[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.