Joan A. Stratton

The subrenal capsule tumor implant assay as a predictor of clinical response to chemotherapy: 3 Years of experience

The clinical response to chemotherapy of a series of female patients with advanced pelvic malignancies was compared to the response of their tumors to the same agents in the murine subrenal capsule implant assay. A total of 194 different patients were studied in 242 different assays; 89.3% of the assays were evaluable. There were 83 prospective assays (assays performed before the patient received the chemotherapy) of 66 different patients for which clinical correlations were available. In these assays the sensitivity (frequency of positive test results in responding patients) was 85.0%, the specificity (frequency of negative test results in nonresponding patients) was 57.1%, and the efficiency (percentage correctly classified) was 63.9%. There were 100 retrospective assays (assays performed after the patient had been treated with the chemotherapy) of 69 different patients for which clinical correlations were available. In these assays the sensitivity was 66.7%, the specificity 70.7%, and the efficiency 70.0%. Thirty-one of the patients had both prospective and retrospective assays. There were 59 patients for whom the clinical response to chemotherapy could not be determined. It is believed that the clinical utility of the SRC assay has been validated by the good prospective sensitivity of the assay.

Action of 2-β-d-ribofuranosylthiazole-4-carboxamide (tiazofurin) against untreated human ovarian cancers in the murine xenograft assay

The activity of 2-beta-D-ribofuranosylthiazole-4-carboxamide (tiazofurin) was determined in nine untreated human ovarian cancer specimens, using the murine subrenal capsule xenograft assay. Tumor cytotoxic effect was demonstrated in seven out of the nine tumors implanted. The drug was well tolerated by the test animals. Tiazofurin may prove to be an effective chemotherapeutic agent in the treatment of ovarian cancer.

Chemosensitivity testing of nonsolid tumors by the subrenal-capsule implant assay

A procedure to test chemosensitivity of nonsolid tumors using the subrenal-capsule xenograft assay has been developed. This technique is applicable to the study of malignant effusions and hematopoietic tumors. The tumor cells are centrifuged to form a pellet and the pellet is resuspended in the presence of bovine fibrinogen to form a jelled clot. This clot is cut into fragments which are implanted beneath the renal capsule of normal mice. The growth of the tumor cells from ovarian adenocarcinoma obtained from ascitic fluid is better than that of tumor fragments from the solid tumors. This is probably a reflection of the greater viability of tumor cells from ascitic fluids. The sensitivity to chemotherapy was the same for the solid tumor and its malignant effusions.

Intraperitoneal cisplatin: Comparison of antitumor activity and toxicity as a function of solvent saline concentration

The use of increasing concentrations of NaCl in the solvent during administration of cisplatin is known to decrease nephrotoxicity, but its effect on antitumor activity is less certain. A murine tumor model employing the subrenal capsule assay was used to test the toxicity and antitumor activity of intraperitoneal cisplatin at different doses of the drug using varying concentrations of NaCl in the vehicle of administration. Toxicity (measured by LD50, weight loss, and nephrotoxicity) was significantly lower in mice treated with cisplatin prepared in 4.5% NaCl as compared to cisplatin prepared in distilled water (DW) or 0.9% NaCl. Administration of 4.5% NaCl subcutaneously along with intraperitoneal cisplatin prepared in DW failed to decrease toxicity. Despite lower toxicity, no decrease in antitumor activity could be demonstrated based on increasing concentrations of NaCl in the solvent during intraperitoneal therapy.

Response of human adenocarcinoma to chemotherapy: As sole agents and in combination with sodium ibuprofen

The sensitivity of 12 human tumors to various chemotherapeutic agents was measured in the 6-day subrenal capsule xenograft assay. All of the tumors were adenocarcinomas: 9 ovarian, 2 colon, and one endometrial. Doxorubicin, cisplatin, melphalan, 5- fluorouracil , methotrexate, and vinblastine sulfate were tested for antineoplastic activity on all tumors. In addition, a prostaglandin synthetase inhibitor, sodium ibuprofen, was assayed for cytostatic activity and for the ability to enhance the cytotoxic activity of melphalan and vinblastine sulfate. The response of the tumors to the cytotoxic agents were variable, but 5 of the 12 tumors showed a significant reduction of growth when the animals were treated with sodium ibuprofen alone. The addition of ibuprofen to the chemotherapeutic agents did not significantly alter the therapeutic activity of melphalan, but decreased the effectiveness of vinblastine in one case. When ibuprofen was given in combination with a cytotoxic drug, the primary cytoreductive effect was that of the cytotoxic agent.

Quantitative nuclear DNA analysis of human ovarian adenocarcinoma: Compared before and after chemotherapy and correlated with clinical response

Quantitative DNA measurements on 18 human ovarian adenocarcinomas were made by computerized image analysis. The DNA content of the tumor cells was measured on specimens of tumor obtained at the initial diagnostic surgery and at second-look surgery after treatment with chemotherapy. The mean DNA content of the specimens and the ploidy pattern of the tumor cells were determined. With the exception that borderline tumors had near normal ploidy patterns and mean DNA content, there was no consistent correlation between the stage of disease, grade, or histiologic character of the tumor and either the DNA content or ploidy pattern. But it was noteworthy that all three of the patients who had complete responses (negative second-looks), also had tumors with DNA content and ploidy patterns near triploid. When the ratio of mean DNA content before and after chemotherapy was determined for each ploidy group, there was an apparent correlation between this ratio and clinical status of the patient 10 month after chemotherapy. That is, patients with low ploidy tumors and high DNA content ratio (greater than 1.25) had a better prognosis than patients with high ploidy tumors and lower DNA content ratios (less than 1.25). Thus, although the mean DNA content of the tumor at the initial surgery was not in itself of sufficient prognostic value, when the mean DNA content of the tumor after chemotherapy is also known, an accurate picture of the patients clinical response could be determined.

Treatment of a syngeneic rat tumor with magnetically responsive albumin microspheres labeled with doxorubicin or protein A

The tumoricidal activity of magnetically responsive albumin microspheres tagged with either doxorubicin or Staphylococcal protein A was tested against an induced mammary adenocarcinoma, 13762, implanted subcutaneously in the tail of female Fischer-344 rats. Magnetically responsive albumin microspheres containing Fe3O4 particles were prepared by an emulsion polymerization method incorporating either doxorubicin or protein A into the albumin matrix. Microspheres were produced with an average diameter of 1 micron (0.2 to 1.5 micron) in a concentration of 10(9) microspheres/mg. Microspheres were injected either directly into the tail artery and localized to the implanted tumor using a permanent bipolar adjustable gap magnet with a field strength of 8000 Oe, or directly into the femoral vein with no magnetic localization. Control groups consisted of animals treated with intravenously or intraarterially administered microspheres containing no active agent, and a no-treatment group. Survival was significantly greater in both the doxorubicin- and protein A-treated animals than in the control groups. First appearance of local metastases was prolonged in only the intraarterial magnetically localized doxorubicin-treated group of animals. Tumor growth rate was significantly depressed in both intraarterially magnetically localized treatment groups when compared to intravenously administered nonlocalized treatment groups. Magnetically responsive albumin microspheres appear to be an effective delivery system for cytotoxic agents and biologic response modifiers. Significant tumoricidal activity can be produced with a one-time administration of these agents utilizing this drug delivery system.

Use of a murine model for comparison of intravenous and intraperitoneal cisplatin in the treatment of microscopic ovarian cancer

The most effective method for the delivery of cisplatin chemotherapy in the treatment of epithelial ovarian cancer limited to the presence of microscopic intraperitoneal disease is a controversial issue. The use of intravenous (iv) versus intraperitoneal (ip) cisplatin was evaluated in a murine tumor model of human epithelial ovarian cancer. Using single dose cisplatin therapy for microscopic disease limited to positive cytology of abdominal disease and microscopic peritoneal involvement, ip therapy had significantly greater (P less than 0.001) survival time than iv therapy (28 +/- 1.6 days vs. 23 +/- 1.6 days, respectively). Once ascites and macroscopically evident intraperitoneal tumor became apparent, no difference could be found in survival time based on iv versus ip therapy (16 +/- 3 days for both groups); though both forms of therapy significantly (P less than 0.05) prolonged survival in mice with macroscopic disease when compared to control animals (13 +/- 1.2 days). The evidence presented implies that ip cisplatin therapy is significantly more effective than iv therapy when dealing with microscopic intraperitoneal disease.

Depressed natural killer cell activity in tumor-bearing rats: effect of immunotherapy and cytoreductive chemotherapy

A single-cell cytotoxicity assay was used to determine the number of effector cells in the peripheral blood of normal and tumor-bearing Fischer 344 female rats which bound to and lysed K562 target cells. Of the blood leukocytes of normal rats 18.4 +/- 2.6% bound to K562 target cells; one-third of the conjugated target cells were killed as evidenced by trypan blue uptake. Cells isolated from the blood of rats bearing mammary adenocarcinoma R3230 or 13762 bound fewer target cells, 6.3 +/- 1.1 and 7.1 +/- 1.8%, respectively. The proportion of dead conjugated target cells was not different from that of normal rat leukocytes if the leukocytes were from rats bearing 13762 but was reduced by one-half if the leukocytes came from rats bearing R3230. Treatment of the tumor-bearing rats with cytoreductive chemotherapy returned the percentage conjugation to target cells to normal levels if the tumor growth was inhibited more than 70%. Treatment of the tumor-bearing rats with immunomodulating agents did not inhibit the growth of the tumors, but treatment with sodium ibuprofen or muramyl dipeptide increased the percentage conjugation significantly.

Depressed Mononuclear Cell Function in Advanced Neoplastic Disease

ABSTRACT: The ascites fluids from 9 patients with invasive gynecologic neoplasms were examined to determine the immunocompetence of the mononuclear ascites cells and the immunoregulatory properties of the cell‐free ascitic fluid. Blood mononuclear cells (from 5 patients) were also tested. The mononuclear cells from the cancer patients responded poorly to stimulation with polyclonal mitogens; only the blood mononuclear cell response to pokeweed mitogen was not significantly less than that of normal subjects. The addition of autologous serum or cell‐free ascitic fluid to the cell cultures enhanced the response of the cells to phytohemagglutinin and pokeweed mitogen, had little effect on the response to concanavalin‐A, and greatly depressed the response to succinyl‐concanavalin‐A. We found no evidence for the presence of suppressor cells in the ascites cell populations. The data are consistent with the thesis that the depressed immune responses are the result of malnutrition associated with advanced malignant disease.