Is omentectomy mandatory in the operation for ovarian cancer? Preliminary results in a rat study.
OBJECTIVE
To investigate whether omentectomy is required in the operation for ovarian cancer, in particular at the early stage.


METHODS
F344 nude rats were divided into two groups: one in which laparotomy and omentectomy were performed (primary omentectomy group, n=6) and one without omentectomy (n=12). Concurrently, DISS cells derived from ovarian cancer were transplanted intraperitoneally. After three weeks, the 12 rats without omentectomy were divided into two more groups: one in which the omentum was resected together with the tumor (sham operation/omentectomy group, n=6) and one without omentectomy (sham operation alone group, n=6).


RESULTS
The survival of the sham operation alone group was shortest with a median of 35 days, while the median of the primary omentectomy group was 42 days. In the sham operation/omentectomy group, four rats survived beyond Day 90, which was significant compared with other two groups. The intraperitoneal findings in the primary omentectomy group revealed extensive disseminated foci on the mesentery and under the abdominal wall. The sham operation alone group was characterized by jaundice resulting from the compression of the biliary system at the liver hilum by the omental mass. Disseminated foci were not observed in the peritoneal cavity from the sham operation/omentectomy group.


CONCLUSIONS
This study suggests the possibility that the omentum has a role in capturing cancer cells and suppressing further peritoneal dissemination. Therefore, although omentectomy is rewarding if disseminated foci are present in the omentum, it is suggested that the timing of omentectomy requires reconsideration in the absence of omental metastasis.
Department of Obstetrics and Gynecology, Hirosaki University Graduate School of Medicine, 5-Zaifu-cho, Hirosaki 036-8562, Japan. yokoyama@cc.hirosaki-u.ac.jp
Yoshihito
Y
Yokoyama
Hachidai
H
Hirakawa
Hui
H
Wang
Hideki
H
Mizunuma
D000818:Animals; D045744:Cell Line, Tumor; D005260:Female; D007813:Laparotomy; D009368:Neoplasm Transplantation; D009852:Omentum / Q000473:pathology / Q000502:physiology / Q000601:surgery*; D010051:Ovarian Neoplasms / Q000556:secondary / Q000601:surgery*; D010534:Peritoneal Neoplasms / Q000556:secondary*; D051381:Rats; D011916:Rats, Inbred F344