection in this disease by comparing the frequency of oesophageal and gastric H. pylori infection in a group of patients with Barrett's oesophagus or adenocarcinoma, with the frequency of infection in a control group without Barrett's disease.

METHODS

The study group included 160 patients (123 male, 37 female; mean age: 61.2 years) who were classified (according to the highest grade pathological lesion in the oesophagus) as having Barrett's intestinal metaplasia (IM; 88 patients), Barrett's oesophagus with low-grade dysplasia (LGD; 28 patients), high-grade dysplasia (HGD; five patients), Barrett's indefinite for dysplasia (n = 4), and Barrett's adenocarcinoma (33 patients). A total of 91 of these patients had gastric antral specimens available for study. The control group consisted of 214 consecutive, prospectively enrolled symptomatic patients (122 male, 92 female; mean age: 57.2 years) who underwent upper gastrointestinal endoscopy and in whom Barrett's oesophagus or Barrett's adenocarcinoma was not found. A modified Warthin-Starry method was used to detect H. pylori infection.

RESULTS

Oesophageal H. pylori infection was found in eight of 160 (5%) patients with Barrett's oesophagus or Barrett's adenocarcinoma. Holicobacter pylori organisms in the oesophagus were found only on non-intestinalized cardiac or oxyntocardiac mucosa. All patients with oesophageal H. pylori infection and an antral biopsy available for study had antral H. pylori infection. Gastric antral H. pylori infection was significantly less prevalent in patients in the Barrett's study group (15/91, 16.5%) than in the non-Barrett's control group (67/214, 31.3%; Fisher's exact test, P = 0.01). Patients from the control group with an endoscopic diagnosis of duodenal ulcer, gastric ulcer, gastritis, or duodenitis had a significantly higher prevalence of infection compared with the Barrett's group, but there was no difference in the infection prevalence in patients in the Barrett's group and patients with reflux oesophagitis, hiatal hernia, no endoscopic abnormality, or any other diagnosis.

CONCLUSIONS

Oesophageal H. pylori infection is uncommon in patients with Barrett's IM, dysplasia, or adenocarcinoma, and may be restricted to non-intestinalized columnar epithelium. Gastric H. pylori infection may have a protective effect for the development of Barrett's oesophagus.

Endoscopic grading of the gastroesophageal valve in patients with symptoms of gastroesophageal reflux disease (GERD)

BACKGROUND

It has been suggested that endoscopic grading of the gastroesophageal flap valve is a good predictor of the reflux status.

METHODS

To test this hypothesis, 268 symptomatic patients underwent endoscopic grading of the gastroesophageal valve using Hill's classification, with grades I through IV. Esophageal acid exposure, lower esophageal sphincter characteristics, and the degree of esophageal mucosal injury were compared among the groups.

RESULTS

The prevalence of a mechanically defective sphincter, abnormal esophageal acid exposure, erosive esophagitis, and Barrett's esophagus increased with increasing alteration of the gastroesophageal valve. The presence of a grade IV valve indicated increased esophageal acid exposure in 75% of patients. As a predictor, this is similar to lower esophageal sphincter pressure but not as good as the presence of esophageal mucosal injury.

CONCLUSIONS

Endoscopic grading of the gastroesophageal valve provides useful information about the reflux status but is less useful as an indicator of gastroesophageal reflux disease (GERD) than the presence of esophageal mucosal injury.

Norman Barrett, "doyen of esophageal surgery"

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Incidence of deep vein thrombosis after laparoscopic vs minilaparotomy cholecystectomy

OBJECTIVES

To determine the frequency of deep vein thrombosis (DVT) associated with minimally invasive cholecystectomy and to determine, using minilaparotomy cholecystectomy as a control operation, the influence of the laparoscopic pneumoperitoneum on DVT formation.

DESIGN

Prospective nonrandomized control trial.

SETTING

Tertiary care university hospital.

PATIENTS

One hundred consecutive patients intended to undergo either laparoscopic cholecystectomy (59 patients) or minilaparotomy cholecystectomy (41 patients) with either of 2 surgeons were prospectively enrolled between April 1996 and April 1997. The minilaparotomy cholecystectomy group served as controls to isolate the effect of the pneumoperitoneum. Patient details, operative details, and any thromboembolic or bleeding complications were recorded. The same thromboprophylaxis regimen was prescribed for each group; namely, preoperative and postoperative subcutaneous low-molecular-weight heparin (LMWH), graduated compression stockings, and intraoperative intermittent calf compression.

INTERVENTION

Minimally invasive cholecystectomy.

MAIN OUTCOME MEASURE

Frequency of DVT. Bilateral lower limb venous color duplex scanning was used to detect DVT. Scans were performed on 3 occasions: (1) preoperatively on admission to hospital, (2) on the first postoperative day, and (3) between 2 and 4 weeks postoperatively.

RESULTS

Three patients in the laparoscopic group and 2 patients in the minilaparotomy group underwent conversion to conventional open cholecystectomy. There were no significant differences between patients in the 2 groups for age, sex, body mass index, preoperative white blood cell count, platelet count, prothrombin time, or activated partial thromboplastin time. There were no significant differences between the 2 groups for elective vs emergency operations, public hospital vs private hospital admissions, or consultant vs resident surgeon. Macroscopic gallbladder pathology grades for both groups were not significantly different, and there was no significant difference in the duration of postoperative hospital stay. Operative cholangiography was performed in a significantly larger proportion of laparoscopic cases (86% vs 66% in the minilaparotomy group; chi(2) test, P=.002), and the duration of anesthesia was significantly longer for the laparoscopic operation (118 minutes vs 98 minutes; t test, P=.05). Ninety-seven patients received preoperative LMWH and all patients received graduated compression stockings, intraoperative intermittent calf compression, and postoperative LMWH. Two of the 100 patients had postoperative DVT, 1 after laparoscopic cholecystectomy and 1 after minilaparotomy cholecystectomy. Both DVTs were detected by duplex examination on the first postoperative day. The DVT found after laparoscopic cholecystectomy was in 1 of the 3 patients who did not receive preoperative LMWH. There were no DVTs in any of the 40 patients who had an additional duplex scan between 2 and 4 weeks after operation.

CONCLUSIONS

Despite the theoretical risk of thromboembolic disease due to use of the laparoscopic pneumoperitoneum, the frequency of DVT after either laparoscopic cholecystectomy or minilaparotomy cholecystectomy is low if adequate thromboprophylaxis is provided.

Rising incidence of oesophageal adenocarcinoma in men in Australia

Adenocarcinomas of the oesophagus and of the gastric cardia have been reported to be increasing in incidence in many countries, while the incidence of squamous cell carcinoma of the oesophagus is stable and non-cardia gastric cancers are decreasing in incidence. Age-standardized incidence rates for the years 1982-1993 for oesophageal adenocarcinoma and non-adenocarcinoma, and gastric cardia and non-cardia cancers were calculated based on state cancer registry incidence data. Time trends in the age-standardized rates were assessed using linear regression. A consistent increasing trend in the incidence of oesophageal adenocarcinoma in men was seen in all states of Australia and was statistically significant in all states except South Australia. There were no consistent nationwide trends in the incidence of oesophageal adenocarcinoma in women, although a trend towards an increase in the incidence of this cancer reached statistical significance (P < 0.05) in three states (New South Wales, Victoria, Queensland). There were no important trends in the incidence of oesophageal non-adenocarcinoma in either men or women. There were no consistent nationwide changes in the incidence of gastric cardia cancer in either men or women, although this cancer was significantly increasing in Tasmania in both men and women. The incidence of cancer of the stomach not arising at the gastric cardia was significantly decreasing in men in all states and was also decreasing in women in all states, although in women this decrease was statistically significant only in New South Wales, Victoria and Western Australia. There has been a dramatic increase in the incidence of oesophageal adenocarcinoma in men in Australia. The incidence of this cancer in men is now approximately equal with that of non-adenocarcinoma of the oesophagus. The incidence of non-cardia stomach cancer continues to fall.

Splenectomy for HIV-related immune thrombocytopenia: comparison with results of splenectomy for non-HIV immune thrombocytopenic purpura

OBJECTIVE

To determine the effectiveness and safety of splenectomy for patients with human immunodeficiency virus (HIV)-related immune thrombocytopenia, using the results of splenectomy for patients with non-HIV immune thrombocytopenic purpura as a control group for comparison.

DESIGN

Retrospective study.

SETTING

Tertiary care university hospital.

PATIENTS

Fourteen patients who underwent splenectomy for symptomatic, medically refractory HIV-related immune thrombocytopenia at this hospital from 1988 to 1997. During the same period, 20 patients had splenectomy for treatment of non-HIV immune thrombocytopenic purpura.

INTERVENTION

Splenectomy.

MAIN OUTCOME MEASURES

Platelet response, need for postsplenectomy medical therapy, progression of HIV disease, and complications.

RESULTS

All patients with HIV-related thrombocytopenia had a complete early platelet response to splenectomy, with an elevation of the platelet count to greater than 100X10(9)/L. After a median follow-up of 26.5 months, all but 1 patient had a sustained complete remission with no need for medical therapy for thrombocytopenia. Splenectomy was more effective in the HIV-related thrombocytopenia group than in the non-HIV immune thrombocytopenic purpura group, with significantly higher platelet counts at 1 week and 1 month after splenectomy in the HIV group (t test, P=.02 and P=.009, respectively). There were significantly fewer patients needing medical therapy for thrombocytopenia after splenectomy in the HIV group (chi2 test, P=.02). There were no remarkable short- or long-term complications in the patients with HIV infection, including no overwhelming postsplenectomy infections. Three patients have died, and 2 patients have developed AIDS since operation.

CONCLUSIONS

Splenectomy is effective treatment for patients with symptomatic HIV-related thrombocytopenia that is resistant to medical therapy. The effectiveness of this treatment suggests that the predominant mechanism of thrombocytopenia in HIV-infected patients is increased destruction of platelets because of platelet-associated immunoproteins.

Cholecystectomy in cardiothoracic organ transplant recipients

OBJECTIVES

To assess the risks associated with cholelithiasis and cholecystectomy in cardiothoracic organ transplant recipients at this hospital and to identify any differences with potential causal significance between the group with known gallstones and the transplant recipient group as a whole.

DESIGN

Medical records survey.

SETTING

Tertiary care university hospital.

PATIENTS

Six hundred forty-five patients had cardiothoracic organ transplantation at this hospital between February 1, 1984, and May 31, 1996. Gallstones were detected in 37 (5.7%) of these patients and 32 patients underwent cholecystectomy, of which 29 operations were performed primarily for symptomatic gallstone disease. All cholecystectomies were performed after transplantation.

MAIN OUTCOME MEASURES

Mortality, morbidity, postoperative biliary disease.

RESULTS

Patients with gallstones were significantly older than the transplant patient group as a whole (Student t test, P=.001); they were more likely to be female (chi2 test, P=.05); and they had a higher body mass index (t test, P=.001). There were no significant differences in the maximum serum bilirubin level during the transplantation admission, incidence of diabetes mellitus, cholestyramine use, or cyclosporine dosage during the first 12 months after transplantation. Cholecystectomy was performed after a median 5-month symptomatic period, mostly by the minilaparotomy method. Forty-five percent of cholecystectomies were urgent or semi-urgent. One patient died of lung infection on the second postoperative day. The median postoperative stay was 3 days. At a median 33 months' follow-up, 4 patients have had further biliary problems (2 patients with common bile duct stones, 1 patient with intrahepatic stones, and 1 patient with biliary dyskinesia). Four other patients with asymptomatic gallstones who did not receive cholecystectomy have remained asymptomatic for between 15 and 67 months.

CONCLUSIONS

Cholecystectomy by the minilaparotomy or laparoscopic methods, with routine operative cholangiography, is the preferred treatment for symptomatic gallstones in cardiothoracic organ transplant recipients. Although the optimum management of asymptomatic gallstones in these patients remains unclear, our favorable experience with a policy of reserving cholecystectomy for symptomatic cases seems noteworthy.

Gastric cancer in the bypassed segment after operation for morbid obesity

A case is reported in which two separate adenocarcinomas were detected in the bypassed distal stomach 13 years after gastric stapling with loop gastro-enterostomy was performed for the treatment of morbid obesity. Retrograde endoscopy via the afferent loop was used to establish the diagnosis. Although gastritis and metaplasia have been described in the bypassed stomach, only one case of carcinoma in this area has previously been reported.

Anorectal surgery in patients infected with human immunodeficiency virus: factors associated with delayed wound healing

OBJECTIVE

A review of all anorectal operations in patients infected with human immunodeficiency virus (HIV) was performed to assess the incidence, variety, and clinical course of anorectal disease in these patients and to identify factors influencing wound healing.

SUMMARY BACKGROUND DATA

Anorectal disease is the most common indication for surgical intervention in patients infected with HIV. The cause and management of HIV-related anorectal conditions, which differ significantly from non-HIV-related diseases, are not clear. There also is considerable variation in the reported results of surgical procedures, including wound healing. St. Vincent's Hospital, Sydney, is situated in an area with the highest concentration of individuals infected with HIV in Australia.

METHODS

The medical records of all identified patients infected with HIV who had an anorectal operation at St. Vincent's General Hospital between January 1, 1988, and January 31, 1995, were reviewed retrospectively. Logistic regression, Mann-Whitney U test, and Fisher's exact tests were used for analysis.

RESULTS

One thousand five hundred two patients with acquired immune deficiency syndrome (AIDS), equivalent to 26.8% of all known patients with AIDS in Australia at this time, were admitted to this hospital during the 7-year period. One hundred one patients infected with HIV underwent 161 anorectal operations. All patients were male homosexuals (98 patients, 97%) or bisexuals (3 patients, 3%), with intravenous drug use an additional risk factor in 5 patients (5%). Thirty-seven percent of patients had more than one operation. Seventy-two percent of patients were Centers for Disease Control (CDC) group 4 (AIDS) at operation, 27% were group 2, 1% was group 3, and none were group 1. Accurate information about wound healing was available for 74% of first operations, and univariate and multivariate logistic analyses of these showed that when the CD4+ T-lymphocyte count was <50 cells/ microL, healing was significantly retarded (p = 0.016). The Centers for Disease Control group, patient age, and serum albumin were not significant predictors of wound healing. The interval between HIV diagnosis and operation was not associated with impaired wound healing, but recognition of AIDS more than 1 year before operation was associated with significantly better wound healing compared with those in whom AIDS developed within the year before operation (p = 0.025). In the patients for whom accurate wound healing information was available, only 40% had healed their wounds by 3 months after operation. Wound healing was worst for patients with chronic fissures, only 16% of whom had healed their wounds at 3 months. The wound healing rate was worse for repeat operations than for first operations. Ten percent of patients had anorectal malignancies, none of which were diagnosed clinically before or during operation.

CONCLUSIONS

Wound healing is a significant problem after anorectal operations in patients infected with HIV, especially when the CD4 count is <50/microL. Although there seems to be little or no benefit from more invasive operations in some cases, thorough examination with adequate biopsies is required in all cases. The best management of anorectal disease in patients infected with HIV still is unclear.

False aneurysm of the popliteal artery complicating acupuncture

This is the first reported case in which acupuncture needle injury of the popliteal artery caused the development of a false aneurysm. The patient presented with rupture of the aneurysm and was successfully managed by arterial repair.

Early discharge after open appendicectomy

BACKGROUND

There is increasing pressure on surgeons to minimize the time patients stay in hospital, and there is therefore a need to establish guidelines for reasonable lengths of stay for common operations. This study was conducted to test the feasibility and safety of early discharge after open appendicectomy. In addition, this study was performed to provide standards for open appendicectomy against which the results of laparoscopic appendicectomy can be compared.

METHODS

A prospective study of all patients having open appendicectomy for suspected acute appendicitis at Liverpool Hospital, Sydney during a 4 month period was undertaken. An early discharge programme was established, with the aim of discharging patients within 48 h of operation in uncomplicated cases. Discharge was allowed when the patient was eating, walking, and had passed flatus. Follow up was with the consultant surgeon at 1 week postoperatively, and with a community nurse at 2 weeks. Multivariate linear regression, using the number of postoperative hours to discharge as the outcome, was used to analyse the data for the following four factors: age, gender, incision type, and pathology.

RESULTS

One hundred and sixteen consecutive patients were enrolled in the study. The median postoperative stay for all patients was 46 h. Perforation of the appendix, use of a midline laparotomy for appendicectomy, and age significantly prolonged hospital stay, but gender had no effect. The main complication was wound infection, which was seen in 7.5% of patients. No patient had a problem directly related to early discharge. A community nurse saw 81% of patients 2 weeks after discharge. Over three-quarters of the patients seen had returned to full normal activities by 2 weeks, including work or school. Eighty-eight per cent of patients considered the timing of their discharge "good' or "excellent'.

CONCLUSIONS

Discharge at 2 days after open appendicectomy is both feasible and safe for patients having an unperforated appendix removed through a right iliac fossa incision. Passage of stool is not required prior to discharge. Early discharge is well accepted by patients and may result in financial savings for hospitals where payment is according to Diagnosis-Related Groups. On the basis of the results of the six randomized controlled trials comparing laparoscopic and conventional open appendicectomy published to date, and on the results of this study, the authors conclude that laparoscopic appendicectomy should not yet be considered the "procedure of choice', and surgeons are justified in performing appendicectomy by either method.

Amphetamine toxicity: experience with 127 cases

We present a retrospective study of 127 cases of amphetamine toxicity in an emergency department (ED). The most common presenting symptoms seen were agitation, hallucinations, suicidal behavior, and chest pain. Toxicologic analysis showed amphetamines are generally not mixed with other stimulants. The vast majority of patients did not require pharmacologic treatment in the ED. Thirteen patients (10%) required admission to the hospital. Toxic medical effects of amphetamine-related compounds seen in our patients are discussed.