TP53 status predicts long-term survival in locally advanced breast cancer after primary chemotherapy.

BACKGROUND: Before the advent of neoadjuvant chemotherapy, radiotherapy and surgery alone were associated with a high risk of uncontrolled locoregional relapses in locally advanced breast cancer (LABC). MATERIAL AND METHODS: In the 1990s we initiated two neoadjuvant protocols, where patients with LABC were given either doxorubicin qW or 5-fluorouracil/mitomycin (FUMI) q3W to shrink the tumours prior to mastectomy and postoperative radiotherapy. Previously, we reported TP53 mutation status to predict a poor response to chemotherapy. Here, we present the long-term survival data, with a follow-up of 20 years in the doxorubicin (n = 90) and 15 years in the FUMI trial (n = 34). RESULTS: Patients in the doxorubicin trial with TP53-mutated tumours experienced a shorter recurrence-free (RFS; 14 vs. 83 months, p < 0.001) and overall survival (OS; 35 vs. 90 months, p < 0.001) than patients with TP53 wt tumours. Similarily, TP53 mutations were associated with a shorter OS (22 vs. 80 months, p = 0.03) and a tendency to shorter RFS (17 vs. 33 months, p = 0.06) in patients treated with FUMI. Furthermore, axillary lymph node metastases predicted shorter OS, but only in patients treated with doxorubicin (49 vs. 142 months, p < 0.04). Applying multivariate analysis, TP53 mutations predicted inferior RFS (p < 0.001) as well as OS (p < 0.001), independently of axillary lymph node status. Isolated local recurrences, without simultaneous distant metastases, occurred in seven patients only in the two trials. Interestingly, chest wall radiation fibrosis predicted improved OS (p = 0.004). CONCLUSION: TP53 inactivating mutations are associated with an inferior long-term prognosis in patients with LABC treated with conventional chemotherapy.

Upfront compared to delayed cytoreductive surgery and perioperative intraperitoneal chemotherapy for pseudomyxoma peritonei is associated with considerably lower perioperative morbidity and recurrence rate.

BACKGROUND: Cytoreductive surgery (CRS) combined with perioperative intraperitoneal chemotherapy (PIC) is a recognized management strategy for pseudomyxoma peritonei. We seek to evaluate the outcomes of patients treated upfront with CRS PIC compared to patients undergoing delayed CRS PIC as salvage or treatment for recurrences after initial debulking surgery. METHODS: Retrospective analysis of patients with low-grade pseudomyxoma peritonei treated within our institution were stratified according to upfront versus delayed CRS PIC after intial debulking surgery. Survival was analyzed using the Kaplan-Meier method and compared using the log-rank test. RESULTS: Of 83 patients treated, 35 patients (42%) underwent upfront and 48 patients (58%) underwent delayed CRS PIC. The peritoneal cancer index (P = 0.048), amount of blood transfusion intraoperatively (P = 0.003) and duration of operation (P = 0.007) was lesser in the upfront compared to delayed group. Upfront treatment confers 5-year recurrence-free survival benefit (77% vs 37%; P = 0.011) and 10-year overall survival benefit (67% vs 35%; P = 0.054) over delayed treatment. CONCLUSION: Upfront CRS PIC seems to confer beneficial perioperative outcomes and lower recurrence rates over delayed CRS PIC. Early referral to centralized treatment centers would seem to be a reasonable strategy to improve outcomes.

Cisplatin-cyclophosphamide-mitomycin combination chemotherapy with supportive care versus supportive care alone for treatment of metastatic non-small-cell lung cancer.

BACKGROUND: Patients with TNM stage IV non-small-cell lung cancer have short survival times. Previous controlled studies comparing chemotherapy and supportive care for the treatment of this type of cancer have not given consistent results, have included patients with different disease stages, and have rarely reported drug dose intensity. PURPOSE: The present trial was designed to assess the safety and the effect on survival of supportive care alone versus chemotherapy with cisplatin, cyclophosphamide, and mitomycin combined with appropriate supportive care in patients with stage IV non-small-cell lung cancer. METHODS: Patients (n = 102) with stage IV non-small-cell lung cancer were randomly assigned to one of two treatment regimens. The combined modality group (52 patients) received supportive care along with cisplatin (75 mg/m2), cyclophosphamide (400 mg/m2), and mitomycin (10 mg/m2) given intravenously at 3-week intervals. The supportive care group (50 patients) received supportive care alone. Randomization was stratified on the basis of histology (squamous versus nonsquamous cell carcinoma), performance status (Karnofsky), and weight loss (during the 6 months preceding randomization). The two groups were well matched for age and sex. Survival analysis was performed after the last patient died. RESULTS: The median number of chemotherapy cycles was 3.5 per patient. Mean weekly delivered doses of drugs were as follows: cisplatin, 22.1 mg/m2; cyclophosphamide, 118 mg/m2; and mitomycin, 2.9 mg/m2. Toxic effects due to chemotherapy were generally mild, but peripheral neuropathy and hematologic and renal toxic effects were observed. In the supportive care group, mean survival was 6.1 months (median, 4.0 months); six patients lived at least 12 months and two lived at least 18 months. In the combined modality group, mean survival was 11.3 months (median, 8.5 months); 20 patients lived at least 12 months, 13 lived at least 18 months, and five lived at least 24 months. Difference in survival was statistically significant (P < .0001). Survival was directly related to initial performance status in both groups (P < .01) and was significantly (P < .01) longer for patients with squamous cell carcinoma than for those with nonsquamous cell carcinoma. CONCLUSIONS: The combination of supportive care and cisplatin-cyclophosphamide-mitomycin therapy offers a survival advantage over supportive care alone in patients with advanced non-small-cell lung cancer. IMPLICATIONS: Metastatic non-small-cell lung cancer, generally considered to be unresponsive or marginally responsive to chemotherapy, can be treated with chemotherapy, with an expectation of prolonging patient survival. Although the results of the present study are encouraging, clinical research should continue to be directed toward developing more effective treatments for this disease.

Treatment of locally unresectable carcinoma of the pancreas: comparison of combined-modality therapy (chemotherapy plus radiotherapy) to chemotherapy alone. Gastrointestinal Tumor Study Group.

Randomized trials of the Gastrointestinal Tumor Study Group have previously demonstrated enhanced survival of patients with locally unresectable pancreatic cancer treated with 5-fluorouracil in combination with radiation therapy compared with that of patients treated with radiation therapy alone. The present study compared the survival of patients treated with multidrug chemotherapy [streptozocin, mitomycin, and 5-fluorouracil (SMF)] versus radiation combined with 5-fluorouracil followed by the same three-drug SMF combination. In 43 patients randomly allocated between these two arms, an improved median survival for the combined-modality therapy (42 weeks) compared with chemotherapy alone (32 weeks) was demonstrated. Overall survival following this combined-modality treatment program (41% at 1 year) was significantly superior to that following SMF chemotherapy alone (19% at 1 year), by a two-tailed log rank test (P less than .02). Serial studies of the Gastrointestinal Tumor Study Group with patients with locally unresectable pancreatic adenocarcinoma have shown that combined-modality therapy is superior to either optimal radiotherapy or chemotherapy alone.

Definitive irradiation and chemotherapy for radiosensitization in management of anal carcinoma: interim report on Radiation Therapy Oncology Group study no. 8314.

Following documented evidence of the synergism of 5-fluorouracil (5-FU) and radiation therapy and an additive effect with mitomycin and irradiation, pilot studies have demonstrated the potential for definitive radiation therapy in the management of squamous cell and basaloid carcinomas of the anal canal, allowing sphincter preservation. Our study explored the long-term effectiveness of combined therapy at this disease site and examined the feasibility of a Radiation Therapy Oncology Group study involving concomitant radiation therapy and chemotherapy. Between 1983 and 1987, 79 assessable patients with any primary tumor stage of anal canal carcinoma were treated by external-beam irradiation combined with mitomycin given by bolus iv injection and 5-FU given by continuous infusion. Radiation was delivered to the perineum and pelvis to a total dose of 4,080 cGy in 4.5-5 weeks. The inguinal nodal areas received 4,080 cGy, calculated at a 3-cm depth in the center of the nodal area. A 96-hour infusion of 5-FU was started on days 2 and 28 of the irradiation at a dose of 1,000 mg/m2 over 24 hours, and a bolus injection of mitomycin was administered on day 2 at a dose of 10 mg/m2. The overall survival rates are 97% at 1 year and 73% at 3 years. Patients with lesions less than 3 cm in diameter and those treated strictly according to the protocol did significantly better than those with larger lesions and those whose treatment did not comply with the protocol. The interim outcome of the study demonstrates that this combined therapy is effective for patients with anal cancer and allows preservation of the sphincter and of sexual function.

Phase I study of hepatic arterial degradable starch microspheres and mitomycin.

Intraarterial administration of 40-microns degradable starch microspheres (DSM) in a drug solution can temporarily retard flow of the drug-blood column through the arteriolar-capillary bed and lead to increased local drug deposition. Premonitory to Phase II-III efficacy studies applying this concept to regional therapy, it was necessary to determine the DSM dose to use. Patients with hepatic cancers were treated with varying doses of DSM with mitomycin C coadministered into the hepatic artery to define a dose of DSM which produces acceptable toxicity with maximal hepatic drug deposition as determined by a reduction in systemic mitomycin C exposure. Comparison of six patients receiving 6 ml of DSM (6 X 10(6) particles/ml) with ten patients receiving 15 ml showed a lower incidence and decreased severity of acute toxicity in terms of nausea/vomiting (16% versus 50%) and right upper quadrant hepatic pain (none versus 40%) with 6 ml of DSM. Reduction in systemic mitomycin C exposure evaluated by decrements in the area under the concentration curve in peripheral blood with time due to DSM was similar in both groups. Another seven patients were treated with escalating doses of DSM concurrently with 5 mg of mitomycin C. Although all seven patients tolerated 6 ml of DSM, higher doses (9 ml, 12 ml, 15 ml) led to incremental patient drop-out due to severe, acute right upper quadrant pain with only two patients able to receive 15 ml of DSM. In these patients, 6 ml of DSM appeared nearly equivalent to higher doses in terms of systemic exposure to mitomycin C. Eleven additional patients were evaluated for tolerance to repeated 6-ml dosing of DSM. Four patients had epigastric pain correlating with flow to the stomach demonstrated by nuclide angiography. The seven patients with no pain and no flow to stomach were treated with good tolerance for three-plus courses. Thus, 6 ml of DSM appear to be appropriate for Phase II-III studies.

Anticancer effects of local administration of mitomycin C via the hepatic artery or portal vein on implantation and growth of VX2 cancer injected into rabbit liver.

Rabbits were inoculated with a suspension of VX2 carcinoma cells in the liver, and mitomycin C was given via the hepatic artery or the portal vein for a study of the anticancer effects. Twenty-eight rabbits were killed for preliminary study at 1 h or 1, 3, 7, 9, 12, or 14 days after the inoculation. Another 36 rabbits were divided into three groups. Groups A and B were given the agent (0.5 mg/kg), 1 h after the inoculation and on Days 2, 4, 6, and 8, into the common hepatic artery or the splenic vein, respectively. Group C was not treated after inoculation. The mean numbers of cancer nodules per rabbit in Groups A, B, and C were 11.9, 36.4, and 83.4, respectively, at 12 days after inoculation. The number of cancer nodules of Group A was smallest (P less than 0.025, F test). The means of the total cross-sectional area of tumor nodules in Groups A, B, and C were 32.7, 79.7, and 217.3 mm2, respectively. The total cross-sectional area of the cancer nodules of Group A was smallest (P less than 0.05, F test). These results suggest that the anticancer agents given via the hepatic artery had better effects on early (small) metastatic liver tumor than those via the portal vein.

Effect of drug exposure duration and sequencing on hyperthermic potentiation of mitomycin-C and cisplatin.

The effects of drug exposure duration and of heat and drug sequencing on hyperthermic potentiation of mitomycin-C (MMC) and cisplatin (DDP) were studied. Heating for 1 h at 42 degrees C was combined with drug exposure times of 1, 2, 4, or 8 h. For both DDP and MMC, hyperthermic potentiation was greatest when heating was done during drug exposure. Dose enhancement ratios for both drugs at 1% survival were highest with the shortest drug exposure times and decreased as the drug exposure time increased from 1 to 8 h. For DDP, the dose enhancement ratio decreased from 1.9 with a 1-h drug exposure to 1.2 with an 8-h drug exposure. For MMC, the dose enhancement ratio decreased from 1.8 to 1.5 as the drug exposure duration was increased from 1 to 8 h. Our results suggest that thermochemotherapy in vivo is likely to be most effective with rapid infusions of DDP or MMC.

Enzyme immunoassay for the quantification of mitomycin C using beta-galactosidase as a label.

A mitomycin C (MMC) antibody was produced following immunization of rabbits with a MMC-bovine serum albumin conjugate, which was newly synthesized by coupling MMC to mercaptosuccinylated bovine serum albumin via a cross-linker, N-maleoyl aminobutyric acid. Enzyme labeling of MMC was performed using beta-D-galactosidase (EC 3.2.1.23) via m-maleoyl benzoic acid. An enzyme immunoassay for MMC was developed utilizing these reagents by a double-antibody technique. The standard curve of the assay was linear on a logit-log plot, and the lower limit of detection was 12 nM (0.2 ng/tube) so the enzyme immunoassay was found to be approximately 25 times more sensitive than a microbiological assay. Further, the enzyme immunoassay is practically free from interference by any other anticancer drugs. No significant decrease in MMC immunoreactivity was observed following 24 hr of incubation of the drug in normal human serum or urine at 37 degrees. Using this assay, serum or urine levels of MMC can be determined accurately after administration of the drug to rats at a single dose of 600 micrograms/kg. The sensitivity and specificity of the enzyme immunoassay for MMC should provide a valuable new tool for use in pharmacokinetic and toxicity studies of MMC.

Immunoprophylactic and immunotherapeutic response by concanavalin A-bound tumor vaccine enhanced by chemotherapeutic agents eliminating possible suppressors.

The combined administration of mitomycin C (MMC) on Day 5 and concanavalin A (Con A)-bound L1210 murine leukemia vaccine on Days 1 and 8 induced an enhanced therapeutic response in animals bearing L1210 leukemia greater than that inducible by either of them. The enhancement was dependent on the administration timing of the vaccine, dependent on vaccine-bound Con A, and specific for L1210 leukemia, as evidenced by the fact that no enhancement was induced in P388 leukemic animals. However, the enhancement was dependent on delayed MMC administration, and MMC administered on Day 3 failed to induce the enhancement, indicating that the chemotherapeutic potency of MMC played no major role in the enhancement. These results suggest that the enhancement may be dependent on antileukemia immunity induced by Con A-bound vaccine and may be further potentiated by MMC. A series of experiments comparing immunoprophylactic and immunotherapeutic responses inducible by different chemotherapeutic agents combined with the vaccine suggested that chemotherapeutic agents enhanced the potency of the vaccine by abrogating suppressors associated with vaccine-bound Con A. This hypothesis was supported by the finding that tumor vaccine induced peritoneal cells of tumor-bearing animals were abrogated in their suppressor activity in polyclonal in vitro spleen cell blastogenesis when these animals were further treated with MMC.

Early postoperative intraperitoneal chemotherapy as an adjuvant therapy to surgery for peritoneal carcinomatosis from gastrointestinal cancer: pharmacological studies.

Gastrointestinal malignancy may spread to peritoneal surfaces in the absence of lymphatic or hematogenous metastases. To treat peritoneal carcinomatosis, a uniformly lethal disease process, extensive cytoreductive surgery and i.p. chemotherapy were combined. Early postoperative i.p. chemotherapy was instilled in the first few days after the surgical procedure in an attempt to treat anatomic sites that would be sealed off by postoperative adhesions. Mitomycin C was given on the first postoperative day at two doses, 10 and 12 mg/m2. 5-Fluorouracil was given on postoperative days 2-5 at 15 and 20 mg/kg, respectively. Median area under the curve ratio i.p./i.v. was 117 for 5-fluorouracil and 21.6 for mitomycin C. Elevated intraportal levels of drug were observed for i.p. 5-fluorouracil but not for mitomycin C. The marked pharmacokinetic advantage of postoperative i.p. suggests that this treatment strategy should be considered in a clinical trial in patients at risk for progression of peritoneal carcinomatosis.

Augmentation of activity of cis-diamminedichloroplatinum(II) and mitomycin C by interferon in human malignant mesothelioma xenografts in nude mice.

Two human mesothelioma xenograft lines, BG and ES, serially passaged in athymic mice, were studied to determine the efficacy of alpha-interferon in this type of tumor. Treatment began after progressive tumor growth was established. Recombinant human alpha-interferon-2a (Roferon- A) was given by s.c. injection, at a site distant from the tumor, at a dose of 2 x 10(5) IU 5 days per wk for 5 wk. Mild inhibitory activity was noted in both lines with interferon alone. cis-Diamminedichloroplatinum(II) (CDDP) (4 mg/kg) weekly x 5 was effective in line BG, while mitomycin C (1.5 mg/kg) weekly x 3 was effective in line ES. CDDP was not as effective in line ES. The moderate activity of CDDP in line BG and of mitomycin C in line ES was markedly increased by the addition of alpha-interferon. The combination of mitomycin C and alpha-interferon was as effective as mitomycin C and CDDP. No additional toxicity was noted by the addition of alpha-interferon. The combination of recombinant human alpha-interferon-2a and active chemotherapeutic agents is effective in mesothelioma xenografts.

Bladder wall penetration of intravesical mitomycin C in dogs.

We examined the kinetics of penetration of mitomycin C (MMC) in the dog bladder wall after intravesical instillation of 20 mg/40 ml, a dose used in patients. Bladder tissues were harvested and concentration-depth profiles were established by analysis of thin tissue slices cut parallel to the urothelial surface of the bladder. Tissue concentrations after a dwell time of 5-7 min were similar to those after 30-120 min. In tissues harvested 60 and 75 min after removal of the dose, MMC was not detected in 5 of 6 samples and was less than 1 micrograms/g at the mucosa in the remaining sample, suggesting a rapid "washout" of the drug. The rapid equilibrium between the drug in urine and bladder tissue indicates that the duration of exposure of the bladder wall tissue was approximately equal to the dwell time of intravesical therapy. Tissue concentrations declined log-linearly with respect to the depth of penetration. The concentration immediately underneath the urothelium (C0) showed considerable intra- and interanimal variability. Bladder distention appeared to increase C0 by several fold. C0 ranged from 2 to 275 micrograms/g wet tissue weight, with a median value of 24 micrograms/g, or 11 micrograms/g when two animals with distended bladders were excluded. MMC concentrations in 3 different sites of the same bladder varied up to 5-fold. Within the capillary-perfused mucosa and muscularis (between 50 and 2000 microns from the urothelial surface), concentrations decreased by 50% for each 500-microns distance. The median concentration at 2000 microns was 1 microgram/g (n = 24). At 2000-3000 microns, tissue concentrations in most (18 of 24) specimens either declined to an asymptotic value or were lower than the detection limit of 0.1 microgram/g. Concentrations in the bladder contents were 200-500 micrograms/ml, the average tissue concentration from 50 to 3000 microns was 10 micrograms/g, and plasma concentrations were less than 0.1 microgram/ml. This supports the therapeutic advantage of intravesical therapy of high local drug concentrations while minimizing systemic exposure. A comparison of the urine concentration and C0 indicated a 30-fold decline in concentration across the urothelium. This suggests the importance of the urothelium as a barrier to MMC absorption. A separate study in our laboratories showed that 16 micrograms/ml of MMC was needed to produce a 90% inhibition of the labeling index of explants of human bladder cancers located in the urothelium (Ta tumor, TNM classification), 25 micrograms/ml in the lamina propria (T1 tumors), and 43 micrograms/ml in the muscle layer (T2 tumors).(ABSTRACT TRUNCATED AT 400 WORDS)

Pharmacokinetics of intraarterial mitomycin C in humans.

The pharmacological advantage of mitomycin C (MMC) given by intraarterial infusion as compared to i.v. infusion was studied in seven patients with cancer metastatic to the liver. Hepatic artery, hepatic vein, and peripheral vein catheters were placed, and then each patient received constant infusions of MMC via the intraarterial and peripheral i.v. routes at 0.4, 1.2, and 4.0 mg/sq m/hr. MMC concentrations were measured in the hepatic artery, hepatic vein, and a peripheral vein by high-pressure liquid chromatography after steady state had been reached at 2 hr. Mean plasma clearance increased significantly with infusion rate from 0.6 liter/min at 0.4 mg/sq m/hr to 1.1 liters/min at 4.0 mg/sq m/hr. The calculated relative advantage of treating hepatic tumors via the intraarterial route (Rt) was found to be 2.5- to 3.6-fold at a plasma flow rate of 0.4 liter/sq m and MMC infusion rates of 0.4 to 4.0 mg/sq m/hr. The hepatic vein MMC concentration averaged 30% higher during intraarterial than during i.v. infusion. Hepatic extraction of MMC averaged only 23%, so that the intraarterial route offered little advantage with respect to reduced systemic toxicity. These data suggest a limited pharmacological rationale for the selection of the intraarterial route for the treatment of hepatic tumors with MMC.

Intratumor chemoimmunotherapy with mitomycin C and components from mycobacteria in regression of line 10 tumors in guinea pigs.

Intratumor chemotherapy with the use of mitomycin C and/or immunotherapy caused regression of line 10 carcinomas in strain 2 guinea pigs and resulted in development of tumor-specific immunity. The immunotherapeutic preparation consisted of oil-in-water emulsions containing Mycobacterium cell walls or residues of cell walls termed cell wall skeletons. The latter preparations were combined with trehalose dimycolate, which was isolated by microparticulate chromatography from whole cells of mycobacteria. Reducing mitomycin C to a single intratumor injection of 50 microgram produced little necrotizing effect and a mean tumor regression rate of 17%. Intratumor immunotherapy 1 day after treatment with 50 microgram of mitomycin C resulted in regression of 90% of the treated tumors as compared to mean regression rates of 30 to 50% for immunotherapy alone. In addition, chemoimmunotherapy was more effective than either chemotherapy or immunotherapy alone in producing regression of relatively large, as well as smaller, tumors.

Enhanced lymphatic delivery of mitomycin C conjugated with dextran.

Absorption and lymphatic transfer of a polymeric prodrug of mitomycin C (MMC), mitomycin C-dextran conjugate (MMC-D), following i.m. injection were studied in rats in order to assess the feasibility of a macromolecular prodrug as a lymphotropic delivery system. Three types of MMC-D, conjugates with dextran with molecular weights of 10,000, 70,000 and 500,000, were synthesized, and the disposition of MMC was determined by bioassay. Following i.m. injection of MMC-D, MMC was retained at the injection site for a long period in a conjugated form while MMC administered as a free form disappeared rapidly. The disappearance was markedly influenced by the size of carrier dextran, because the remaining amount of MMC increased with an increase of molecular size. The lymphatic uptake of the drug was evaluated by determining the concentration in the regional lymph nodes and thoracic lymph fluid. In contrast to a slight lymphatic uptake following i.v. and i.m. injection of free MMC, MMC-D exhibited remarkable accumulation in the regional lymph nodes after i.m. injection which persisted up to 48 hr. MMC-D (Mr 10,000) appeared in the thoracic lymph as both the conjugated and the free form. Larger MMC-D gave a persistent supply of free MMC in thoracic lymph, suggesting that it was accumulated in the lymph node and supplying MMC continuously. These MMC-Ds suppressed the lymph node metastases introduced by a s.c. inoculation of L1210 leukemia cells. The usefulness of MMC-D as a lymphotropic delivery system for preventing lymphatic metastasis of cancer was suggested.

Experimental and clinical activity of mitomycin C and cis-diamminedichloroplatinum in malignant mesothelioma.

Little information is available regarding the effectiveness of chemotherapeutic agents in malignant mesothelioma. Human malignant mesothelioma specimens from two patients were successfully transplanted and maintained in homozygous nude mice. Screening of chemotherapeutic agents revealed that cisplatin was the most active single agent in one line, and mitomycin C in the other. The combination of mitomycin C and cisplatin, however, was the most effective regimen for both lines of xenografted human mesothelioma. Based on these results in nude mice, a clinical trial of mitomycin C and cisplatin was undertaken. Four of 12 patients showed objective response (one complete and three partial). These clinical results support the usefulness of the nude mouse model for malignant mesothelioma.

Experimental model for combination chemotherapy with metronidazole using human uterine cervical carcinomas transplanted into nude mice.

Human uterine cervical carcinomas (Yumoto strain) and HeLa cell tumors were transplanted into nude mice, and their transplantable strains were established. The fundamental histological features of these tumors were analyzed according to their histological construction and cytological maturation. The effect of administered drugs was examined morphologically. The Yumoto strain is a well-differentiated epidermoid-type carcinoma consisting of regularly arranged basal-type, parabasal-type, and keratinizing-type cells. The HeLa cell tumor is made up of solid medullary carcinoma cell nests in which trabecular arrangements begin to appear around the medullary areas after the third passage. This feature is maintained up to the 17th generation. The basal layer-type cancer cells of the Yumoto strain as well as trabecularly arranged cancer cells in the HeLa cell tumor were selectively influenced by administration of bleomycin and/or mitomycin and showed considerable degeneration or complete disappearance. On the contrary, metronidazole (a drug for vaginal trichomoniasis; Flagyl) displayed a cytotoxic effect on the parabasal-type and/or more mature cancer cells of the Yumoto strain as well as on the solid medullary area of the HeLa cell tumor. This result may indicate a selective affinity of drugs for malignant cells according to their histological construction, and it is conceivable that these types of carcinoma can be affected by combination administration of metronidazole and oncostatic chemicals such as bleomycin and mitomycin. This speculation was realized in this experimental animal research.

Cellular interaction and in vitro antitumor activity of mitomycin C-dextran conjugate.

Cellular interaction and in vitro antitumor activity of a polymeric prodrug of mitomycin C (MMC), mitomycin C-dextran conjugate (MMC-D), were studied in relation to its physicochemical characteristics. MMC-D with cationic and anionic charges were examined. The cationic MMC-D was synthesized using a spacer, epsilon-aminocaproic acid and dextrans with molecular weights of 10,000, 70,000, or 500,000 [MMC(C6)Dcat]. The anionic MMC-D was synthesized using 6-bromohexanoic acid as a spacer and dextran with a molecular weight of 70,000 [MMC(C6)Dan]. Cellular adsorption was determined by measuring the concentration of the drug in the medium after incubation with three tumor cell lines, Ehrlich ascites carcinoma, L1210 leukemia, and AH66 ascites hepatoma cells. MMC(C6)Dcat was adsorbed more readily than MMC or MMC(C6)Dan on the tumor cell surface by an electrostatic force. The percentage of adsorption remained almost constant during the course of incubation and no significant difference was observed between the incubation at 4 degrees C and that at 37 degrees C. A corresponding increase in the amounts of MMC(C6)Dcat adsorbed on with higher molecular weights was noted, which conformed to Langmuir's adsorption isotherm. In vitro antitumor activity was evaluated using L1210 and EAC cell culture systems and human tumor colony forming assay. MMC(C6)Dcat showed growth inhibition essentially equal to that of MMC in continuous drug exposure experiments. In a 1-h drug exposure experiment, MMC(C6)Dcat with a molecular weight of 70,000 or 500,000 was more active than MMC, and a good correlation was observed between the effects of MMC(C6)Dcat and the extent of cellular interaction. These results show that cellular interaction played an important role in the manifestation of the antitumor effect of MMC-D and that these phenomena are governed by the physicochemical properties of macromolecular prodrugs, such as electric charge and molecular weight.

Disposition of anticancer drugs after bolus arterial administration in a tissue-isolated tumor perfusion system.

Disposition characteristics of various anticancer drugs in a tissue-isolated tumor preparation were studied in Walker 256 carcinosarcoma-bearing rats using an in situ single-pass vascular perfusion technique. Three anticancer drugs, 5-fluorouracil, mitomycin C, and Adriamycin, and two lipophilic prodrugs of mitomycin C were tested in the tumor preparation perfused with Tyrode's solution containing 4.7% bovine serum albumin. After bolus arterial injection of test drugs, their outflow concentration-time curves were analyzed based on statistical moment theory. In each tumor preparation, the injection of drug was paired with that of vascular reference substance, Evans' blue-labeled bovine serum albumin, and disposition parameters of the drug were corrected with those of vascular reference substance. From the mean transit time values of vascular reference substance, the average vascular volume of the tumor preparation was calculated to be 0.063 ml/g, which decreased with tumor growth. All drugs showed significant extraction by the tumor tissue, depending on their physicochemical properties. Distribution volumes of tested drugs were from 1.53 to 3.33 times larger than the vascular volume. Calculated intrinsic clearance values for the protein-unbound fractions increased as the lipophilicity of the drug increased. The potential increase in tumor uptake was observed in lipophilic prodrugs of mitomycin C. The present experimental system is thus suggested to be useful for analyzing drug disposition in tumor tissue.