Successful evaluation of a new animal model using mice for esophageal adenocarcinoma.

Introduction: For the better understanding of the pathophysiological events occurring in the sequence inflammation-metaplasia-carcinoma in esophageal adenocarcinoma, an animal model would be desirable. In the past, several rat models have been used yielding conflicting results. Some demonstrated a sequence similar to the human situation whereas others failed to initiate true esophageal adenocarcinoma or even Barrett's metaplasia. For the study of the molecular events involved in the carcinogenesis of Barrett's carcinoma, a mouse model would be much more promising since most of the genetically altered animals are mice. However, as of now no such model exists, in the past predominately due to the high mortality involved with the surgical procedure to create a mixed duodenogastric reflux.

Methods: Forty BALB-C mice weighing between 22 and 25 g underwent an esophagojejunostomy. The animals were sacrificed at 3, 4, and 5 months. Pathological evaluation was performed with HE staining.

Results: Overall mortality was 17%. However, mortality within the first ten animals was 30%. Reasons were technical problems with the anastomosis, opening of the pleural cavity, or bleeding events. All animals had a severe esophagitis regardless of the time. Intestinal metaplasia could be found in 60% of the animals after 4 months and esophageal adenocarcinoma in 55% after 5 months. One animal showed multiple lung metastases.

Conclusion: After a certain learning curve esophagojejunostomy is feasible in mice with an acceptable mortality rate and leads to esophageal adenocarcinoma.