Esophageal cancer: a European perspective

New orthotopic implantation model of human esophageal squamous cell carcinoma in athymic nude mice

BACKGROUND

Subcutaneous xenograft is a common method to establish animal models of human esophageal squamous cell carcinoma (ESCC). However, the growth microenvironment of transplanted tumors is different from primary tumors. Orthotopic implantation models can provide more biologically relevant context in which to study the disease. So far, an orthotopic implantation model of ESCC has rarely been reported.

METHODS

The human ESCC cell line KYSE30 was transfected with pLVX-Luciferase plasmids. KYSE30-Luciferase cells were isolated and injected into the flanks of nude mice to develop a subcutaneous tumor. An orthotopic implantation model was established using the fragments derived from the subcutaneous tumor. Fluorescence imaging was used to observe the development of the orthotopic implanted tumor. Hematoxylin and eosin staining was performed to evaluate the invasion and metastasis of the tumor.

RESULTS

KYSE30 cells were successfully transfected with pLVX-Luciferase plasmids. A primary tumor was developed in all mice. The mice experienced body weight loss. The implanted tumor infiltrated into the esophageal muscularis propria. However, neither distant organ nor lymph node metastasis was found. The progression of the primary tumor was monitored by in vivo fluorescence imaging.

CONCLUSION

The orthotopic implantation model can be established by sewing the fragments of human ESCC to the abdominal esophagus of a nude mouse. The progression of an orthotopic implantation tumor can be monitored in real time by in vivo fluorescence imaging.

Narrow-band imaging endoscopy with magnification is useful for detecting metachronous superficial pharyngeal cancer in patients with esophageal squamous cell carcinoma

BACKGROUND AND AIMS

Head and neck cancers, especially pharyngeal cancers, as well as esophageal cancers frequently coexist either synchronously or metachronously, but most cases of pharyngeal cancer are detected at an advanced stage resulting in poor prognosis. The aim of this study is to evaluate the effectiveness of using narrow-band imaging (NBI) endoscopy with magnification for early detection of pharyngeal cancer on patients following their treatment for esophageal squamous cell carcinoma (SCC).

METHODS

This case series was conducted at the National Cancer Center Hospital in Tokyo between April and October 2005 and included 424 consecutive patients for surveillance endoscopy who had previously undergone chemoradiotherapy (CRT) and/or surgery for esophageal SCC. Observation of the pharyngeal region was randomly conducted on 91 patients using NBI endoscopy with magnification (NBI group) and 333 patients using conventional white light endoscopy (control group).

RESULTS

The detection rate for pharyngeal cancer was significantly higher using NBI endoscopy with magnification (10.9%; 10/91) compared with conventional endoscopy (1.2%; 4/333) (P < 0.0001). In particular, the detection rate in CRT patients was significantly higher in the NBI group (12.9%; 7/54) than the control group (0.5%; 1/191) (P < 0.0001). In addition, diagnostic sensitivity, specificity, accuracy, positive predictive value and negative predictive value for the NBI group were 100% (10/10), 97.5% (79/81), 97.8% (89/91), 83.3% (10/12) and 100% (79/79), respectively.

CONCLUSION

NBI endoscopy with magnification is a promising technique for detecting superficial pharyngeal cancer at an early stage in patients previously treated for esophageal SCC.

Interaction of MT1-MMP and laminin-5gamma2 chain correlates with metastasis and invasiveness in human esophageal squamous cell carcinoma

To gain insights into metastatic mechanisms in esophageal squamous cell carcinoma (ESCC), we established sublines (MLuB1 and MLuC1) with different capacity of spontaneous lung metastasis by subcutaneous injection of a human ESCC cell line (EC 9706) into nude mices. The incidence of the mice with lung metastasis produced by MLuC1 (87%) was significantly higher than that of MLuB1 (22%). The gene expression profiles of the two sublines were compared with cDNA arrays containing 5,000 known genes, and 47 genes were differentially expressed > or =2.0 fold. Laminin-5gamma2 chain (Ln-5gamma2) was one of the up-regulated genes in MLuC1 cells. Proteolytically processed forms of gamma2 are known to promote migration of a multitude of epithelial cells in vitro. Western-blotting analysis revealed that degraded fragments of Ln-5gamma2 and active form of membrane-type matrix metalloproteinase-1 (MT1-MMP) in MLuC1 was significantly higher than those in MLuB1. Expression of MT1-MMP was observed in 60 of 75 Ln-5gamma2-positive carcinoma tissues (80%). Co-expression of the two proteins was significantly associated with depth of invasion (P = 0.012). Moreover, proteolytic fragments of Ln-5gamma2 and active forms of MT1-MMP were frequently found in tumor tissues, whereas in the corresponding normal esophageal tissues there were only intact forms of gamma2 and MT1-MMP. siRNA-mediated silencing of MT1-MMP significantly reduced production of gamma2' and gamma2x in MLuC1 cells and inhibited cell migration. The results suggest that MT1-MMP is an enzyme responsible for Ln-5gamma2 cleavage in ESCC, and interaction between them may play a critical role in promoting invasion and metastasis of human ESCC.

Surgical treatment for cancer of the oesophagus and gastric cardia in Hebei, China

BACKGROUND

Southern Hebei Province has one of the highest incidences of oesophageal cancer in the world. This study describes a single-centre experience with oesophagectomy for this condition.

METHODS

The reported articles on surgical treatment for cancer of the oesophagus and gastric cardia from a single department between September 1952 and December 2000 were summarized and the results compared.

RESULTS

Between September 1952 and December 2000, the resectability rate increased from 78.8 to 96.0 per cent for oesophageal cancer and from 69.6 to 94.8 per cent for cancer of the cardia. The surgical mortality rate decreased from 4.6 to 1.1 per cent. There was little change in the overall 5-year survival rate; it increased from 21.2 to 23.9 per cent for patients with oesophageal cancer and from 15.2 to 17.6 per cent for those with cancer of the cardia.

CONCLUSION

The rate of postoperative complications and deaths following oesophagectomy for cancer has fallen steadily over the past five decades but long-term survival remains disappointing. Improved survival is likely to be dependent on earlier diagnosis and adjunctive therapies.

Risk of second primary malignancy after esophagectomy for squamous cell carcinoma of the thoracic esophagus

PURPOSE

To assess the risk of subsequent malignancies after esophagectomy for squamous cell carcinoma of the thoracic esophagus for the establishment of an adequate follow-up program.

PATIENTS AND METHODS

We statistically analyzed clinical factors in 114 cases of second malignancy after esophagectomy that developed in 94 of 679 patients who underwent curative resection. The cancer incidence rates in the general population estimated by the Research Group for Population-Based Cancer Registration in Japan were used as standards for comparison.

RESULTS

The 10-year cumulative risk of second malignancy was 34.5%, and the overall relative risk (RR) was 2.98 (95% CI, 2.41 to 3.65). The risk of head and neck cancer was markedly elevated (RR, 34.9; 95% CI, 24.3 to 48.6), followed by the risks of lung cancer (RR, 3.24; 95% CI, 1.89 to 5.19) and stomach cancer (RR, 2.00; 95% CI, 1.17 to 3.21). Multifactor analysis demonstrated that independent factors affecting the risk of subsequent malignancies were presence of other malignancies detected before esophagectomy and any of the following factors: masculine sex, alcohol consumption, and smoking. The 5-year survival rate after detection of subsequent malignancy was 45%. The outcome in patients with subsequent head and neck cancer was significantly less favorable as a result of difficulty in early detection.

CONCLUSION

Patients had a remarkably high risk of subsequent cancer of the upper aerodigestive tract after esophagectomy, in particular, head and neck cancer. Minute postoperative surveillance is strongly recommended, especially in patients with a history of malignancies before esophagectomy. Early detection of second malignancies allowed less invasive treatment with favorable outcome.

[Surgery for oesophageal cancer: current controversies]

Any attempt to define the present role of surgery in the treatment of oesophageal cancer should integrate the dramatic changes that occurred within this disease over the last 2 decades: major shift in the histologic type of tumours, improved staging methods, spectacular reduction of operative risks, standardization of oncologic principles focusing on the completeness of resection, and development of multimodality therapeutic strategies. Surgery has still a pivotal role. Esophagectomy should be performed by trained surgeons in high-volume institutions. Radical surgery with en-bloc resection and 2 fields lymphadenectomy, should be encouraged in low-risk patients with subcarinal tumors. Although multimodality treatment strategy is commonly applied for locally advanced disease, few data support its superiority over surgical resection alone, followed by adjuvant therapy when appropriate. One may thus hypothesize that the risk/benefit ratio of such strategies is probably optimal in case of early stage tumors, and future studies may further clarify this issue. Conversely, locally advanced tumors, particularly those located in the upper mediastinum and the neck, may be managed alternatively without surgery. However, surgery remains an important tool to ensure optimal palliation of dysphagia, to achieve local control, and finally to improve quality of life. In that way, video-assisted techniques and/or trans hiatal approaches aiming to minimize the surgical insult may have a place in the treatment of patients who have substantially responded to induction therapy. Tumors located close to the pharyngo-oesophageal junction are best managed with chemotherapy and radiotherapy. Finally, salvage surgery may be considered in highly selected patients in case of non-response or local relapse without distant metastases.

Neoadjuvant chemoradiation therapy in patients with surgically treated esophageal cancer

Over the past 10 years, 232 patients were treated at the East Carolina School of Medicine for cancer of the esophagus. Of these, 73 received neoadjuvant chemoradiation therapy and subsequent surgical resection. The results in this group suggest improved cancer control, with 18 patients (25%) remaining free of recurrence 3 years after treatment, compared with 11 out of 159 patients (7%) in the group that was not treated with neoadjuvant therapy (p < 0.0001). The 5-year recurrence-free survival with neoadjuvant chemoradiotherapy and surgery was 16% (12/73) compared with 3% (5/159) with other types of therapy. Two protocols of neoadjuvant chemoradiotherapy with subsequent surgery were compared: I: Split-course, once-a-day radiotherapy and concomitant cisplatinum/5-fluorouracil followed by esophagectomy. II: Accelerated, twice-a-day radiotherapy with concomitant triple chemotherapy using cisplatinum/5-fluorouracil/vinblastine followed by transhiatal extrathoracic esophagectomy. The survival rate was similar in the two groups of patients but the complication rate was higher in group II. Neoadjuvant chemoradiation therapy and the techniques of transhiatal esophagectomy may have contributed to the improved results in the treatment of esophageal carcinoma. Accelerated radiotherapy with triple chemotherapy was more toxic and did not give better survival rates than split-course, once-a-day, conventional, fractionated-protracted radiotherapy combined with two drugs.

A novel orthotopic implantation model of human esophageal carcinoma in nude rats: CD44H mediates cancer cell invasion in vitro and in vivo

A new orthotopic esophageal cancer model was developed by implanting fragments of xenografts of T.T human esophageal squamous carcinoma cells into the cervical esophagus of athymic rats. The rats had symptoms analogous to the human clinical course such as respiratory distress, dysphagia, vomiting of blood, or Horner syndrome, followed by death resulting from suffocation. Microscopic metastases of lymph node were observed around the tumor in 3 of 18 rats. A new cell line (T.T-1) was established from these metastases. Flow cytometry showed that T.T-1 and T.T parental cells had nearly the same surface levels of beta1-integrin, alpha2-integrin, alpha3-integrin and E-cadherin, and no expression of CD44v3, CD44v6 and alpha5-integrin. T.T-1 cells had a higher level of CD44H, however, and a greater binding efficiency to the extracellular matrix components; laminin, type IV collagen, hyaluronic acid, and fibronectin than T.T cells. Anti-CD44H antibody significantly decreased the binding efficiency of T.T-1 cells. T.T-1 cells were also significantly more invasive than T.T cells through all the extracellular matrix components except hyaluronic acid. After orthotopic implantation histological examination showed that T.T-1 tumors invaded beyond the esophageal mucosa and tracheal muscle layer and obstructed the esophagus and trachea. No invasion was observed with T.T tumors. Rats with T.T-1 or T.T tumors survived an average of 32.0 and 50.7 days, respectively (p < 0.01). In addition T.T-1 tumors expressed higher levels of CD44H mRNA than T.T tumors. In summary, our newly developed orthotopic implantation model is a valid model of esophageal cancer because it followed the same clinical course experienced by humans. Moreover, using cells derived from this model, we were able to demonstrate that CD44H is involved in esophageal cancer cell invasion.