Overexpression of PFTK1 predicts resistance to chemotherapy in patients with oesophageal squamous cell carcinoma

Background:

Recently, PFTK1 was identified as a member of the cyclin-dependent kinase family; however, its expression and clinical significance in oesophageal squamous cell carcinoma (ESCC) have not been evaluated.

Methods:

PFTK1 expression was initially examined by expression microarray in 77 ESCC patients. Using independent samples of 223 patients, PFTK1 expression was evaluated immunohistochemically to assess the relationship between expression and various clinicopathological parameters. The association between PFTK1 and the response to chemotherapy was also investigated in pretreatment samples of 85 patients who received chemotherapy as first treatment.

Results:

Significant upregulation of PFTK1 expression was noted in ESCC compared with normal epithelium. PFTK1 expression was positive in 51.6% (115 out of 223) of the tumours, but did not correlate with any clinicopathological parameter. The 5-year overall survival rate was poorer in patients positive for PFTK1 (43.6%) than those with negative expression (66.2%, P<0.001). Uni- and multivariate analyses identified PFTK1 as an independent marker of prognosis (RR=2.428, 95% CI=1.615–3.711, P<0.001). Out of 85 biopsy samples, 40 (47.1%) tumours showed PFTK1-positive expression, and the response rate to chemotherapy was significantly lower than PFTK1-negative tumours (27.9% vs 72.1%, P<0.001).

Conclusion:

PFTK1 is not only useful as a prognostic marker, but also as a predictor of the response to chemotherapy.

The significance of abdominal para-aortic lymph node metastasis in patients with lower thoracic esophageal cancer

Para-aortic lymph node (PALN) recurrence is often seen in patients with lower thoracic esophageal cancer treated by esophagectomy with extended lymph node dissection. However, the clinicopathological characteristics of patients with PALN metastasis and the significance of PALN dissection are unknown. A total of 283 patients with lower thoracic esophageal cancer underwent esophagectomy with lymphadenectomy at our hospital between April 1984 and March 2007. Among these 283 patients, 60 patients were enrolled in this retrospective study according to following criteria: (i) clinical T2 to T4 tumor, (ii) no clinical PALN metastasis, and (iii) received PALN dissection. PALN dissection was indicated by a tumor depth of at least T2 and no severe complications. The clinicopathological data, recurrence pattern, and overall survival were compared between patients with PALN and without PALN metastasis. The mean length of surgery was 587 min and the mean blood loss was 1383 mL. The morbidity was 33.3% and mortality was 5% in this series. Sixteen patients (26.7%) had PALN metastasis; these showed significantly more lymph node metastases (15.8 ± 13.2 vs. 3.0 ± 3.2, P < 0.0001) and significantly worse survival rates (53.3% vs. 79.9% at 1 year, 6.7% vs. 62.0% at 3 years, P < 0.0001) than patients without PALN metastasis. The incidence of lymph node recurrence (P < 0.0001) and hematogenous recurrence (P= 0.0487) was also higher in patients with PALN metastasis than in patients without PALN metastasis. Among the 16 patients with PALN metastasis, a univariate analysis revealed total number of metastatic nodes < 8 (P= 0.0325) to be a significant prognostic factor. A multivariate logistic regression analysis of the regional lymph nodes identified the invasion of the lower mediastinal nodes (hazard ratio = 6.120) and retroperitoneal nodes (hazard ratio = 15.167) to be significantly correlated with PALN metastasis. PALN metastasis is suggested to be related to the systemic spread of lymphatic metastasis even in lower thoracic esophageal cancer. PALN dissection for pathological PALN(+) patients should not be performed. It remains to be determined in future prospective studies whether patients without pathological PALN metastasis, but showing PALN micrometastasis, could achieve improved survival with PALN dissection.

Ten cases of gastro-tracheobronchial fistula: a serious complication after esophagectomy and reconstruction using posterior mediastinal gastric tube

Gastro-tracheobronchial fistula (GTF) is a rare but life-threatening complication specifically observed after esophagectomy and reconstruction using posterior mediastinal gastric tube. Ten cases of GTF were encountered in three hospitals in 2000-2009. Their clinicopathological, surgical, and postoperative care are summarized, together with a review of previously reported cases. GTF was classified as anastomotic leakage (n= 5), gastric necrosis (n= 4), and gastric ulcer type (n= 1). The anastomotic leakage type appeared about 2 weeks (postoperative day [POD]: 8-35) after esophagectomy, was located in the cervical or higher thoracic trachea. Breathing and pneumonia were controlled by tracheal tube placed in the distal of fistula. The gastric necrosis type was noted in patients who developed necrosis of the upper part of the gastric tube and abscess formation behind the tracheal wall, at POD 20-36 around the carina, the site of pronounced ischemia. Due to the large fistula around the carina, emergency surgery with muscle patch repair was frequently required for the control of aspiration pneumonia. Patients of the gastric ulcer type had peptic ulcer in the lesser curvature of the gastric tube, which perforated into the right bronchus long after surgery (POD 630). With respect to tracheobronchial factors, preoperative chemoradiation (three cases) and pre-tracheal node dissection (three cases) tended to increase the risk of GTF. Closure of GTF by surgery (muscle patch repair) was successful in four cases and by nonsurgical treatment in three cases. In one case, stable oral intake was achieved by bypass operation without closure of GTF. Hospital death occurred in three cases. Understanding the pathogenesis and treatment options of GTF is important for surgeons who deal with esophageal cancer.

Rapamycin causes upregulation of autophagy and impairs islets function both in vitro and in vivo

Autophagy is a lysosomal degradation process of redundant or faulty cell components in normal cells. However, certain diseases are associated with dysfunctional autophagy. Rapamycin, a major immunosuppressant used in islet transplantation, is an inhibitor of mammalian target of rapamycin and is known to cause induction of autophagy. The objective of this study was to evaluate the in vitro and in vivo effects of rapamycin on pancreatic β cells. Rapamycin induced upregulation of autophagy in both cultured isolated islets and pancreatic β cells of green fluorescent protein-microtubule-associated protein 1 light chain 3 transgenic mice. Rapamycin reduced the viability of isolated β cells and down-regulated their insulin function, both in vitro and in vivo. In addition, rapamycin increased the percentages of apoptotic β cells and dead cells in both isolated and in vivo intact islets. Treatment with 3-methyladenine, an inhibitor of autophagy, abrogated the effects of rapamycin and restored β-cell function in both in vitro experiments and animal experiments. We conclude that rapamycin-induced islet dysfunction is mediated through upregulation of autophagy, with associated downregulation of insulin production and apoptosis of β cells. The results also showed that the use of an autophagy inhibitor abrogated these effects and promoted islet function and survival. The study findings suggest that targeting the autophagy pathway could be beneficial in promoting islet graft survival after transplantation.

Results of a national survey on laparoscopic bariatric surgery in Japan, 2000-2009

INTRODUCTION

In Japan, laparoscopic bariatric surgery has not been popular until recently because morbidly obese patients were infrequently encountered previous and Japanese health insurance does not cover this type of surgery. In 2010, the Japan Research Society for Endoscopic and Laparoscopic Treatments of Obesity undertook the first nationwide survey on laparoscopic bariatric surgery to evaluate its current status and outcomes.

METHODS

A mail survey was sent to the society's 64 member institutions, which included almost all institutions in Japan actively performing laparoscopic gastrointestinal surgery.

RESULTS

From 2000 to 2009, 340 laparoscopic bariatric procedures, in total, were performed in nine of the 64 institutions (14%). The most popular procedure was laparoscopic Roux-en-Y gastric bypass (LRYGB, n=147), second was laparoscopic sleeve gastrectomy (LSG, n=102), and third was laparoscopic adjustable gastric banding (LAGB, n=55). However, the number of LRYGB procedures has decreased while the number of LSG procedures has rapidly increased. Total morbidity rates were 12.2% for LRYGB, 10.9% for LAGB, and 7.8% for LSG. Percent excess weight loss was 78% at 5 years after LRYGB, 52% at 4 years after LAGB, and 68% at 2 years after LSG. Although the bariatric procedures frequently resolved or improved obesity-related comorbidities, LRYGB appears to be superior to LAGB, as was previously reported.

CONCLUSION

The first nationwide survey of laparoscopic bariatric surgery in Japan clearly showed the current status and outcomes of this group of procedures. The Japanese results appear to be comparable to similarly undertaken surveys in Europe and the USA.

Ep-CAM is a significant prognostic factor in pancreatic cancer patients by suppressing cell activity

The identification of molecular markers useful for predicting prognosis in pancreatic cancer patients is crucial for advances in disease management. The epithelial cell adhesion molecule (Ep-CAM) is known to express in most epithelial malignancies and was reported as a tumor marker or a candidate of molecular targeting therapy. However, the clinical significance of Ep-CAM expression in pancreatic cancer is not well-known. We determined the difference of malignant potential between parental and Ep-CAM-transfected pancreatic cancer cell lines by using proliferation, invasion and migration assay. Furthermore, we determined the relationship between tumoral Ep-CAM expression of resected specimens and clinical prognosis in 95 pancreatic cancer patients receiving radical surgery at two different cancer centers. One of the three Ep-CAM-transfected cell lines showed significantly low proliferation rate compared with the parental cell, while there was no difference in the other two cell lines. In invasion and migration assays, Ep-CAM-transfected cells showed significantly lower malignant potential than parental in all of the three cell lines. In 95 pancreatic cancer patients, 47 patients showed high-Ep-CAM expression, while 48 patients showed low, and there was no difference of clinicopathological features between Ep-CAM high and low-expression group. High-Ep-CAM expression group showed significantly good prognosis in overall survival (3-year survival; 56.2 versus 19.2%, P=0.0018) as well as in disease-free survival (3-year survival; 40.3 versus 14.4%, P=0.038) compared with low-expression group. In addition, the impact of Ep-CAM was observed strongly in LN-negative group when the influence of Ep-CAM was examined with dividing patients into LN-positive and negative group. In multivariate analysis, Ep-CAM expression was one of the independent prognostic factors as well as histology and lymph node metastasis. Ep-CAM expression was found to be related to the suppression of pancreatic cancer cell activity and the good prognosis in pancreatic cancer patients receiving the curative resection.

Randomized controlled trial comparing Billroth-I and Roux-en-Y reconstruction in distal gastrectomy for gastric cancer

65

Background: In distal subtotal gastrectomy for gastric cancer, Billroth-I (B-I) reconstruction has been performed predominantly in Japan, while increasing number of surgeons chose Roux-en-Y (R-Y) reconstruction recently. To evaluate the safety and superiority of R-Y we conducted a multi-institutional prospective randomized controlled trial.

Methods: Gastric cancer patients who underwent distal gastrectomy were randomized to B-I or R-Y intraoperatively. The primary endpoint was the ratio of body weight loss 1 year after surgery, the secondary endpoints were the incidence of delayed gastric emptying (DGE) and postoperative morbidity.

Results: Between Aug 2005 and Dec 2008, a total of 332 patients were enrolled and 163 patients were assigned to B-I and 169 patients to R- Y. The patient's characteristics were well balanced between the two groups. The operation time was significantly longer in R-Y than B-I (median 180 min in B-I vs 214 min in R-Y, p < 0.0001). The postoperative morbidity was 14 patients (8.6%) in B-I and 23 (13.6%) in R-Y (p = 0.14), the incidence of DGE was 7 (4.3%) in B-I vs 16 (9.5%) in R-Y (p = 0.06), and the hospital stay after surgery was 14.1days in B-I vs 16.4 days in R-Y (p = 0.02). There was no hospital death in the two groups. The body weight loss at 1 year after surgery compared to preoperation was -5.4kg (-9.1%) in B-I vs -6.2kg (-9.8%) in R-Y (p = 0.11).

Conclusions: The advantage of R- Y reconstruction compared to B-I was not proved in terms of postoperative morbidity either the body weight loss 1 year after surgery.

No significant financial relationships to disclose.

Randomized controlled trial of omental bursectomy for resectable cT2-3 gastric cancer

72

Background: Omental bursectomy, a traditional surgical procedure to dissect the peritoneal lining covering the pancreas and the anterior plane of the transverse mesocolon, has often been performed against resectable gastric cancer. We have conducted a multi- institutional randomized controlled trial to elucidate the safety and usefulness of this procedure.

Methods: Patients with cT2 or cT3 gastric adenocarcinoma were intraoperatively randomized to radical gastrectomy plus D2 lymphadenectomy either with or without bursectomy. The primary endpoint was overall survival (OS). The planned sample size was 464, with an alpha error of 0.05 and statistical power of 80% to detect a 10% margin of non-inferiority for the non-bursectomy group. The first interim analysis was conducted on Sep 2008, and we decided the preliminary data release according to Korn's proposal (J Clin Oncol. 2005).

Results: Between Jul 2002 and Jan 2007, a total of 210 patients were randomized to either the bursectomy group or the non-bursectomy group. Background characteristics were well balanced. Intraoperative blood loss was greater in the bursectomy group than in the non-bursectomy group (median, 475 mL vs. 350 mL, p=0.047), while other surgical factors did not vary significantly. The overall morbidity rate was 14%, the same between two groups. The hospital mortality rate was 0.95%; one patient per group. In the first interim analysis, the 3-year OS were 86% in bursectomy group and 79% in non-bursectomy group, and the hazard ratio was 1.55 (95% CI: 0.84-2.84). The non-bursectomy group had more patients with peritoneal recurrences than the bursectomy group (14% vs. 8%).

Conclusions: Experienced surgeons could safely perform a D2 gastrectomy with an additional bursectomy. First interim analysis suggested the survival advantage of omental bursectomy for cT2-3 gastric cancer patients. Final analysis will be conducted in 2012.

No significant financial relationships to disclose.

Role of multidrug resistance protein 2 (MRP2) in chemoresistance and clinical outcome in oesophageal squamous cell carcinoma

BACKGROUND

Although multidrug resistance protein 2 (MRP2) confers chemoresistance in some cancer types, its implication on oesophageal squamous cell carcinoma (ESCC) remains unclear.

METHODS

We evaluated MRP2 expression by immunohistochemistry and RT-PCR using 81 resected specimens from ESCC patients who did or did not receive neo-adjuvant chemotherapy (NACT), including 5-fluorouracil, doxorubicin, and cisplatin (CDDP). Correlation between MRP2 expression and response to chemotherapy was also examined in 42 pre-therapeutic biopsy samples and eight ESCC cell lines.

RESULTS

MRP2-positive immunostaining was more frequently observed in ESCCs with NACT than in those without NACT (27.3 vs 5.4%). The MRP2-positive patients showed poorer prognosis than MRP2-negative patients (5-year survival rate, 25.6 vs 55.7%). Concordantly, ESCC with NACT showed 2.1-fold higher mRNA expression of MRP2 than those without NACT (P=0.0350). In pre-therapeutic biopsy samples of patients with NACT, non-responders showed 2.9-fold higher mRNA expression of MRP2 than responders (P=0.0035). Among the panel of ESCC cell lines, TE14 showed the highest MRP2 mRNA expression along with the strongest resistance to CDDP. Inhibition of MRP2 expression by small-interfering RNA reduced chemoresistance to CDDP.

CONCLUSION

Our data suggested that MRP2 is one of molecules, which regulate the sensitivity to chemotherapy including CDDP in advanced ESCC patients.

Abnormal expression of TRIB3 in colorectal cancer: a novel marker for prognosis

BACKGROUND

TRIB3 is a human homologue of Drosophila tribbles. Previous studies have shown that TRIB3 controls the cell growth through ubiquitination-dependent degradation of other proteins, whereas its significance in the prognosis of colorectal cancer (CRC) is not yet fully understood.

MATERIALS

This study comprised 202 patients who underwent surgery for CRC, as well as 22 cell lines derived from human gastrointestinal cancer. The correlation of gene expression with clinical parameters in patients was assessed. The biological significance was evaluated by knockdown experiments in seven colorectal cancer cell lines.

RESULTS

A total of 20 cancer cell lines (90.9%) expressed the TRIB3 gene. The assessment in surgical specimens indicated that the gene expression was significantly higher in the cancerous region than in the marginal non-cancerous region. Patients with high TRIB3 expression were statistically susceptible to a recurrence of the disease, and showed poorer overall survival than those with low expression. The assessment of TRIB3 knockdown in five cell lines showed that small interfering RNA (siRNA) inhibition resulted in a statistically significant reduction in cell growth.

CONCLUSION

These data strongly suggest the usefulness of TRIB3 as a marker for predicting the prognosis of CRC patients, showing a basis for the development of effective treatments for CRC.

Cytokeratins 18 and 8 are poor prognostic markers in patients with squamous cell carcinoma of the oesophagus

Background:

Cytokeratins (CKs) are structural marker proteins specific for epithelial cells. However, recent studies indicate their involvement in cancer progression.

Methods:

We evaluated CK18 and its filament partner, CK8 expression, by immunohistochemistry in 210 resected specimens from patients with oesophageal squamous cell carcinoma (OSCC). We also analysed the relationship between their expression and various clinicopathological parameters including prognosis.

Results:

Neither CK18 nor CK8 was expressed in non-cancerous squamous epithelium whereas proper oesophageal glands expressed both CKs. Ninety (42.9%) tumours were CK18 positive and 85 (40.5%) CK8 positive, and the concordance rate for immunohistochemical classification for CK18 and CK8 was 82.4%. CK18 expression correlated with poorly differentiated tumours, use of neo-adjuvant chemotherapy, and advanced stage. Prognosis of patients with CK18-positive tumours was poorer than that of patients with negative OSCC (P<0.001). A similar trend was noted for CK8 expression. Multivariate analysis identified pT (P=0.020), pN number (P=0.001), and CK18 expression (P=0.004) as independent prognostic factors. CK18 expression in 83 pretreatment biopsy specimens was detected in 47 cases (56.6%) and also correlated with prognosis (P=0.045).

Conclusion:

CK18/CK8 expression correlated with progression of OSCC. The significant correlation with prognosis and stable expression in biopsy specimen suggest usefulness of CK18 in selection of treatment strategies for OSCC.

Early Surgeryfor Treatment of Spontaneous Hemopneumothorax

Purpose:

Spontaneous hemopneumothorax (SHP) is a rare life threatening disorder. We retrospectively investigated patients with SHP who were treated with video- assisted thoracic surgery (VATS), and report our results.

Methods:

From January 1993 to July 2006, 239 patients with spontaneous pneumothorax were treated, among whom 11 (4.6%) were diagnosed with SHP.

Results:

All 11 patients had a collapsed lung condition worse than moderate and a chest tube inserted, of whom 10 underwent an emergency operation. The points of hemorrhaging, each of which were in the apical portion of the lung, were easily revealed during VATS, and we were able to distinguish between brisk flow and seepage. Hemostasis was acquired using VATS in all surgery cases, while the other was treated with tube drainage. The single patient who did not undergo surgical treatment had recurrent spontaneous pneumothorax 3 months later.

Conclusion:

It is important to perform surgery for SHP at the appropriate time. VATS was found to be an easily performed and safe procedure for initial treatment in patients with active hemorrhaging and massive blood clotting in the thorax. The long-term outcome of our patients with early surgical indication was excellent and we recommend early surgical treatment for SHP.

Activation of Wnt/beta-catenin signalling pathway induces chemoresistance to interferon-alpha/5-fluorouracil combination therapy for hepatocellular carcinoma

Type I IFN receptor type 2 (IFNAR2) expression correlates significantly with clinical response to interferon (IFN)-α/5-fluorouracil (5-FU) combination therapy for hepatocellular carcinoma (HCC). However, some IFNAR2-positive patients show no response to the therapy. This result suggests the possibility of other factors, which would be responsible for resistance to IFN-α/5-FU therapy. The aim of this study was to examine the mechanism of anti-proliferative effects of IFN-α/5-FU therapy and search for a biological marker of chemoresistance to such therapy. Gene expression profiling and molecular network analysis were used in the analysis of non-responders and responders with IFNAR2-positive HCC. The Wnt/β-catenin signalling pathway contributed to resistance to IFN-α/5-FU therapy. Immunohistochemical analysis showed positive epithelial cell adhesion molecule (Ep-CAM) expression, the target molecule of Wnt/β-catenin signalling, only in non-responders. In vitro studies showed that activation of Wnt/β-catenin signalling by glycogen synthesis kinase-3 inhibitor (6-bromoindirubin-3′-oxime (BIO)) induced chemoresistance to IFN-α/5-FU. BrdU-based cell proliferation ELISA and cell cycle analysis showed that concurrent addition of BIO and IFN-α/5-FU significantly to hepatoma cell cultures reduced the inhibitory effects of the latter two on DNA synthesis and accumulation of cells in the S-phase. The results indicate that activation of Wnt/β-catenin signalling pathway induces chemoresistance to IFN-α/5-FU therapy and suggest that Ep-CAM is a potentially useful marker for resistance to such therapy, especially in IFNAR2-positive cases.

Rapamycin induces autophagy in islets: relevance in islet transplantation

Islet transplantation can provide insulin independence in patients with type 1 diabetes mellitus. However, islet allograft recipients exhibit a gradual decline in insulin independence, and only 10% do not require insulin at 5 years. This decline may reflect drug toxicity to islet beta cells. Rapamycin, a central immunosuppressant in islet transplantation, is a mammalian target of rampamycin inhibitor that induces autophagy. The relative contributions of autophagy in transplanted islets are poorly understood. Therefore, in the present study we sought to evaluate the effects of rapamycin on islet beta cells. Rapamycin treatment of islets resulted in accumulation of membrane-bound light chain 3 (LC3-II) protein, an early marker of autophagy. In addition, rapamycin treatment of isolated islets elicited not only reduction of viability but also downregulation of in vitro potency. To further examine the occurrence of autophagy in rapamycin-treated islets, we used GFP (green fluorescent protein)-LC3 transgenic mice that express a fluorescent autophagosome marker. The GFP-LC3 signals were markedly increased in rapamycin treated islets compared with control islets. In addition, to show improvement by blockade of autophagic signaling, islets were treated with rapamycin in the presence of 3-methyladenine, which inhibits autophagy. Thereafter, both islet viability and islet potency were dramatically improved. The number of GFP-LC3 dots clearly increased after 3-MA treatment. Thus, rapamycin treatment of islets induces autophagy in vitro. This phenomenon may contribute to the progressive graft dysfunction of transplanted islets. Therapeutically targeting this novel signaling may yield significant benefits for long-term islet survival.

Adenovirus-mediated gene expression of the human c-FLIP(L) gene protects pig islets against human CD8(+) cytotoxic T lymphocyte-mediated cytotoxicity

Cell-mediated immunity, especially of human CD8+ cytotoxic T lymphocytes (CTLs) is believed to have an important role in the long-term survival of pig islet xenografts. Protection against human CD8+ CTL cytotoxicity may reduce the direct damage to pig islets and enable long-term xenograft survival in pig-to-human islet xenotransplantation. We have previously reported that c-FLIP(S/L) genes, which are potent inhibitors of death receptor-mediated proapoptotic signals through binding competition with caspase-8 for recruitment to the Fas-associated via death domain (FADD), markedly suppress human CD8+ CTL-mediated xenocytotoxicity. In addition, the cytoprotective effects of c-FLIP(L) seem to be significantly stronger than those of c-FLIP(S). Accordingly, in the present study, expression of c-FLIP(L) was induced in intact pig islets by adenoviral transduction. Consequently, the cytoprotective capacity of the transgene in pig islets was examined in in vitro and in vivo exposure to human CD8+ CTLs. Cells from untransduced islets or mock islets were sensitive to CD8+ CTL-mediated lysis (59.3% +/- 15.9% and 64.0% +/- 8.9% cytotoxicity, respectively). In contrast, cells from pig islets transduced with the c-FLIP(L) gene were markedly protected from lysis (30.5% +/- 3.5%). Furthermore, prolonged xenograft survival was elicited from pig islets transduced with this molecule as assessed using an islet transplant model using the rat kidney capsule. Thus, these data indicate that intact pig islets can be transduced to express c-FLIP(L) with adenovirus. Pig islets expressing c-FLIP(L) are significantly resistant to human CTL killing and further exhibit beneficial effects to prolong xenograft survival.

Intracellular and extracellular remodeling effectively prevents human CD8(+)cytotoxic T lymphocyte-mediated xenocytotoxicity by coexpression of membrane-bound human FasL and pig c-FLIP(L) in pig endothelial cells

Human CD8(+) cytotoxic T lymphocyte (CTL)-mediated cytotoxicity, which participates in xenograft rejection, is mediated mainly by the Fas/FasL apoptotic pathway. We previously developed methods to inhibit human CTL xenocytotoxicity by extracellular remodeling using overexpression of membrane-bound human FasL on pig xenograft cells, and by intracellular blockade of death receptor-mediated apoptotic signals, such as the Fas/FasL pathway using the pig c-FLIP(L) molecule. To investigate the cooperative effects of both membrane-bound FasL and pig c-FLIP(L), we cotransfected both genes into pig endothelial cells (PEC). The double remodeling with these molecules effectively prevented CD8(+) CTL killing. Although double transfectants and single high transfectants of either membrane-bound FasL or c-FLIP(L) gene displayed similar inhibition of CTL cytotoxicity, the expression levels of these 2 molecules in double transfectants were almost half the expression levels of single transfectants. Furthermore, to show in vivo prolongation of xenograft survival, we transplanted PEC transfectants under the rat kidney capsule. Prolonged survival was displayed by PEC double transfectant xenografts whereas those from either parental PEC or MOCK (vehicle control) were completely rejected by day 5 posttransplantation. These data suggested that intracellular and extracellular remodeling by coexpression of membrane-bound FasL and pig c-FLIP(L) in xenograft cells may prevent an innate cellular response to xenografts. The gene compatibility of these molecules to generate transgenic pigs may be sufficient to create a window of opportunity to facilitate long-term xenograft survival.

Evaluation of clinical significance of 18F-fluorodeoxyglucose positron emission tomography in superficial squamous cell carcinomas of the thoracic esophagus

(18)F-fluorodeoxyglucose (FDG) positron emission tomography (PET) is used for pre-treatment staging and evaluation of response to pre-operative therapy in advanced thoracic esophageal cancers. To evaluate the clinical significance of PET diagnosis of superficial thoracic esophageal cancers, FDG-PET was conducted preoperatively in 41 patients with such cancers without pre-operative therapy. We compared the PET diagnosis with clinicopathological findings with respect to both the primary tumor and lymph node (LN) metastasis. Of the 41 superficial thoracic esophageal cancers, 21 (51.2%) were PET positive for primary tumors. Although tumor length and histological type did not correlate with FDG uptake by primary tumors, non-flat (elevated or depressed) tumors showed significantly stronger FDG uptake than flat ones. Of 28 tumors infiltrating the deep submucosal layer, 19 (67.9%) were PET positive, while only two (15.4%) of 13 tumors infiltrating only the mucosa or shallow submucosal layer were PET positive. Manova identified FDG uptake as the only independent risk factor for deep submucosal invasion (odds ratio, 7.407; P = 0.0279). In 13 patients with pathological LN metastasis, although no LN metastasis was detected by FDG-PET, FDG uptake by the primary tumors was the only risk factor for LN metastasis (P = 0.0318). PET-negative tumors tended to reflect longer disease-free survival than PET-positive tumors, although this was not significant. FDG-PET is useful for detecting tumors infiltrating the middle or deep submucosal layer (sm2/sm3), and for predicting LN metastasis in patients with superficial thoracic esophageal cancers. FDG-PET is helpful for decision-making regarding treatment of such patients.

[Uncontrollable midbrain hemorrhage due to brain metastasis of pulmonary pleomorphic carcinoma]

A 54-year-old man who had been treated hypertension admitted our hospital due to midbrain hemorrhage. Pulmonary abnormal shadow was also found by chest radiological examinations and it was diagnosed as stage IB (T2N0M0) non-small-cell lung cancer. Right upper lobectomy with combined resection of azygos vein and parietal pleura facing to the tumor was conducted because the direct invasion of the tumor was strongly suspected. Pathological diagnosis was pleomorphic carcinoma. Although, postoperative course was uneventful, midbrain hemorrhage recurred 3rd postoperative day. Since the hemorrhage continued in spite of the conservative treatment, the craniotomy was performed on the 13th postoperative day. The pathological examination revealed the hemorrhage to be caused by the brain metastasis.

Long-term and short-term evaluation of esophageal reconstruction using the colon or the jejunum in esophageal cancer patients after gastrectomy

For esophageal cancer patients, the gastric tube is the first choice as an esophageal substitute, with the colon or the jejunum being used when the stomach cannot be used. We retrospectively compared these two methods from the viewpoint of peri-operative complications and long-term bodyweight alteration. From 1998 to 2005 53 patients who had undergone subtotal esophagectomy due to thoracic esophageal cancers were given reconstruction with the colon (28 cases) or the jejunum (25 cases). Both intestines were reconstructed via the subcutaneous route and were anastomosed to the internal mammalian artery and vein for a supercharged blood supply. There was no difference in operating time and blood loss. Compared with the colon reconstruction group, the hospital stay of the jejunum reconstruction group was significantly shorter (65 days vs 45 days, P = 0.0120) and the incidence of anastomotic leakage tended to be less (13 cases, 46%vs 6 cases, 24%, P = 0.1507), while other operative morbidity did not differ between the two groups. Bodyweight loss, which is a serious postoperative sequela after esophagectomy, was less in the jejunum group than in the colon group, showing a significant difference at 12 months after surgery. Our retrospective study revealed the jejunum to be superior to the colon for the reconstruction after esophagectomy along with gastrectomy, with respect to anastomotic leakage and bodyweight loss. The next step will be to conduct a prospective large cohort study.

Preoperative chemotherapy for clinically node-positive patients with squamous cell carcinoma of the esophagus

Lymph node metastasis is one of the strongest prognostic factors for patients with esophageal cancer. Whether neoadjuvant chemotherapy is effective for metastatic nodes and improves the prognosis of clinically node-positive patients is unknown. Seventy-seven patients with clinically node-positive esophageal cancer, who were given preoperative chemotherapy (5-fluorouracil, cisplatin and adriamycin) followed by surgery, were retrospectively analysed. The histological effectiveness of the chemotherapy against the main tumor in the resected specimen was correlated with nodal status and prognosis. Of the 77 patients, the histological effects in the main tumors were grade 3 in one patient (1.3%), grade 2 in 10 (13.0%), grade 1b in seven (9.1%), grade 1a in 50 (64.9%) and grade 0 in nine (11.7%). Eleven patients (14.3%) were found to be pathologically node-negative. The pathological stages were significantly earlier in responders (grades 3-1b) than in non-responders (grades 1a-0) (P = 0.0001). The responders showed a significantly lesser degree of lymph node metastasis (P = 0.0005), fewer metastatic nodes (2.2 +/- 3.1 vs. 12.0 +/- 20.5, P = 0.0482) and better survival (P = 0.002) than the non-responders. The most common failure pattern for the non-responders was lymphatic recurrence, with an incidence of 47.5% (28/59), while that for the responders was 16.7%. Responders to neoadjuvant chemotherapy show fewer metastatic nodes and better prognosis than non-responders. Neoadjuvant chemotherapy may offer clinical benefit to responders.

[Mediastinal lymph node metastasis of thyroid cancer occurring 15 years after the initial operation; report of a case]

A 71-year-old woman was found to have an abnormal shadow on a chest X-ray. Fifteen years earlier she had undergone a subtotal thyroidectomy for thyroid cancer without any lymph node metastasis. Chest computed tomography (CT) revealed a mediastinal tumor with full of blood stream. Since the positron emission tomography (PET) disclosed an increased uptake of fluoro-2-deoxy-D-glucose (FDG) in the tumor, a malignant lymphatic tumor was therefore suspected. An immunohistological examination of biopsy specimens taken by thoracoscopic procedure demonstrated tumor to be lymph node metastasis of the previous thyroid cancer. After a tumor resection by means of a thoracotomy and total thyroidectomy, the patient was scheduled to receive radioiodine therapy. The previously reported cases are also herein reviewed.

Prognosis of patients who develop cervical lymph node recurrence following curative resection for thoracic esophageal cancer

Patients with esophageal cancer often display relapse at cervical nodes after surgery, but their prognosis and a suitable therapy remains unknown. We retrospectively reviewed the records for 35 patients who underwent esophagectomy with lymphadenectomy who then displayed relapse at the cervical lymph nodes alone between 1985 and 2003 in order to observe the prognostic factors for such patients. Median survival time from the date of recurrence for all 35 patients was 12 months with 1-year, 2-year, 3-year and 5-year survival rate of 47.2%, 26.5%, 17.7% and 8.8%, respectively. With regard to the initial treatment against cervical node recurrence, 15 patients were treated by radiotherapy alone, eight by chemoradiotherapy, 11 by surgery and one by chemotherapy alone. Univariate analysis revealed that cervical node dissection at the prior esophagectomy (yes/no, P = 0.0178), time to recurrence (> 9 months or < 9 months, P = 0.0497) and the number of relapsed nodes (solitary/multiple, P = 0.0029) were significant prognostic factors. Among these factors, the number of relapsed nodes (solitary/multiple) was found to be the only significant prognostic factor with an odds ratio of 2.409 and 95% confidence interval of 1.033-5.619 by multivariate analysis. In conclusion, cervical node metastasis is generally considered to be distant organ metastasis. However, if it is a solitary node recurrence, substantial survival can be attained by appropriate loco-regional therapy.

[Diaphragmatic hernia following pneumonectomy; report of a case]

We report a case of diaphragmatic hernia following left pleuropneumonectomy. A 70-year-old man was referred to our hospital after tube drainage for 3 months due to left pyothorax. He had a past history of left lung tuberculosis. Pleuropneumonectomy with partial resection of the muscle layer of the diaphragm was performed because adhesion of pleurae was severe. On the 19th postoperative day, he started to develop a slight fever. Chest X-ray and computed tomography (CT) demonstrated diaphragmatic hernia. On the 22nd postoperative day, we performed surgery because panperitonitis developed. At laparotomy, the transverse colon was pierced by the cut end of the rib. We successfully repaired the diaphragm and established transverse colostomy. The patient has been in good health for more than 10 years after the surgery.

[Sternal metastasis of breast cancer; report of a case]

A 51-year-old woman presented with a painful sternal lump. Nine years earlier she had undergone right modified mastectomy for breast cancer, followed by chemotherapy. Computed tomography and bone scintigraphy demonstrated a solitary sternal bone metastasis. The patient was treated by partial sternectomy. Thereafter, the sternal defect was reconstructed with Marlex mesh and rectus abdominis myocutaneous flap. The postoperative course was uneventful. The patient subsequently developed brain metastasis and died within 52 months after sternal resection. The stability of the chest wall was well preserved for the duration of follow-up.

[Thoracic surgical approach for traumatic diaphragmatic hernia]

Four patients with traumatic diaphragmatic hernias are reported and are discussed from the view point of surgical approach for the repair of diaphragm. All hernias were caused by car accidents and the diagnoses were made by routine radiography, computed tomography (CT) and magnetic resonance imaging (MRI) examinations. All patients were diagnosed clinically and radiologically. There was no associated intraabdominal trauma and the surgical approach was through the chest in all cases. All but 1 of the patients survived. Abdominal approach at surgery has been considered preferable because associated injuries to intra-abdominal organs have frequently been encountered in the United States. The outcomes in our series indicate that the surgical approach should be based on the clinical and radiographic findings in each indicated patient.

[Familial spontaneous pneumothorax]

A case of familial spontaneous pneumothorax was reported. A 52-year-old man was referred to our hospital complaining of exertional dyspnea. He had experienced right spontaneous pneumothorax and cured with tube drainage last year. Five of his 7 brothers and his son too had had spontaneous pneumothorax. Chest X-ray film and computed tomography (CT) scan on admission showed giant bulla of the left lung with compression of normal lungs. Pulmonary function studies revealed obstructive pulmonary disease and mild hypoxemia. Partial resection of the lung with open thoracotomy surgery was performed. Air leaks sealed in 14 days and the patient discharged the hospital with inadequate expansion of the left lung. Three years later the patient experienced right hemicolectomy for colon cancer and died for recurrence 7 years later with adequate expansion of the left lung.

[Irrigation for the post-pneumonectomy empyema infected by methicillin-resistant Staphylococcus aureus without broncho-pleural fistula; report of a successful case]

It has been known that treatments of post-pneumonectomy empyema are difficult. We report a successful case of irrigation for the post-pneumonectomy. The patient was 68-year-old man with advanced lung cancer. He underwent induction chemoradiotherapy following by pneumonectomy of the right side. A few days later after the chest drain was withdrawn, spike fever appeared. Empyema was suspected, so a 28 Fr diameter double lumen chest drain was intubated again. Turbid effusion was discharged through the drain, in which methicillin-resistant staphylococcus aureus (MRSA) was cultured. Irrigation using a lot of saline and acid electrolyzed water started. A month later, irrigator through the drain was looking clear, however, MRSA was cultured so far. After putting minomycine into the irrigator, MRSA died away. This physical and chemical irrigations were effective.

[Traumatic diaphragmatic hernia repaired by video-assisted thoracic surgery; report of two cases]

Two cases of traumatic diaphragmatic hernia treated by video-assisted thoracic surgery (VATS) were experienced. Both a 67-year-old female (left side) and a 44-year-old female (right side) was admitted to our hospital in a traffic accident. These patients were diagnosed as diaphragmatic hernia by chest magnetic resonance imaging (MRI). We tried VATS to this trauma, but the combined mini-thoracotomy for 7 cm in length was necessary to replace sliding organs for both cases. The rupture of diaphragm was repaired by direct suture of 2-0 viclyl. VATS will be recommended in the hernia of the diaphragm.

Prediction of the response to chemoradiation and prognosis in oesophageal squamous cancer

BACKGROUND

The sensitivity of cancer cells to chemotherapy and radiation therapy depends on various biological properties. This study investigated the expression of p53, CDC25B and metallothionein (MT), and evaluated their clinical significance in chemoradiation therapy (CRT) for oesophageal squamous cell carcinoma.

METHODS

The expression of p53, CDC25B and MT was evaluated by immunohistochemistry using biopsy specimens taken before CRT for 77 patients with oesophageal squamous cell carcinoma, and correlated with the pathological effects of CRT and survival.

RESULTS

p53-positive tumours and MT-positive tumours had a poor response to CRT, whereas tumours with strong CDC25B expression were associated with a good response. When each patient was scored for the presence of the three biological factors, there was a strong correlation between the sensitivity score and the pathological effect of CRT (P < 0.001), and a (non-significant) difference in the 5-year survival rate between patients with a high score and those with a low score (67 versus 34 per cent respectively; P = 0.12).

CONCLUSION

The combined evaluation of p53, CDC25B and MT may help to identify patients with advanced oesophageal squamous cell carcinoma who will benefit from preoperative CRT.

Lymph node metastasis along the recurrent nerve chain is an indication for cervical lymph node dissection in thoracic esophageal cancer

This study examined whether recurrent nerve chain node metastasis serves as an indicative factor for cervical lymph node dissection in thoracic esophageal cancer. The association of recurrent nerve chain lymph node metastasis and cervical node metastasis was analyzed for 91 patients with thoracic esophageal cancer who had undergone three-field lymph node dissection. In patients with upper thoracic esophageal cancer, the incidence of cervical lymph node metastasis was similar regardless of recurrent nerve chain node metastasis. On the other hand, in patients with middle or lower esophageal cancer, the incidence was significantly higher in recurrent nerve-positive (16/31, 51.6%) than in recurrent nerve-negative (5/43, 11.6%) patients. The prognosis of patients with recurrent nerve chain node metastasis was significantly better in the three-field dissection group than in the two-field dissection group, while in patients with no recurrent nerve chain node metastasis, survival was similar between the two groups. In conclusion, cervical lymphadenectomy can be omitted for recurrent nerve chain node-negative patients with middle and lower thoracic esophageal cancer.

Cyclic AMP specific phosphodiesterase activity and colon cancer cell motility

To investigate mechanisms for regulation of intracellular cAMP involved in cancer cell invasion, phosphodiesterase (PDE) activity in a colon cancer cell line, DLD-1, was studied. Activities of PDE 2, 4, and 5 were detected in DLD-1 cells by pharmacological approach. Specific and cell permeable inhibitors for those PDEs were used to determine which PDE is responsible for cAMP turnover involved in cancer cell motility. Treatment of DLD-1 cells with rolipram and Ro-20-1724 inhibitors for PDE 4, elevated intracellular cAMP contents three to five times of control. EHNA, an inhibitor for PDE 2, and zaprinast. an inhibitor for PDE 5, did not affect cAMP levels. To assess cellular motility, we utilized chemotaxis assay. EHNA and zaprinast did not suppress serum-induced chemotaxis. In contrast, rolipram and Ro-20-1724, suppressed chemotaxis in a dose dependent fashion. These suggest that PDE 4 plays a critical role in regulating intracellular cAMP levels of colon cancer cells and is involved in cancer invasion. PDE 4 can be a novel target of anti-invasion drug.

Correlation of beta-catenin and cyclin D1 expression in colon cancers

OBJECTIVE

Beta-catenin activates transcription by TCF/LEF and has been regarded as an oncogene in a wide range of malignant tumors. Among various molecules regulated by beta-catenin/Tcf, cyclin D1 is the most likely candidate for stimulation of the oncogenic pathway. The association between beta-catenin and cyclin D1 was investigated using clinical samples from colorectal cancers.

METHODS

The expression of beta-catenin and cyclin D1 was investigated by immunohistochemical analyses of samples from 70 patients with colorectal cancers. In 28 of the fresh tumor samples, beta-catenin protein was separated into soluble and insoluble fractions and quantitatively correlated with cyclin D1 protein by Western blot analysis.

RESULTS

Compared with noncancerous epithelium, beta-catenin and cyclin D1 were overexpressed (+) in 35 (50%) and 30 cases (43%), respectively. Cyclin D1 (+) was observed in 74% (26/35) of beta-catenin (+) cases, but only in 11% (4/35) of the beta-catenin (-) cases. Thus, there was a strong association between the expression of beta-catenin and that of cyclin D1 (p < 0.001). In the Western blot analysis, the amount of cyclin D1 correlated well with beta-catenin expression in the soluble fraction (p = 0.0016), but not with beta-catenin in the insoluble fraction or with E-cadherin expression. Beta-catenin (-)/cyclin D1 (-) cases displayed less tumor invasion than the remaining cases. However, there were no significant differences in lymph node metastasis or other clinicopathological findings.

CONCLUSION

Our results indicate that beta-catenin overexpression in the cytoplasm may promote malignant transformation by triggering cyclin D1 expression in colorectal cancers.

Regulation of activator protein-1 activity in the mediastinal lymph node metastasis of lung cancer

Orthotopic implantation of a metastatic cell line of Lewis lung carcinoma (LLC-MLN), which was isolated by an in vivo selection method, resulted in greater metastatic growth in mediastinal lymph nodes as compared with that of the original LLC cells. LLC-MLN cells also had increased invasive ability and activator protein-1 (AP-1) transcriptional activity as compared with the original LLC cells. This is well consistent with the previously reported finding that overexpression of AP-1 is associated with lymphatic metastasis in lung cancer patients. Oral administration of curcumin, which downregulates AP-1 transcription, significantly inhibited the mediastinal lymph node metastasis of orthotopically implanted LLC cells in a dose-dependent manner, but did not affect the tumor growth at the implantation site. Combined treatment with curcumin and an anti-cancer drug, cis-diamine-dichloroplatinum (CDDP), resulted in a marked inhibition of tumor growth at the implanted site and of lymphatic metastasis, and a significant prolongation of the survival time. The downregulation of transcriptional AP-1 activity by curcumin as seen in the dual luciferase assay caused inhibition of LLC cell invasion through the repression of expression of the mRNAs for urokinase-type plasminogen activator (u-PA) and its receptor (u-PAR). Inhibition of AP-1 transcriptional activity may offer improved therapeutic efficacy for lung cancer patients with lymphatic metastasis.

Genetic detection of lymph node micrometastases in patients with gastric carcinoma by multiple-marker reverse transcriptase-polymerase chain reaction assay

BACKGROUND

Some patients with gastric carcinoma experience local disease recurrence despite undergoing curative resection of the tumor and regional lymph nodes (LNs), suggesting the presence of occult micrometastases. To evaluate the presence of gastric carcinoma micrometastasis in patients with otherwise histologically negative LNs, the authors established and tested a multiple-marker reverse transcriptase-polymerase chain reaction (RT-PCR) assay.

METHODS

The authors assessed 435 LNs from 28 patients with gastric carcinoma who underwent gastrectomy with lymphadenectomy using the multiple-marker RT-PCR assay in addition to histologic examination. Carcinoembryonic antigen (CEA), cytokeratin-20 (CK-20), and MAGE-3 gene markers were used in this assay. LNs were scored positive for metastasis if at least one marker was positive. The presence of LN micrometastases also was verified by immunohistochemistry in histologically negative and RT-PCR positive LNs.

RESULTS

Sixty-nine of 435 LNs (16%) were positive for CEA (12%), CK-20 (10%), or MAGE-3 (5%). None of 16 control LNs obtained from disease free patients was positive by RT-PCR assay. Of 414 histologically negative LNs, 50 LNs (12%) were scored as positive for metastasis by the assay. Of 26 patients who underwent curative resection, the disease stage was upgraded in 10 patients by genetic diagnosis (from Stage IA to Stage IB in 5 patients, from Stage IB to Stage IIIA in 2 patients, from Stage IB to Stage IV in 1 patient, from Stage IB to Stage II in 1 patient, and from Stage II to Stage IIIB in 1 patient). In the latter 10 patients, immunohistochemistry identified LN micrometastases in 4 patients. Two patients with micrometastasis by genetic diagnosis had recurrent disease within 1 year.

CONCLUSIONS

The current results indicate that the multiple-marker RT-PCR assay is a useful tool for the detection of micrometastases in regional LNs in patients with gastric carcinoma and may improve the staging system of gastric carcinoma for these patients.

Genetic detection of lymph node micrometastases in patients with gastric carcinoma by multiple-marker reverse transcriptase-polymerase chain reaction assay

BACKGROUND

Some patients with gastric carcinoma experience local disease recurrence despite undergoing curative resection of the tumor and regional lymph nodes (LNs), suggesting the presence of occult micrometastases. To evaluate the presence of gastric carcinoma micrometastasis in patients with otherwise histologically negative LNs, the authors established and tested a multiple-marker reverse transcriptase-polymerase chain reaction (RT-PCR) assay.

METHODS

The authors assessed 435 LNs from 28 patients with gastric carcinoma who underwent gastrectomy with lymphadenectomy using the multiple-marker RT-PCR assay in addition to histologic examination. Carcinoembryonic antigen (CEA), cytokeratin-20 (CK-20), and MAGE-3 gene markers were used in this assay. LNs were scored positive for metastasis if at least one marker was positive. The presence of LN micrometastases also was verified by immunohistochemistry in histologically negative and RT-PCR positive LNs.

RESULTS

Sixty-nine of 435 LNs (16%) were positive for CEA (12%), CK-20 (10%), or MAGE-3 (5%). None of 16 control LNs obtained from disease free patients was positive by RT-PCR assay. Of 414 histologically negative LNs, 50 LNs (12%) were scored as positive for metastasis by the assay. Of 26 patients who underwent curative resection, the disease stage was upgraded in 10 patients by genetic diagnosis (from Stage IA to Stage IB in 5 patients, from Stage IB to Stage IIIA in 2 patients, from Stage IB to Stage IV in 1 patient, from Stage IB to Stage II in 1 patient, and from Stage II to Stage IIIB in 1 patient). In the latter 10 patients, immunohistochemistry identified LN micrometastases in 4 patients. Two patients with micrometastasis by genetic diagnosis had recurrent disease within 1 year.

CONCLUSIONS

The current results indicate that the multiple-marker RT-PCR assay is a useful tool for the detection of micrometastases in regional LNs in patients with gastric carcinoma and may improve the staging system of gastric carcinoma for these patients.

Does pleural lavage cytology before thoracic closure predict both patient's prognosis and site of cancer recurrence after resection of esophageal cancer?

BACKGROUND

Operative manipulation occasionally exfoliates and spreads cancer cells in the surgical field, and it is a matter of concern whether the exfoliated cancer cells actually affect the patient's prognosis and sites of cancer recurrence.

METHODS

In 240 patients with esophageal cancers, lavage cytology (LC) of the right pleural cavity was performed before and after esophageal resection combined with regional lymphadenectomy. The cytologic results were compared with the pathologic factors associated with cancer extension, postoperative survival, and cause of surgical failure.

RESULTS

Only 3 patients (1.3%) were LC positive before resection. Of the 237 LC-negative patients, LC was also negative after resection in 215 patients (90.7%) (LC-/-), but LC became positive after resection in 22 patients (9.3%) (LC-/+). The 3-year survival rate was 0% in the LC-/+ group versus 65% in the LC-/- group, and the median survival rates were 10.9 months and 25.0 months, respectively (P <.0001). Multivariate analysis revealed that LC-/+ was an independent prognostic factor (P =.0331), along with nodal involvement and depth of cancer invasion. However, there were no significant differences in the sites of cancer recurrence between the 2 groups. Only 1 patient was found to develop the first recurrence in the pleural cavity. The LC-/+ group had a higher incidence of bulky lymph-node metastasis (P =.0009).

CONCLUSIONS

Pleural LC after resection of esophageal cancer seems to be a prognostic indicator of overall recurrence, but not necessarily in the pleural cavity. Patients with a positive LC after resection may benefit most by effective systemic adjuvant chemotherapy.

Genetic detection of lymph node micrometastases in patients with gastric carcinoma by multiple-marker reverse transcriptase-polymerase chain reaction assay

BACKGROUND

Some patients with gastric carcinoma experience local disease recurrence despite undergoing curative resection of the tumor and regional lymph nodes (LNs), suggesting the presence of occult micrometastases. To evaluate the presence of gastric carcinoma micrometastasis in patients with otherwise histologically negative LNs, the authors established and tested a multiple-marker reverse transcriptase-polymerase chain reaction (RT-PCR) assay.

METHODS

The authors assessed 435 LNs from 28 patients with gastric carcinoma who underwent gastrectomy with lymphadenectomy using the multiple-marker RT-PCR assay in addition to histologic examination. Carcinoembryonic antigen (CEA), cytokeratin-20 (CK-20), and MAGE-3 gene markers were used in this assay. LNs were scored positive for metastasis if at least one marker was positive. The presence of LN micrometastases also was verified by immunohistochemistry in histologically negative and RT-PCR positive LNs.

RESULTS

Sixty-nine of 435 LNs (16%) were positive for CEA (12%), CK-20 (10%), or MAGE-3 (5%). None of 16 control LNs obtained from disease free patients was positive by RT-PCR assay. Of 414 histologically negative LNs, 50 LNs (12%) were scored as positive for metastasis by the assay. Of 26 patients who underwent curative resection, the disease stage was upgraded in 10 patients by genetic diagnosis (from Stage IA to Stage IB in 5 patients, from Stage IB to Stage IIIA in 2 patients, from Stage IB to Stage IV in 1 patient, from Stage IB to Stage II in 1 patient, and from Stage II to Stage IIIB in 1 patient). In the latter 10 patients, immunohistochemistry identified LN micrometastases in 4 patients. Two patients with micrometastasis by genetic diagnosis had recurrent disease within 1 year.

CONCLUSIONS

The current results indicate that the multiple-marker RT-PCR assay is a useful tool for the detection of micrometastases in regional LNs in patients with gastric carcinoma and may improve the staging system of gastric carcinoma for these patients.

[Reconstruction of the cervical esophagus using cutaneous or musculocutaneous flaps]

Reconstruction of the cervical esophagus using cutaneous or musculocutaneous flaps is described. The delto-pectoral cutaneous flap, latissimus dorsi or pectoris major musculocutaneous flap, free forearm cutaneous flap, and free rectus abdominis musculocutaneous flap are generally used for reconstruction of the cervical esophagus. Although free jejunal transfer with microsurgery is now common for reconstruction of the cervical esophagus, cutaneous or musculocutaneous flaps remain useful in high-risk patients or patients in whom free jejunal transfer or gastrointestinal reconstruction would prove incompetency due to a history of abdominal surgery or other reasons. Cutaneous or musculocutaneous flaps are also used in patients with failure of free jejunal transfer or incurable fistula after reconstruction using the stomach or colon for thoracic esophageal cancer.

Clinical significance of CDC25A and CDC25B expression in squamous cell carcinomas of the oesophagus

CDC25A, CDC25B and CDC25C belong to a family of protein phosphatases which activate the cyclin-dependent kinase at different points of the cell cycle. According to accumulating evidence, CDC25A and CDC25B seem to possess oncogenic properties. We have analysed these expressions by immunohistochemistry, western blot and RT-PCR in a series of 100 patients with squamous cell carcinoma of the oesophagus. When compared with non-cancerous cells, CDC25A and CDC25B were strongly expressed in the cytoplasm of cancer cells, with positive (+) classification in 46% (46 cases) and 48% (48 cases), respectively. There was no significant correlation between CDC25A and CDC25B expression, nor was there any association with the expression of other cell cycle-regulating molecules, including cyclin D1, Rb, p16(INK4), p27(KIP1)and PCNA (proliferating cell nuclear antigen). CDC25A (+), as well as CDC25B (+), was more frequently found in patients with deeper tumour invasion and lymph node metastasis, while tumour size was correlated only with CDC25A expression. Postoperative survival was significantly poorer for CDC25A (+) patients than CDC25A (-) patients, but was not affected by the CDC25B status. Nuclear localization of CDC25A was observed in 51 cases (51%), regardless of its cytoplasmic expression, and was not associated with clinico-pathological factors or prognosis. Multivariate analysis revealed only the CDC25A status to be an independent significant prognostic factor among these biological and clinico-pathological factors. CDC25A but not CDC25B may be a new prognostic factor for squamous cell carcinoma of the oesophagus. Thus, regulation of the G1 checkpoint in the cell cycle may be important in oesophageal carcinogenesis, which may also involve many other oncogenes.

Detection of peritoneal micrometastases of gastric carcinoma with green fluorescent protein and carcinoembryonic antigen promoter

The aim of this study was to specifically visualize micrometastases in the peritoneal cavity, which cannot be detected by conventional methods, by using enhanced Green Fluorescent Protein (EGFP) containing carcinoembryonic antigen (CEA) promoter in an upstream position. In in vitro experiments, two cell lines from human gastric cancer, MKN45 and MKN1, and a cell line from human fibrosarcoma, HT1080, were transduced with pCEA-EGFP, which contains the CEA promoter region. MKN45 and MKN1, which expressed CEA mRNA, showed positive fluorescence after transduction of pCEA-EGFP, whereas HT1080 did not. In in vivo experiments, 7 days after 10(7) MKN45 had been injected into the peritoneal cavity of BALB/c nude mice, pCEA-EGFP was transduced in the peritoneal cavity using a fusogenic liposome with the envelope protein of Hemagglutinating Virus of Japan on the surface. On the peritoneum of the abdominal wall, fluorescent nodules were detected by fluorescence stereomicroscopy. These nodules had a minimal size of approximately 0.15 mm and could not be detected by conventional stereomicroscopy or macroscopy. They were histologically confirmed to be cancer cells by H&E staining. The results suggest that visualization of peritoneal micrometastasis of gastric cancer using CEA promoter and EGFP can offer a new strategy for diagnosis of micrometastasis.

Transmediastinal approach to exploring the lung contralateral to the thoracotomy site

OBJECTIVE

The approach to contralateral lung through the mediastinum is assumed useful in managing oddly distributed bilateral lung tumors.

SUBJECTS AND METHODS

To remove a tumor located in the contralateral lung, a transmediastinal approach from the thoracotomy site to the contralateral lung was used in 6 patients having oddly distributed bilateral lung tumors, 1 of which was located in the contralateral lung close to the anterior or posterior mediastinum.

RESULTS

All cases were treated successfully. One patient required an additional small incision on the contralateral anterior chest wall to insert an endoscopic stapler without intraoperative postural change. The postoperative course was uneventful and, to date, no local recurrence has been seen at the resected margin of the contralateral lung.

CONCLUSION

This novel approach is useful, offering the advantages of reduced invasiveness and pain, shorter surgical duration, and favorable cosmetic results for patients with a tumor close to the mediastinum in the contralateral lung.

Larynx preservation in surgical treatment of cervical esophageal cancer--combined procedure of laryngeal suspension and cricopharyngeal myotomy

From July 1994 to July 1998, a larynx-preserving procedure was performed on 10 out of 22 (45%) patients in the surgical treatment of hypopharyngeal and cervical esophageal cancer. At first, all 10 patients were treated with concurrent radiochemotherapy with cisplatin (10 mg/m2/day), 5-fluorouracil (500 mg/m2/day) and radiation (2 Gy/day) five times per week for 4 weeks. After preoperative radiochemotherapy, the larynx-preserving procedure, combining laryngeal suspension and cricopharyngeal myotomy, was performed. The operative and hospital mortality rate was 0%. The incidence of post-operative morbidity with minor complications was 70% in the present study. Laryngeal speech and oral food intake were preserved in all patients after this procedure. The new larynx-preserving procedure combining laryngeal suspension and cricopharyngeal myotomy for cervical esophageal cancer is a favorable operative method for retaining intelligible laryngeal speech and good food intake.

Evaluation of the histologic effect of chemoradiation therapy for squamous cell carcinomas of the esophagus by assessing morphologic features of surgical specimens

The histologic effects of chemoradiation therapy (CRT) for esophageal cancer, which determine the benefit obtained from a salvage operation, are difficult to evaluate preoperatively. We therefore investigated whether or not the morphologic features of esophageal cancer tissue after CRT can be correlated with the histologic features of the tissue. Seventy-six patients with advanced esophageal squamous cell carcinoma underwent CRT followed by esophagectomy. The effects of CRT were evaluated by histologic examination of the residual tumors in the surgical specimen and correlated with clinicopathologic factors, including postoperative prognosis. The histologic effects of CRT were used to classify tumors as grade 1 (CRT poorly effective; 23 cases, 30.3%); grade 2 (CRT moderately effective; 31 cases, 40.8%); or grade 3 (CRT completely effective with no residual tumors; 22 cases, 28.9%). Among the gross findings of the removed esophagus, significant correlation with the CRT effects was observed in the case of wall thickness and ulceration but not in the case of longitudinal tumor length. Tumors with no wall thickening or ulceration were never classified as grade 1, whereas tumors with both wall thickening and ulceration were frequently rated as grade 1 (18/30, 60%). Microscopic examination of grade 2 tumors (23/31, 74.1%) revealed residual tumor cells growing below the mucosal layer, whereas tumor cells were exposed to the esophageal surface in 22 out of 23 patients with grade 1 tumors. The morphologic features after CRT can be used to evaluate its histologic effect, especially in the case of grade 1 tumors. However, the detection and prediction of grade 2 tumors remains difficult because of the presence of small amounts of residual tumor underneath the mucosa.

Synchronous esophageal and renal cell carcinoma

Multiple cancer associated with esophageal cancer is not uncommon; however, synchronous esophageal and renal cell carcinoma is very rare. Only three cases have been reported to date, and one of these patients was treated in our institution. We have since successfully treated another patient. Here, we report the two cases treated in our institution. In the first case, esophagectomy, nephrectomy, and reconstruction using a gastric tube were carried out in one stage. Post-operative renal function was temporarily impaired by the complications of anastomotic leakage and pyothorax but no hemodialysis was needed. In the second case, as the patient had undergone distal gastrectomy because of gastric cancer, we chose a two-stage operation, i.e. esophagectomy and nephrectomy as the first stage, followed by reconstruction using a colon substitute after 4 weeks, resulting in only slight renal dysfunction. Patients 1 and 2 are alive and well 7 years and 2 years after the operations respectively.

Overexpression of CDC25B overrides radiation-induced G2-M arrest and results in increased apoptosis in esophageal cancer cells

CDC25B phosphatase plays a key role in controlling G2-M progression by dephosphorylating two inhibitory residues of CDC2 and also has been suggested to have an oncogenic property. In this study, we investigated the effect of CDC25B overexpression on radiation-induced G2-M arrest and radiation sensitivity in esophageal cancer cells. TE8-CDC25B, in which CDC25B was overexpressed under an inducible system, was more radiosensitive than the vector control (TE8-neo) in a clonogenic survival assay. Without radiation, CDC25B overexpression had little effect on cell cycle fractions or growth rate. After 10-Gy radiation, TE8-CDC25B showed decreased G2-M arrest and increased apoptosis, whereas TE8-neo displayed prolonged G2-M arrest and less apoptosis. During this period, there were no differences in the protein amounts of CDC2 and cyclin B1 between the two cell lines. However, more CDC25B expression, which was reduced immediately by radiation, was sustained in TE8-CDC25B than in TE8-neo. Moreover, induction of tyrosine phosphorylation of CDC2 and reduction of CDC2 kinase activity after irradiation was less significant in TE8-CDC25B than in TE8-neo. These results indicate that cancer cells that overexpress CDC25B override G2-M arrest by retaining CDC2 kinase activity and undergo apoptosis after radiation. This may point to an effective approach toward improving radiotherapy outcomes of various cancers.

Localization of IQGAP1 is inversely correlated with intercellular adhesion mediated by e-cadherin in gastric cancers

Down-regulation of E-cadherin function is characteristic of cancer cells and might involve the small G-protein Rho family, including Rac1 and Cdc42. IQGAP1 has been reported to be one of the target proteins of Rac1 and Cdc42. To elucidate the role of IQGAP1 in cancer-cell adhesion, its expression was investigated in 47 cases of human gastric cancer by immunohistochemistry and Western blot upon protein fractionation, especially in comparison with E-cadherin and catenin expression. In the non-cancerous columnar epithelium of the stomach, IQGAP1, as well as E-cadherin/catenin, was expressed at the cell-cell boundary. IQGAP1 was frequently observed diffusely in the cytoplasm in intestinal-type tumors (20/22 cases) but was expressed at the cell membrane in diffuse-type tumors (19/25 cases), thus showing significant association with tumor differentiation (p < 0.01). Interestingly, membranous expression of IQGAP1 was inversely correlated with that of E-cadherin (p < 0.05) or alpha-catenin (p < 0.001). These observations were consistent with the Western blot results following protein fractionation. IQGAP1 was dominantly expressed in the soluble fraction in differentiated tumors; however, in undifferentiated tumors, it was mostly in the insoluble fraction. In contrast, both E-cadherin and alpha-catenin were detected only in the insoluble fraction. Thus, subcellular localization of IQGAP1 from the cytoplasm to the cell membrane was correlated with E-cadherin dysfunction and tumor dedifferentiation in gastric carcinogenesis.