Intraperitoneal radioimmunotherapy to treat the early phase of peritoneal dissemination of human colon cancer cells in a murine model.
OBJECTIVE
In patients with a high risk of peritoneal dissemination of colon cancer, a treatment adjuvant to surgical resection would improve their prognosis. We aimed to determine whether radioimmunotherapy employing radiolabelled monoclonal antibody would work in this situation.


METHODS
A murine model of peritoneal dissemination was established in female Balb/c nu/nu mice by intraperitoneal injection of LS180 human colon cancer cells. Radioimmunotherapy with 7.4 MBq of a murine IgG1, anti-colorectal A7 monoclonal antibody, radiolabelled with (131)I by the chloramine-T method was conducted intraperitoneally on days 0, 3, 7 and 14 after cell inoculation, respectively.


RESULTS
Radioimmunotherapy at any timing improved survival of mice as compared with those of non-treated mice and mice treated with a daily dose of 30 mg x kg(-1) of 5-fluorouracil for 4 consecutive days. The best improvement was obtained when radioimmunotherapy was conducted on day 0.


CONCLUSIONS
These results indicate that intraperitoneal radioimmunotherapy may effectively kill colon cancer cells disseminated in the peritoneal cavity before formation of tumours and, therefore, may work as an adjuvant treatment to prevent peritoneal metastasis of colon cancer.
Kinuya
Seigo
S
Department of Biotracer Medicine, Kanazawa University Graduate School of Medical Sciences, Kanazawa, Ishikawa 920-8640, Japan. kinuya@med.kanazawa-u.ac.jp
Yokoyama
Kunihiko
K
Fukuoka
Makoto
M
Hiramatsu
Takashi
T
Mori
Hirofumi
H
Shiba
Kazuhiro
K
Watanabe
Naoto
N
Shuke
Noriyuki
N
Michigishi
Takatoshi
T
Tonami
Norihisa
N
D000818:Animals; D000911:Antibodies, Monoclonal / Q000737:chemistry; D045744:Cell Line, Tumor; D003110:Colonic Neoplasms / Q000628:therapy*; D005260:Female; D006801:Humans; D007274:Injections, Intraperitoneal / Q000379:methods*; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D009362:Neoplasm Metastasis; D010534:Peritoneal Neoplasms / Q000628:therapy*; D016499:Radioimmunotherapy / Q000379:methods*; D013997:Time Factors
D000911:Antibodies, Monoclonal