Interferon-beta inhibits liver metastases from murine colon 26 carcinoma and its highly metastatic variant.

PURPOSE: The antitumor effects of Interferon-beta (IFN-beta) are due to its direct inhibition of cell proliferation, immunostimulatory activity, and the inhibition of angiogenesis. We investigated the mechanism of the effects of IFN-beta on a murine colon 26 cell line (CT 26) and its highly metastatic variant (L5). METHODS: We examined its inhibitory effects on cell proliferation in vitro and the development of liver metastases in vivo. RESULTS: The proliferation of CT 26 in vitro was inhibited by IFN-beta in a dose- and time-dependent manner. The number of metastases was reduced in mice inoculated with CT 26 (P<0.01) and L5 (P<0.01) on Day 14 after treatment with IFN-beta. The median survival rate of the mice inoculated with L5 administered IFN-beta every other day, or every day was higher than in the control group (P<0.05). A dorsal air sac assay demonstrated that IFN-beta inhibited angiogenesis in mice inoculated with CT 26, but the effects disappeared with aminoguanidine, an inducible nitric oxide synthase inhibitor. CONCLUSION: These results showed that IFN-beta directly inhibits the proliferation of CT 26. In addition, the in vivo experiments suggested that IFN-beta might effectively inhibit liver metastases.

[A phase I study of postoperative combination therapy with TS-1 and low dose cisplatin against stage IV gastric carcinoma].

A dose-escalation study was conducted for postoperative patients with stage IV gastric cancer to determine the recommended dose of daily intravenous cisplatin combined with a fixed dose of TS-1. TS-1 was administered orally twice daily for 2 weeks followed by a 1-week rest. The dose of TS-1 was based on the body surface area (BSA) as follows: 80 mg/day for BSA less than 1.25, 100 mg/day for BSA 1.25 to less than 1.50, and 120 mg/day for BSA 1.5 or more. Three dose levels of cisplatin (2, 4, 6 mg/m(2)) were studied, and two courses were performed. Cisplatin was infused on day 1-5 and 8-12 for 30 minutes. The National Cancer Institute common toxicity criteria (NCI-CTC Version 3) were used to evaluate the grade of toxicity. Three patients enrolled in each level. Dose escalation was performed when dose-limiting toxicities (DLT) were seen in 0/3, and 3 more cases of the same level were added when DLTs were seen 1-2/3. Maximum-tolerated dose (MTD) were determined when DLTs were seen in 3 cases. DLTs were not recorded during the administration of CDDP up to 4 mg/m(2). However, DLTs were seen 3/3 at level 3. From these results, cisplatin of 4 mg/m(2)was determined to be the recommended dose (RD) in this protocol for postoperative stage IV gastric carcinoma.

[Evaluation of low-dose FP therapy as adjuvant therapy for gastric cancer].

In the present study, we demonstrate the result of low-dose FP treatment as an adjuvant therapy for 30 patients of stage II or more progressive gastric cancer. 5-FU and CDDP were injected intravenously for 10 days from day 1 through day 5, and day 8 through 12 for 2 weeks at a dose of 250 mg/body and 10 mg/body, or for 14 days at a dose of 250 mg/m2/day and 5 mg/m2/day, respectively. Patients were excluded if they received less than 80% of the respective doses in a course of treatment by the protocol. This constituted a course of chemotherapy, which was repeated every 4 weeks. Grade 3 neutropenia was observed in one case. Other toxicities were anorexia, nausea, weight loss, diarrhea, general fatigue and elevation of serum creatinine, but they were not so severe. The two-year survival rate was 100% in cur A cases, 85% in cur B, and 0% in cur C. The median survival time of the cur C patients was 10 months. These results indicate that low-dose FP therapy is safe and recommendable for cur A and cur B patients. However, other treatment methods such as sequential chemotherapy are needed for cur C gastric cancer patients.

A randomized controlled study of immunochemotherapy with OK-432 after curative surgery for gastric cancer.

The effect of adjuvant immunochemotherapy including OK-432 (Picibanil) on survival was assessed in patients who underwent curative resection of gastric cancer. Patients enrolled in this randomized controlled study were randomly assigned to group A or group B. Group A patients received 800 mg/d 5'-DFUR (Furtulon) for 2 years from 2 weeks after the operation. Group B patients received OK-432 plus 5'-DFUR by the same regimen as in group A. This study enrolled 288 patients, and 1 patient with malignant lymphoma was excluded. Among the remaining 287 patients, 143 and 144 were allocated to group A and group B, respectively, and their data were included in statistical analysis. The 5-year survival rates for groups A and B were 62.9% and 63.8%, respectively, showing no significant difference (P = 0.7996).

Evaluation of malignancy using Ki-67 labeling index for gastric stromal tumor.

BACKGROUND: Assessment of malignant potential in gastrointestinal stromal tumors (GISTs) is still problematic. The maximum tumor diameter and the mitotic index are generally used as an index of malignancy of GISTs. The Ki-67 labeling index has recently been used as an index of cell growth, and the prognosis of GISTs was reported to be significantly poor when the value of this index was 10% or higher. METHODS: Clinicopathological and immunohistological factors were analyzed in 15 patients who underwent surgical resection of gastric stromal tumors at our department between April 1997 and July 2002. The patients were divided into "metastasis/recurrence" and "benign" groups. Also, the relationship of changes in the Ki-67 labeling index to the degree of malignancy in recurrent lesions was assessed in an 84-year-old woman who underwent five reoperations because of recurrences in the peritoneum. RESULTS: Significant differences were noted between the metastasis/recurrence and benign groups in relation to the mean maximum tumor diameter (186.7 +/- 80.8 mm vs 41.3 +/- 22.9 mm), mitotic index (88.3 +/- 5.0/50 high-power fields [HPF] vs 3.0 +/- 2.9/50 HPF), and the Ki-67 labeling index (11.4 +/- 2.5% vs 0.01 +/- 0.51%). In the patient who had metastasis to the liver 3.5 years after initial operation and underwent five reoperations before death, the intervals until detection of recurrence tended to be shortened gradually. The Ki-67 labeling index varied with each operation, and tended to be higher at the time of reoperations than at the initial operation. CONCLUSION: The maximum tumor diameter, mitotic index, and Ki-67 labeling index were useful as an index of malignancy for gastric stromal tumor. The efficacy of surgical resection alone may be insufficient in patients with disseminated metastasis to the peritoneum.