Quantitative Evaluation of Periodontitis for Predicting the Occurrence of Postoperative Pneumonia After Oncologic Esophagectomy

BACKGROUND

Periodontitis is a biofilm-associated inflammatory periodontal disease associated with postoperative complications after esophagectomy. However, few studies have evaluated the inflammatory burden posed by periodontitis quantitively for patients undergoing oncologic esophagectomy. This study aimed to clarify the relationship between periodontitis and postoperative pneumonia using periodontal inflammatory surface area (PISA).

METHODS

The study analyzed 251 patients who underwent esophagectomy for esophageal cancer. The patients were classified into low-PISA and high-PISA groups according to preoperative PISA, and the relationship between the occurrence and severity of postoperative pneumonia was investigated.

RESULTS

The high-PISA group (n = 69) included more males (P < 0.001) and patients with poor performance status (P < 0.024). Postoperative pneumonia occurred more frequently in the high-PISA group than in the low-PISA group (31.9 % vs. 15.9 %; P = 0.008), whereas the incidences of other complications did not differ significantly. In addition, the incidence of severe pneumonia was significantly higher in the high-PISA group (7.2 % vs. 1.6 %; P = 0.038). In the multivariable analysis for adjustment of preoperative confounders, age older than 70 years (odds ratio [OR], 2.62; P = 0.006), high PISA (OR, 2.45; P = 0.012), and smoking history (OR, 2.78; P = 0.006) were the independent variables predicting postoperative pneumonia.

CONCLUSION

Preoperative higher PISA was significantly associated with the occurrence of overall and severe postoperative pneumonia. The quantitative evaluation of periodontitis using PISA is a useful measure for predicting postoperative pneumonia, and intensive periodontal intervention may contribute to decreasing postoperative pneumonia.

Early postoperative hyperglycemia as a predictor of postoperative infectious complications and overall survival in non-diabetic patients with esophageal cancer

BACKGROUND

Diabetes mellitus (DM) is known to be a risk factor for postoperative infectious complications (PICs). However, the significance of postoperative hyperglycemia in non-DM cases has not been well investigated. We sought to establish whether postoperative hyperglycemia is associated with PICs and survival among patients with esophageal cancer, with a focus on non-DM cases.

METHODS

A total of 430 patients who underwent subtotal esophagectomy for esophageal cancer between 2014 and 2018 were enrolled. Postoperative blood glucose was measured by arterial blood gas test every 8 h from postoperative day (POD) 1 to POD4. The association between hyperglycemia (mean ≥ 200 mg/dl) and PICs or long-term outcomes on each POD was investigated.

RESULTS

There were 53 DM and 377 non-DM cases. PICs occurred in 127 patients. In the multivariate analysis of all cases, PICs were associated with hyperglycemia on POD1 or -2 (odds ratio [OR] = 1.69, 95% CI, 1.05-2.73, P = 0.031 for POD1; OR = 2.55, 95% CI, 1.10-5.93, P = 0.029 for POD 2). Among non-DM cases, the association was more evident, and persisted until POD4 (OR = 1.94, 95% CI, 1.16-3.24, P = 0.012 for POD1; OR = 3.68, 95% CI, 1.28-10.6, P = 0.016 for POD2; OR = 3.07, 95% CI, 1.11-8.51, P = 0.031 for POD4). Survival analyses limited to R0 cases revealed hyperglycemia on POD2 as an independent prognostic factor in all cases (N = 412) [hazard ratio (HR) = 2.61, 95%CI, 1.21-5.63, P = 0.014], with the prognostic impact more evident among non-DM cases (N = 360) (HR = 4.38, 95% CI, 1.82-10.57, P = 0.0010).

CONCLUSION

Postoperative hyperglycemia is associated with PICs and worse survival after esophagectomy, particularly in patients without DM.

McKeown Versus Ivor-Lewis Esophagectomy for Patients with a History of Total Pharyngolaryngectomy: A Comparison Study

BACKGROUND

Oncologic esophagectomy in patients with a history of total pharyngolaryngectomy (TPL) is challenging. There are two different esophagectomy procedures: total esophagectomy with cervical anastomosis (McKeown) and subtotal esophagectomy with intrathoracic anastomosis (Ivor-Lewis). Differences in outcomes between McKeown and Ivor-Lewis esophagectomies for patients with this history remain unclear.

METHODS

We retrospectively reviewed 36 patients with a history of TPL who underwent oncologic esophagectomy and compared the clinical outcomes between the procedures.

RESULTS

Twelve (33.3%) and 24 (66.7%) patients underwent McKeown and Ivor-Lewis esophagectomies, respectively. McKeown esophagectomy was more frequently performed for the supracarinal tumors (P = 0.002). Other baseline characteristics, including the history of radiation therapy, were comparable between the groups. Postoperatively, the incidences of pneumonia and anastomotic leakage were higher in the McKeown group than in the Ivor-Lewis group (P = 0.029 and P < 0.001, respectively). Neither tracheal necrosis nor remnant esophageal necrosis was observed. The overall and recurrence-free survival rates were comparable between the groups (P = 0.494 and P = 0.813, respectively).

CONCLUSIONS

When performing esophagectomy for patients with a history of TPL, if it is oncologically acceptable and technically available, Ivor-Lewis is preferable over McKeown esophagectomy for avoiding postoperative complications.

Prognostic significance of circulating basophil counts in patients who underwent esophagectomy for esophageal cancer

PURPOSE

Recent reports have suggested that basophils influence allergic reactions and tumor immunity. In this study, we aimed to elucidate the association between preoperative circulating basophil (CB) counts and the outcomes of patients who underwent esophagectomy for esophageal cancer.

METHODS

A total of 783 consecutive patients who underwent esophagectomy for esophageal cancer were eligible. The clinicopathological factors and prognoses were compared between the groups stratified by the preoperative counts of CB.

RESULTS

There were more advanced clinical T and N stages in the low CB group than in the high CB group (P = 0.01 and = 0.04, respectively). The incidences of postoperative complications were comparable between the groups. The low CB count was associated with unfavorable overall and recurrence-free survivals (P = 0.04 and 0.01, respectively). In the multivariate analysis, low CB count was one of the independent prognostic factors for poor recurrence-free survival (HR 1.33; 95% CI 1.04-1.70; P = 0.02). In addition, hematogenous recurrence occurred more frequently in the low CB group than in the high CB group (57.6% vs. 41.4%, P = 0.04).

CONCLUSION

A preoperative low CB count was an unfavorable prognosticator in patients who underwent esophagectomy for esophageal cancer.

Postoperative Complications Following Pharyngolaryngectomy With Total Esophagectomy: Comparison Between Cervical and Anterior Mediastinal Tracheostomy

OBJECTIVES

Pharyngolaryngectomy with total esophagectomy (PLTE) is associated with high morbidity and mortality rates. Cervical tracheostomy (CT) is the first choice of tracheostomy, whereas anterior mediastinal tracheostomy (AMT) is sometimes required due to tumor extension or insufficient blood supply to the tracheal tip. However, the differences in the outcomes between CT and AMT after PLTE remain unclear.

METHODS

We retrospectively reviewed 67 patients who underwent PLTE and compared the clinical features and postoperative complications between patients with CT and AMT. The characteristics and the outcomes were compared between the groups stratified by the causes of AMT.

RESULTS

Of the 67 patients, 42 (62.7%) patients underwent PLTE with CT (CT group), whereas 25 (37.3%) underwent PLTE with AMT (AMT group). The AMT group included more cervicothoracic esophageal cancers and had showed an advanced T stage compared to the CT group (P < .01 and .01, respectively). The incidences of pneumonia and surgical site infection (SSI) were more frequent in the AMT group than in the CT group (P = .03 and .01, respectively). Surgery-related mortality was only observed in the AMT group. In the AMT group, 17 (68.0%) and 8 (32.0%) patients underwent AMT because of tumor extension and insufficient supply to the tracheal tip. The latter cases underwent transthoracic esophagectomy more frequently than former cases (P = .03).

CONCLUSION

AMT after PLTE had more postoperative complications and mortality than CT. In cases that may need AMT, a transthoracic approach is preferable over transhiatal esophagectomy to avoid fatal complications when oncologically permissive.

Fecal Microbes Associated with the Outcomes After Esophagectomy in Patients with Esophageal Cancer

BACKGROUND

Although accumulating evidence suggests that an imbalanced gut microbiota leads to cancer progression, few studies demonstrated the implication in patients who underwent oncologic esophagectomy. This study aimed to elucidate the association between gut microbes and the outcomes after oncologic esophagectomy, as well as the host's inflammatory/nutritional status.

METHODS

Overall, 783 consecutive patients who underwent oncologic esophagectomy were eligible. We investigated the microbiota detected by fecal culture tests and then assessed the association between the gut microbiota and patient characteristics, short-term outcomes, and long-term survival.

RESULTS

Seventeen different species could be cultivated. We comprehensively examined the impact of each detected microbe on survival. The presence of Bacillus species (Bacillus sp.; 26.8%) was associated with favorable prognosis on overall and cancer-specific survival (p = 0.02 and 0.02, respectively). Conversely, the presence of Proteus mirabilis (P. mirabilis; 3.4%) was associated with unfavorable overall and recurrence-free survivals (p = 0.02 and < 0.01, respectively). Multivariate analysis showed that the presence of P. mirabilis was one of the independent prognostic factors for poor recurrence-free survival (p < 0.01). Patients with Bacillus sp. had lower modified Glasgow prognostic score and better response to preoperative treatment than those without (p = 0.01 and 0.03, respectively). Meanwhile, patients with P. mirabilis were significantly associated with higher systemic inflammation scores and increased postoperative pneumonia incidence than those without (p = 0.01 and 0.02, respectively).

CONCLUSIONS

Preoperative fecal microbiota was associated with the host's inflammatory and nutritional status and may influence the outcomes after oncologic esophagectomy.

Is Prophylactic Cervical Drainage Effective in Patients Undergoing McKeown Esophagectomy Reconstructed Through the Retrosternal Route with Two-Field Lymphadenectomy?

BACKGROUND

McKeown esophagectomy with two-field lymphadenectomy is the treatment of choice for oncologic esophagectomy. A cervical drain is placed in cases after modern two-field lymph node dissection (M2FD) to provide information on anastomotic leakage. However, the necessity of prophylactic cervical drainage during surgery remains unknown. This study aimed to clarify the clinical significance of cervical drainage in patients who underwent McKeown esophagectomy with M2FD.

METHODS

A total of 293 patients underwent McKeown surgery with two-field lymphadenectomy at our institute between January 2013 and December 2019. We compared the day of drain removal, amount of drainage volume, and the appearance of drainage fluid between patients with and without anastomotic leakage.

RESULTS

McKeown esophagectomy reconstructed through the retrosternal route is 203 patients (69.3%) of all. Nineteen patients (6.5%) experienced anastomotic leakage. The amount of cervical drain discharge was comparable between patients with and without anastomotic leakage. In addition, no purulent or salivary discharge was observed in patients with anastomotic leakage. There was no difference in the median day of drain removal between the groups. The initial clinical findings for the diagnosis of anastomotic leakage were surgical site infection in 10 (52.6%), fever in 5 (26.3%), prolonged inflammation in a blood test in 3 (15.8%), and bloody discharge from the chest tube in 1 (5.3%). There was no mortality due to any cause.

CONCLUSION

A prophylactic cervical drain may not be mandatory in patients with esophageal cancer undergoing McKeown esophagectomy reconstructed through the retrosternal route with two-field lymphadenectomy.

C-reactive protein to prealbumin ratio: a useful inflammatory and nutritional index for predicting prognosis after curative resection in esophageal squamous cell carcinoma patients

PURPOSE

Although C-reactive protein to prealbumin ratio (CPR) can predict the outcomes of several types of cancer surgeries, little is known about the implication of CPR in patients undergoing esophagectomy for esophageal squamous cell carcinoma (ESCC).

METHODS

Between 2009 and 2018, 682 consecutive ESCC patients who underwent curative esophagectomy were enrolled. The clinicopathological factors and prognoses were compared between the groups stratified by preoperative CPR levels. A logistic regression model was used to determine the risk factors of postoperative pneumonia. Survival curves were constructed using the Kaplan-Meier method and compared using the log-rank test. The Cox proportional hazards model was used to elucidate prognostic factors.

RESULTS

There were more elderly patients, more males, and more advanced clinical T and N categories in the high CPR group than in the low CPR group. Also, the incidence of postoperative pneumonia was significantly higher in the high CPR group than in the low CPR group (32.4% vs. 20.3%, p < 0.01). In multivariate analyses, high CPR was one of the independent predictive factors for postoperative pneumonia (OR, 1.71; 95% CI, 1.15-2.54; p < 0.03). Moreover, high CPR was an independent prognostic factor for overall, cancer-specific, and recurrence-free survivals (HR 1.62; 95% CI 1.18-2.23; p < 0.01, HR 1.57; 95% CI 1.08-2.32; p = 0.02, HR 1.42; 95% CI 1.06-1.90; p = 0.02).

CONCLUSION

Preoperative CPR was found to be a useful inflammatory and nutritional indicator for predicting the occurrence of pneumonia and prognosis in patients with ESCC undergoing esophagectomy.

Long-Term Insufficiency of Oral Intake after Esophagectomy; Who Needs Intense Nutritional Support after Esophagectomy?

BACKGROUND

Patients with esophageal cancer are at a high risk of malnutrition after esophagectomy, and nutritional support may at times be required for several months following surgery. In this study, we aimed to clarify the clinical features and preoperative risk factors of patients with long-term insufficiency of oral intake after esophagectomy by evaluating the duration of feeding enterostomy placement.

METHODS

A total of 306 patients who underwent esophagectomy, reconstruction with gastric conduit, and feeding enterostomy creation were retrospectively reviewed. We analyzed the clinical features and preoperative risk factors for long-term placement of feeding enterostomy.

RESULTS

The feeding enterostomy tube was removed less than 90 days after esophagectomy in 234 patients (76.5%) (Short group), whereas 72 patients still needed enteral nutrition after 90 days (23.5%; Long group). Although severe malnutrition was observed more frequently in the long group compared with the short group (p=0.021), overall survival time was comparable between the groups (p=0.239). Multivariate analysis revealed that higher age (OR 1.04; 95% CI, 1.01-1.07; p=0.021), poor performance status(OR 2.94; 95% CI, 1.10-7.87; p=0.032), and lower preoperative body weight(OR 0.96; 95% CI, 0.94-0.99; p=0.009) were the independent variables predicting the long-time placement of feeding enterostomy.

CONCLUSION

Nutritional support via feeding enterostomy for more than 90 days after esophagectomy was required in 23.5% of patients. The elderly, poor performance status, and lower body weight were the independent preoperative factors for predicting the long-term placement of feeding enterostomy.

Current status of robot-assisted minimally invasive esophagectomy: what is the real benefit?

Robot-assisted minimally invasive esophagectomy (RAMIE) for esophageal cancer has been performed increasingly frequently over the last few years. Robotic systems with articulated devices and tremor filtration allow surgeons to perform such procedures more meticulously than by hand. The feasibility of RAMIE has been demonstrated in several retrospective comparative studies, which showed similar short-term outcomes to conventional minimally invasive esophagectomy (cMIE). Considering the number of harvested lymph nodes, RAMIE may be superior to cMIE in terms of left upper mediastinal lymph node dissection. However, whether or not the addition of a robotic system to cMIE can help improve perioperative and oncological outcomes remains unclear. Given the lack of established evidence from randomized controlled trials, we must await the results of ongoing studies to reach any meaningful conclusions. Further advancements in robotic platforms, as well as the reduction in medical expenses, will be essential to demonstrate the real benefit of RAMIE.

Additional Treatment Following Noncurative Endoscopic Resection for Esophageal Squamous Cell Carcinoma: A Comparison of Outcomes between Esophagectomy and Chemoradiotherapy

BACKGROUND

Endoscopic resection (ER) has been widely implemented for cT1N0 esophageal squamous cell carcinoma (ESCC). Additional therapy, including esophagectomy and chemoradiotherapy (CRT), is sometimes required after noncurative ER.

METHODS

We retrospectively reviewed 108 patients who received any additional treatment following noncurative ER (positive vertical margins, lymphovascular invasion, or invasion depth of submucosa or more), and compared the short- and long-term outcomes between the two treatment modalities.

RESULTS

Of 108 patients, 56 underwent esophagectomy (E group), and 52 received CRT (CRT group). A positive vertical margin was observed in 17 (14.8%) patients and high risks of occult lymph node metastasis were observed in 91 (85.2%) patients, as well as lymphovascular invasion in 35 (32.4%) patients, invasion depth of the submucosa or more in 27 (25.0%) patients, and both in 29 (26.9%) patients. The E group patients were significantly younger (p = 0.046) and tended to present with larger tumors than those in the CRT group (p = 0.057). Lymphatic invasion was more frequent in the E group (p = 0.019), and, furthermore, one treatment-related death was observed in the E group. There were no significant differences between the groups in overall and disease-specific survival (p = 0.406 and 0.151, respectively), however, recurrence was only observed in the CRT group.

CONCLUSION

Both esophagectomy and CRT are safe and effective as additional treatments after noncurative ER in patients with ESCC. Esophagectomy is oncologically safe, whereas a risk of postoperative morbidity and mortality remains. Although the adverse events are acceptable, CRT has a certain degree of risk of disease recurrence.

Influence of Damaged Stomach on Anastomotic Leakage following Cervical Esophagogastrostomy in Patients with Esophageal Cancer

BACKGROUND

Anastomotic leakage (AL) is one of the most common complications after esophagectomy. Although some patients have a history of peptic ulcers or other prior stomach diseases, the influence of a damaged stomach (DS) on AL incidence remains unclear. Therefore, we investigated the association between DS and incidence of AL in patients who underwent esophagectomy.

PATIENTS AND METHODS

Between 2015 and 2019, a total of 447 consecutive patients who underwent cervical esophagogastrostomy using gastric tube following esophagectomy were enrolled. DS was defined on the basis of endoscopic findings of ulcers or scars due to medical history or prior treatment. We compared the incidence of AL between patients with DS and those with a healthy stomach (HS). Univariate and multivariate logistic regression analyses were used to identify factors that could predict AL incidence.

RESULTS

Fifty-one patients (11.4%) had DS. Causes of DS included peptic ulcer (n = 36), endoscopic resection for early gastric cancer (n = 9), percutaneous endoscopic gastrostomies (n = 5), and post-chemotherapy scar for gastric malignant lymphoma (n = 1). Overall, AL occurred in 35 patients (7.8%). The incidence of AL in the DS group was significantly higher than in the HS group (15.7 vs. 6.8%, p = 0.03). DS was one of the independent predictive factors for AL (odds ratio, 2.75; 95% confidence interval, 1.10-6.92; p = 0.03) on multivariate analysis. Further, the diseases in the lower third of the conduit were associated with AL.

CONCLUSIONS

Presence of DS can predict AL in patients who underwent cervical esophagogastrostomy after esophagectomy.

Airflow Limitation Predicts Postoperative Pneumonia after Esophagectomy

BACKGROUND

Chronic obstructive pulmonary disease (COPD) is known to be a risk factor of pneumonia after esophagectomy. In this study, we investigated the relationship of airflow limitation with the occurrence and the severity of pneumonia in esophageal cancer patients who underwent esophagectomy.

METHODS

We enrolled 844 patients who underwent curative esophagectomy between 2009 and 2018. The airflow limitation was evaluated using the percent-predicted forced expiratory volume at 1 s (%FEV1) with spirometry.

RESULTS

There were 597 (70.7%), 141 (16.7%), 68 (8.1%), and 38 patients (4.5%) with %FEV1 of ≥ 90%, 80-90%, 70-80%, and < 70% categories, respectively. One hundred and ninety-one patients (22.6%) occurred pneumonia, and the incidences of pneumonia in each category of patients were 18.8%, 28.4%, 29.4%, and 50.0%, respectively. In multivariate analysis, the categories of 80%-90%, 70-80%, and < 70% were significantly associated with a higher incidence of postoperative pneumonia (OR 1.57; 95% CI 1.02-2.43, OR 1.87; 95% CI 1.04-3.36, OR 3.34; 95% CI 1.66-6.71, respectively), with the %FEV1 category of ≥ 90% as reference. The incidence of severe pneumonia of Clavien-Dindo grade III or higher was also significantly associated with the %FEV1. In patients without COPD, the incidence of pneumonia was significantly higher in those with %FEV1 < 90% than in those with %FEV1 ≥ 90% (32.2% versus 17.5%, p < 0.001).

CONCLUSIONS

The airflow limitation can help predict the occurrence of pneumonia after esophagectomy in patients with and without COPD. Exclusive preventive measures should be considered in patients with reduced %FEV1 undergoing esophagectomy.

Clinical Significance of Serum Squamous Cell Carcinoma Antigen for Patients with Recurrent Esophageal Squamous Cell Carcinoma

BACKGROUND

Squamous cell carcinoma antigen (SCC-Ag) is a widely used tumor marker of SCC. However, the clinical significance of serum SCC-Ag levels in recurrent esophageal SCC (ESCC) remains unclear. This study aimed to investigate the clinical relevance of serum SCC-Ag levels in patients with recurrent ESCC after surgery.

METHODS

This study retrospectively analyzed 208 patients who experienced recurrence after curative resection for ESCC. Serum SCC-Ag levels at the time of recurrence were collected from the patients' records. The patients were classified into tertiles based on the serum SCC-Ag values (low, middle, and high), and the clinical characteristics and outcomes were compared among the groups.

RESULTS

Significant differences in sex (p = 0.001), pathologic T (p = 0.034), and N stages of primary cancer (p = 0.015) were observed among the groups. Although the recurrence patterns did not differ significantly, a high SCC-Ag was significantly associated with multiple recurrences (p = 0.019). The high-SCC-Ag group patients demonstrated a shorter time to recurrence than the other groups (p = 0.044). The SCC-Ag levels were significantly associated with overall survival after recurrence (p = 0.036). Multivariate analysis showed that serum SCC-Ag value at recurrence was an independent poor prognosticator (p = 0.031).

CONCLUSION

Elevated serum SCC-Ag levels at recurrence were significantly associated with a reduced time to recurrence, multiple recurrences, and a poor prognosis after recurrence. An alternative to the current standard treatment is required to improve the outcome for patients with high serum SCC-Ag levels at recurrence.

Significance of D-dimer-based screening for detecting pre-operative venous thromboembolism in patients with esophageal cancer after neoadjuvant chemotherapy

BACKGROUND

A limited number of studies have evaluated the risk of developing venous thromboembolism (VTE) during neoadjuvant chemotherapy (NAC) for esophageal cancer and the efficacy of a D-dimer (DD)-based VTE screening (DBS). In the present study, we aimed to clarify the changes in DD levels and the effectiveness of DBS.

METHODS

We included 234 patients who underwent esophagectomy between August 2017 and July 2019 and evaluated the changes in DD levels before and after NAC. We had introduced the DBS strategy in August 2018, in which we recommended ultrasound (US) of the leg or computed tomography (CT) with the deep vein thrombosis (DVT) protocol. We then evaluated the incidence of VTE detected by DBS compared with that in the clinical practice as a control.

RESULTS

The DD levels were significantly increased after NAC. After the introduction of DBS, the proportion of patients who underwent US and CT after NAC was significantly increased. VTE was more frequently detected in the DBS group than in the control group (16.7% vs. 3.0%, p < 0.02) among patients who underwent NAC. Pulmonary embolism (PE) during NAC was also more frequent in the DBS than in the control group (7.6% vs. 1.5%, p = 0.06). The DD levels after NAC were significantly higher in patients with VTE than in those without.

CONCLUSIONS

NAC for patients with esophageal cancer increases the risk of developing VTE. DBS is useful in identifying asymptomatic DVT and may contribute to improving patient safety.

Comparison of Outcomes Between Additional Esophagectomy After Noncurative Endoscopic Resection and Upfront Esophagectomy for T1N0 Esophageal Squamous Cell Carcinoma

BACKGROUND

Esophagectomy with lymph node dissection is a choice of additional treatment after noncurative endoscopic resection (ER) of T1N0 esophageal squamous cell carcinoma (ESCC). The efficacy and safety of esophagectomy in this situation remain unclear when compared with upfront esophagectomy.

METHODS

We investigated the short- and long-term outcomes of 321 patients with clinical T1N0M0 ESCC who underwent curative esophagectomy, and compared the status of lymph node metastasis, surgical results, and the prognosis between the ER and non-ER groups.

RESULTS

The ER group consisted of 57 patients (17.8%), while the non-ER group consisted of 264 patients (82.2%). The incidence of lymph node metastasis was not significantly different between the ER (24.6%) and non-ER groups (30.7%), and there was no significant difference in surgical outcomes between the groups. The distribution of metastatic lymph nodes was very similar between the groups. However, 13 of 14 patients (93%) with lymph node metastasis in the ER group and 63 of 82 patients (77%) with lymph node metastasis in the non-ER group had pN1 disease, while the remaining 18 patients (23%) with lymph node metastasis in the non-ER group had pN2 or N3 disease. Overall and relapse-free survival rates were significantly better in the ER group than in the non-ER group (p < 0.05 and p < 0.01, respectively). To date, no patients in the ER group experienced disease recurrence.

CONCLUSIONS

Additional esophagectomy is a safe and effective treatment modality for patients after noncurative ER.

Synthesis and structural investigation of a series of mannose-containing oligosaccharides using mass spectrometry

A series of compounds associated with naturally occurring and biologically relevant glycans consisting of α-mannosides were prepared and analyzed using collision-induced dissociation (CID), energy-resolved mass spectrometry (ERMS), and ¹H nuclear magnetic resonance spectroscopy. The CID experiments of sodiated species of disaccharides and ERMS experiments revealed that the order of stability of mannosyl linkages was as follows: 6-linked > 4-linked ≧ 2-linked > 3-linked mannosyl residues. Analysis of linear trisaccharides revealed that the order observed in disaccharides could be applied to higher glycans. A branched trisaccharide showed a distinct dissociation pattern with two constituting disaccharide ions. The estimation of the content of this ion mixture was possible using the disaccharide spectra. The hydrolysis of mannose linkages at 3- and 6-positions in the branched trisaccharide revealed that the 3-linkage was cleaved twice as fast as the 6-linkage. It was observed that the solution-phase hydrolysis and gas-phase dissociation have similar energetics.

Synthesis and enzymatic evaluation of five-membered iminocyclitols and a pseudodisaccharide

Described here are the synthesis of five-membered iminocyclitols with galacto-configuration and a pseudodisaccharide, and their inhibitory activities against beta-galactosyltransferase, beta-galactosidase and alpha-mannosidase.

Enzymatic assay of galactosyltransferase by capillary electrophoresis

The kinetic parameters of a galactosyltransferase-catalyzed reaction were determined for the first time using capillary zone electrophoresis (CZE) using the methylumbelliferyl (MU) glycoside of N-acetylglucosamine as the acceptor molecule. The CZE was performed using borate buffer and the enzymatic transformations were monitored at 214 nm. The kinetic parameters obtained for MU-GlcNAc were Km = 35.9 microM and Vmax = 7.5 micromol/min/mg, and those for UDP-Gal were Km = 115.3 microM and Vmax = 12.4 micromol/min/mg. A representative inhibition assay was also carried out using UDP as an inhibitor to give the Ki value of 83.9 microM against MU-GlcNAc. The structure of the synthetic product was also confirmed using 1H NMR spectroscopies after isolation by simple chromatography.