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Purpose: Studies were conducted to test whether fever-range whole body thermal therapy would boost the efficacy of oxaliplatin chemotherapy without substantial toxicity., Materials and Methods: The effect of mild heat (40 degrees C) on oxaliplatin cytotoxicity, cellular uptake, and platinum-DNA adduct formation was studied in vitro using the MTLn3 tumour cell line. In vivo oxaliplatin was administered at various doses and times before, during and after fever-range thermal therapy (6 h at 40 degrees C) to rats bearing an MTLn3 mammary adenocarcinoma. Tumour growth, survival, and toxicity were measured to determine treatment outcome., Results: Heating halved the oxaliplatin IC-50 dose for MTLn3 cells. Cellular uptake of platinum and platinum adducts increased by 34% and 36%, respectively, with heat. In vivo, 50% of all rats given 10 mg/kg oxaliplatin 24 h before thermal therapy were completely immunologically cured, while a further 11% regressed their primary tumour but ultimately succumbed to metastases, and 17% experienced a limited response with increased survival. The curative response occurred only in a narrow range of doses, with most cures at 10 mg/kg. Thermochemotherapy-treated, but uncured, animals had delayed incidence and slowed growth of metastases. Anti-tumour efficacy was greatest, and toxicity was least, when oxaliplatin was administered 12 or 24 h before fever-range whole body thermal therapy., Conclusions: When properly dosed and scheduled, oxaliplatin thermochemotherapy achieved permanent eradication of all primary and metastatic tumours in 50% of animals, seemingly through an immune response. Successful clinical translation of this protocol would yield hitherto unseen cures and substantial improvement in quality of life.

Purpose: The purpose of the Phase I component of this study was to find the maximally tolerated dose (MTD) of cisplatin administered within a regimen of fever-range whole body thermal therapy (FR-WB-TT), cisplatin, gemcitabine, and low-dose interferon-alpha (IFN-alpha). The Phase II component aimed to assess which cancer diagnoses responded to the regimen, the response rate, and response duration., Materials and Methods: The protocol design derived from a schedule-optimized preclinical regimen. Drugs were administered together, and also with thermal therapy in a schedule that optimized the therapeutic index. Eligible patients were those with therapy-resistant, metastatic or advanced solid malignancies. Beginning at 40 mg/m(2), the cisplatin dose was escalated by 10 mg/m(2) to the maximally tolerated dose (MTD) in successive cohorts of 3 patients. A treatment cycle consisted of cisplatin on day one, followed by thermal therapy and simultaneous gemcitabine 36 hours later; then a second dose of gemcitabine one week later; and daily IFN- alpha., Results: Thirty-seven patients were treated on protocol. The MTD of cisplatin in the thermochemotherapy regimen was established to be 60 mg/m(2). The dose limiting toxicities (DLT) were peripheral neuropathy and ototoxicity. Complete and partial responses combined were 43%. The therapy improved the quality of life of responding patients., Conclusion: The protocol was well tolerated and was associated with antitumor activity in patients with a variety of advanced metastatic solid tumors. Tumor response occurred with the thermochemotherapy treatment despite treating malignancies that had progressed on the same chemotherapy drugs administered as standard treatment. Notably, good responses were observed in patients with high-grade neuroendocrine and pancreas cancers. This regimen will be tested in a phase II study.

Purpose: To determine an effective triple-agent schedule combining fever-range whole body thermal therapy (FR-WB-TT) with cisplatin and gemcitabine by optimizing the timing of drug with heat, and drug with drug., Materials and Methods: Using an orthotopically implanted syngeneic breast adenocarcinoma in an immunologically normal female Fischer rat model, we investigated various schedules of a thermochemotherapy regimen combining FR-WB-TT with chemotherapy agents, cisplatin and gemcitabine. Differently timed combinations of a) cisplatin with FR-WB-TT, b) gemcitabine with FR-WB-TT, and c) cisplatin with gemcitabine were examined for anti-tumor efficacy and toxicity. A combination of the three agents based on the optimal two-agent schedules was then tested., Results: The greatest primary tumor and axillary metastasis growth delay and lowest toxicity was induced with administration of cisplatin 24 h prior to gemcitabine and cisplatin 24 h prior to simultaneous gemcitabine and FR-WB-TT. Administering cisplatin 24 h prior to gemcitabine was more effective and less toxic than giving the two drugs simultaneously or gemcitabine prior to cisplatin. Survival was greatest when gemcitabine and FR-WB-TT were administered 24 h after cisplatin, even with reduced drug doses. One complete cure resulted from the triple agent treatment., Conclusions: The relative timing of agents in multiple modality treatments is critically important in achieving tumor control or cures, and in reducing toxicity. Optimizing the relative timing of multiple agents in thermochemotherapy allows use of lower drug doses to achieve maximal anti-tumor efficacy and minimal toxicity.

The natural course of tumor microvascularity in rat MTLn3 mammary adenocarcinomas was studied. The relationship between microvessel density (MVD), vascular endothelial growth factor (VEGF) expression, and histopathology was compared in primary and metastatic axillary (ALN) and inguinal lymph node (ILN) tumors over 5-6 tumor doublings. Excised tumors were examined for (i) MVD assessed by immunostaining with anti-CD31 antibody, (ii) VEGF expression assessed by immunostaining with anti-VEGF antibody, and (iii) histopathologic extent of metastatic lymph node invasion. MVD and VEGF scores rose asymptotically with increasing tumor weight in both primary and metastatic tumors. The MVD saturation level was significantly greater for primary tumors (MVD = 22) than for ALNs or ILNs (MVD = 14). Maximal VEGF score was not statistically different between the three kinds of tumors, however the rate of rise in VEGF expression was different. Near-maximal VEGF expression occurred early in tumor growth, preceding microvessel development. Both MVD and VEGF expression in lymph nodes were proportional to the pathology score characterizing increasing metastatic invasion. LNMs limited to the subcapsular sinus had the lowest MVD, indicating an ability to survive without significant vasculature. These findings underscore the differences in angiogenesis between primary tumors and LNMs and have implications for therapy of metastatic cancer.

Many women diagnosed with invasive breast cancer have undetected occult metastases at the time of their primary tumour diagnosis. The development and growth of these micro-metastases relies heavily on angiogenesis. Therefore, administering an angiogenesis-blocking treatment from the time of diagnosis could reduce the incidence of metastasis and, ultimately, increase patient survival. It is hypothesized that an antiangiogenesis strategy combining fever-range whole-body hyperthermia (FR-WBH) and metronomic chemotherapy could inhibit the development of metastatic disease with minimal toxicity. To test this theory, a low, daily dose of the topoisomerase-I inhibitor irinotecan hydrochloride (CPT-11) was administered over a prolonged period of time to rats bearing the highly metastatic MTLn3 mammary adenocarcinoma primary tumour surgically excised on day 12 after implantation. The metronomic CPT-11 was combined with long-duration, low-temperature, fever-range whole body hyperthermia (FR-WBH). This systemic hyperthermia enhances chemotherapy-induced cytotoxicity as well as immunological activity. Both the group treated with FR-WBH alone and the combined FR-WBH + CPT-11 group had delayed onset and reduced incidence of axillary lymph node metastases compared to control (p < 0.05). Combination therapy of FR-WBH + CPT-11 resulted in a significantly greater inhibition of axillary lymph node metastasis volume compared to both control and CPT-11 alone (p < 0.02) at day 16. Interestingly, none of the therapies significantly affected inguinal lymph node metastases. Lung metastases were decreased by 36% at the time of death in rats treated with FR-WBH + CPT-11, by 25% in the CPT-11 alone group and by 14% in the FR-WBH alone group. Rats treated with FR-WBH, + CPT-11 survived significantly longer (35%) than control animals (p < 0.04). Neither significant body weight loss nor gastrointestinal toxicity was observed in any group. These data suggest that, after excision of the primary tumour, FR-WBH and metronomic CPT-11 can be safely combined to reduce distant lymph node and lung metastases and, thus, to increase survival.

We investigated the correlation between antitumor efficacy and kinetics of tumor and normal tissue apoptosis when cis-diamminedichloroplatinum (II) (CDDP) was combined with two different durations of whole body hyperthermia [SH-WBH, at 41.5 degrees C for 1 h (1 h WBH) or 2 h (2 h WBH)]. Rats bearing a mammary adenocarcinoma (MTLn3) were treated with 1 or 2 h WBH CDDP and then assessed for tumor growth delay (TGD). A separate study examined the amount of induced apoptosis in tumor and normal tissue (thymus and ileum) over 96 h following the same treatments. 1 h WBH + CDDP increased the TGD to 10.5+/-0.5 days, which was not statistically different from the TGD of 12.3+/-0.5 days obtained with 2 h WBH + CDDP. The area under the curve (AUC) of percentage tumor apoptosis for 1 h WBH + CDDP was 50% of that of 2 h WBH + CDDP. The AUC of percentage thymus apoptosis for 1 h WBH + CDDP was 25% of that of 2 h WBH + CDDP, and the AUC of the score of ileal apoptosis for 1 h WBH + CDDP was 81% of that of 2 h WBH + CDDP. These data indicate that while 1 h WBH + CDDP induced less tumor apoptosis than 2 h WBH + CDDP, antitumor activity was enhanced to a similar degree by both 1 h and 2 h WBH + CDDP, and since 1 h WBH + CDDP caused less normal tissue apoptosis than 2 h WBH + CDDP, a 1 h duration of WBH + CDDP may be a therapy that is both, as effective as, and safer than a 2 h duration of WBH + CDDP.

We have compared the therapeutic efficacy as well as the kinetics of treatment-induced apoptosis and necrosis of the maximum tolerated dose (MTD) of doxorubicin (DOX) or cisplatin (CDDP) combined with long-duration, low-temperature whole-body hyperthermia (LL-WBH, at 40.0 degrees C for 6 hr), with the combination of the MTDs of either DOX or CDDP with short-duration, high-temperature WBH (SH-WBH, at 41.5 degrees C for 2 hr), in a rat mammary adenocarcinoma (MTLn3). The MTD of LL-WBH + DOX resulted in increased therapeutic efficacy, compared with the MTD of DOX alone and SH-WBH + DOX. The MTD of LL-WBH + CDDP, however, did not increase therapeutic efficacy, when compared with the MTD of CDDP alone or SH-WBH + CDDP. The MTD of LL-WBH + DOX caused a significant delay in the development of spontaneous axillary lymph node (ALN) metastasis and tended to cause longer mean survival, compared with SH-WBH + DOX. The peak of treatment-induced apoptosis was higher for the MTD of DOX + LL-WBH, compared with SH-WBH + DOX, whereas the apoptosis peak of the MTD of SH-WBH + CDDP was higher than that of LL-WBH + CDDP. The most extensive levels of tumor necrosis appeared to occur earlier with SH-WBH alone and the MTD of SH-WBH + DOX or CDDP than with other groups. Our results suggest that LL-WBH + DOX may be a promising therapy for breast cancer, and the extent of treatment-induced tumor apoptosis appears to correlate with antitumor response for MTDs of LL-WBH + DOX and SH-WBH + DOX, but not for the MTDs of CDDP with SH-WBH or LL-WBH.

This study examines antitumour effect and induction of apoptosis and necrosis after treatment with long-duration, mild whole body hyperthermia (LL-WBH, 40.0 degrees C, for 6 h) in simultaneous combination with cisplatin (CDDP) on primary and metastatic tumour growth in a rat mammary adenocarcinoma. A significantly greater delay in primary mammary tumour growth was observed after treatment with LL-WBH + CDDP, compared to either modality alone (p < 0.05). LL-WBH alone caused a significant delay in spontaneous metastasis to the axillary lymph node (ALN) and LL-WBH + CDDP tended to further increase the delay in ALN metastasis. Survival was longest in rats receiving LL-WBH + CDDP, compared to other groups (p < 0.05). CDDP induced a peak of tumour apoptosis at 24 h after treatment beginning that was significantly greater than LL-WBH alone (p < 0.05). The peak of tumour apoptosis induced by LL-WBH + CDDP from 12 to 24 h was significantly greater than any other group (p < 0.01). These results suggest that the extent of treatment-induced apoptosis seems to correlate positively with antitumour response and the combination or LL-WBH with CDDP may lead to a promising adjuvant therapy for breast cancer.

Minimizing normal tissue toxicity can enhance the therapeutic gain of thermochemotherapy. For this purpose, we investigated the optimal duration of whole body hyperthermia (WBH) (41.5 degrees C) when administered simultaneously with carboplatin (CBDCA). Using a transplantable fibrosarcoma in Fischer 344 rats, we measured tumor growth delay (TGD) as well as normal tissue toxicities (body weight loss, thrombocytopenia) induced by various durations of WBH (0.5, 1.0, 1.5, 2.0 or 2.5 hours) when combined with CBDCA (30 mg/kg, i.v.). When combined with CBDCA, 1.0 hour WBH increased the TGD compared to 0.5 hour of WBH, but with WBH durations greater than 1.0 hour, the TGD did not further significantly increase. Measuring CBDCA-induced myelosuppression, the platelet count on day 6 post-treatment decreased from a control mean of 6.8 x 10(8)/ml to 1.8 x 10(8)/ml after 2.5 hour WBH exposure in a duration-dependent manner (p < 0.001). To estimate the specific therapeutic efficacy (STE), we calculated a ratio of TGD to myelosuppression (thrombocytopenia). Compared to other WBH exposure times, 1.0 hour duration of WBH combined with CBDCA produced the highest STE (2.8) and over 1.5 hour duration of WBH did not result in any additional increase in STE. We conclude that 1.0 hour WBH exposure is optimal when combined with CBDCA in order to maximize the therapeutic gain.

The feasibility and efficacy of low temperature (40 degrees C) long duration whole body hyperthermia (LL-WBH) was investigated in rats bearing a highly metastatic mammary adenocarcinoma (MTLn3). We compared the treatment effects of various durations of LL-WBH (40 degrees C for 2-12 h) to that of conventional short duration-high temperature WBH (SH-WBH, 41.5 degrees C for 2 h). SH-WBH, 2 h LL-WBH, and 4 h LL-WBH resulted in only modest primary tumour growth delays (TGDs) of 0.9, 1.1 and 1.8 d (days) respectively. In contrast, significantly increased TGDs of 2.8, 3.2, 2.6, and 3.1 d were achieved with 6, 8, 10 and 12 h LL-WBH, respectively (p < 0.05 compared to SH-WBH, 2 h-LL-WBH, and 4 h-LL-WBH). Notably, LL-WBH reduced the incidence of axillary lymph node metastasis at 14 days post-treatment, from 100% in normothermic controls and 92% after SH-WBH, to 33, 40, 50, and 60% following 4, 6, 8 and 10 h LL-WBH respectively. When the duration of LL-WBH was extended to 12 h, no reduction in axillary lymph node metastasis was observed. Normal tissue toxicity of LL-WBH appeared to be minimal and LL-WBH durations of up to 12 h were well tolerated. These data show that LL-WBH for durations of from 4 to 10 h has greater antitumour activity than SH-WBH, against mammary adenocarcinoma, suggesting that LL-WBH may have therapeutic potential in the treatment of malignant disease.

We studied: (a) the adverse effects of tumour necrosis factor-alpha (TNF) given during whole body hyperthermia (WBH) on mean arterial pressure (MAP) and gut mucosa in anaesthetized rats; (b) the potential protective effect of NG-monomethyl-L-arginine (L-NMA), an inhibitor of nitric oxide synthase; and (c) the influence of L-NMA on the antitumour effect of the trimodality therapy, WBH + TNF + Carboplatin (CBDCA). In normothermic rats, TNF alone (10(5) or 10(6) U/kg) did not cause hypotension, but increased MAP (p < 0.05). L-NMA alone (5, 10 and 20 mg/kg) increased MAP moderately and dose-dependently (p < 0.05). WBH (41.5 degrees C for 2 h) increased MAP markedly (from 103 +/- 4 to 161 +/- 4 mm Hg). This increase in MAP was sustained throughout the hyperthermia, but was followed by a transient relative hypotension (MAP = 80 +/- mm Hg) on cessation of WBH and an eventual return to near baseline at 30 min post-WBH (MAP = 94 +/- 5 mm Hg). WBH + TNF (10(5) or 10(6) U/kg) initially increased MAP similarly to WBH alone. During the second hour of WBH, however, MAP decreased towards pre-treatment levels, and cessation of WBH was followed by sustained hypotension. This late hypotensive state was associated with a mortality during the early (first 2 h) post-WBH period of 17 and 100% at TNF dose of 10(5) and 10(6) U/kg TNF, respectively. L-NMA given to rats receiving WBH + TNF (10(6) U/kg) maintained MAP at levels similar to WBH alone during WBH treatment. L-NMA prevented the post-WBH hypotension, and extended the survival beyond the early (first 2 h) post-WBH period. No rat, however, receiving high dose TNF (10(6) U/kg) survived more than 12 h even with L-NMA (totally 40 mg/kg). WBH + TNF (10(5) and 10(6) U/kg) also produced marked histopathological injury to the gut mucosa at 2 h post-treatment. L-NMA substantially protected the gut from this injury. In rats bearing a transplantable fibrosarcoma, L-NMA did not decrease the antitumour effect consisting of WBH + TNF (10(5) U/kg) + CBDCA, while it decreased (p < 0.05) the general toxicity (weight loss, diarrhea and foot oedema) of this combination. We conclude that L-NMA may prevent or ameliorate the early toxicity but not the late lethal effects of WBH + high dose TNF (10(6) U/kg). Additionally, L-NMA reduces some of the toxicity of WBH + TNF (10(5) U/kg) + CBDCA without decreasing the antitumour effect of this trimodality therapy. Inhibitors of nitric oxide synthase such as L-NMA may provide a novel approach to overcoming the toxicity of TNF in combination with WBH.

The pattern of spontaneous apoptosis and necrosis was investigated in an untreated, transplantable rat mammary adenocarcinoma (MTLn3) throughout the natural course of primary and metastatic tumor growth. The occurrence of spontaneous apoptosis was different when comparing primary to metastatic tumor growth. In the primary MTLn3 tumor growing at the mammary fat pad inoculation site we observed an inverse association between tumor growth and apoptosis. As the primary tumor increased in size, the extent of spontaneous apoptosis decreased. In contrast, an increase in apoptosis was associated with tumor growth of MTLn3 metastases in the axillary lymph node and the lung. In regard to necrosis, a similar pattern of increased necrosis was associated with tumor progression in both primary and metastatic tumors. Differences between primary and metastatic tumors in their pattern of spontaneous apoptosis may have important implications for the design of clinical treatment strategies.

Apoptosis in tumor and normal tissues was examined in rats treated with whole-body hyperthermia (WBH; 41.5 degrees C for 2 h). WBH alone produced 0.5 day of tumor growth delay (TGD) in a fibrosarcoma and 5.8 days of TGD in the Ward colon carcinoma. This difference in WBH-induced TGD indicates that the fibrosarcoma is relatively resistant to WBH, whereas the Ward colon carcinoma is relatively heat sensitive. A quantitative histological assay for apoptosis demonstrated that the extent of apoptosis in the fibrosarcoma reached a maximum level of 19% 4 h after WBH and returned to the control level by 24 h. In contrast, WBH induced apoptosis with a peak value of 43% at 8 h in the Ward colon carcinoma, and the apoptotic level remained elevated above the control level until 48 h after WBH. Within normal tissues, the spleen and the lymph nodes showed WBH-induced apoptosis; however, the highest level of WBH-induced apoptosis as well as the most prolonged increase in apoptotic levels occurred in the thymus. The WBH-induced apoptosis in the thymus remained elevated above the control level until 48 h after WBH. Within the entire gastrointestinal tract, the small intestine was the most sensitive to WBH. Apoptotic cells were observed in the small bowel mucosa following WBH exposure. We also noted a minor WBH-induced increase in the apoptotic level in the bone marrow. Except for the case of the thymus, increased apoptotic levels in the normal tissues declined after peak levels at 4 h, and apoptosis above control levels was not seen beyond 12 h following WBH. Thus, within the normal tissues, WBH-induced apoptosis declined to basal levels within 12-48 h. These data indicate that both the extent and the kinetics of WBH-induced apoptosis differ between the two tumors and, meaningfully, between tumor and normal tissues. The extent and duration of apoptosis seem to correlate with tumor response to WBH.

Long-term effects of cisplatin (DDP) (6 mg/kg) alone at 37 degrees C and DDP (2 mg/kg) plus whole body hyperthermia 120 min at 41.5 degrees C) on DDP-mediated normal tissue toxicities were compared up to 12 months post-treatment using a F344 rat model. Acute renal damage, represented by an increase in blood urea nitrogen (BUN) at day 5 posttreatment, was significantly higher after DDP (6 mg/kg) alone at 37 degrees C than the increase in BUN after DDP (2 mg/kg) plus whole body hyperthermia. After recovery, BUN levels as a result of both treatments remained elevated. From 9 months onwards BUN levels as a result of the combined treatment gradually increased to values > 100 mg/dl. At 12 months, side toxicities as a result of the combined treatment were more severe than the side effects noted after DDP (6 mg/kg) alone at 37 degrees C. Red blood cell and hematocrit values were significantly reduced, whereas BUN was significantly increased. The results obtained with histological examination of the kidneys corresponded with the observed functional differences. Platinum levels in the kidney, however, were highest in the DDP (6 mg/kg) alone at 37 degrees C group. This observation does not explain why the chronic toxicity as a result of the combined modality treatment was more severe.

The induction of apoptosis in normal tissues was histopathologically examined in rats treated with 5-fluorouracil (5-FU). 5-FU was administered by either bolus intravenous injection or 72-hr prolonged intravenous infusion (PIF). Bolus injection and PIF of 5-FU induced different kinetic profiles of apoptosis in the thymus, spleen and ileum. The bolus injections of 5-FU induced a greater extent of apoptosis in these tissues, compared to PIF 5-FU. These data indicate that the kinetics and extent of apoptosis induced by 5-FU depends on the schedule of the 5-FU administration, and that 5-FU-induced toxicity may be related to 5-FU-induced apoptosis in normal tissues.

This study examines the effects of a combined modality regimen of long duration-low temperature whole body hyperthermia (6 h at 40.0 degrees C; LL-WBH), recombinant human tumor necrosis factor-alpha (TNF) and carboplatin (CBDCA) on a transplantable fibrosarcoma as well as normal tissue. We compare LL-WBH with short duration-high temperature whole body hyperthermia (2 h at 41.5 degrees; SH-WBH). LL-WBH alone had no significant effect on tumor growth. Tumor growth delay (TGD) with TNF alone (0.1 days) and that with CBDCA alone (1.3 days) were significantly increased to 2.6 days (P < 0.05) and 2.8 days (P < 0.05), respectively, when combined with LL-WBH. Although TNF+CBDCA produced minimally increased TGD of 1.9 days, the combination of LL-WBH+TNF+CBDCA produced a significantly greater TGD of 5.6 days, compared to the other dual combinations (P < 0.01). There was no difference between TGDs for SH-WBH and LL-WBH in combination with TNF+CBDCA. Trimodality treatment-induced normal tissue toxicities, characterized by body weight loss, diarrhea, foot edema, and myelosuppression, were significantly greater in rats treated with SH-WBH+TNF+CBDCA, compared to LL-WBH+TNF+CBDCA. Histopathological examination also demonstrated that SH-WBH+TNF+CBDCA caused severe damage to the lymphoid tissues, intestinal tract, and peripheral microvasulature. We observed minimal histopathological changes observed in rats treated with LL-WBH+TNF+CBDCA. These data suggest that LL-WBH in combination with TNF and CBDCA has a greater therapeutic efficacy than SH-WBH.

Thermal enhancement of cis-diamminedichloroplatinum (II) (DDP)-mediated antitumour activity and normal tissue toxicities by whole body hyperthermia were compared in a F344 rat model under different anaesthetic conditions. Whole body hyperthermia (WBH: 120 min at 41.5 degrees C) enhanced both DDP-mediated antitumour activity and toxic side-effects. Our present study shows that anaesthetics might influence the thermal enhancement ratios (TER) calculated for DDP-mediated normal tissue toxicity but did not influence the TER calculated for antitumour activity. The TER calculated for DDP-mediated antitumour activity was 2.9. As a result of the anaesthetics used, the TER calculated for kidney and gastrointestinal toxicity ranged from 1.8 to 4.5 and from 1.2 to 2.3, respectively. The TER estimated for DDP-mediated general toxicities varied between 2.9 and 4.0 for weight loss, and from 2.0 to 2.3 based on the LD50. The differential effect of anaesthetics on TER calculated for antitumour activity and normal tissue toxicity led to different therapeutic ratios. For example the therapeutic ratio for combined WBH and DDP, using kidney damage as an end-point for normal tissue damage, ranged from 0.6 (without anaesthesia) to 1.6 (using nembutal as anaesthetic). The significantly elevated platinum levels in serum, kidney, jejunum and tumour tissue after WBH treatment may explain the thermal enhancement of DDP-mediated antitumour activity and side-effects but no correlation could be found for the differences in DDP-mediated normal tissue toxicities induced by the anaesthetics.

This study examined the effect of a trimodality therapy of the combination of recombinant human tumor necrosis factor alpha (TNF), whole-body hypertheria (WBH), and cis-diamminedichloroplatinum(II) (CDDP) or cis-diammine-1,1-cyclobutane dicarboxylate platinum(II) (CBDCA) on a fibrosarcoma and normal tissue in F344 rats. TNF (1 x 10(5) units/kg) increased the antitumor effect of both CDDP (1.5 mg/kg) + WBH (2 h at 41.5 degrees C) and CBDCA (30 mg/kg) + WBH. Tumor growth delay, which was 1.9 days for CDDP + WBH and 2.7 days for CBDCA + WBH (P less than 0.01 compared to control), was significantly increased to 2.9 days with TNF + CDDP + WBH and 5.4 days with TNF + CBDCA + WBH (P less than 0.05). WBH, TNF, CDDP or CBDCA alone, TNF + CDDP, TNF + CBDCA, or TNF + WBH had no significant effect on tumor growth. In contrast, administration of TNF did not enhance the CDDP- or CBDCA-mediated dose limiting normal tissue toxicity. CDDP + WBH-mediated acute renal injury and CBDCA + WBH-mediated acute myelosuppression, as determined by blood urea nitrogen and peripheral blood cell counts, respectively, were not increased with the addition of TNF to either dual modality therapy. Histopathologically, addition of TNF produced no significant alterations in the kidney and the bone marrow as compared to CDDP + WBH or CBDCA + WBH. These data show that TNF enhanced the platinum + WBH-mediated antitumor effect without increasing normal tissue toxicity, suggesting that TNF may increase the therapeutic efficacy of CDDP or CBDCA combined with WBH.

Thermal enhancement of Adriamycin-mediated antitumor activity and normal tissue toxicities by whole body hyperthermia were compared using a F344 rat model. Antitumor activity was studied using a tumor growth delay assay. Acute normal tissue toxicities (i.e., leukopenia and thrombocytopenia) and late normal tissue toxicities (i.e., myocardial and kidney injury) were evaluated by functional/physiological assays and by morphological techniques. Whole body hyperthermia (120 min at 41.5 degrees C) enhanced both Adriamycin-mediated antitumor activity and toxic side effects. The thermal enhancement ratio calculated for antitumor activity was 1.6. Thermal enhancement ratios estimated for "acute" hematological changes were 1.3, whereas those estimated for "late" damage (based on morphological cardiac and renal lesions) varied between 2.4 and 4.3. Thus, while whole body hyperthermia enhances Adriamycin-mediated antitumor effect, normal tissue toxicity is also increased, and the potential therapeutic gain of the combined modality treatment is eroded.

The use of [(+)-1,2-bis(3,5-dioxopiperazinyl-1-yl)]propane (ICRF-187) as a protective agent against normal tissue toxicity caused by combined Adriamycin (ADR) and whole body hyperthermia (WBH; 2 h at 41.5 degrees C) was assessed in a rat model. The effect of ICRF-187 on the antitumor response induced by the combination of ADR and WBH was also investigated in order to assess alterations in the therapeutic index of this combined therapeutic modality treatment. ICRF-187 significantly reduced ADR-mediated body weight loss, renal toxicity, and cardiomyopathy under both normothermic and hyperthermic conditions as shown by morphological and functional assays. ADR-induced neuropathy (seen only in normothermic rats) was also ameliorated by ICRF-187. Although this study did not show a pronounced effect of ICRF-187 on ADR-induced acute myelosuppression, ADR-mediated chronic anemia, leukocytosis, and thrombocytosis were reduced by ICRF-187 in both normothermic and WBH-treated rats. The effect of ICRF-187 on antitumor response was evaluated with a tumor growth delay assay using an in vivo transplantable fibrosarcoma. ICRF-187 caused no significant change in tumor growth delay induced by either ADR alone or ADR combined with WBH. Indeed, the only complete tumor regression following treatment resulted from the combination of ICRF-187 plus ADR plus WBH. Thus, ICRF-187 significantly increases the therapeutic index of the combined modality treatment of ADR and WBH by selectively reducing normal tissue toxicity without interfering with antitumor efficacy.

The antitumor activity and normal tissue toxicity of cis-diammine-1,1-cyclobutane dicarboxylate platinum (II) (carboplatin) in combination with whole body hyperthermia (WBH) (41.5 degrees C, 120 min.) were examined in an F344 rat model. Carboplatin data were compared with those of cis-diamminedichloroplatinum (II) (cisplatin). At 37 degrees C, carboplatin showed minimal activity against a rat fibrosarcoma, but when combined with WBH, the antitumor effect-of the drug was greatly enhanced. The major carboplatin-induced acute toxicity at both normothermic and hyperthermic temperatures was marked hypocellularity of the bone marrow. A significant decrease in peripheral blood platelet counts was caused by the maximum tolerated doses (MTD) of carboplatin alone and with WBH. While the lethal dose of carboplatin alone caused only minimal renal damage, mild acute tubular necrosis was observed at the MTD of carboplatin with WBH, although no significant increase in blood urea nitrogen occurred. Therapeutic ratios of the combined chemotherapy and WBH modalities were calculated by comparing tumor growth response at the MTD of drug alone and drug combined with WBH. The combination of the nephrotoxic cisplatin with WBH resulted in a therapeutic ratio of only 0.8, whereas when carboplatin was combined with WBH, a value of 3.0 was obtained, representing a 3- to 4-fold increase over cisplatin in the therapeutic ratio. These data indicate that the less nephrotoxic carboplatin in combination with WBH improves therapeutic gain and may provide a more promising clinical combination for cancer treatment than cisplatin combined with WBH.

Schmidt-Ruppin Rous sarcoma virus, subgroup B (SR-RSV-B), was inoculated into the wingwebs of chickens from three partially congenic inbred lines, G-B1, G-B2 and G-B3, homozygous for different MHC (B region) haplotypes (genotypes = B1/B1, B2/B2 and B3/B3 respectively). All birds developed tumours but only the G-B2 line resisted progressive tumour growth. Birds from lines G-B1 and G-B3 approached 100% susceptibility to progressive tumour growth, whereas most (G-B1 X G-B3) F1 hybrids were resistant to tumours induced by SR-RSV-B. The association of the resistance trait in F1 hybrids with genes of the B region was investigated by testing progeny of (G-B1 X G-B3) X B-B1 F1 and (G-B1 X G-B2) X G-B3 F1 backcross matings. Approximately 27% of the backcross population was resistant to SR-RSV-B-induced tumours and these resistant offspring were predominantly of the B1/B3 phenotype. We interpret these results to mean that resistance to progressive tumour growth involves complementation between genes (allelic or at separate loci) linked to or within the B region and that resistance is effective only when the complementing B region genes act in concert with complementing genes which assort independently of the MHC. We suggest that complementing B region-linked genes are homologues of complementing murine H-2-linked Ir genes. The function of the B region in determining growth of sarcomas may therefore be analogous to that of Ir genes.

A comparison was made of growth patterns (progression/regression) of tumours induced by different strains of avian sarcoma virus in two partially congenic inbred lines of chickens homozygous for different MHC haplotypes. In each instance studied, the ability to regress tumours was shown to be a dominant trait controlled by MHC-linked genes. The results also demonstrate a difference in growth pattern between tumours induced by different strains of virus in an inbred line as well as different growth patterns of tumours induced by the same strain of virus in the two inbred lines. We conclude that the MNC-linked resistance gene is part of a polymorphic genetic region and, in addition, that there is immunogenic heterogeneity of the viral gene product expressed on tumour cells induced by closely related viral strains which is relevant to tumour regression. We suggest that the product of the src gene, p60src, is a plausible candidate for the immunogenic target of the MHC-linked rejection response.

The effects of progressive malignant disease on gut/liver glutamine metabolism were studied in order to gain further insight into the altered glutamine metabolism that characterizes the host with cancer and to further elucidate the causes and consequences of glutamine depletion in tumor-bearing rats. Rats were inoculated on Day 0 with 2 X 10(6) viable fibrosarcoma cells and blood glutamine was measured every 6 days. On Day 24 the animals underwent laparotomy and sampling of arterial, portal venous, and hepatic venous blood. Arterial glutamine fell by more than one-third in tumor-bearing rats and the arterial-portal venous concentration difference for glutamine across the intestinal tract was diminished by 50% (P less than 0.01). Simultaneously the fractional extraction of glutamine by the gut was reduced from 21 to 15% (P less than 0.05). The liver switched from an organ of near glutamine balance in control rats to one of marked glutamine output in tumor-bearing rats (P less than 0.01). The wet weight of the small intestine was diminished by 15% in tumor-bearing rats and villous height was uniformly decreased in tumor-bearing rats with an average reduction in villous height of 26% (P less than 0.05). The causes of glutamine depletion in this tumor-bearing rat model remain unclear. The growing tumor may behave as a glutamine trap but also appears to alter glutamine metabolism in vital metabolic processing centers such as the gut and liver. Malignant cells may compete with gut mucosal cells for glutamine resulting in a diminished gut glutamine utilization and detrimental changes in mucosal architecture.(ABSTRACT TRUNCATED AT 250 WORDS)

Thermal enhancement of cis-diamminedichloroplatinum (II) (DDP) induced renal and intestinal toxicities by whole body hyperthermia (WBH) were compared using a F344 rat model. Thermal enhancement ratios (TER) for DDP-induced nephrotoxicity were calculated using renal functional assays and morphological techniques. TER values for gastrointestinal (G.I.) toxicity were calculated using "severity of diarrhea" and jejunal crypt cell survival as assays. TER's for renal damage varied between 3 and 3.4, whereas the TER measured for G.I.-toxicity was 1.8. Physiological changes caused by WBH or intrinsic differences in the sensitivities of normal tissues to DDP +/- WBH may be responsible for the differences in thermal enhancement of DDP-induced renal and intestinal toxicities.

Different patterns of tumour growth resulted from inoculation of separate isolates of the Subgroup C Bratislava 77 strain (B77) of Avian Sarcoma Virus (ASV) into three closely-related inbred lines of chickens. The major genetic difference between these chicken lines is that each is homozygous for a different MHC haplotype. Since for one of the viral isolates, resistance to progressive tumour growth has been shown to be controlled by MHC-linked genes, the data presented here suggest that MHC-controlled tumour rejection operates on viral or cellular determinants different from those which define classical viral group of subgroup specificity.

To maximize therapeutic gain, the timing sequence of whole body hyperthermia (WBH) and cis-diamminedichloroplatinum (II) (DDP) was examined. Normal tissue injury as well as growth of a s.c. transplanted fibrosarcoma were measured in F344 rats treated with variable schedules of WBH and DDP. Simultaneous application of DDP (2 mg/kg i.v.) with WBH (120 min at 41.5 degrees C) resulted in severe renal injury, body weight loss, and mortality; while sequential use of the modalities caused minimal to no toxicity. DDP or WBH alone produced only minimal tumor growth delay, whereas supraadditive antitumor effects occurred with all tested schedules of DDP combined with WBH, regardless of sequence or interval between the two modalities. We designated the ratio of antitumor effect to nephrotoxicity as specific therapeutic efficacy (STE). DDP given simultaneously with WBH produced the lowest STE (0.6-1.2), which was less than or equal to either DDP (STE = 1.2) or WBH (STE = 1.5) alone. On the other hand, schedules of DDP prior to and after WBH resulted in a STE of 1.8-3.0, a supraadditive effect. These results indicate that an optimal scheduling of DDP with WBH significantly improves therapeutic gain by reducing normal tissue injury while maintaining enhanced antitumor activity.

A bioflavonoid, o-(beta-hydroxyethyl)-rutoside, has been investigated for its potential to increase the therapeutic index of the combined treatment modalities of whole body hypothermia (WBH) (41.5 degrees C) and chemotherapy (cisplatin) in studies utilizing a transplantable fibrosarcoma solid tumor model in Fischer rats. When whole body WBH was induced 45 min after cisplatin administration, a significantly increased tumor growth delay was noted beyond that achieved by either treatment modality alone. The combination of WBH and cisplatin treatments, however, produced an unacceptable increase in renal injury. o-(beta-Hydroxyethyl)-rutoside administration was found to effectively block the renal injury without interfering with the antitumor efficacy of the combined regimen. Potential explanations for the ability of o-(beta-hydroxyethyl)-rutoside to affect the increase in WBH-cisplatin therapeutic regimen are discussed.

The effects of various anaesthetics, including a balanced combination of different anaesthetics (consisting of ketamine, xylazine, and acepromazine), Nembutal, and halothane anaesthesia on DDP-induced renal and intestinal toxicities at 37 degrees C and at 41.5 degrees C were studied using a F344 rat model. The combination anaesthesia decreased the DDP-induced lethality (LD50) and toxic side-effects as evidenced by decreased in BUN and diarrhoea at day 5, whereas nembutal anaesthesia increased DDP-induced toxic side-effects at 37 degrees C. The inhalation anaesthetic halothane had only minor influence on these DDP-induced toxicities. Increasing the NaCl concentration of the DDP vehicle from 0.9 to 1.8 per cent decreased the DDP-induced toxicity both in non-anaesthetized and anaesthetized animals. When applied simultaneously with DDP administration, whole-body hyperthermia (WBH; 120 min at 41.5 degrees C) increased the DDP-induced toxicity as indicated by the thermal enhancement ratio of between 2.1 and 2.7 for the LD50 values. With combined WBH + DDP treatment the effect of anaesthetics on DDP-induced toxicities was generally similar to that observed at 37 degrees C. The protective effects of the high NaCl (1.8 vs 0.9 per cent) concentration of the DDP vehicle, however, were minimal under hyperthermic conditions. The data suggest the need for caution in the use of DDP in combination with WBH.

The effect of whole body hyperthermia (WBH) on cis-diamminedichloroplatinum (II) (DDP) induced renal toxicity and antitumor effect was studied using a F344 rat model. Renal injury at 5 and 14 days after treatment was evaluated using animal mortality, renal functional assays (blood urea nitrogen, creatinine), and histopathological methods. WBH (120 min at 41.5 degrees C) enhanced both antitumor effects and toxic side effects. The latter included increased mortality, increased blood urea nitrogen and creatinine levels, and increased renal damage. After simultaneous treatment with WBH and DDP, thermal enhancement ratios (TER) for renal damage between 2.5 and 3.0 were calculated. The histopathological changes observed in the kidney after DDP alone or combined with WBH were primarily found in the proximal pars recta tubules (S3 segment) in the outer stripe of the outer medulla. There was no qualitative difference in tubular damage between rats treated with DDP alone or those treated with DDP combined with WBH. However, at a fixed DDP dose, damage in the combined treatment modality group was significantly greater than in the DDP-only treated group.

Cis-platinum (CP) is an important antineoplastic chemotherapeutic agent which causes significant renal toxicity in humans and experimental animals. This present study was designed to determine whether the free radical scavenger, O-(beta-hydroxyethyl)-rutoside (HR), exerts beneficial effects on the kidneys of rats receiving an intravenous injection of 6 mg/kg body weight of CP. Renal functional and structural changes were evaluated and quantitated in three groups of Fischer 344 female rats. Group HR/S control rats received HR treatment and a sham injection of sterile saline (S). Group S/CP rats were treated with S and intravenous CP while rats in group HR/CP received both HR and CP. The experimental group S/CP and HR/CP rats had markedly elevated blood urea nitrogen and creatinine concentrations, increased fractional excretion of sodium chloride, and decreased glomerular filtration rate when compared to group HR/S controls. Group HR/CP rats, however, had significantly lower blood urea nitrogen and creatinine values when compared to the group S/CP rats, 69 +/- 14 mg/dl versus 267 +/- 41, and 1.5 +/- 0.4 versus 5.9 +/- 0.9, respectively (p less than 0.001 for both). Renal function was also better preserved in group HR/CP rats when compared to those in group S/CP. The glomerular filtration rate in group HR/CP rats, 329 +/- 67 microliter/min/gm of kidney weight and urinary osmolality, 586 +/- 42 mOsmoles/kg H2O, was significantly greater than in group S/CP rats, 46 +/- 19 microliter/min/gm of kidney weight, and 374 +/- 28 mOsmoles/kg H2O, respectively (p less than 0.005 for both). The fractional sodium excretion was also less in group HR/CP rats, 2.7% +/- 0.6, when compared to group S/CP rats, 10.2% +/- 0.8 (p less than 0.001). There were no apparent pathological changes in group HR/S rats. In contrast, renal tubular injury and necrosis were observed in both group S/CP and HR/CP rats which were both treated with CP. The injury was confined to the S3 segment of the proximal tubule located in the outer stripe region of the outer medulla. While the injury was readily apparent in both experimental groups, group HR/CP rats had significantly less proximal tubule injury than group S/CP rats when the Wilcoxon nonparametric rank sum test was applied to the morphological data. We conclude that the free radical scavenger, O-(beta-hydroxyethyl)-rutoside, provides partial protection against the structural and functional alterations which are induced in the kidney after the intravenous administration of cis-platinum.