Effects of a controlled-release cisplatin delivery system used after resection of mammary carcinoma in mice.
OBJECTIVE
To evaluate efficacy of a controlled-release cisplatin delivery system, used after marginal resection of mammary carcinoma (ie, resection of grossly evident tumor) in mice, to prevent tumor regrowth and metastasis.


METHODS
42 female C3H-HeJ mice.


METHODS
Mice were inoculated with mammary carcinoma cells. Between 2 and 6 days later, tumors were marginally resected and mice were assigned to 1 of 3 groups: no treatment (control; n = 14), cisplatin administered intraperitoneally (i.p. cisplatin; 14), and cisplatin delivered by use of an open-cell polylactic acid system placed within the tumor bed (slow-release cisplatin; 14). Tumor regrowth was measured daily. Mice were euthanatized 14 days after surgery, and complete necropsies were performed.


RESULTS
Tumor regrowth was not detected in the slow-release cisplatin group; however, tumor regrowth was detected in 7 of 14 mice in the i.p. cisplatin group and 14 of 14 mice in the control group. Median (+/-SD) number of days to tumor regrowth was 13.5+/-0.64 and 7.79+/-0.87 in the i.p. cisplatin and control groups, respectively. Mice in the i.p. cisplatin group had significantly delayed tumor regrowth, compared with control mice. Metastases to lungs were detected in 8 of 14 control mice but were not detected in mice in either cisplatin treatment group.


CONCLUSIONS
The open-cell polylactic acid with cisplatin delivery system was successful in delaying local tumor regrowth and metastasis in mice with marginally resected mammary carcinoma. Use of a controlled-release cisplatin delivery system may be an effective adjunct treatment following excision of mammary carcinoma in humans and other animals.
Ehrhart
N
N
College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins 80523, USA.
Dernell
W S
WS
Ehrhart
E J
EJ
Hutchison
J M
JM
Douple
E B
EB
Brekke
J H
JH
Straw
R C
RC
Withrow
S J
SJ
D000818:Animals; D002945:Cisplatin / Q000008:administration & dosage* / Q000627:therapeutic use; D003131:Combined Modality Therapy; D003692:Delayed-Action Preparations; D005260:Female; D007274:Injections, Intraperitoneal; D019344:Lactic Acid; D008325:Mammary Neoplasms, Experimental / Q000188:drug therapy* / Q000473:pathology / Q000601:surgery*; D051379:Mice; D008809:Mice, Inbred C3H; D011091:Polyesters; D011108:Polymers; D013997:Time Factors
D003692:Delayed-Action Preparations; D011091:Polyesters; D011108:Polymers; D019344:Lactic Acid; C033616:poly(lactide); D002945:Cisplatin