The effect of various chemotherapeutic agents given with mild hyperthermia on different types of tumours

Adjuvant hyperthermic intraperitoneal chemotherapy in patients with colon cancer at high risk of peritoneal metastases: individual patient data meta-analysis

BACKGROUND

About a quarter of patients with locally advanced colon cancer (pT4) develop locoregional recurrence, including peritoneal metastases. The aim of this individual patient data meta-analysis (IPDMA) was to evaluate the efficacy of adjuvant hyperthermic intraperitoneal chemotherapy (HIPEC) with regard to reducing the locoregional recurrence rate in the overall population and high-risk subgroups of patients with locally advanced colon cancer.

METHODS

A systematic literature search was conducted in July 2024 to identify RCTs on adjuvant HIPEC in addition to routine adjuvant systemic chemotherapy in locally advanced colon carcinoma. An IPDMA was performed, with the locoregional recurrence rate as the primary endpoint and disease-free survival (DFS) and overall survival (OS) as secondary endpoints.

RESULTS

The search identified two trials (COLOPEC and HIPECT4). Individual patient data were pooled for 386 patients, of whom 189 patients received adjuvant HIPEC and 197 patients constituted the control group. The median follow-up was 36 (interquartile range 32-60) months. A modified intention-to-treat analysis showed a 36-month locoregional recurrence rate of 16.0% for HIPEC patients and 21.2% for control patients (P = 0.295). Predefined subgroup analyses revealed a significant reduction in locoregional recurrence after HIPEC in patients with right-sided tumours (HR 0.56 (95% c.i. 0.48 to 0.67)) (P < 0.001). No significant differences in survival were found for the overall study population; low event rates in subgroups did not allow for survival analyses.

CONCLUSION

Adjuvant HIPEC significantly reduced the locoregional recurrence rate in right-sided locally advanced colon cancer, but not in the overall study population. Definitive conclusions on DFS and OS require longer follow-up.

Generating and monitoring mild hyperthermia using a ring array ultrasound transducer

OBJECTIVE

To demonstrate the feasibility of using a ring array ultrasound (US) transducer, guided by ultrasound tomography (UST), for generating and monitoring mild hyperthermia (MHTh).

METHODS

In silico and in vitro experiments were designed to evaluate the efficacy of a ring array US transducer for generating MHTh and monitoring changes in temperature. In a series of in silico studies, we compared the acoustic focal profiles produced by a ring array US transducer transmitting at different frequencies and further investigated the effectiveness of UST-guidance in implementing aberration correction to enhance the focal profile. In vitro experiments evaluated the capability of using a ring array US transducer to generate and maintain MHTh and the accuracy of using UST to monitor temperature changes.

RESULTS

The simulations demonstrated that a ring array US transducer achieves symmetrical and localized acoustic focusing. In a heterogenous tissue model, a ring array US transducer achieved a superior acoustic focus by implementing aberration correction with guidance from UST. In vitro experiments demonstrated the capability of a ring array US transducer to generate MHTh in a tissue-mimicking phantom in an average of 117 ± 18 s and subsequently maintain MHTh. Lastly, a ring array US transducer utilized UST to track temperature changes in a preheated water-filled inclusion while it passively cooled from 45 °C to 25 °C, with a maximum error of 0.58 °C.

CONCLUSION

A ring array US transducer can noninvasively generate and monitor MHTh, overcoming many limitations of current clinical systems. The closed geometry of the transducer is optimal for acoustic focusing and UST-guidance allows for improved aberration correction in a heterogenous medium. Utilizing UST thermometry with the same ring array US transducer will allow for implementing an image-guided, temperature-controlled, all-acoustic MHTh system.

Research progress of hyperthermia in tumor therapy by influencing metabolic reprogramming of tumor cells

Cellular metabolic reprogramming is an important feature of malignant tumors. Metabolic reprogramming causes changes in the levels or types of specific metabolites inside and outside the cell, which affects tumorigenesis and progression by influencing gene expression, the cellular state, and the tumor microenvironment. During tumorigenesis, a series of changes in the glucose metabolism, fatty acid metabolism, amino acid metabolism, and cholesterol metabolism of tumor cells occur, which are involved in the process of cellular carcinogenesis and constitute part of the underlying mechanisms of tumor formation. Hyperthermia, as one of the main therapeutic tools for malignant tumors, has obvious effects on tumor cell metabolism. In this paper, we will combine the latest research progress in the field of cellular metabolic reprogramming and focus on the current experimental research and clinical treatment of hyperthermia in cellular metabolic reprogramming to discuss the feasibility of cellular metabolic reprogramming-related mechanisms guiding hyperthermia in malignant tumor treatment, so as to provide more ideas for hyperthermia to treat malignant tumors through the direction of cellular metabolic reprogramming.

Localized chemotherapy approaches and advanced drug delivery strategies: a step forward in the treatment of peritoneal carcinomatosis from ovarian cancer

Peritoneal carcinomatosis (PC) is a common outcome of epithelial ovarian carcinoma and is the leading cause of death for these patients. Tumor location, extent, peculiarities of the microenvironment, and the development of drug resistance are the main challenges that need to be addressed to improve therapeutic outcome. The development of new procedures such as HIPEC (Hyperthermic Intraperitoneal Chemotherapy) and PIPAC (Pressurized Intraperitoneal Aerosol Chemotherapy) have enabled locoregional delivery of chemotherapeutics, while the increasingly efficient design and development of advanced drug delivery micro and nanosystems are helping to promote tumor targeting and penetration and to reduce the side effects associated with systemic chemotherapy administration. The possibility of combining drug-loaded carriers with delivery via HIPEC and PIPAC represents a powerful tool to improve treatment efficacy, and this possibility has recently begun to be explored. This review will discuss the latest advances in the treatment of PC derived from ovarian cancer, with a focus on the potential of PIPAC and nanoparticles in terms of their application to develop new therapeutic strategies and future prospects.

Acute renal disease in patients with ovarian peritoneal carcinomatosis treated with cytoreduction and HIPEC: the influence of surgery and the cytostatic agent used

BACKGROUND

The main objective of this study was to evaluate the differences between cisplatin and paclitaxel in the development of postoperative renal toxicity, using as a reference the RIFLE (Risk, Injury, Insufficiency, Loss, and End-stage renal function) and AKIN (Acute Kidney Injury Network) criteria in patients with primary or recurrent ovarian cancer with peritoneal dissemination treated with cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (HIPEC).

METHODS

One hundred fifty-two patients who were treated between December 2007 and June 2017 were analyzed.

RESULTS

Patients who received previous platinum-based chemotherapy had higher baseline creatinine levels than those who had not (p = 0.05). A total of 11 (7.2%) and 4 (2.6%) patients developed an acute renal dysfunction (ARD) during the postoperative period of cytoreduction and HIPEC according to the RIFLE and AKI criteria respectively. RIFLE detects a higher rate of ARD due to different parameters such as GFR (7.2% versus 2.6%, p = 0.016). Performing ostomy (p = 0.007; OR: 39.320; 95% CI = 2.74-56.13) and using of cisplatin during HIPEC treatment (p = 0.017; OR = 13.619; 95% IC = 1.600-25.95) were factors independently related to a higher rate of ARD.

CONCLUSION

ARD has a multifactorial origin. Cisplatin was associated with the development of a higher rate of ARD than paclitaxel. Diagnosis of ARD did not correlate with worse survival figures.

Hyperthermic intraperitoneal chemotherapy (HIPEC) for colorectal and appendiceal peritoneal metastases: lessons learned from PRODIGE 7

The treatment for peritoneal metastases from appendiceal, colon and rectal cancer (MO1) has relied on cytoreductive surgery (CRS) to remove all visible evidence of disease plus a perioperative chemotherapy for the entire abdomen to eliminate microscopic residual disease. Using the results obtained from the PRODIGE 7 randomized controlled trial, methodological issues were discussed and possible improvements to the hyperthermic intraperitoneal chemotherapy (HIPEC) with oxaliplatin were sought. Possible methodological and pharmacologic flaws were identified. Several methodological flaws included the sample size, cross-over option, neoadjuvant chemotherapy use and timing of the peritoneal disease evaluation. The sample size issue raised the question of what the minimal clinically relevant benefit we want in future trials. Neoadjuvant FOLFOX may have induced acquired drug resistance to oxaliplatin. Several pharmacological issues were identified including limited 5-fluorouracil exposure as well as limited oxaliplatin peritoneal exposure time. Insufficient 5-fluorouracil accompanied the oxaliplatin as only a bolus dose was used and continuous 5-FU infusion has previously been an integral part of oxaliplatin treatment. Finally, only approximately one-half of the oxaliplatin entered body tissues or tumor. Three suggestions from the lessons learned from a critique of PRODIGE 7 were offered as adjustments to the HIPEC protocol. The Efficacy of HIPEC, a perioperative FOLFOX or a return to HIPEC with mitomycin C were described.

Effect of Cilastatin on Cisplatin-Induced Nephrotoxicity in Patients Undergoing Hyperthermic Intraperitoneal Chemotherapy

Cisplatin is one of the most widely used chemotherapeutic agents in oncology, although its nephrotoxicity limits application and dosage. We present the results of a clinical study on prophylaxis of cisplatin-induced nephrotoxicity in patients with peritoneal carcinomatosis undergoing cytoreduction and hyperthermic intraperitoneal intraoperative chemotherapy (HIPEC-cisplatin). Prophylaxis was with imipenem/cilastatin. Cilastatin is a selective inhibitor of renal dehydropeptidase I in the proximal renal tubule cells that can reduce the nephrotoxicity of cisplatin. Unfortunately, cilastatin is not currently marketed alone, and can only be administered in combination with imipenem. The study has a retrospective part that serves as a control (n = 99 patients receiving standard surgical prophylaxis) and a prospective part with imipenem/cilastatin prophylaxis corresponding to the study group (n = 85 patients). In both groups, we collected specific data on preoperative risk factors of renal damage, fluid management, hemodynamic control, and urine volume during surgery (including the hyperthermic chemotherapy perfusion), as well as data on hemodynamic and renal function during the first seven days after surgery. The main finding of the study is that cilastatin may exert a nephroprotective effect in patients with peritoneal carcinomatosis undergoing cytoreduction and hyperthermic intraperitoneal cisplatin perfusion. Creatinine values remained lower than in the control group (ANOVA test, p = 0.037). This translates into easier management of these patients in the postoperative period, with significantly shorter intensive care unit (ICU) and hospital stay.

Surgical and oncologic outcomes of hyperthermic intraperitoneal chemotherapy for uterine leiomyosarcoma: A systematic review of literature

OBJECTIVE

To examine the perioperative and survival outcomes in women with disseminated peritoneal uterine leiomyosarcoma (uLMS) who underwent cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC).

METHODS

A comprehensive systematic review of literature was conducted using multiple public search engines, PubMed, Scopus, and the Cochrane Library, in compliance with the PRISMA guidelines. Women with disseminated peritoneal uLMS treated with CRS-HIPEC were analyzed. Perioperative morbidity and mortality rate as well as oncologic outcomes related to CRS-HIPEC were assessed.

RESULTS

Ten studies met the inclusion criteria from 2004 to 2020, including 8 case series (n=28) and 2 original articles (n=47). Of the 75 patients, 68 (90.7%) were women with uLMS whereas 7 women were non-uLMS. Of these, 64 (85.3%) had recurrent disease, and 39 (52.0%) received chemotherapy or radiotherapy prior to CRS-HIPEC. The perioperative mortality rate was 4.0% (intraoperative 1.3%, and postoperative 2.7%), and postoperative complications (grade ≥3) rate ranged 21.4-22.2%. With regard to HIPEC regimens (n=75), cisplatin was most frequently used (n=55, 73.3%) followed by melphalan (n=17, 22.7%) and others (n=3, 4.0%). Among the two observational studies, the median overall survival after CRS-HIPEC treatment was 29.5-37 months. In one limited comparative effectiveness study (n=13), albeit statistically non-significant CRS-HIPEC was associated with higher progression-free survival versus CRS alone (3-year rates, 71.4% versus 0%, P=0.10). When the HIPEC regimens were compared, melphalan use was associated with decreased uLMS-related mortality compared to a cisplatin-based regimen, but the association was not statistically significant (hazard ratio 0.35, 95% confidence interval 0.04-3.05, P=0.35).

CONCLUSION

Effectiveness of CRS-HIPEC for disseminated peritoneal uLMS is yet to be determined. As interpretation of the available data on survival is limited due to small sample sizes or the lack of an active comparator, further study is warranted to examine the safety and survival effect of CRS-HIPEC in disseminated peritoneal uLMS.

An overview and update of hyperthermic intraperitoneal chemotherapy in ovarian cancer

INTRODUCTION

Despite, the strong rationale and evidence of the benefit of postoperative intraperitoneal chemotherapy in advanced ovarian cancer, it has not been widely adopted, mainly due to its high morbidity and logistical difficulties. Intraoperative hyperthermic intraperitoneal chemotherapy (HIPEC) is a more tolerable and technically feasible method of intraperitoneal chemotherapy, whereas other potential advantages include homogenous drug distribution, application before tumor regrowth and combination with hyperthermia, which is directly cytotoxic and enhances the efficacy of many drugs.

AREAS COVERED

In this review, the authors explain the rationale and indications for cytoreductive surgery (CRS) and HIPEC in advanced ovarian cancer. Data of major clinical studies, meta-analyses, and recent randomized trials are discussed.

EXPERT OPINION

After many encouraging clinical studies and meta-analyses, a recent randomized study demonstrated survival benefit for HIPEC during interval CRS in primary ovarian cancer, without increased morbidity, whereas another implied its benefit in recurrent ovarian cancer. Results of recently completed and numerous ongoing randomized studies will further determine the benefit of HIPEC in ovarian cancer at different time points. Patient selection and appraisal of the best protocols are crucial. The field of gynecological oncology will most likely evolve to include HIPEC eventually as a routine treatment for ovarian cancer.

Advances in DNA Repair-Emerging Players in the Arena of Eukaryotic DNA Repair

Genomic DNA is constantly damaged by factors produced during natural metabolic processes as well as agents coming from the external environment. Considering such a wide array of damaging agents, eukaryotic cells have evolved a DNA damage response (DRR) that opposes the influence of deleterious factors. Despite the broad knowledge regarding DNA damage and repair, new areas of research are emerging. New players in the field of DDR are constantly being discovered. The aim of this study is to review current knowledge regarding the roles of sirtuins, heat shock proteins, long-noncoding RNAs and the circadian clock in DDR and distinguish new agents that may have a prominent role in DNA damage response and repair.

Heated Intravesical Chemotherapy: Biology and Clinical Utility

Non-muscle-invasive bladder cancer can be a challenging disease to manage. In recent years, hyperthermia therapy in conjunction with intravesical therapy has been gaining traction as a treatment option for bladder cancer, especially if Bacillus Calmette-Guerin might not be available. Trials of intravesical chemotherapy with heat are few and there has been considerable heterogeneity between studies. However, multiple new trials have accrued and high-quality data are forthcoming. In this review, we discuss the role of combined intravesical hyperthermia and chemotherapy as a novel approach for the treatment of bladder cancer.

Radiofrequency deep hyperthermia combined with chemotherapy in the treatment of advanced non-small cell lung cancer

Background

In the era of precision medicine, chemotherapy is still considered the cornerstone of treatment for lung cancer patients without gene mutations. How to reduce the toxicity and increase the efficiency of chemotherapy is worth exploring. This study aimed to investigate the curative effects and safety of hyperthermia combined with chemotherapy (HCT) for advanced patients with non-small cell lung cancer (NSCLC), especially those with malignant pleural effusion.

Methods

We retrospectively evaluated medical records of 93 patients with advanced NSCLC (stage IIIB-IV) from March 2011 to January 2014. The patients were divided into HCT and chemotherapy (CT) groups. The HCT group was treated with gemcitabine and cisplatin (GP) regimen combined with regional radiofrequency deep hyperthermia, while the CT group was treated with GP regimen only. Those with malignant pleural effusion extra underwent thoracentesis and intrapleural injection chemotherapy combined with hyperthermic or not. Clinical treatment results and adverse reactions were compared and analyzed after treatment. SPSS 19.0 software (SPSS Inc., USA) was used for statistical data processing. P values less than 0.05 were accepted to be statistically significant.

Results

Among the 93 patients, HCT group included 48 patients (16 patients with malignant pleural effusion), CT group included 45 patients (10 patients with malignant pleural effusion). There was no significant difference between the two groups in patient characteristics. The overall response rate (ORR) of pleural effusions was much better in HCT group than that in CT group (81.2% vs. 40.0%, P = 0.046). The patients in HCT group had lower incidence rate of weakness (12.5% vs. 46.7%, χ² = 13.16, P < 0.001) and gastrointestinal (25.0% vs. 77.8%, χ² = 25.88, P < 0.001) adverse reactions than that in CT group. The objective tumor response and survival showed no significant differences.

Conclusions

Hyperthermia combined with chemotherapy might lead to the development of better therapeutic strategy for advanced NSCLC with malignant pleural effusion patients. Also, it could greatly reduce the chemotherapy toxic effects in the incidence of weakness and gastrointestinal adverse reactions in advanced NSCLC patients.

Modified-FOLFIRINOX combined with deep regional hyperthermia in pancreatic cancer: a retrospective study in Chinese patients

BACKGROUND

FOLFIRINOX chemotherapy displays significant survival improvements in patients with pancreatic cancer. However, toxicities have hampered enthusiasm for the use of FOLFIRINOX in full dose. In order to increase the tolerability, many researchers focused on the modification of FOLFIRINOX. On the other hand, hyperthermia (HT) has been considered as an effective ancillary treatment for cancer therapy. Up to now, there is no report evaluating combining deep regional hyperthermia (DRHT) with modified-FOLFIRINOX for pancreatic cancer patients.

METHODS

In this study, we conducted a retrospective review of pancreatic cancer patients treated with the combination of new form modified-FOLFIRINOX and DRHT (BSD2000). Patients underwent chemotherapy that included low-dose irinotecan (70-130 mg/m²), oxaliplatin (65-70 mg/m²) on day 1 and 5-FU (2400 mg/m² as a 46 h continuous infusion, no bolus) or capecitabine (CAP) (1000 mg/m² twice daily on days 1-10) or tegafur, gimeracil and oteracil potassium (TS-1) (80-120 mg/d twice daily on days 1-10), 2-week schedule. Generally, DRHT treatment was performed weekly, 45 min for each time during chemotherapy.

RESULTS

The patients receiving mFOLFIRINOX as the first line chemotherapy combining with DRHT, obtained an improvement in OS and PFS, 17 months (95% CI 1.97-32.03 months) and 4 months (95% CI 0-8.29 months) respectively. Overall, this combination regimen was safe; 17.6% patients suffered from grade 3/4 toxicities.

CONCLUSIONS

In conclusion, we conducted a retrospective study combining mFOLFIRINOX and DRHT, which was well tolerated. The efficacy in the treatment of pancreatic cancer was encouraging, but further studies would be required to prove its merit, compared with conventional treatment.

Comparison of Survival in Patients with Isolated Peritoneal Carcinomatosis from Colorectal Cancer Treated with Cytoreduction and Melphalan or Mitomycin-C as Hyperthermic Intraperitoneal Chemotherapy Agent

Background

The role of hyperthermic intraperitoneal chemotherapy (HIPEC) for peritoneal carcinomatosis (PC) from colorectal cancer (CRC) is debated. Melphalan as a perfusion agent has also demonstrated survival benefit in other recurrent and chemoresistant malignancies. Thus, we hypothesize that melphalan as a HIPEC agent may improve overall survival (OS) and progression-free survival (PFS) in patients with PC from CRC.

Methods

A retrospective review of a prospective database of 48 patients who underwent optimal CRS (CC-0/1) and HIPEC from 2001-2016 was performed. Nineteen had CRS/HIPEC with melphalan (group I) and 29 with mitomycin-C (group II). Survival was estimated using the Kaplan-Meier method. Cox regression was used for multivariate analysis. Perioperative variables were compared.

Results

Mean age at CRS/HIPEC was 53±10 years. Median peritoneal cancer index (PCI) was 17 vs 13 in groups I and II, respectively (p=0.86). PCI≥20 occurred in 9 (47%) and 13 (45%) patients in groups I and II, respectively. Positive lymph nodes were identified in 8/19 (42%) vs 12/29 (41%) in groups I and II, respectively (p=0.73). Multivariate analysis identified PCI≥20 as a predictive factor of survival (HR: 7.5). Median OS in groups I and II was 36 and 28 months, respectively (p=0.54). Median PFS in groups I and II was 10 and 20 months, respectively (p=0.05).

Conclusions

CRS/HIPEC with MMC had longer median PFS in PC from CRC. PCI≥20 was the only independent predictive factor for survival. Until longer follow-up is available, we recommend using MMC in CRS/HIPEC for PC from CRC. Further prospective randomized studies are necessary.

Magnetically-responsive DDS

Magnetic-responsive drug delivery systems have received great attention due to the possibility of building theranostic systems. The application of a non-invasive external stimuli as a magnetic field that also allows the imaging and localization of the devices and the release of therapeutic drugs means a great opportunity for the development of new treatments to prevent diseases such as cancer. This chapter will focus on smart materials based on magnetic nanoparticles that have been studied for the formulation of such delivery systems and their synergic effect in combination with drugs for potential applications in the biomedical field. In addition, the possibility of applying hyperthermia at the macro and nanoscale levels and their implications will be discussed.

Cytoreductive surgery and hyperthermic intraperitoneal chemotherapy in seven patients with peritoneal sarcomatosis from uterine sarcoma

Peritoneal sarcomatosis from uterine sarcoma is a rare disease with no effective treatment and poor prognosis. Cytoreductive surgery with hyperthermic intraperitoneal chemotherapy (CRS/HIPEC) has successful results in peritoneal carcinomatosis from gastrointestinal/gynecological origins. We show that CRS/HIPEC is safe, feasible, and may benefit selected patients with peritoneal sarcomatosis from uterine sarcoma.

5-fluorouracil combined with cisplatin and mitomycin C as an optimized regimen for hyperthermic intraperitoneal chemotherapy in gastric cancer

BACKGROUND AND OBJECTIVES

Optimized drug regimens for hyperthermic intraperitoneal chemotherapy (HIPEC) have not been standardized completely in patients with advanced gastric cancer (GC). We evaluated an optimized anti-tumor protocol comprising 5-fluorouracil (5-FU) combined with cisplatin (CDDP) and mitomycin C (MMC) in vitro for clinical use of HIPEC.

METHODS

The sensitivities of 5-FU, CDDP, or MMC, alone or in combination, using different drug concentrations, exposure times, and hyperthermic conditions (42°C) were determined in vitro by the CD-DST method using 3 different differentiated GC cell lines.

RESULTS

The tumor cell growth-inhibitory effect of 5-FU was concentration-dependent for all cell lines. In addition, 5-FU showed a hyperthermic sensitization effect at all drug concentrations for all cell lines. The appropriate concentration of each drug was 5-FU, 200 µg/mL; CDDP, 10 µg/mL; MMC, 2 µg/mL. Under hyperthermic conditions, most growth-inhibitory effects for each drug at 30 min was equivalent to 60 min of exposure; use of three drugs combined significantly inhibited growth compared with any of the drugs alone.

CONCLUSION

An appropriate in vitro intraperitoneal chemotherapy regimen for GC was combined use of 5-FU, CDDP, and MMC at 42°C for 30 min.

Multi-institutional study of peritoneal sarcomatosis from uterine sarcoma treated with cytoreductive surgery and hyperthermic intraperitoneal chemotherapy

OBJECTIVE

Uterine sarcoma (US) is a rare tumor representing 1% of female genital tract malignancies. Peritoneal sarcomatosis (PS) after US, diminishes median overall survival (OS) and progression-free survival (PFS) with cytoreductive surgery (CRS) alone, with or without systemic chemotherapy is <1 year and 6 months, respectively. A multi-institutional review of PS from US was conducted to evaluate CRS and hyperthermic intraperitoneal chemotherapy (HIPEC) and effects on survival outcomes.

METHODS

A retrospective review of 36 patients from 7 specialized international centers was performed. Selection criteria included PS of uterine origin with CRS/HIPEC treatment. Clinical data were analyzed. OS and PFS were estimated with Kaplan-Meier method.

RESULTS

Thirty-six patients underwent a total 38 HIPEC procedures performed from 2005 to 2014; 35 previous treatment and 1 primary treatment. Twenty-nine (81%) LMS patients, 3 (8%) endometrial stromal sarcoma (ESS), 3 (8%) adeneosarcoma (AS), and 1 (3%) categorized as other. Median PCI was 16 (range: 2-39), 10 patients had PCI ≥20. Thirty-four patients (94%) had complete cytoreduction (CC 0-1), 19 patients recurred. CRS/HIPEC OS at 1, 3, and 5-years was 75%, 53%, and 32% respectively, with median OS of 37 months (CI 95%: 20-54). PFS in 32 patients with CC at 1, 3, and 5-years was 67%, 32% and 32%, respectively with median PFS of 18.9 months (CI 95%: 6.7-31).

CONCLUSIONS

CRS/HIPEC is a promising treatment modality for patients with PS. Histological subtype may influence survival. A global prospective registry of patients to further assess the efficacy of CRS/HIPEC is needed.

Non-Invasive Radiofrequency Field Treatment to Produce Hepatic Hyperthermia: Efficacy and Safety in Swine

The Kanzius non-invasive radio-frequency hyperthermia system (KNiRFH) has been investigated as a treatment option for hepatic hyperthermia cancer therapy. The treatment involves exposing the patient to an external high-power RF (13.56 MHz) electric field, whereby the propagating waves penetrate deep into the tumor causing targeted heating based on differential tissue dielectric properties. However, a comprehensive examination of the Kanzius system alongside any associated toxicities and its ability to induce hepatic hyperthermia in larger animal models, such as swine, are the subjects of the work herein. Ten Yucatan female mini-swine were treated with the KNiRFH system. Two of the pigs were treated a total of 17 times over a five-week period to evaluate short- and long-term KNiRFH-associated toxicities. The remaining eight pigs were subjected to single exposure sessions to evaluate heating efficacy in liver tissue. Our goal was to achieve a liver target temperature of 43°C and to evaluate toxicities and burns post-treatment. Potential toxicities were evaluated by contrast-enhanced MRI of the upper abdomen and blood work, including complete metabolic panel, complete blood count, and liver enzymes. The permittivities of subcutaneous fat and liver were also measured, which were used to calculate tissue specific absorption rates (SAR). Our results indicate negligible KNiRFH-associated toxicities; however, due to fat overheating, liver tissue temperature did not exceed 38.5°C. This experimental limitation was corroborated by tissue permittivity and SAR calculations of subcutaneous fat and liver. Significant steps must be taken to either reduce subcutaneous fat heating or increase localized heating, potentially through the use of KNiRFH-active nanomaterials, such as gold nanoparticles or single-walled carbon nanotubes, which have previously shown promising results in murine cancer models.

Effect of temperature on the interaction of cisplatin with the model protein hen egg white lysozyme

The products of the reaction between cisplatin (CDDP) and the model protein hen egg white lysozyme (HEWL) at 20, 37 and 55 °C in pure water were studied by UV-Vis absorption spectroscopy, intrinsic fluorescence and circular dichroism, dynamic and electrophoretic light scattering and inductively coupled plasma mass spectrometry. X-ray structures were also solved for the adducts formed at 20 and 55 °C. Data demonstrate that high temperature facilitates the formation of CDDP-HEWL adducts, where Pt atoms bind ND1 atom of His15 or NE2 atom of His15 and NH1 atom of Arg14. Our study suggests that high human body temperature (fever) could increase the rate of drug binding to proteins thus enhancing possible toxic side effects related to CDDP administration.

Effects of hyperthermia on DNA repair pathways: one treatment to inhibit them all

The currently available arsenal of anticancer modalities includes many DNA damaging agents that can kill malignant cells. However, efficient DNA repair mechanisms protect both healthy and cancer cells against the effects of treatment and contribute to the development of drug resistance. Therefore, anti-cancer treatments based on inflicting DNA damage can benefit from inhibition of DNA repair. Hyperthermia – treatment at elevated temperature – considerably affects DNA repair, among other cellular processes, and can thus sensitize (cancer) cells to DNA damaging agents. This effect has been known and clinically applied for many decades, but how heat inhibits DNA repair and which pathways are targeted has not been fully elucidated. In this review we attempt to summarize the known effects of hyperthermia on DNA repair pathways relevant in clinical treatment of cancer. Furthermore, we outline the relationships between the effects of heat on DNA repair and sensitization of cells to various DNA damaging agents.

The incidence of cisplatin nephrotoxicity post hyperthermic intraperitoneal chemotherapy (HIPEC) and cytoreductive surgery

BACKGROUND

Cisplatin is commonly used in hyperthermic intraperitoneal chemotherapy (HIPEC) for the management of peritoneal carcinomatosis. Little is known about the nephrotoxic effects of cisplatin use in HIPEC.

OBJECTIVES

To report the incidence of nephrotoxicity post-HIPEC using cisplatin 50 mg/m(2) plus doxorubicin 15 mg/m(2). The incidence of hypomagnesemia was investigated as a secondary endpoint.

METHODS

This is a retrospective study evaluating patients who received cisplatin with doxorubicin during HIPEC. RIFLE classification was used to assess the development of nephrotoxicity. Variables, such as comorbidities and nephrotoxic medications were obtained. Renal function parameters were also collected, including serum creatinine levels and serum magnesium levels at baseline and at days 3, 7 and 30 after HIPEC. Perioperative urine output (UO) was also recorded.

RESULTS

Fifty-three patients were identified. Based on the RIFLE classification, two patients (3.7%) developed acute kidney injury (AKI) following HIPEC with cisplatin. One patient met criteria for renal failure and progressed to chronic renal failure. The other patient had renal injury. Comparable mean creatinine levels were observed at baseline and on day 30 following HIPEC (p > 0.05). The incidence of hypomagnesemia increased to 24.5% by day 7 (p = 0.041) and 30.1% by day 30 (p < 0.001) following HIPEC. Low intraoperative UO, angiotensin II receptor antagonist use and hypertension were associated with development of AKI (p < 0.05).

CONCLUSION

Nephrotoxicity can complicate HIPEC with cisplatin therapy and that permanent renal dysfunction may rarely occur. More attention to be directed toward monitoring magnesium levels after cisplatin use with HIPEC.

Thermal potentiation of chemotherapy by magnetic nanoparticles

Clinical studies have demonstrated the effectiveness of hyperthermia as an adjuvant for chemotherapy and radiotherapy. However, significant clinical challenges have been encountered, such as a broader spectrum of toxicity, lack of patient tolerance, temperature control and significant invasiveness. Hyperthermia induced by magnetic nanoparticles in high-frequency oscillating magnetic fields, commonly termed magnetic fluid hyperthermia, is a promising form of heat delivery in which thermal energy is supplied at the nanoscale to the tumor. This review discusses the mechanisms of heat dissipation of iron oxide-based magnetic nanoparticles, current methods and challenges to deliver heat in the clinic, and the current work related to the use of magnetic nanoparticles for the thermal-chemopotentiation of therapeutic drugs.

Principles and Innovations in Peritoneal Surface Malignancy Treatment

Cytoreductive surgery with heated intraperitoneal chemotherapy (CRS/HIPEC) remains a controversial treatment for malignant disease of the peritoneal cavity. We review the scientific principles underscoring the rationale for CRS/HIPEC, recent innovations and ongoing controversies. Lack of level 1 data limits the understanding of the true benefit of CRS/HIPEC.

Hyperthermic intraperitoneal chemotherapy in ovarian cancer: rationale and clinical data

The outcome of ovarian cancer remains poor with conventional therapy. Intraperitoneal chemotherapy has some advantages over systemic chemotherapy, including favorable pharmacokinetics and optimal treatment timing. Intraoperative hyperthermic intraperitoneal chemotherapy (HIPEC) provides improved exposure of the entire seroperitoneal surface to the agent and utilizes the direct cytoxic and drug-enhancing effect of hyperthermia. While standard normothermic, nonintraoperative, intraperitoneal chemotherapy has been demonstrated to be beneficial in randomized trials and meta-analyses, there are no data from randomized HIPEC trials available yet. Cautious extrapolation of data from standard normothermic, nonintraoperative, intraperitoneal chemotherapy and data from Phase II and nonrandomized comparative studies suggest that HIPEC delivered at the time of surgery for ovarian cancer has definite potential. Data from ongoing randomized HIPEC trials to adequately answer the question of whether the addition of HIPEC actually prolongs survival in patients with peritoneal dissemination of primary and recurrent ovarian cancer are awaited in the near future.

Tamoxifen in Trimodal Therapy with Cytotoxic Drugs and Hyperthermia in Vivo Significantly Enhance Therapeutic Efficacy against B16-F10 Melanoma

Aims and background

The aim of the study was to investigate whether use of the antiestrogen tamoxifen and heat treatment in combined therapy with the well-known anticancer drugs cisplatin, dacarbazine and cyclophosphamide enhances their therapeutic efficacy on mouse B16-F10 melanoma in vivo. The results of systemic melanoma therapy have been mostly disappointing. Therefore, there is still a great need for strategies that can improve existing chemotherapy options.

Methods and study design.

The tumor model for the investigation of antitumor activity was a mouse B16–F10 melanoma transplanted into the footpad of C57BL/6 Zgr/Hr mice. Drugs were given intraperitoneally 15 min before the application of local hyperthermia, and tumor growth and mouse survival were followed.

Results

Hyperthermia alone determined a significant delay of tumor growth, but mouse survival was not affected. In bimodal combinations with hyperthermia, all the tested antitumor drugs significantly increased both tumor growth delay and mouse survival. Tamoxifen alone did not show any inhibitory effect on B16–F10 melanoma in vivo. However, in the trimodal therapy with a particular drug and hyperthermia, it potentiated the inhibitory effects of the respective bimodal treatments, especially that of cyclophosphamide and hyperthermia.

Conclusions

Our results obtained on the mouse B16–F10 melanoma in vivo confirmed the enhanced therapeutic efficacy of the trimodal therapy tamoxifen, hyperthermia and anticancer drug combinations in melanoma treatment. Further studies should optimize the heat-drug time scheduling and drug doses that will result in the best possible therapeutic achievement for these trimodal therapy options.

Heat Shock Protein translocation induced by membrane fluidization increases tumor-cell sensitivity to chemotherapeutic drugs

Treatment of chronic lymphocytic leukemia (CLL) remains a challenge due to the frequency of drug resistance amongst patients. Improving the delivery of chemotherapeutic agents while reducing the expression of anti-apoptotic Heat Shock Proteins (HSPs) within the cancer cells may facilitate in overcoming this drug resistance. We demonstrate for the first time that sub-lethal doses of chemotherapeutic agents can be combined with membrane fluidizing treatments to produce a significant increase in drug efficacy and apoptosis in vitro. We show that fluidizers result in a transient decrease in intracellular HSPs, resulting in increased tumor-cell sensitivity and a membrane-associated induction of HSP gene expression.

MAGNETIC NANOPARTICLE HYPERTHERMIA IN CANCER TREATMENT

The activation of magnetic nanoparticles (mNPs) by an alternating magnetic field (AMF) is currently being explored as technique for targeted therapeutic heating of tumors. Various types of superparamagnetic and ferromagnetic particles, with different coatings and targeting agents, allow for tumor site and type specificity. Magnetic nanoparticle hyperthermia is also being studied as an adjuvant to conventional chemotherapy and radiation therapy. This review provides an introduction to some of the relevant biology and materials science involved in the technical development and current and future use of mNP hyperthermia as clinical cancer therapy.

Hyperthermic intraperitoneal chemotherapy: Rationale and technique

The combination of complete cytoreductive surgery and perioperative intraperitoneal chemotherapy provides the only chance for long-term survival for selected patients diagnosed with a variety of peritoneal neoplasms, either primary or secondary to digestive or gynecologic malignancy. Hyperthermic intraperitoneal chemotherapy (HIPEC) delivered in the operating room once the cytoreductive surgical procedure is finalized, constitutes the most common form of administration of perioperative intraperitoneal chemotherapy. This may be complemented in some instances with early postoperative intraperitoneal chemotherapy (EPIC). HIPEC combines the pharmacokinetic advantage inherent to the intracavitary delivery of certain cytotoxic drugs, which results in regional dose intensification, with the direct cytotoxic effect of hyperthermia. Hyperthermia exhibits a selective cell-killing effect in malignant cells by itself, potentiates the cytotoxic effect of certain chemotherapy agents and enhances the tissue penetration of the administered drug. The chemotherapeutic agents employed in HIPEC need to have a cell cycle nonspecific mechanism of action and should ideally show a heat-synergistic cytotoxic effect. Delivery of HIPEC requires an apparatus that heats and circulates the chemotherapeutic solution so that a stable temperature is maintained in the peritoneal cavity during the procedure. An open abdomen (Coliseum) or closed abdomen technique may be used, with no significant differences in efficacy proven to date. Specific technical training and a solid knowledge of regional chemotherapy management are required. Concerns about safety of the procedure for operating room personnel are expected but are manageable if universal precautions and standard chemotherapy handling procedures are used. Different HIPEC drug regimens and dosages are currently in use. A tendency for concurrent intravenous chemotherapy administration (bidirectional chemotherapy, so-called “HIPEC plus”) has been observed in recent years, with the aim to further enhance the cytotoxic potential of HIPEC. Future trials to ascertain the ideal HIPEC regimen in different diseases and to evaluate the efficacy of new drugs or drug combinations in this context are warranted.

Thermoresponsive core-shell magnetic nanoparticles for combined modalities of cancer therapy

Thermoresponsive polymer-coated magnetic nanoparticles loaded with anti-cancer drugs are of considerable interest for novel multi-modal cancer therapies. Such nanoparticles can be used for magnetic drug targeting followed by simultaneous hyperthermia and drug release. Gamma-Fe(2)O(3) iron oxide magnetic nanoparticles (MNP) with average sizes of 14, 19 and 43 nm were synthesized by high temperature decomposition. Composite magnetic nanoparticles (CNP) of 43 nm MNP coated with the thermoresponsive polymer poly-n-isopropylacrylamide (PNIPAM) were prepared by dispersion polymerization of n-isopropylacrylamide monomer in the presence of the MNP. In vitro drug release of doxorubicin-(dox) loaded dehydrated CNP at temperatures below and above the lower critical solution temperature of PNIPAM (34 degrees C) revealed a weak dependence of drug release on swelling behavior. The particles displayed Fickian diffusion release kinetics; the maximum dox release at 42 degrees C after 101 h was 41%. In vitro simultaneous hyperthermia and drug release of therapeutically relevant quantities of dox was achieved, 14.7% of loaded dox was released in 47 min at hyperthermia temperatures. In vivo magnetic targeting of dox-loaded CNP to hepatocellular carcinoma (HCC) in a buffalo rat model was studied by magnetic resonance imaging (MRI) and histology. In summary, the good in vitro and in vivo performance of the doxorubicin-loaded thermoresponsive polymer-coated magnetic nanoparticles suggests considerable promise for applications in multi-modal treatment of cancer.

The role of hyperthermic intraperitoneal chemotherapy (HIPEC) in ovarian cancer

Overall outcomes for women with epithelial ovarian cancer (EOC) remain relatively poor, and superior methods of treatment are needed. EOC is a peritoneal surface malignancy that is relatively sensitive to chemotherapy agents, making it a good target for i.p. chemotherapy. Because there is strong laboratory data demonstrating the ability of hyperthermia to increase the efficacy of chemotherapeutic agents, the addition of hyperthermia to i.p. chemotherapy, hyperthermic intraperitoneal chemotherapy (HIPEC), makes theoretical sense. This article reviews the current literature and discusses the possible role for HIPEC in EOC at significant natural history time points: front line, at the time of interval debulking, in consolidation, and for recurrent disease. The conclusion is that much further research is needed but that HIPEC could sensibly be researched at all the natural history time points in EOC.

Iron oxide nanoparticle hyperthermia and chemotherapy cancer treatment

The benefit of combining hyperthermia and chemotherapy to treat cancer is well established. However, combined therapy has not yet achieved standard of care status. The reasons are numerous and varied, however the lack of significantly greater tumor cell sensitivity to heat (as compared to normal cells) and the inability to deliver heat to the tumor in a precise manner have been major factors. Iron oxide nanoparticle (IONP) hyperthermia, alone and combined with other modalities, offers a new direction in hyperthermia cancer therapy via improved tumor targeting and an improved therapeutic ratio. Our preliminary studies have demonstrated tumor cell cytotoxicity (in vitro and in vivo) with IONP heat and cisplatinum (CDDP) doses lower than those necessary when using conventional heating techniques or cisplatinum alone. Ongoing studies suggest such treatment could be further improved through the use of targeted nanoparticles.

METHODS

In vivo: IONPs (5mg of iron per gram of tumor) were administered into MTG-B flank tumors in female C3H-HEJ mice directly after cisplatinum chemotherapy (0.1ml/kg of body mass) was intraperitoneally injected. An 160 KHz, 350-450 Oe AMF (alternating magnetic field) was used to induce particle heating. In vitro: Mouse mammary adenocarcinoma cells (MTG-B) cells were grown and exposed to IONP hyperthermia and cisplatinum. IONPs not associated with cells were removed by washing prior to heat induction by an AMF field. Acute cell survival, via trypan blue assay, was used to quantify the level of cytotoxicity.

RESULTS

In vitro studies, using IONP + cisplatinum, have demonstrated promising cytotoxicity enhancement. Ongoing studies are being pursued to further define the mechanism of action, temporal associations and pathophysiology of combined IONP hyperthermia and chemotherapy treatment. Preliminary in vivo IONP /cisplatinum studies have shown a tumor growth delay/volume reduction greater than either modality alone at comparable doses. Further enhancement of this treatment success appears to depend on a better understanding of IONP dose and tumor cell association, chemotherapy dose and administration technique, the spatial and temporal treatment relationship of the two modalities and optimal AMF - IONP coupling.

The antitumor effect of novel docetaxel-loaded thermosensitive micelles

To further evaluate the novel docetaxel-loaded micelle based on the biodegradable thermosensitive copolymer poly(N-isopropylacrylamide-co-acrylamide)-b-poly(dl-lactide) that we had synthesized before, in this paper, we studied its in vitro cytotoxicity in three different tumor cell lines by standard MTT assays using different tumor cell lines, followed by studies of acute toxicity and the tumor distribution studies which were conducted in Kunming mice. Meanwhile, the in vivo antitumor efficacy as well as toxicity of the micelle was evaluated in C57BL/6 mice. According to our findings, the in vitro cytotoxicity of docetaxel-loaded micelles was lower than that of the conventional docetaxel formulation at 37 degrees C, while hyperthermia greatly enhanced the efficacy of drug-loaded micelles. The acute toxicity study showed reduced toxicity of docetaxel-loaded micelle compared to that of conventional docetaxel formulation. Moreover, docetaxel-loaded micelle enabled a prominent higher docetaxel concentration in tumor than conventional docetaxel formulation. Furthermore, a significantly higher antitumor efficacy was observed in mice treated with docetaxel-loaded micelles accompanied by hyperthermia; docetaxel-loaded micelles also caused less body weight loss of mice. This study demonstrates an increased antitumor efficacy and reduced toxicity of the novel docetaxel-loaded micelle and indicates its prospect of clinical applications.

Antiangiogenic metronomic chemotherapy and hyperthermia in the palliation of advanced cancer

Among a large series of cancer patients treated with a combination of chemotherapy and sessions of hyperthermia, particular attention was given to a specific group of patients with advanced cancer who refused standard, aggressive, treatment. In these cases, hyperthermia was associated to low-dose (metronomic) chemotherapy. No toxicity was reported in any of our patients, while a marginal benefit in terms of tumour progression was observed. During therapy, we could detect a coagulative perturbation that deserves careful discussion. In our opinion, this experience should be matter of debate to conclude if current response criteria (WHO/UICC and RECIST) in treating cancer patients are really suitable tools to evaluate new, and non-aggressive anticancer strategies.

Histamine, a vasoactive agent with vascular disrupting potential, improves tumour response by enhancing local drug delivery

Tumour necrosis factor (TNF)-based isolated limb perfusion (ILP) is an approved and registered treatment for sarcomas confined to the limbs in Europe since 1998, with limb salvage indexes of 76%. TNF improves drug distribution in solid tumours and secondarily destroys the tumour-associated vasculature (TAV). Here we explore the synergistic antitumour effect of another vasoactive agent, histamine (Hi), in doxorubicin (DXR)-based ILP and evaluate its antivascular effects on TAV. We used our well-established rat ILP model for in vivo studies looking at tumour response, drug distribution and effects on tumour vessels. In vitro studies explored drug interactions at cellular level on tumour cells (BN-175) and Human umbilical vein endothelial cells (HUVEC). There was a 17% partial response and a 50% arrest in tumour growth when Hi was combined to DXR, without important side effects, against 100% progressive disease with DXR alone and 29% arrest in tumour growth for Hi alone. Histology documented an increased DXR leakage in tumour tissue combined to a destruction of the TAV, when Hi was added to the ILP. In vitro no synergy between the drugs was observed. In conclusion, Hi is a vasoactive drug, targeting primarily the TAV and synergises with different chemotherapeutic agents.

Management of pseudomyxoma peritonei

Pseudomyxoma peritonei (PMP) is a rare disease. It refers to a progressive disease process within the peritoneum which originates from the appendix or ovaries and is characterised by the production of copious amounts of mucinous fluid resulting in a “jelly belly”. If untreated the condition is fatal. The traditional approach to PMP is based on repeated surgical debulking procedures, often associated with intraperitoneal or systemic chemotherapy. The natural history of this disease has been drastically modified since the introduction of a new surgical approach defined as a peritonectomy procedure. This paper is to review the literature on this treatment strategy.

Treatment of ovarian cancer using intraperitoneal chemotherapy with taxanes: from laboratory bench to bedside

The combination of a taxane, paclitaxel or docetaxel, and a platinum compound has become the systemic chemotherapy of choice for primary ovarian cancer and has demonstrated high efficacy. However, ultimately most patients will die from this disease. Hence, there is a need for even more effective systemic chemotherapy or different treatment strategies. Intraperitoneal chemotherapy with taxanes is such an alternative treatment option. Ovarian cancer is theoretically an attractive malignancy for this regional treatment, because the disease remains largely confined to the peritoneal cavity. The choice of taxanes for this kind of chemotherapy is rational, because of its high activity against ovarian cancer cells and expected favourable pharmacokinetics because of limited absorption from the peritoneal cavity due to their large molecular weight and first-pass effect in the liver. In animal model and human pharmacokinetic studies, very high intraperitoneal drug concentrations and exposure and high peritoneal tumour concentrations were achieved, while systemic drug levels were low. The combination of intraperitoneal chemotherapy with hyperthermia enhances the penetration and cytotoxic activity of many drugs. Although data concerning thermal enhancement of taxane cytotoxicity are inconsistent, experimental studies show that at high locoregional concentrations there seems to be such an effect. Recently, feasibility and efficacy of this treatment have evidently been demonstrated in various clinical studies. A large randomized trial revealed improvement of outcome by intraperitoneal instillation chemotherapy with paclitaxel and cisplatin as first-line treatment. Moreover, promising results have been observed after intraoperative hyperthermic intraperitoneal chemotherapy with docetaxel for recurrent disease.

Optimizing the factors which modify thermal enhancement of melphalan in a spontaneous murine tumor

BACKGROUND

Hyperthermia enhances the cytotoxicity of some chemotherapeutic agents. Both clinical and laboratory studies suggest melphalan may be an important drug when hyperthermia is added to chemotherapy treatments. Factors that may modify the thermal enhancement of melphalan were studied to optimize its clinical use with hyperthermia.

METHODS

The tumor studied was an early-generation isotransplant of a spontaneous C3Hf/Sed mouse fibrosarcoma, Fsa-II. All studies were performed under supervision of the Animal Care and Use Committee. Hyperthermia was administered by immersing the tumor-bearing foot into a constant temperature water bath. Four factors were studied: duration of hyperthermia, sequencing of hyperthermia and melphalan, intensity of hyperthermia, and tumor size. To study duration of hyperthermia tumors were treated at 41.5 degrees C for 30 or 90 min immediately after intraperitoneal administration of melphalan. For sequencing of hyperthermia and melphalan, animals received hyperthermia treatment of tumors for 30 min at 41.5 degrees C immediately after drug administration, both immediately and 3 h after administration of drug or only at 3 h after administration of drug. Intensity of hyperthermia was studied using heat treatment of tumors for 30 min at 41.5 or 43.5 degrees C immediately following drug administration. Effect of tumor size was studied by delaying experiments until three times the tumor volume (113 mm3) was observed. Treatment of tumors was for 30 min at 41.5 degrees C immediately following drug administration. Tumor response was studied by the mean tumor growth time.

RESULTS

Hyperthermia in the absence of melphalan had a small but significant effect on tumor growth time at 43.5 degrees C but not at 41.5 degrees C. Hyperthermia at 41.5 degrees C immediately after melphalan administration doubled mean tumor growth time at 30 min and caused a threefold increase at 90 min (P=0.0002) when compared to tumors treated with melphalan alone at room temperature. Application of hyperthermia for one-half hour immediately following drug administration was the most effective in delaying tumor growth. No significant difference in mean tumor growth time was observed with an increase in temperature from 41.5 to 43.5 degrees C. For large tumors heat alone and melphalan alone caused a moderate increase in tumor growth delay. These effects in large tumors were greatly increased by a combination of chemotherapy and hyperthermia.

CONCLUSIONS

From our data it would appear that the administration of intraperitoneal melphalan immediately prior to 90 min of heat at 41.5 degrees C may optimize anti-neoplastic activity. These data may be useful in formulating clinical protocols in which melphalan and heat are combined.

Therapeutic effects of hypothermia on Lewisite toxicity

The cytotoxicity of the arsenical vesicant Lewisite was assessed in first passage cultures of proliferating neonatal human skin keratinocytes. Both munitions grade and distilled Lewisite were extremely toxic with LC(50) values in the low ng/ml range, with no significant differences between them. This similarity in toxicity was also mirrored with respect to their toxic effects on hairless guinea pig skin. Two-, 4- and 6-min vapour exposures of these agents resulted in similar and severe skin injury that was obvious by 3-5h post-exposure and almost maximal at 24h. The toxicity of Lewisite in culture was temperature dependent, with a >10-fold reduction in 24h LC(50) values as the incubation temperature was reduced from 37 to 25 degrees C. However, this cooling induced protection was not persistent. In contrast, cooling of Lewisite exposed hairless guinea pig skin at approximately 10 degrees C for as little as 30 min post-exposure resulted in dramatic and permanent protection, with 4h of cooling almost completely eliminating Lewisite induced skin injury. Further, significant protection was also evident even when cooling was delayed for as long as 2h post-Lewisite exposure. In an effort to investigate whether cooling might also increase the window in which chelation therapy against this vesicant agent would be useful, we examined the protective effects of the heavy metal chelator dimercaptosuccinic acid (DMSA). Topical application to Lewisite exposed skin was extremely protective, even when delayed for 2h after Lewisite. Cooling of Lewisite exposed skin for 2h, followed by DMSA topical application resulted in decreased skin injury compared to either treatment in isolation. It appears that the simple and non-invasive application of cooling measures may provide not only significant therapeutic relief to Lewisite exposed skin, but that it may also increase the therapeutic window in which medical countermeasures against this vesicant agent are useful.

Optimizing a Novel Regional Chemotherapeutic Agent against Melanoma: Hyperthermia-Induced Enhancement of Temozolomide Cytotoxicity

PURPOSE

Previous preclinical studies have shown that regional temozolomide therapy via isolated limb infusion is more effective than melphalan, the current drug of choice for regional chemotherapy for advanced extremity melanoma. The aim of this study was to determine whether hyperthermia could further augment the efficacy of temozolomide, an alkylating agent, against melanoma and improve its therapeutic index in a rat model of isolated limb infusion.

EXPERIMENTAL DESIGN

Athymic rats bearing s.c. human melanoma xenografts (DM6) in their hind limbs were randomized to a 15-minute isolated limb infusion procedure with or without temozolomide at room temperature, normothermic (37.5 degrees C), or hyperthermic (43 degrees C) conditions.

RESULTS

The concomitant administration of hyperthermia during an infusion with temozolomide led to the greatest increase in tumor growth delay, decreased proliferative index, and increased cell death. Isolated limb infusion treatment with a low dose (350 mg/kg) of temozolomide was ineffective at producing tumor growth delay (P = 0.07). Similarly, temozolomide infusion under normothermia yielded minimal tumor growth delay (P = 0.08). In contrast, the combination of hyperthermia plus temozolomide treatment produced marked tumor growth delay of 10.4 days (P = 0.02) with minimal toxicity. The addition of heat to temozolomide treatment yielded the smallest proliferative index (P = 0.001), while markedly increasing the level of apoptosis 48 hours after isolated limb infusion.

CONCLUSION

This study, the first to examine the interaction between hyperthermia and temozolomide, shows a strong, synergistic antitumor effect when hyperthermia is combined with temozolomide for regional treatment of melanoma confined to an extremity. The mechanism of this synergy seems to be through an augmentation, by hyperthermia, of the antiproliferative and proapoptotic effects of temozolomide.