title: Effects of irradiation combined with cis-diamminedichloroplatinum (CDDP) suppository in rabbit VX2 rectal tumors.
abstract: To decrease local recurrence and increase disease free survival, various preoperative therapies for patients with advanced rectal cancer have been studied. Cis-diamminedichloroplatinum (II) (CDDP) has become one of the most widely used cancer chemotherapeutic drugs. It has also been found to have radiosensitizing properties. In this experimental study, the efficacy of chemoradiotherapy using a novel CDDP suppository, and one with mixed micelles, was examined in a rabbit VX2 rectal tumor model. Rabbits were divided into four groups: control group, irradiation (R) group, CDDP suppository plus irradiation (CR) group, and mixed micelles plus CDDP suppository plus irradiation (CMR) group. Tumor growth ratios were reduced significantly in the CR and CMR groups as compared with the ratio in the control group. Microscopically, response rates of main tumors were 0%, 33.3%, 70.0%, and 91. 7%, respectively. The number of metastatic lymph nodes in the CR and CMR groups decreased significantly compared to the control group and the R group. The microscopic response rates of metastatic lymph nodes were 0%, 11.1%, 40.0%, and 41.7%, respectively. Lung metastases were observed in three rabbits in the R group, and in one rabbit in the CMR group. Tissue platinum concentrations both in tumors and in regional lymph nodes increased significantly when mixed micelles were used. Chemoradiotherapy using the CDDP suppository and mixed micelles was effective for local control in the rabbit VX2 rectal tumor model.
authors.affiliation: Department of General Surgery, Graduate School of Medicine, Chiba University, 1-8-1 Inohana, Chuo-ku, 260-8670, Chiba City, Chiba, Japan.
authors.forename: Kazuo
authors.initials: K
authors.lastname: Wakatsuki
authors.forename: Kenji
authors.initials: K
authors.lastname: Oda
authors.forename: Keiji
authors.initials: K
authors.lastname: Koda
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Seike
authors.forename: Nobuhiro
authors.initials: N
authors.lastname: Takiguchi
authors.forename: Norio
authors.initials: N
authors.lastname: Saito
authors.forename: Masaru
authors.initials: M
authors.lastname: Miyazaki
mesh_terms: D000818:Animals; D000970:Antineoplastic Agents / Q000008:administration & dosage*; D002945:Cisplatin / Q000008:administration & dosage*; D003131:Combined Modality Therapy; D004195:Disease Models, Animal; D005260:Female; D008207:Lymphatic Metastasis; D008823:Micelles; D011817:Rabbits; D012004:Rectal Neoplasms / Q000188:drug therapy* / Q000473:pathology / Q000532:radiotherapy*; D013488:Suppositories
chemical_list: D000970:Antineoplastic Agents; D008823:Micelles; D013488:Suppositories; D002945:Cisplatin