Immune response of mice exposed to cis-diamminedichloroplatinum

Low-dose cisplatin-5-fluorouracil prevents postoperative suppression of natural killer cell activity in patients with gastrointestinal cancer

BACKGROUND

The effect of administering low-dose cisplatin (CDDP)-5-fluorouracil (5-FU) postoperatively on the activity of the immune system is not known. To clarify the effect on natural killer (NK) cell activity of treatment with low-dose CDDP-5-FU, we compared NK cell activity after surgery for gastrointestinal cancer in patients treated with low-dose CDDP-5-FU, a bolus dose of mitomycin C (MMC) or no anticancer drug.

METHODS

Sixty-two patients consisted of three groups: low-dose CDDP-5-FU (n = 15), MMC (n = 20) and no-drug (n = 27). Chemotherapy was initiated immediately after surgery. NK cell activity was measured on the day before surgery (pre-op) and on postoperative days 7 (POD7) and 21 (POD21).

RESULTS

The NK cell activities of the CDDP-5-FU group were 37.7% at pre-op, 36.1% on POD7 and 33.6% on POD21. However, the NK cell activities in the no-drug and MMC groups were significantly decreased on POD7 (from 36.6 to 24.8% and from 31.4 to 16.6%, respectively). The NK cell activity in the MMC group remained depressed on POD21 (18.6%) whereas that in the no-drug group recovered (31.6%).

CONCLUSIONS

Consecutive administration of low-dose CDDP-5-FU appears to be useful as postoperative adjuvant chemotherapy because of its preventive effect on NK cell suppression after surgery.

Treatment of hepatic-metastatic colorectal cancer with a chemotherapeutic emulsion: interim results of a phase I trial

BACKGROUND

Hepatic arterial infusion of 5-fluoro-2-deoxyuridine (FUdR) is associated with a 60% response rate among previously untreated patients who have hepatic-metastatic colorectal cancer. One obstacle to further dose escalation has been concomitant hepatic toxicity. We are evaluating a FUdR-containing chemotherapeutic emulsion to further dose intensify therapy without associated toxicity.

METHODS

The in vitro pharmacokinetics of the emulsion were determined using high-pressure liquid chromatography (HPLC). The rate at which FUdR is released from emulsion into an overlying aqueous phase was determined in static and dynamic assays. Fifteen patients with hepatic-metastatic colorectal cancer were treated with intrahepatic arterial infusions of emulsion on a phase I dose-escalating clinical protocol. Serum collection determined systemic drug levels using HPLC.

RESULTS

In vitro studies demonstrate that FUdR is slowly released from emulsion into overlying aqueous medium. The emulsion serves as a depot for FUdR. Therapy was well tolerated. Emulsion was sequestered in the liver after infusion in all treated patients.

CONCLUSIONS

This Ethiodol-based, oil-in-water emulsion serves as a sustained-release preparation of FUdR. An Ethiodol-based oil-in-water emulsion is a clinically effective vehicle for delivering FUdR to hepatic-metastatic colorectal tumors.

In vitro analysis of the anticancer potential of tumor necrosis factor in combination with cisplatin

We have recently shown that cisplatin increases the natural cytotoxic (NC) cell-mediated lysis of a variety of human adenocarcinoma cell lines that are resistant to cisplatin or NC activity alone. Because NC lysis is mediated by tumor necrosis factor alpha (TNF) bound to the surface of NC effector cells, we analyzed the ability of TNF in combination with cisplatin to increase the lysis of tumor cells. The in vitro anticancer potential of the combination of TNF and cisplatin was determined for both dividing and nondividing populations of two human ovarian carcinoma cell lines, SK-OV-3 and OVCAR-3. Nondividing SK-OV-3 and OVCAR-3 cells are resistant to cisplatin and TNF when used as single agents. Dividing OVCAR-3 cells are approximately two times more sensitive to TNF than dividing SK-OV-3 cells, whereas dividing SK-OV-3 cells are approximately ten times more sensitive to cisplatin than dividing OVCAR-3 cells. TNF at 1000 units/ml in the presence of clinically low concentrations of cisplatin (0.6-0.25 micrograms/ml) increased the lysis of dividing OVCAR-3 cells above the value expected for the sum lysis mediated by cisplatin alone and lysis mediated by TNF alone. Similar results were obtained with dividing populations of the SK-OV-3 cell line. The combination of cisplatin and TNF did not increase the lysis of the nondividing populations of either cell line. The increased lysis of tumor cells combined with the maintenance of specificity for only dividing cells indicates that the combination of cisplatin and TNF may be useful for the treatment of tumors that are resistant to either cisplatin or TNF.

The effectiveness of cis-platinum, cyclophosphamide and melphalan in treating disseminated tumor cells in mice

Both B16 melanoma and Lewis lung carcinoma growing in C57/Bl mice spontaneously metastasize to the lungs and other organs. When the tumors are grown in the mouse tail to a specific volume and amputated, the spontaneously disseminated tumor cells can then be independently treated. The effects of a single dose of cyclophosphamide (200 mg/kg), cis-platinum (6 mg/kg) and melphalan (10 mg/kg) on the appearance of pulmonary and other metastases were measured. The cis-platinum treatment was shown to reduce the number and incidence of metastases of both tumors at various times after treatment. The antimetastatic effectiveness of cis-platinum against these two tumors was increased when 2.4 mg/kg was administered each day for five consecutive days after amputation of the primary. Cyclophosphamide, when administered at two-thirds maximum tolerated dose, had a small promoting effect on the number and incidence of pulmonary metastases of Lewis lung carcinoma, whereas, applied in the same dose, it had efficacy in the treatment of disseminated B16 melanoma and inhibited appearance of both pulmonary and lymph-node metastases. When melphalan was administered in single- and multiple-dose regimens, the number and incidence of metastases of both tumors increased at various times after primary tumor amputation. These data suggest that melphalan can promote the growth of disseminated tumor cells in both the lungs and other sites and that some systemic chemotherapies may result in promotion instead of suppression of metastatic disease.