Influence of omentum transposition on experimental tumors

It has been observed that in human breast cancer transposition of the greater omentum to cover the excision site after removal of recurrent tumor appears to inhibit further recurrences at the site, without affecting spread to other sites. To establish an experimental model of this, inbred rats were transplanted in two sites on the chest with pieces of either an epithelioma or a mammary tumor. A flap of the omentum was then drawn through the peritoneal wall and then secured over one of the implants. In one group, this omentoplasty was carried out 1 week after tumor implantation. In most rats, the tumor in contact with the omentum was actually larger than the control, in contrast to the clinical observations. In many animals, the omentum was also a route of metastasis of the tumor.