Noise patterns in visceral surgical procedures: Analysis of second-by-second dBA data of 599 procedures over the course of one year

The objective of this study is to analyze noise patterns during 599 visceral surgical procedures. Considering work-safety regulations, we will identify immanent noise patterns during major visceral surgeries. Increased levels of noise are known to have negative health impacts. Based on a very fine-grained data collection over a year, this study will introduce a new procedure for visual representation of intra-surgery noise progression and pave new paths for future research on noise reduction in visceral surgery. Digital decibel sound-level meters were used to record the total noise in three operating theatres in one-second cycles over a year. These data were matched to archival data on surgery characteristics. Because surgeries inherently vary in length, we developed a new procedure to normalize surgery times to run cross-surgery comparisons. Based on this procedure, dBA values were adjusted to each normalized time point. Noise-level patterns are presented for surgeries contingent on important surgery characteristics: 16 different surgery types, operation method, day/night time point and operation complexity (complexity levels 1–3). This serves to cover a wide spectrum of day-to-day surgeries. The noise patterns reveal significant sound level differences of about 1 dBA, with the most-common noise level being spread between 55 and 60 dBA. This indicates a sound situation in many of the surgeries studied likely to cause stress in patients and staff. Absolute and relative risks of meeting or exceeding 60 dBA differ considerably across operation types. In conclusion, the study reveals that maximum noise levels of 55 dBA are frequently exceeded during visceral surgical procedures. Especially complex surgeries show, on average, a higher noise exposure. Our findings warrant active noise management for visceral surgery to reduce potential negative impacts of noise on surgical performance and outcome.

Stenosis of the celiac trunk is associated with anastomotic leak after Ivor-Lewis esophagectomy

Transthoracic esophagectomy with gastric tube formation is the surgical treatment of choice for esophageal cancer. The surgical reconstruction induces changes of gastric microcirculation, which are recognized as potential risk factors of anastomotic leak. This prospective observational study investigates the association of celiac trunk (TC) stenosis with postoperative anastomotic leak. One hundred fifty-four consecutive patients with esophageal cancer scheduled for Ivor-Lewis esophagectomy were included. Preoperative staging computed tomography (CT) was used to identify TC stenosis. Any narrowing of the lumen due to atherosclerotic changes was classified as stenosis. Percentage of stenotic changes was calculated using the North American Symptomatic Carotid Endarterectomy Trial formula. Multivariable analysis was used to identify possible risk factors for leak. The overall incidence of TC stenosis was 40.9%. Anastomotic leak was identified in 15 patients (9.7%). Incidence of anastomotic leak in patients with stenosis was 19.4% compared to 2.3% in patients without stenosis. Incidence of stenosis in patients with leak was 86.7% (13 of 15 patients) and significantly higher than 38.8% (54 of 139 patients) in patients without leak (P < 0.001). There was a significant difference in median degree of TC stenosis (50.0% vs 39.4%; P = 0.032) in patients with and without leak. In the multivariable model, TC stenosis was an independent risk factor for anastomotic leak (odds ratio: 5.98, 95% CI: 1.58-22.61). TC stenosis is associated with postoperative anastomotic leak after Ivor-Lewis esophagectomy. Routine assessment of TC for possible stenosis is recommended to identify patients at risk.

Is the Urokinase-type Plasminogen Activator System a Reliable Prognostic Factor in Gastric Cancer?

Aim

The aim of this prospective study was to evaluate the clinical and prognostic impact of immunohisto-chemically assessed uPA and PAI-1 in patients with gastric cancer.

Methods

This prospective study analyzed specimens obtained from 105 gastric cancer patients who underwent gastrectomy with extended lymphadenectomy. The immunohistochemical expression of uPA and PAI-1 was studied semiquantitatively in the tumor epithelium and was correlated with the clinicopathological features of each patient.

Results

Univariate analysis revealed no statistically significant association of uPA levels with pT and pN category (p=0.655 and 0.053, respectively), grading (p=0.374), depth of tumor invasion (p=0.665), UICC classification (p=0.21) and the Laurén classification (p=0.578). PAI-1 expression showed no statistically significant correlation with pT, pN and M category (p=0.589, 0.414, and 0.167, respectively), grading (p=0.273), and the Laurén classification (p=0.368). Only the UICC classification was significantly correlated with PAI-1 (p=0.016). Kaplan-Meier analysis revealed no significant association of uPA and PAI-1 with overall survival (p=0.0929 and 0.0870, respectively).

Conclusions

Our results could not verify any prognostic value of uPA and PAI-1 levels in patients with gastric carcinoma. Therefore, the uPA-system as a biologically defined prognostic marker to identify high-risk gastric cancers should be applied with caution. However, considering the number of patients involved and the borderline level of significance observed in this study, a larger number of events may have resulted in significant differences.

HIF-1alpha protein expression is associated with the environmental inflammatory reaction in Barrett's metaplasia

The oxygen-regulated transcription factor subunit hypoxia inducible factor-1alpha (HIF-1alpha) is involved in angiogenesis, energy metabolism, cell survival, and inflammation. We examined the protein expression of HIF-1alpha within the progression of Barrett's sequence as well as the type and degree of the environmental inflammatory reaction. Squamous epithelium (SE), metaplastic, low- and high-grade dysplastic lesions, and tumor tissue of 57 resection specimens from patients with Barrett's adenocarcinoma were immunohistochemically analyzed. Active and chronic inflammatory reactions were classified according to the Updated Sydney System. HIF-1alpha protein expression increased significantly from SE to Barrett's metaplasia (BM) (P < 0.0001). From metaplasia through low- and high-grade dysplasia to cancer, no further increase could be detected. Active and chronic inflammation were also significantly different between SE and BM (P < 0.0001) but not during further progression in the sequence. HIF-1alpha protein expression did not correlate with histopathologic parameters or survival. HIF-1alpha protein expression pattern resembles the active and chronic environmental inflammatory reaction. All were significantly increased in metaplasia compared to SE without further change in tumor development. HIF-1alpha protein expression appears to be associated with inflammatory processes in the development of BM.

Association of COX-2 expression with corresponding active and chronic inflammatory reactions in Barrett's metaplasia and progression to cancer

AIMS

Risk reduction for Barrett's cancer in individuals taking non-steroidal anti-inflammatory drugs has been reported. Cyclooxygenase (COX)-2, one of the inhibited enzymes, is putatively involved in Barrett's cancer pathogenesis. The aim of this study was to examine a possible association between COX-2 protein expression and the development and progression of the Barrett's metaplasia-dysplasia-carcinoma sequence and the type and degree of associated inflammatory reaction.

METHODS AND RESULTS

Squamous epithelium, metaplastic, low-grade, high-grade dysplastic lesions and tumour tissue of 49 resection specimens from patients with Barrett's adenocarcinoma were immunohistochemically analysed. Active and chronic inflammatory reactions were classified according to the Updated Sydney System. Within the Barrett's sequence, a significant progressive increase in COX-2 expression was identified (P < 0.0001). The most significant differences were detected between squamous epithelium and Barrett's metaplasia (P < 0.001) and from low- to high-grade dysplasia (P < 0.0001). Active and chronic inflammation were significantly different between squamous epithelium and Barrett's metaplasia (P < 0.0001), but not during further progression in the sequence.

CONCLUSIONS

Increasing COX-2 expression in Barrett's metaplasia is significantly associated with a change in the local inflammatory reaction, but not during further progression through dysplasia to cancer. This supports the potential of a chemoprevention strategy using COX-2 inhibitors independent of the extent and type of the inflammatory reaction in Barrett's oesophagus.

Survivin mRNA in peripheral blood is frequently detected and significantly decreased following resection of gastrointestinal cancers

BACKGROUND AND OBJECTIVES

We evaluated if mRNA expression of survivin, an inhibitor of apoptosis, can be used to detect circulating tumor cells in peripheral blood of patients with various gastrointestinal cancers and if they decrease following complete surgical resection.

METHODS

Blood samples from 40 gastrointestinal cancer patients were analyzed prior and following surgical resection by direct quantitative real-time reverse transcriptase-PCR (RT-PCR) assays.

RESULTS

Survivin mRNA expression was pre-operatively detected in 35 of 40 cancer patients (88%). Post-operative survivin levels were significantly lower than pre-operative levels in 59% of resected patients and were non-detectable in 38% (Wilcoxon rank test: P < 0.04).

CONCLUSIONS

This is the first report showing that direct quantitative real-time RT-PCR analysis of survivin mRNA expression in peripheral blood of patients with gastrointestinal cancers is technically feasible. Survivin mRNA levels fall significantly following complete resection and might become a molecular marker for the completeness of surgical resection.

Feasibility of sentinel node concept in gastric carcinoma: clinicopathological analysis of gastric cancer with solitary lymph node metastases

BACKGROUND

The feasibility and diagnostic reliability of sentinel lymph node biopsy of gastric carcinoma are still unclear and controversial.

PATIENTS AND METHODS

To assess the applicability of the sentinel node concept to gastric carcinoma, we retrospectively analyzed the location of metastatic lymph nodes in patients with only one or two lymph node metastases.

RESULTS

A total of 135 patients, who underwent gastrectomy with D2 lymphadenectomy for primary gastric adenocarcinoma between 1997 and 2001, were enrolled in this study. An average of 39 lymph nodes were resected and analyzed for each patient. Of the 135 patients, 88 (65%) were subtyped as pN+ (with lymph node metastasis); of the latter, 15 cases (pT1-3; 17% of N+ cases) showed one or two lymph node metastases. In 14 (93%) of these patients, lymph nodes directly adjacent to the primary tumor were involved. Skip metastases were only seen in one patient with cardia carcinoma and lymph node involvement of compartment II (left gastric artery).

CONCLUSION

In patients with gastric carcinoma, especially in early stage carcinoma, the phenomenon of skip metastasis is infrequent. Therefore, the sentinel node concept may be feasible in gastric cancer.

Masaoka staging is of prognostic relevance in type B3 / C thymomas

BACKGROUND

The purpose of this study was to correlate the Ki67 labelling index (LI) with the Masaoka classification and the new WHO-classification in type B3 / C thymomas.

PATIENTS AND METHODS

Fourteen patients with type B3 / C thymomas were evaluated, and archived specimens were histologically reclassified according to Masaoka staging, the new WHO classification and the Ki-67 LI in a retrospective analysis.

RESULTS

Four patients presented with Masaoka stage II disease (all WHO-type B3), 1 patient had stage III (WHO-type C), 6 stage IVa (3 WHO-type B3 and 3 WHO-type C), and another 3 patients stage IVb (all WHO-type C). The statistical analysis revealed a significant correlation between Masaoka staging and Ki-67 LI (II, III vs. IV; p = 0.007). As well, WHO-classification correlated significantly with Ki-67 LI (B3 vs. C; p = 0.015). Masaoka staging (II, III vs. IV) correlated significantly with survival status (p = 0.0237) in patients with type B3 / C thymoma whereas WHO-classification did not (p = 0.3266). Between survivors and non-survivors there was no statistically significant correlation concerning Ki-67 LI (p = 0.075).

CONCLUSION

Our study indicated that the Masaoka staging system is of prognostic relevance in type B3 / C thymomas.

Quantitative c-erbB-2 but not c-erbB-1 mRNA expression is a promising marker to predict minor histopathologic response to neoadjuvant radiochemotherapy in oesophageal cancer

We examined the potential of quantitative epidermal growth factor receptor (EGFR, synonym: c-erbB-1) and c-erbB-2 (synonym: HER2/neu) mRNA expression to predict minor or major histopathologic response to neoadjuvant radiochemotherapy (cis-platinum, 5-FU, 36 Gy), followed by radical surgical resection, in patients with oesophageal cancer. Tissue samples were collected by endoscopic biopsy prior to treatment. RNA was isolated from biopsies and quantitative real-time reverse transcriptase–polymerase chain reaction assays were performed to determine c-erbB-1 and c-erbB-2 mRNA expression. Relative expression (tumour/paired normal tissue ratio standardised for β-actin) was calculated for EGFR and c-erbB-2 mRNA. Expression levels were correlated with the objective histopathologic response in resected specimens. Histomorphologic regression was defined as major response when resected specimens contained less than 10% of residual vital tumour cells, or in case a pathologically complete response was achieved. Expression of c-erbB-1 mRNA was not associated with the degree of histomorphological response. In contrast, the relative expression levels of c-erbB-2 mRNA >1 were not associated with major histopathologic responses (sensitivity 41.6%, specificity 100%), and 10 out of 36 (28%) patients could be unequivocally identified, whose tumours did not respond well to the delivered neoadjuvant radiochemotherapy (P<0.01). Quantitative expression levels of c-erbB-2, but not c-erbB-1 mRNA, in pretreatment biopsies appear to predict minor histopathologic response to our neoadjuvant radiochemotherapy protocol. This test could be used to prevent expensive, noneffective and potentially harmful therapies in approximately one-fourth of our patients, and leads to a more individualised type of combined modality treatment.

[Heterotopic gastric pancreas: a rare cause of abdominal complaints]

Heterotopic pancreas is an uncommon cause of gastrointestinal complaints such as epigastric pain, nausea, vomiting, and upper gastrointestinal bleeding. Despite the development of modern diagnostic procedures, it is still difficult to differentiate heterotopic pancreatic tissue from other benign or malignant gastric tumors. Local excision of the gastric wall is regarded as the diagnostic and therapeutic procedure of choice. We present two cases and an overview of the literature.

Chemokines and interleukin-18 are up-regulated in bronchoalveolar lavage fluid but not in serum of septic surgical ICU patients

Our objective was to investigate the levels of chemokines (MIP1-alpha, MCP-1, and Gro-alpha), Interleukin-18 (IL-18), and Interleukin (IL-6) in bronchoalveolar lavage (BAL) fluid and serum at the onset and ongoing states of sepsis as defined by the American College of Chest Physicians/Society of Critical Care Medicine in septic surgical ICU patients. Our summary background data was to understand the significance of compartmentalized inflammatory mediator production in an immunologically active organ (lung) in comparison with levels in the systemic circulation. The study group consisted of 20 septic patients and 10 non-septic patients on surgical ICU. At the onset of sepsis, both BAL fluid and serum samples were taken and levels of MIP-1alpha, MCP-1, GRO-alpha, IL-18, and IL-6 were measured by ELISA. Furthermore, over a subsequent 8-day period, levels of these mediators were determined in serum. In some experiments, IL-18 mRNA levels were determined in peripheral blood lymphocytes (PBL) of septic and non-septic patients. At the onset of sepsis, MIP-1alpha, MCP-1, GRO-alpha, IL-18, and IL-6 levels were significantly up-regulated in BAL fluid as compared with non-septic controls. In marked contrast, with the exception of IL-18 mRNA and IL-6 peptide, there was no increase in serum levels of inflammatory mediators determined both at the onset and during the ongoing states of sepsis. Based on the present data, monitoring levels of serum chemokines and IL-18 protein as markers of sepsis might be misleading since despite their non-detection in serum, they were highly up-regulated in the lung tissue compartment. These data might underscore the role of MIP-1alpha, MCP-1, GRO-alpha, and IL-18 in the mediation of local tissue damage. Furthermore, these findings raise the notion that mediator measurement in immunologically active organs might serve as pivotal indicators of sepsis prior to the actual fulfillment of specific clinical criteria that defines the patient as being septic.

Caspase-1-inhibitor ac-YVAD-cmk reduces LPS-lethality in rats without affecting haematology or cytokine responses

The effect of acetyl - tyrosyl-valyl-alanyl-aspartyl - chloromethylketone (ac-YVAD-cmk), an irreversible caspase-1 (IL-1beta converting enzyme, ICE) inhibitor on mortality, leukocyte and platelet counts and cytokine levels was investigated in a double-blind rat model of endotoxaemia. Intravenous (i.v.) bolus administration of lipopolysaccharide (LPS) (25-75 mg kg(-1), n=12 per group) to anaesthetized rats induced a dose dependent increase in mortality over 8 h (LD(50)=48 mg kg(-1)). During this period, animals became leukopenic and thrombocytopenic. Serum levels of IL-beta, IL-6, and TNF-alpha were highly elevated. Pretreatment of rats with ac-YVAD-cmk at a dose of 12.5 micromol kg(-1) significantly reduced mortality from 83 to 33% using Log Rank analysis. However, ac-YVAD-cmk did not modify blood cell counts or cytokine profiles as compared with the LPS-drug vehicle group. These data lay credence to the potential importance of caspase-1-inhibition in modifying the inflammatory response to endotoxin. Further investigations are warranted in understanding the relationship between caspase-1 inhibition, cytokine production and animal survival in different experimental paradigms of sepsis.

Experimental low-level direct current therapy in liver metastases: influence of polarity and current dose

Several authors recently reported on the successful local treatment of malignant disease with low-level direct current therapy. However, antitumoral effects in colorectal metastases has not been investigated experimentally. The aim of the present study was to assess the effectiveness of this therapy and the influence of polarity and current dose. Colorectal metastases were established in BD IX rats by the injection of colon cancer cells under the liver capsule. After three weeks, the liver tumor volumes were determined by magnetic resonance imaging of the liver. Low-level direct current therapy was applied via five platinum electrodes. Four different applications were used: 60 C/cm(3), anode at the center; 60 C/cm(3), cathode at the center; 80 C/cm(3), anode at the center; and 80 C/cm(3), cathode at the center. In the control group, five electrodes were placed without applying any direct current. All animals were sacrificed on postoperative day 7. Liver metastases were histologically examined for vital tumor cells. Statistical analysis was performed with chi(2)-test. The mean initial tumor diameter before treatment was 3.6 +/- 1.4 mm (volume: 25.2 +/- 9.7 mm(3)). Histological examination of the removed livers revealed significant destruction of the metastases with localized necroses in all treatment groups; 37% had a complete response rate and 63% a partial response rate. There were no significant necroses in the control group (P < 0.0001). The best treatment results were obtained in the group with an anode at the center and a current dose of 80 C/cm(3). Direct current therapy offers a new and safe method for the local treatment of liver metastases. We were able to observe that tumor damage is related to current dose but not to the polarity of the central electrode.

P53 mutational status improves estimation of prognosis in patients with curatively resected adenocarcinoma in Barrett's esophagus

The incidence of adenocarcinomas in Barrett's esophagus has been rising in the last two decades in the United States and Western Europe for yet unknown reasons. We reported previously a large multi-institutional trial implicating p53 mutations as being involved in the pathogenesis of Barrett's cancer and representing an early marker for the malignant potential of Barrett's epithelium. A prospective study was performed to evaluate the prognostic impact of p53 mutations on survival in 59 patients with Barrett's cancer. Tissue for DNA analysis was obtained by endoscopic biopsy or immediately after surgical resections from the tumor, Barrett's epithelium, and normal stomach and esophagus. p53 mutation analysis was performed by PCR-single strand conformational polymorphism screening of exons 5-9 and DNA sequencing to unequivocally prove the presence of a mutation. p53 mutations were identified in 30 of 59 (50.8%) patients. The presence of a p53 mutation in the tumor had a significant impact on survival after curative resections (RO-resections) with cumulative 5-year survival probabilities of 68.8+/-9.7% for mutation-negative tumors and 24.3+/-9.9% for mutation-positive tumors (log rank: P < 0.001). By Cox proportional hazard analysis, including the parameters of gender, age, Union International Contre Cancer tumor stage, grading, and p53 mutation status, only Union International Contre Cancer tumor stage (P < 0.0001) and p53 mutation status (P < 0.02) were of significant independent prognostic importance. p53 mutation analysis by DNA sequencing is of significant independent prognostic importance next to histopathological tumor stage in patients with curatively resected (RO-resection) Barrett's cancer. It appears that p53 mutational status is a valuable parameter to define low-risk (p53 mutation-negative) and high-risk (p53 mutation-positive) groups for treatment failure after curative resections.

Multiple molecular marker testing (p53, C-Ki-ras, c-erbB-2) improves estimation of prognosis in potentially curative resected non-small cell lung cancer

A prospective study was performed in patients with non-small cell lung cancer (NSCLC) to evaluate the prognostic importance of multiple molecular marker (p53, c-Ki-ras, c-erbB-2) testing. 103 patients with potentially curative resections (RO resection) for NSCLC in histopathological stages I-IIIA were included. SSCP analysis and DNA sequencing for p53 and c-Ki-ras genes were performed on paired tumour and normal lung tissue samples and immunohistochemistry (c-erbB-2) was done on frozen tissue sections with a specific anti-c-erbB-2 monoclonal antibody. 46/103 (44.6%) NSCLC showed p53 mutations and 17/103 (16.5%) c-Ki-ras mutations including 12/37 (32.4%) adenocarcinomas. Overexpression of c-erbB-2 (p185) was detected in 56/103 (54.4%) tumours. 24/103 (23.3%) NSCLC were negative for alterations in all 3 parameters (c-Ki-ras, p53 and p185) whereas 79/103 (76.7%) were positive for at least one of the 3 parameters. In a regression model including a multiple molecular marker parameter (negative for all 3 markers versus positive for at least one marker), histopathological stage (P<0.00001), respectively the pT (P<0.01) and pN (P<0.00001) categories and the multiple molecular marker parameter (P<0.01) were of significant prognostic importance. This study demonstrates that testing 3 molecular markers (c-Ki-ras, p53 and c-erbB-2) improves estimation of prognosis compared to single marker testing and appears to define low (82.6%+/-7.9% 5-year survival) and high risk (40.2%+/-5.5% 5-year survival) groups for treatment failure in potentially curative (RO) resected NSCLC.

Local treatment of hepatic metastases with low-level direct electric current: experimental results

BACKGROUND

Several authors have recently reported encouraging results from low-level direct current therapy in easily accessible malignant tumors. However, antitumoral effects in colorectal metastases have not been investigated experimentally.

METHODS

Using an animal model with induced hepatic metastases, we analyzed the effectiveness and the tumor growth dynamics after direct current application. Three weeks after induction tumor volumes were estimated with magnetic resonance imaging (MRI). Then direct current (80 C/cm3) was applied in the treatment group by means of one anode in the tumor center and four cathodes peripherally. In the control group electrodes were placed without applying current. Tumor growth dynamics was analyzed with MRI after 3 and 5 weeks. After this all animals were killed, and the livers histologically examined.

RESULTS

After 5 weeks MRI showed a 1.6-fold tumor enlargement in the treatment group versus a 2.9-fold enlargement in the control group (Student t test, P=0.0051). The histopathologic analysis of the treated livers yielded a 21% complete response rate and a 78% partial response rate. No necroses were found in the control group.

CONCLUSIONS

These results confirm the effectiveness of low-level direct current application as a potential modality for the treatment of hepatic metastases.

Prognostic impact of p21/waf1/cip1 in colorectal cancer

In addition to the tumor suppressor gene p53, Cyclin Dependent Kinases (CDK) are well known to influence the cell cycle in normal human tissues and various neoplasias as well. The purpose of our present study was to evaluate the expression of the CDK-inhibitor p21/waf1/cip1 in colorectal cancer with special emphasis on the prognostic impact. Between 1985 and 1991, 294 patients (median age, 65 years) underwent surgical operative therapy for colorectal cancer. Formalin-fixed and paraffin-embedded tumor specimens were investigated. For immunohistochemistry the Catalysed Reporter Deposition (CARD) technique was performed. The survival probability was calculated and possible prognostic risk factors were tested using multivariate analysis. The p21/ waf1/cip1 staining pattern was positive in 197 (67%) specimens and negative in 97 (33%) samples. No significant correlation could been calculated between p21/waf1/cip1 expression and other variables such as age, sex, WHO-Classification, localisation, grading, TNM-classification or UICC-stage. Patients with a positive staining reaction had a significantly better survival (p < 0.0052). Moreover, p21/waf1/cip1 was shown to be an independent prognostic parameter by multivariate analysis (p < 0.022). In contrast with these findings, the p53 tumor status had no impact on survival. P21/ waf1/cip1 appears to be an independent prognostic parameter in colorectal cancer and is associated with a favorable survival. This feature may be related to a cell cycle arrest in the G1 phase induced by p21/waf1/cip1, resulting in lower tumor cell proliferative activity.

Mutations of p53 in Barrett's esophagus and Barrett's cancer: a prospective study of ninety-eight cases

We had previously identified p53 mutations in Barrett's esophagus and therefore began a multiinstitutional study to determine their significance as a marker for malignancy. Ninety-eight patients from four institutions were studied. Forty-eight patients (37 men and 11 women, mean age 56.2 years) had Barrett's esophagus with metaplasia or dysplasia but no evidence of malignancy at a mean follow-up of 2.2 years. Barrett's esophagus was classified as metaplasia with no evidence of dysplasia in 32 patients, as low-grade dysplasia in 13, and as high-grade dysplasia in three. The other 50 patients (46 men and four women, mean age 60.2 years) had adenocarcinoma arising in Barrett's esophagus. Tissues from normal stomach or esophagus, tumor, and Barrett's esophagus were obtained for deoxyribonucleic acid analysis by endoscopic biopsy from patients with Barrett's esophagus or cancer or during operations on some patients with Barrett's cancer. Exons 5 through 9 of the p53 gene were studied for mutations by single-strand conformational polymorphism analysis after polymerase chain reaction amplification. Mutations detected by single-strand conformational polymorphism analysis were confirmed by deoxyribonucleic acid sequencing. None of the tissue samples from patients with Barrett's esophagus alone and no dysplasia or low-grade dysplasia had any p53 mutations, but one of the three patients with high-grade dysplasia and no evidence of invasive malignancy did have a p53 mutation. Of the 50 patients with Barrett's cancer, however, 23 (46%) had p53 mutations in Barrett's epithelium, tumors, or both. Twenty of these patients had p53 mutations in the tumor only (n = 16) or in both tumor and Barrett's epithelium (n = 4), suggesting that the mutation plays a direct role in carcinogenesis. Mutations in Barrett's epithelium were found in one patient in the group without malignancy and in seven patients with cancer (one with no dysplasia, two with low-grade dysplasia, and five with high-grade dysplasia). In three patients with cancer, mutations occurred only in Barrett's epithelium, suggesting that such mutations may also be a marker for genomic instability. Mutations were predominantly found in exons 5, 7, and 8, and transitions from guanine to adenine were the most frequent changes. Mutations of p53 are clearly involved in the pathogenesis of Barrett's cancer for a subset of patients (46%), and the fact that we could detect mutations in premalignant Barrett's epithelium supports the hypothesis that p53 mutations may be a useful marker for patients at increased risk for development of invasive cancer.

Prognostic value of DNA ploidy and c-erbB-2 oncoprotein overexpression in adenocarcinoma of Barrett's esophagus

BACKGROUND

During the last two decades, a rising incidence of adenocarcinoma of the esophagus has been observed in the Western world. The prognostic relevance of tumor-biological factors, such as DNA ploidy or c-erbB-2 overexpression, for overall survival following complete resection is still unknown.

METHODS

In a retrospective study of 80 patients with adenocarcinoma of Barrett's esophagus, the prognostic significance of flow cytometric DNA ploidy determination was investigated. Overexpression of c-erbB-2 oncoprotein was studied by immunohistochemical alkaline phosphatase-antialkaline phosphatase staining of formalin fixed, paraffin embedded tissue sections of the primary tumor.

RESULTS

The rate of aneuploidy was 86%. Aneuploidy was significantly correlated with lymph node metastases only. c-erbB-2 oncoprotein overexpression of the primary tumor was detected in 15 patients (19%). A significant correlation was seen between c-erbB-2 overexpression and depth of tumor invasion, lymph node involvement, distant metastases, and status of residual tumor after resection (R category, International Union Against Cancer [UICC], 1987). All primary tumors with c-erbB-2 oncoprotein overexpression were aneuploid. In a multivariate Cox regression analysis for overall survival of those 62 patients (78%) whose tumor resection was macroscopically and microscopically complete (R0-UICC), depth of invasion, distant metastases, and c-erbB-2 overexpression were independent prognostic factors. The relative risk of death due to recurrence was nearly identical for patients with either c-erbB-2 oncoprotein overexpression or distant metastases: 4.06 (1.4-11.8) and 3.94 (1.6-9.5). In a multivariate Cox regression analysis of the subgroup of lymph node-negative patients (n = 26), the ploidy status of the primary tumor (defined as near-diploid plus tetraploid versus aneuploid plus multiploid) was the only independent prognostic factor for overall survival.

CONCLUSIONS

These findings demonstrate that DNA ploidy as well as c-erbB-2 oncoprotein overexpression are valuable prognostic factors in patients with adenocarcinoma of Barrett's esophagus after complete tumor resection.

Is the prognosis for Japanese and German patients with gastric cancer really different?

BACKGROUND

Differing survival rates have been reported between patients having undergone surgical intervention for the treatment of gastric carcinoma in Japan and Western industrialized countries. Through the actual availability of the data compiled at a major Japanese medical center (National Cancer Center, Tokyo), it was possible, for the first time, to compare the patients and therapeutic results of a Japanese center (n = 1475) with that of a German center (Department of Surgery, Technical University of Munich, Munich; n = 453).

METHODS

The prognostic factors involving both groups were compared. Survival rates were analyzed in univariate and multivariate fashions.

RESULTS

Some of the examined prognostic factors, such as sex, histologic type, tumor size, and Borrmann classification, were similarly distributed. Differences in frequency were discovered concerning pathologic tumor (pT), node (pN), and metastasis (pM) categories, localization, and age groups. Univariate analysis showed a 2-year survival rate of 88% for all Japanese patients with gastric cancer compared with 58% for German patients. The 5-year survival rates were 77% and 44%, respectively. The difference in the 2-year and 5-year survival rates for both departments may be related to differences in frequencies of several characteristics. In performing the same analysis in a multivariate fashion for the patient populations at both centers, it became clear that an important prognostic factor was the center itself. The survival curves of patients from Tokyo and Munich with the same prognostic factors demonstrate this difference. These differences, however, were small in comparison with those of univariate analysis.

CONCLUSIONS

Using a similar classification of the tumor stage and similar prognostic characteristics, the prognosis for gastric cancer in Japan and Germany may be the same.

Preoperative assessment of lymph node metastases in patients with gastric cancer: evaluation of the Maruyama computer program

The probability of survival of patients with gastric cancer depends upon depth of wall penetration by the primary tumour and metastatic lymph node burden. Radical lymphadenectomy may lead to prolonged survival but with increased morbidity. A computer program from Maruyama, National Cancer Centre, Tokyo enables evaluation of individual survival time and infiltration of lymph nodes. This analysis was applied to a German population. Computer-aided predictions were determined retrospectively using the prognostic factors of sex, age, Borrmann classification, histology, depth of wall penetration, location and diameter of the tumour. Data were collected from 222 patients at the Technical University of Munich (median age 66 years, sex ratio (M:F) 2:1), who had been operated on (72 per cent total gastrectomy, 28 per cent subtotal gastrectomy) for gastric cancer. The predicted results were compared with the postoperative pathological findings. The prediction of node metastases was highly accurate (lymph nodes 13-16, 96 per cent; 7-12, 89 per cent; 1-6, 82 per cent). These computer predictions may provide perioperative information of therapeutic value.

A new concept in the surgical treatment of gastroesophageal reflux

Surgical treatment of gastroesophageal reflux has been thought to depend on the construction of a valve mechanism at the gastroesophageal junction (GEJ). Recently, a silicone prosthesis that does not construct a valve has been introduced, and in preliminary studies in the human, shown to be effective in the treatment of reflux. A precise mode of action has not been demonstrated for the prosthesis. This study was undertaken to investigate the mechanics of the prosthesis and determine its effectiveness in an animal model. Six canine gastroesophageal specimens were excised and the lower esophageal sphincter (LES) simulated by a rubber band placed around the GEJ at a tension calibrated to give 25 mmHg "sphincter" pressure. Circumferential silk ligatures of varying length were then placed on the stomach 3.0 cm distal to the GEJ. With no ligature, the LES opening pressure (LESOP) was 8.0 mmHg, varying to 17.0 mmHg with an 8.0 cm ligature. Further, 24 adult mongrel dogs were randomly divided into four equal groups: controls, circular myomectomy of the LES alone, myomectomy combined with fundoplication, and myomectomy combined with implantation of the silicone antireflux prosthesis. Evaluation included manometry, endoscopy, and histology. Although only the normal sphincter and fundoplication responded physiologically, the prosthesis was just as effective in preventing reflux, as evidenced by reducing acid exposure time of myomectomized dogs from 35.4% to 1.8%, and by preventing endoscopic esophagitis. It was concluded that the silicone antireflux prosthesis acts in the same fashion as the ligature in the model, by interrupting distraction of the LES by gastric wall tension. This concept is an effective method for raising LESOP, treating experimental gastroesophageal reflux, and eliminating the sequelae of reflux. Long-term evaluations of the prosthesis are required.