Regional hyperthermia for soft tissue sarcoma - a survey on current practice, controversies and consensus among 12 European centers

PURPOSE

To analyze the current practice of regional hyperthermia (RHT) for soft tissue sarcoma (STS) at 12 European centers to provide an overview, find consensuses and identify controversies necessary for future guidelines and clinical trials.

METHODS

In this cross-sectional survey study, a 27-item questionnaire assessing clinical subjects and procedural details on RHT for STS was distributed to 12 European cancer centers for RHT.

RESULTS

We have identified seven controversies and five consensus points. Of 12 centers, 6 offer both, RHT with chemotherapy (CTX) or with radiotherapy (RT). Two centers only offer RHT with CTX and four centers only offer RHT with RT. All 12 centers apply RHT for localized, high-risk STS of the extremities, trunk wall and retroperitoneum. However, eight centers also use RHT in metastatic STS, five in palliative STS, eight for superficial STS and six for low-grade STS. Pretherapeutic imaging for RHT treatment planning is used by 10 centers, 9 centers set 40-43 °C as the intratumoral target temperature, and all centers use skin detectors or probes in body orifices for thermometry.

DISCUSSION

There is disagreement regarding the integration of RHT in contemporary interdisciplinary care of STS patients. Many clinical controversies exist that require a standardized consensus guideline and innovative study ideas. At the same time, our data has shown that existing guidelines and decades of experience with the technique of RHT have mostly standardized procedural aspects.

CONCLUSIONS

The provided results may serve as a basis for future guidelines and inform future clinical trials for RHT in STS patients.

Regional hyperthermia with cisplatin added to gemcitabine versus gemcitabine in patients with resected pancreatic ductal adenocarcinoma: The HEAT randomised clinical trial

BACKGROUND

Regional hyperthermia (RHT) with cisplatin added to gemcitabine showed efficacy in gemcitabine-pre-treated patients with advanced pancreatic ductal adenocarcinoma. We conducted a randomised clinical trial to investigate RHT with cisplatin added to gemcitabine (GPH) compared with gemcitabine (G) in the adjuvant setting of resected pancreatic ductal adenocarcinoma.

METHODS

This randomised, multicentre, open-label trial randomly assigned patients to either GPH (gemcitabine 1000 mg/m² on day 1, 15 and cisplatin 25 mg/m² with RHT on day 2, 3 and 15,16) or to G (gemcitabine 1000 mg/m² on day 1,8,15), four-weekly over six cycles. Disease-free survival (DFS) was the primary end-point. Secondary end-points included overall survival (OS) and safety.

RESULTS

A total of 117 eligible patients (median age, 63 years) were randomly allocated to treatment (57 GPH; 60 G). With a follow-up time of 56.6 months, the median DFS was 12.7 compared to 11.2 months for GPH and G, respectively (p = 0.394). Median post-recurrence survival was significantly prolonged in the GPH-group (15.3 versus 9.8 months; p = 0.031). Median OS reached 33.2 versus 25.2 months (p = 0.099) with 5-year survival rates of 28.4% versus 18.7%. Excluding eight patients who received additional capecitabine in the G-arm (investigators choice), median OS favoured GPH (p = 0.052). Adverse events CTCAE (Common Terminology Criteria for Adverse Events) grade ≥3 occurred in 61.5% (GPH) versus 63.6% (G) of patients. Two patients in the G-group died because of treatment-related toxic effects.

CONCLUSIONS

The randomised controlled Hyperthermia European Adjuvant Trial study failed to demonstrate a significant difference in DFS. However, it suggests a difference in post-recurrence survival and a trend for improved OS.

CLINICALTRIALS

gov, number NCT01077427.

Immune infiltrates in patients with localised high-risk soft tissue sarcoma treated with neoadjuvant chemotherapy without or with regional hyperthermia: A translational research program of the EORTC 62961-ESHO 95 randomised clinical trial

BACKGROUND

The EORTC 62961-ESHO 95 randomised trial showed improved long-term survival of patients with high-risk soft-tissue sarcoma by adding regional hyperthermia to neoadjuvant chemotherapy. We hypothesised that immune infiltrate of patients treated with neoadjuvant therapy associate with clinical outcome.

METHODS

Tumour infiltrating lymphocytes (TILs) and CD8, FOXP3, PD-1, and PD-L1 were evaluated in sequential biopsies of patients after four cycles of therapy.

RESULTS

From a subgroup of 109 patients who had been randomised between July 1997 and November 2006 to neoadjuvant chemotherapy (53 patients) or neoadjuvant chemotherapy with regional hyperthermia (56 patients), 137 biopsies were obtained. TILs increased in paired second biopsies independent of treatment allocation (p < 0.001). FOXP3 regulatory T cells decreased (p = 0.002), and PD-L1 expression of tumours became undetectable. In the multivariate analysis, post-treatment high TILs correlated to LPFS (HR: 0.34; 95% CI 0.15-0.75; p = 0.008) and DFS (HR: 0.38; 95% CI 0.17-0.82; p = 0.015). In comparing post-treatment immune infiltrate between treatment arms, tumour response was associated with neoadjuvant chemotherapy with regional hyperthermia (p = 0.013) and high TILs (p = 0.064). High CD8 cell infiltration was associated with improved LPFS (HR: 0.27; 95% CI 0.09-0.79; Log-rank p = 0.011) and DFS (HR: 0.25; 95% CI 0.09-0.73; Log-rank p = 0.006). Improved survival at 10 years was associated with immune infiltrate after neoadjuvant chemotherapy with regional hyperthermia.

CONCLUSION

Preoperative therapy re-programs a non-inflamed tumour at baseline into an inflamed tumour. The post-treatment immune infiltrate became predictive for clinical outcomes. The combination with regional hyperthermia primes the tumour microenvironment, enabling enhanced anti-tumour immune activity in high-risk soft tissue sarcomas.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT00003052.

Perioperative chemotherapy and regional hyperthermia for high-risk adult-type soft tissue sarcomas

A group of patients with adult-type soft tissue sarcoma is at high risk of local recurrence and distant metastases. Age, tumour site, histological subtype, tumour size and grade have been identified as the most important independent adverse prognostic factors. Macroscopically complete tumour resection is considered as the mainstay of treatment with the addition of preoperative or postoperative radiotherapy for extremity or trunk localisation. Retroperitoneal localisation requires compartmental resection and is associated with a worse prognosis. Here, radiotherapy is of no proven value. Perioperative chemotherapy is considered to treat micrometastatic disease not detectable at the time of diagnosis. The neoadjuvant application gives the risk of distant metastasis the greatest importance as therapy is carried out at the earliest possible time, whereas adjuvant chemotherapy is delayed by surgery and the necessary wound healing. With reported response rates up to 30%, both the operability may be improved and the risk of intraoperative tumour cell dissemination may be reduced, resulting also in reduced local relapse rates. However, the potential risk of early tumour progression may counteract this benefit. Optimised strategies with multimodality approaches including chemotherapy, regional hyperthermia (RHT) and immunotherapeutic agents have been shown to improve survival in high-risk patients. Here, we focus on the data from available randomised studies investigating the use of perioperative chemotherapy in patients with high-risk adult-type soft tissue sarcoma, including the use of RHT for local enhancement of chemotherapy effect and immune induction.

Cancer Testis Antigens and Immunotherapy: Expression of PRAME Is Associated with Prognosis in Soft Tissue Sarcoma

(1) Background: PRAME, NY-ESO-1, and SSX2 are cancer testis antigens (CTAs), which are expressed in testicular germ cells with re-expression in numerous cancer types. Their ability to elicit humoral and cellular immune responses have rendered them promising targets for cancer immunotherapy, but they have never been studied in a large and well-characterised cohort of soft tissue sarcomas (STS). (2) Methods: On a protein level, we examined PRAME, NY-ESO-1, and SSX2 expression in tumour tissues of 249 high-risk STS using immunohistochemistry. We correlated expression levels with clinicopathological parameters including tumour-infiltrating lymphocyte (TIL) counts, grading, and long-term survival. (3) Results: Expression of PRAME, NY-ESO-1, and SSX2 was observed in 25 (10%), 19 (8%), and 11 (4%) of 249 specimens with distinct patterns for histo-subtypes. Expression of PRAME was associated with shorter patient survival (p = 0.005) and higher grade (G2 vs. G3, p = 0.001), while NY-ESO-1 expression was correlated with more favourable survival (p = 0.037) and lower grade (G2 vs. G3, p = 0.029). Both PRAME and NY-ESO-1 expression were more frequent in STS with low TIL counts. In multivariate analysis, high PRAME and low SSX2 expression levels as well as metastatic disease and non-radical resections were independent predictors of shorter overall survival. (4) Conclusions: CTAs PRAME, NY-ESO-1, and SSX2 show distinct expression patterns in different STS subtypes. These results demonstrate their prognostic relevance and may guide future immunotherapeutic approaches in STS.

Systemic antitumor effect by regional hyperthermia combined with low-dose chemotherapy and immunologic correlates in an adolescent patient with rhabdomyosarcoma - a case report

Introduction: An abscopal effect is a clinical observation whereby a local treatment is associated with regression of metastatic cancer at a site distant from the primary location of treatment. Here, we describe the clinical systemic effect induced by regional hyperthermia combined with low-dose chemotherapy and provide immunologic correlates.Case presentation: A 15-year-old patient had been diagnosed with alveolar rhabdomyosarcoma (ARMS). All previous treatment options failed in the patient including haploidentical stem cell transplantation and donor lymphocyte infusion. The patient presented with local and metastatic disease, and upon admission, underwent regional hyperthermia combined with low-dose chemotherapy. Immediately following therapy severe skin reactions were observed. Skin biopsies revealed an intraepithelial lymphocytic infiltration dominated by CD3⁺/CD8⁺ T cells with a regular network of dendritic cells. Clinical images compared before and during sequential treatment cycles showed complete metabolic response of the local tumor for more than 10 months of therapy. In addition, metastases completely regressed although they were not direct targets of regional hyperthermia. The systemic effect was associated with enhanced frequency of NK cells and T cells expressing the lectin-like natural-killer group 2 D activating receptor (NKG2D), an increase of the CD56^bright subset of NK cells, as well as an increase of effector/memory and effector CD8⁺ and CD4⁺ T cells in the blood while the percentage of CD25⁺FOXP3⁺ regulatory T cells declined.Conclusions: Regional hyperthermia combined with low-dose chemotherapy had the potential to create a systemic effect which was associated with activation of NK cells and T cells.

Effect of Neoadjuvant Chemotherapy Plus Regional Hyperthermia on Long-term Outcomes Among Patients With Localized High-Risk Soft Tissue Sarcoma: The EORTC 62961-ESHO 95 Randomized Clinical Trial

Importance

Patients with soft tissue sarcoma are at risk for local recurrence and distant metastases despite optimal local treatment. Preoperative anthracycline plus ifosfamide chemotherapy improves outcome in common histological subtypes.

Objective

To analyze whether the previously reported improvement in local progression-free survival by adding regional hyperthermia to neoadjuvant chemotherapy translates into improved survival.

Design, Setting, and Participants

Open-label, phase 3 randomized clinical trial to evaluate the efficacy and toxic effects of neoadjuvant chemotherapy plus regional hyperthermia. Adult patients (age ≥18 years) with localized soft tissue sarcoma (tumor ≥5 cm, French Federation Nationale des Centers de Lutte Contre le Cancer [FNCLCC] grade 2 or 3, deep) were accrued across 9 centers (6, Germany; 1, Norway; 1, Austria; 1, United States) from July 1997 to November 2006. Follow-up ended December 2014.

Interventions

After stratification for tumor presentation and site, patients were randomly assigned to either neoadjuvant chemotherapy consisting of doxorubicin, ifosfamide, and etoposide alone, or combined with regional hyperthermia.

Main Outcomes and Measures

The primary end point was local progression-free survival. Secondary end points included treatment safety and survival, with survival defined from date of randomization to death due to disease or treatment. Patients lost to follow-up were censored at the date of their last follow-up.

Results

A total of 341 patients were randomized, and 329 (median [range] age, 51 [18-70] years; 147 women, 182 men) were eligible for the intention-to-treat analysis. By December 2014, 220 patients (67%; 95% CI, 62%-72%) had experienced disease relapse, and 188 (57%; 95% CI, 52%-62%) had died. Median follow-up was 11.3 years. Compared with neoadjuvant chemotherapy alone, adding regional hyperthermia improved local progression-free survival (hazard ratio [HR], 0.65; 95% CI, 0.49-0.86; P = .002). Patients randomized to chemotherapy plus hyperthermia had prolonged survival rates compared with those randomized to neoadjuvant chemotherapy alone (HR, 0.73; 95% CI, 0.54-0.98; P = .04) with 5-year survival of 62.7% (95% CI, 55.2%-70.1%) vs 51.3% (95% CI, 43.7%-59.0%), respectively, and 10-year survival of 52.6% (95% CI, 44.7%-60.6%) vs 42.7% (95% CI, 35.0%-50.4%).

Conclusions and Relevance

Among patients with localized high-risk soft tissue sarcoma the addition of regional hyperthermia to neoadjuvant chemotherapy resulted in increased survival, as well as local progression-free survival. For patients who are candidates for neoadjuvant treatment, adding regional hyperthermia may be warranted.

Trial Registration

clinicaltrials.gov Identifier: NCT00003052.

Abstract A28: Donor lymphocyte infusion after allogeneic stem cell transplantation is a feasible therapy option with acceptable toxicity rates in patients with refractory Ewing’s sarcoma and rhabdomyosarcoma

Background: New therapy options are urgently needed for patients with treatment-refractory Ewing’s sarcoma (ES) or rhabdomyosarcoma (RMS). In these subgroups, the role of allogeneic stem cell transplantation (allo-SCT) to induce a graft-versus-tumor effect (GvT) remains unclear. Here, we describe our experience and the general feasibility of donor lymphocyte infusion (DLI) following allo-SCT for those patients.

Patients and Methods: We retrospectively evaluated data of eight patients with treatment-refractory ES (ES #1-4) and RMS (RMS #1-4) after DLI following allo-SCT. Data were individually evaluated for presence of graft-versus-host disease (GvHD), relapse-free survival (RFS), and overall survival (OS). Three of four ES and one of four RMS patients had received haploidentical grafts; the remaining patients received HLA-matched grafts prior to DLI. Patients received donor lymphocytes ranging from 2.5 x 104 to 1 x 108 CD3+ cells/kg body weight.

Results: ES #4 and RMS #4 developed acute GvHD after DLI. Limited chronic GvHD was observed in RMS #3. In two patients, DLI was associated with stable disease for nine (ES #2) and six months (ES #4), respectively. RMS #4 showed partial remission lasting for eight months after one dose of DLI with 1 x 106 CD3+ cells/kg combined with local hyperthermia and chemotherapy. ES #4 had residual disease before allo-SCT and was converted to CR after DLI. Altogether, seven patients died of disease and none of toxicity. RMS #2 received seven doses up to 1 x 108 CD3+ cells/kg and IL-2 including surgery and chemotherapy and remained in CR for 97 months at the date of data assessment. Median follow-up after allo-SCT was 27.5 months.

Conclusion: DLI after allo-SCT is a feasible therapy option for treatment-refractory ES and RMS patients. In this analysis, DLI-related toxicity is acceptable. These findings have to be evaluated in prospective analyses.

Citation Format: Sebastian J. Schober, Maximilian Steinhauser, Angela Wawer, Irene Teichert-von Luettichau, Christoph Salat, Rolf D. Issels, Wolfgang Schwinger, Marek Ussowicz, Petar Antunovic, Luca Castagna, Hans-Jochem Kolb, Stefan E.G. Burdach, Uwe Thiel. Donor lymphocyte infusion after allogeneic stem cell transplantation is a feasible therapy option with acceptable toxicity rates in patients with refractory Ewing’s sarcoma and rhabdomyosarcoma [abstract]. In: Proceedings of the AACR Special Conference: Pediatric Cancer Research: From Basic Science to the Clinic; 2017 Dec 3-6; Atlanta, Georgia. Philadelphia (PA): AACR; Cancer Res 2018;78(19 Suppl):Abstract nr A28.

Hyperthermia adds to trabectedin effectiveness and thermal enhancement is associated with BRCA2 degradation and impairment of DNA homologous recombination repair

The tetrahydroisoquinoline trabectedin is a marine compound with approved activity against human soft-tissue sarcoma. It exerts antiproliferative activity mainly by specific binding to the DNA and inducing DNA double-strand breaks (DSB). As homologous recombination repair (HRR)-deficient tumors are more susceptible to trabectedin, hyperthermia-mediated on-demand induction of HRR deficiency represents a novel and promising strategy to boost trabectedin treatment. For the first time, we demonstrate enhancement of trabectedin effectiveness in human sarcoma cell lines by heat and characterize cellular events and molecular mechanisms related to heat-induced effects. Hyperthermic temperatures (41.8 or 43°C) enhanced significantly trabectedin-related clonogenic cell death and G2/M cell cycle arrest followed by cell type-dependent induction of apoptosis or senescence. Heat combination increased accumulation of γH2AX foci as key marker of DSBs. Expression of BRCA2 protein, an integral protein of the HRR machinery, was significantly decreased by heat. Consequently, recruitment of downstream RAD51 to γH2AX-positive repair foci was almost abolished indicating relevant impairment of HRR by heat. Accordingly, enhancement of trabectedin effectiveness was significantly augmented in BRCA2-proficient cells by hyperthermia and alleviated in BRCA2 knockout or siRNA-transfected BRCA2 knockdown cells. In peripheral blood mononuclear cells isolated from sarcoma patients, increased numbers of nuclear γH2AX foci were detected after systemic treatment with trabectedin and hyperthermia of the tumor region. The findings establish BRCA2 degradation by heat as a key factor for a novel treatment strategy that allows targeted chemosensitization to trabectedin and other DNA damaging antitumor drugs by on-demand induction of HRR deficiency.

Topotecan plus cyclophosphamide in adults with relapsed or refractory pediatric-type sarcoma: a retrospective analysis from the German Sarcoma Medical Oncology Group (AIO)

BACKGROUND

To assess the efficacy and safety of topotecan and cyclophosphamide (TC) in adult patients with pediatric-type sarcoma subtypes who failed induction chemotherapy.

PATIENTS AND METHODS

Patients with pediatric sarcoma subtypes, refractory to or relapsed after at least one prior induction chemotherapy, inoperable, ECOG PS 0-2, with measurable, progressive disease (PD), adequate organ functions, who have been treated with TC combination were retrospectively analysed within the AIO and SAREZ/BMBF network.

RESULTS

Thirty-nine patients, median age 28 years (18-58), 14 females, 25 males, have been identified. All patients had received induction treatment according to (inter)national study protocols. Second-line TC was applied in 33 patients (≥3rd-line in 6 patients). Twenty-three patients had refractory disease (evidence of PD during induction chemotherapy); 8 patients experienced an early relapse within 6 months as well as 8 patients after more than 24 months (late relapse). A median of 3 cycles (range, 1-6) had been applied and antitumor activity was: CR 2.6 %, PR 7.9 %, and disease stabilisation (SD) 26.3 %. PR lasted 32.8 months and median duration in patients with SD was 5 months (range, 2.0-14.7). The 3/6-months progression-free rates were 43.2 and 18.9 %.

CONCLUSIONS

Limited activity was seen in adult pts with refractory or relapsed pediatric-type sarcomas with the regimen which has proven activity in pediatric patients. Adults with refractory small cell sarcoma appear to have a similar dismal outcome as seen in pts with common adult-type histologies; however, a subset of patients has achieved long-lasting remissions on TC resulting in long-term survival.

Evaluation of several FDG PET parameters for prediction of soft tissue tumour grade at primary diagnosis and recurrence

OBJECTIVES

This study evaluates the diagnostic accuracy of SUV-based parameters derived from [(18) F]-2-fluoro-2-deoxy-D-glucose positron emission tomography (FDG-PET) in order to optimize non-invasive prediction of soft tissue tumour (STT) grade.

METHODS

One hundred and twenty-nine lesions from 123 patients who underwent FDG-PET for primary staging (n = 79) or assessment of recurrence (n = 44) of STT were analyzed retrospectively. Histopathology was the reference standard for tumour grading. Absolute values and tumour-to-liver ratios of several standardized uptake value (SUV) parameters were correlated with tumour grading.

RESULTS

At primary diagnosis SUVmax, SUVpeak, SUVmax/SUVliver and SUVpeak/SUVliver showed good correlation with tumour grade. SUVpeak (area under the receiver-operating-characteristic, AUC-ROC: 0.82) and SUVpeak/SUVliver (AUC-ROC: 0.82) separated best between low grade (WHO intermediate, grade 1 sarcoma, and low risk gastrointestinal stromal tumours, GISTs) and high grade (grade 2/3 sarcoma and intermediate/high risk GISTs) lesions: optimal threshold for SUVpeak/SUVliver was 2.4, which resulted in a sensitivity of 79 % and a specificity of 81 %. At disease recurrence, the AUC-ROC was <0.75 for each parameter.

CONCLUSIONS

A tumour SUVpeak of at least 2.4 fold mean liver uptake predicts high grade histopathology with good diagnostic accuracy at primary staging. At disease recurrence, FDG-PET does not reliably separate high and low grade lesions.

KEY POINTS

• Several SUV parameters accurately predict soft tissue sarcoma grade at primary diagnosis. • Tumour-to-liver ratios are of comparable value to absolute SUV parameters. • SUV peak /SUV liver >2.4 had 79 % sensitivity and 81 % specificity for high grade lesions. • At recurrence, FDG PET does not reliably indicate high grade sarcomas.

Heat-shock (H-S) and trabectedin efficacy in human soft-tissue sarcoma (STS) cells in vitro

e13540

Background: Regional hyperthermia improves response and survival when combined with chemotherapy in patients with high-risk STSs (Issels, R.D. Lancet Oncol 2010). Trabectedin is the first marine-derived antineoplastic drug approved in Europe for the treatment of advanced STS after failure of anthracyclines and ifosfamide, or for patients who are unsuited to receive these drugs. Trabectedin’s cytotoxicity is associated with the induction of lethal DNA double-strand breaks (DSB). The rationale to combine trabectedin with H-S is that heat-exposure sensitizes tumor cells by inhibiting the repair of induced DSBs (Krawczyk, P.M. PNAS 2011). Methods: Combinations of trabectedin and H-S at clinically relevant temperatures were examined in 3 different human cell lines: Osteosarcoma (U2Os), liposarcoma (SW872) and synovial sarcoma (SW982). Cells were treated with trabectedin at the dose of 500-4000 pM for 3 hours. H-S was applied in an incubator at 41.8°C and 43°C for 90 or 150 min before, during or after trabectedin incubation. Cytotoxicity was assessed measuring clonogenic survival of cells. Expression of BRCA2, which recruits homologous recombination repair recombinase Rad 51 to DSBs, was measured by Western Blot (WB). Recruitment of Rad 51 and the amount of gH2AX positive DSB-repair-foci were analysed by immunocytochemistry (ICC). Results: All cell lines showed reduced viability after increasing doses of trabectedin at 37°C. Combined treatment with trabectedin and H-S additionally enhanced cytotoxicity of trabectedin with strongest effects observed after simultaneous administration of both. WB-analysis showed strong heat-dependent reduction of BRCA2 expression. ICC revealed that recruitment of Rad 51 to DSBs was reduced after heat exposure at 41.8°C and abolished after exposure at 43°C. Accordingly, combined treatment significantly increased the amount of cells with severe DNA damage (>50 DSBs). Conclusions: Combined treatment with trabectedin and H-S in vitro resulted in significantly enhanced cytotoxicity that was accompanied by elevated DNA-damage in term of DSB-accumulation. The mechanisms of interaction between trabectedin and H-S concerning DNA repair are under investigation.

Proteins and cholesterol lipid vesicles are mediators of drug release from thermosensitive liposomes

Thermosensitive liposomes (TSL) are a promising tool for triggered drug delivery in combination with local hyperthermia. Objective of this study was to investigate the influence of serum on TSL in more detail and to identify serum components which are responsible for increasing drug release. Four different formulations were investigated: DPPC/DSPC/1,2-dipalmitoyl-sn-glycero-3-phosphodiglycerol (DPPG(2)) 50/20/30 (mol/mol) (DPPG(2)-TSL); DPPC/DSPC/DPPG(2)/DSPE-PEG2000 50/15/30/5 (mol/mol) (DPPG(2)/PEG-TSL), DPPC/P-Lyso-PC/DSPE-PEG2000 90/10/4 (mol/mol) (PEG/Lyso-TSL), and DPPC/DSPC/DSPE-PEG2000 80/15/5 (mol/mol) (PEG-TSL). DPPG(2)-TSL was the only formulation which was unaffected by osmotic stress. All formulations tested were influenced by serum components but the susceptibility was depended on the lipid composition of the vesicle. Presence of albumin (HSA) or cholesterol-containing lipid vesicles (DPPC/Chol-LLV) increased the membrane permeability for all tested formulations at temperatures around and above T(m) in a concentration based manner. PEGylation was not able to prevent the observed effect. PEG-TSL and PEG/Lyso-TSL were more susceptible to DPPC/Chol-LLV than DPPG(2)-containing TSL. In contrast, immunoglobulin type G (IgG) affected only anionic formulations. The membrane of DPPG(2)-TSL and DPPG(2)/PEG-TSL was more susceptible toward IgG as compared to HSA. DPPG(2)-TSL and PEG/Lyso-TSL were differentially influenced by fetal calf serum (FCS). As DPPG(2)-TSL was stabilized by pre-incubation with FCS at 37°C, this was the opposite for PEG/Lyso-TSL which were destabilized under these conditions. Individual serum components were unable to mimic the complex situation in full serum. Hence, the use of plasma or serum is still inevitable to investigate stability and release properties of novel TSL formulations until all serum components have been identified that alter TSL integrity.

Early response to neoadjuvant chemotherapy (NAC) in combination with regional hyperthermia (RHT) to predict long-term survival for adult-type high-risk soft tissue sarcoma (HR-STS): Results of the EORTC-ESHO intergroup phase III study

10054

Background: A randomized phase III completed trial showed that RHT added to NAC was beneficial in terms of local progression-free (LPFS), and disease-free (DFS) survival. Overall survival (OS) was improved in patients (pts) who completed the preoperative induction therapy with RHT (Lancet Oncol 2010). Here we analyzed both the radiographic (RR) and histopathologic (HR) response as early predictors for survival. Methods: 341 pts were randomized to receive 4 cycles of NAC + RHT (169 pts) or NAC alone (172 pts) as induction therapy. RR (CR/PR vs NC/PD) and HR (>75% vs <75% necrosis) were used to define responder vs non-responder. Predictive impact of response on LPFS, DFS, DDFS (distant disease-free survival) and OS was evaluated by intention-to-treat using Kaplan-Meier estimates and the log-rank test. Stratified (surgery before study entry yes/no; extremity vs non-extremity tumors) multivariate analyses were carried out by Cox regression. Results: Early response in pts with measurable disease was performed in 238 pts (103 pts not evaluable because of surgery before study entry). In the NAC+RHT group (114 pts) response rate was 49.1% (56 responders: RR: 18; HR: 22; RR + HR: 16) and substantially higher (p<0.001) compared to the NAC alone group (124 pts) which was 26,6% (33 responders: RR: 7; HR: 17; RR + HR: 9). In the NAC + RHT group, tumor response was associated with improved DFS (HR 0.58 CI 0.36-0.95; p=0.031) and OS (HR 0.50 CI 0.27-0.90; p=0.020) but not LPFS (HR 0.91 CI 0.49-1.71; p=0.78). For responders, OS median time was > 120 months vs 33 months for non-responders. For the entire NAC + RHT group (169 pts, including pts with surgery before study entry) response remained predictive for better OS (HR 0.54 CI 0.32-0.94; p=0.028) and was also associated with better DDFS (HR 0.47 CI 0.27-0.83; p=0.009). Conclusions: Adding RHT to NAC as induction therapy compared to NAC alone leads to significantly higher early response in almost half of the pts classified as responders which translates in better OS and prevention of distant metastases.

Ifosfamide, carboplatin and etoposide (ICE) as second-line regimen alone and in combination with regional hyperthermia is active in chemo-pre-treated advanced soft tissue sarcoma of adults

PURPOSE

To evaluate the efficacy and safety of the combination of ICE (ifosfamide 1.5 g m(-2), carboplatin 100 mg m(-2) and etoposide 150 mg m(-2), days 1-4, q 28 days, G-CSF 5 microg kg(-1) starting from day 6) alone and in combination with regional hyperthermia (RHT) in soft tissue sarcoma (STS) refractory to previous standard doxorubicin-ifosfamide-based chemotherapy.

PATIENTS AND METHODS

Twenty patients with advanced STS of different histological sub-types were treated with the ICE regimen with 13 patients receiving additional RHT. A median of four courses of ICE were administered with RHT on days 1 and 3 (60 min, T(max) 42 degrees C).

RESULTS

The objective response rate was 20%, with four partial responses (all treated with hyperthermia). In addition, two patients showed mixed responses and five patients stable disease. After a median follow-up time of 15 months, median time to progression was 6 months. Progression free rate estimates were 60% and 45% at 3 and 6 months, respectively. Median overall survival for all patients was 14.6 months.

CONCLUSION

These results suggest that ICE alone or combined with RHT shows activity as second-line therapy in doxorubicin-ifosfamide-refractory STS.

Interaction of human heat shock protein 70 with tumor-associated peptides

Molecular chaperones of the heat shock protein 70 (Hsp70) family play a crucial role in the presentation of exogenous antigenic peptides by antigen-presenting cells (APCs). In a combined biochemical and immunological approach, we characterize the biochemical interaction of tumor-associated peptides with human Hsp70 and show that the strength of this interaction determines the efficacy of immunological cross-presentation of the antigenic sequences by APCs. A fluorescein-labeled cytosolic mammalian Hsc70 binding peptide is shown to interact with human Hsp70 molecules with high affinity (Kd=0.58 μm at 25°C). Competition experiments demonstrate weaker binding by Hsp70 of antigenic peptides derived from the tumor-associated proteins tyrosinase (Kd=32 μm) and melanoma antigen recognized by T cells (MART-1) (Kd=2.4 μm). Adding a peptide sequence (pep70) with high Hsp70 binding affinity (Kd=0.04 μm) to the tumor-associated peptides enables them to strongly interact with Hsp70. Presentation of tumor-associated peptides by B cells resulting in T cell activation in vitro is enhanced by Hsp70 when the tumor-associated peptides contain the Hsp70 binding sequence. This observation has relevance for vaccine design, as augmented transfer of tumor-associated antigens to APCs is closely linked to the vaccine's efficacy of T cell stimulation.

Regional hyperthermia of the abdomen in conjunction with chemotherapy for peritoneal carcinomatosis: evaluation of two annular-phased-array applicators

BACKGROUND

Peritoneal carcinomatosis is a stage of gynecological and gastrointestinal malignancies with poor prognosis. Options for enhancing the effect of standard chemotherapy, such as aggressive surgery and intraperitoneal chemotherapy, have limitations. In this phase I/II study, we evaluated regional hyperthermia of the pelvis and abdomen using the annular-phased-array technique as an adjunct to chemotherapy.

METHODS

Forty-five patients with peritoneal carcinomatosis (with or without liver metastases) in colorectal cancer (CRC) (n = 16), ovarian cancer (OC) (n = 17), or gastric/pancreatic/biliary cancer (n = 12) underwent standard chemotherapy and regional hyperthermia. Most CRC patients received second-line chemotherapy. All OC patients were platinum resistant. Regional hyperthermia was applied using a SIGMA-60 applicator (OC), a SIGMA-Eye/MR applicator (CRC), or various ring applicators (gastric/pancreatic/biliary cancer).

RESULTS

Abdominal regional hyperthermia was well tolerated, with acceptable acute discomfort and no long-term morbidity. The SIGMA-Eye/MR applicator achieved higher systemic temperatures (associated with higher systemic stress) and more effective heating of the upper abdomen; the SIGMA-60 applicator achieved higher temperatures (and power densities) in the pelvis. Three-year overall survival was encouraging for patients with CRC (22%) and OC (29%) but not gastric/pancreatic/biliary cancer. For the SIGMA-60 applicator (patients with OC), higher measured temperatures at the vaginal stump correlated with better outcome. CONCLUSIONS. The SIGMA-60 and SIGMA-Eye/MR applicators are feasible for abdominal heating and have low toxicity. The SIGMA-60 applicator is specifically suitable for malignancies with high pelvic burden; the SIGMA-Eye/MR applicator better heats the upper abdomen, including the liver. Further randomized investigations are warranted.

Hyperthermia adds to chemotherapy

The hallmarks of hyperthermia and its pleotropic effects are in favour of its combined use with chemotherapy. Preclinical research reveals that for heat killing and synergistic effects the thermal dose is most critical. Thermal enhancement of drug cytotoxicity is accompanied by cellular death and necrosis without increasing its oncogenic potential. The induction of genetically defined stress responses can deliver danger signals to activate the host's immune system. The positive results of randomised trials have definitely established hyperthermia in combination with chemotherapy as a novel clinical modality for the treatment of cancer. Hyperthermia targets the action of chemotherapy within the heated tumour region without affecting systemic toxicity. In specific clinical settings regional hyperthermia (RHT) or hyperthermic perfusion has proved its value and deserve a greater focus and investigation in other malignancies. In Europe, more specialised centres should be created and maintained as network of excellence for hyperthermia in the field of oncology.

Calcium signaling in dendritic cells by human or mycobacterial Hsp70 is caused by contamination and is not required for Hsp70-mediated enhancement of cross-presentation

Extracellular heat shock proteins (HSPs) can stimulate antigen-specific immune responses. Using recombinant human (rhu)Hsp70, we previously demonstrated that through complex formation with exogenous antigenic peptides, rhuHsp70 can enhance cross-presentation by antigen-presenting cells (APCs) resulting in stronger T cell stimulation. T cell stimulatory activity has also been described for mycobacterial (myc)Hsp70. MycHsp70-assisted T cell activation has been reported to act through the binding of mycHsp70 to chemokine receptor 5 (CCR5), calcium signaling, phenotypic maturation, and cytokine secretion by dendritic cells (DCs). We report that highly purified rhuHsp70 and mycHsp70 proteins both strongly enhance cross-presentation of exogenous antigens. Augmentation of cross-presentation was seen for different APCs, irrespective of CCR5 expression. Moreover, neither of the purified Hsp70 proteins induced calcium signals in APCs. Instead, calcium signaling activity was found to be caused by contaminating nucleotides present in Hsp70 protein preparations. These results refute the hypothesis that mycHsp70 proteins require CCR5 expression and calcium signaling by APCs for enhanced antigen cross-presentation for T cell stimulation.

Differential effects of ifosfamide on dendritic cell-mediated stimulation of T cell interleukin-2 production, natural killer cell cytotoxicity and interferon-gamma production

Ifosfamide is a DNA-alkylating agent used frequently in chemotherapy of human malignancies. Ifosfamide and its major decomposition products deplete intracellular glutathione (GSH). Glutathione is the major intracellular thiol reductant that protects cells against oxidative injury. Ifosfamide depletion of intracellular GSH in human dendritic cells (DC), T cells and natural killer (NK) cells impairs their functional activity which can be restored by reconstituting GSH. Here we assessed the effect of ifosfamide on DC-mediated stimulation of NK cell proliferation via T cells and on direct DC stimulation of NK cell cytotoxicity and interferon (IFN)-gamma production. Indirect DC stimulation of NK cell proliferation via T cells and T cell-derived interleukin (IL)-2 were reduced by ifosfamide treatment of DC and reconstitution of GSH in DC restored both responses. When DC and NK cells were treated with ifosfamide, DC could overcome the negative effect of ifosfamide on NK cytotoxic function whereas NK cell IFN-gamma production was less efficiently restored. The ability of IL-2 activated NK cells to kill autologous immature DC or to induce DC maturation was reduced moderately by treatment of both cell types with ifosfamide. Overall, our results suggest that DC may stimulate anti-tumour effector cells in patients even if they had received treatment with chemotherapeutic agents such as ifosfamide.

Oral capecitabine in gemcitabine-pretreated patients with advanced pancreatic cancer

OBJECTIVE

To date, no standard regimen for salvage chemotherapy after gemcitabine (Gem) failure has been defined for patients with advanced pancreatic cancer (PC). Oral capecitabine (Cap) has shown promising activity in first-line chemotherapy trials in PC patients.

METHODS

Within a prospective single-center study, Cap was offered to patients who had already received at least 1 previous treatment regimen containing full-dose Gem (as a single agent, as part of a combination chemotherapy regimen or sequentially within a chemoradiotherapy protocol). Cap was administered orally at a dose of 1,250 mg/m(2) twice daily for 14 days followed by 7 days of rest. Study endpoints were objective tumor response rate by imaging criteria (according to RECIST), carbohydrate antigen 19-9 (CA19-9) tumor marker response, time to progression, overall survival and toxicity.

RESULTS

A median of 3 treatment cycles (range 1-36) was given to 39 patients. After a median follow-up of 6.6 months, 27 patients were evaluable for response: no complete or partial responses were observed, but 15 patients (39%) had stable disease. A CA19-9 reduction of >20% after 2 cycles of Cap was documented in 6 patients (15%). Median time to progression was 2.3 months (range 0.5-45.1) and median overall survival (since start of Cap treatment) was 7.6 months (range 0.7-45.1). Predominant grade 2 and 3 toxicities (per patient analysis) were hand-foot syndrome 28% (13% grade 3); anemia 23%; leg edema 15%; diarrhea 13%; nausea/vomiting 10%, and leukocytopenia 10%.

CONCLUSION

Single-agent Cap is a safe treatment option for Gem-pretreated patients with advanced PC. Further evaluation of Cap in controlled clinical trials of Gem-pretreated patients with advanced PC is recommended.

The cystine/cysteine cycle: a redox cycle regulating susceptibility versus resistance to cell death

The glutathione-dependent system is one of the key systems regulating cellular redox balance, and thus cell fate. Cysteine, typically present in its oxidized form cystine in the extracellular space, is regarded as the rate-limiting substrate for glutathione (GSH) synthesis. Cystine is transported into cells by the highly specific amino-acid antiporter system xc-. Since Burkitt's Lymphoma (BL) cells display limited uptake capacity for cystine, and are thus prone to oxidative stress-induced cell death, we stably expressed the substrate-specific subunit of system xc-, xCT, in HH514 BL cells. xCT-overexpressing cells became highly resistant to oxidative stress, particularly upon GSH depletion. Contrary to previous predictions, the increase of intracellular cysteine did not affect the cellular GSH pool, but concomitantly boosted extracellular cysteine concentrations. Even though cells were depleted of bulk GSH, xCT overexpression maintained cellular integrity by protecting against lipid peroxidation, a very early event in cell death progression. Our results show that system xc- protects against oxidative stress not by elevating intracellular GSH levels, but rather creates a reducing extracellular environment by driving a highly efficient cystine/cysteine redox cycle. Our findings show that the cystine/cysteine redox cycle by itself must be viewed as a discrete major regulator of cell survival.

Human heat shock protein 70 enhances tumor antigen presentation through complex formation and intracellular antigen delivery without innate immune signaling

Heat shock proteins (HSPs) have shown promise for the optimization of protein-based vaccines because they can transfer exogenous antigens to dendritic cells and at the same time induce their maturation. Great care must be exercised in interpretating HSP-driven studies, as by-products linked to the recombinant generation of these proteins have been shown to mediate immunological effects. We generated highly purified human recombinant Hsp70 and demonstrated that it strongly enhances the cross-presentation of exogenous antigens resulting in better antigen-specific T cell stimulation. Augmentation of T cell stimulation was a direct function of the degree of complex formation between Hsp70 and peptides and correlated with improved antigen delivery to endosomal compartments. The Hsp70 activity was independent of TAP proteins and was not inhibited by exotoxin A or endosomal acidification. Consequently, Hsp70 enhanced cross-presentation of various antigenic sequences, even when they required different post-uptake processing and trafficking, as exemplified by the tumor antigens tyrosinase and Melan-A/MART-1. Furthermore, Hsp70 enhanced cross-presentation by different antigen-presenting cells (APCs), including dendritic cells and B cells. Importantly, enhanced cross-presentation and antigen-specific T cell activation were observed in the absence of innate signals transmitted by Hsp70. As Hsp70 supports the cross-presentation of different antigens and APCs and is inert to APC function, it may show efficacy in various settings of immune modulation, including induction of antigen-specific immunity or tolerance.

In vitro stability and content release properties of phosphatidylglyceroglycerol containing thermosensitive liposomes

Recently, we reported that 1,2-dipalmitoyl-sn-glycero-3-phosphoglyceroglycerol (DPPGOG) prolongs the circulation time of thermosensitive liposomes (TSL). Since the only TSL formulation in clinical trials applies DSPE-PEG2000 and lysophosphatidylcholine (P-lyso-PC), the objective of this study was to compare the influence of these lipids with DPPGOG on in vitro stability and heat-induced drug release properties of TSL. The content release rate was significantly increased by incorporating DPPGOG or P-lyso-PC in TSL formulations. DPPC/DSPC/DPPGOG 50:20:30 (m/m) and DPPC/P-lyso-PC/DSPE-PEG2000 90:10:4 (m/m) did not differ significantly in their release rate of carboxyfluorescein with >70% being released within the first 10s at their phase transition temperature. Furthermore, DPPC/DSPC/DPPGOG showed an improved stability at 37 degrees C in serum compared to the PEGylated TSL. The in vitro properties of DPPGOG-containing TSL remained unchanged when encapsulating doxorubicin instead of carboxyfluorescein. The TSL retained 89.1+/-4.0% of doxorubicin over 3 h at 37 degrees C in the presence of serum. The drug was almost completely released within 120s at 42 degrees C. In conclusion, DPPGOG improves the in vitro properties in TSL formulations compared to DSPE-PEG2000, since it not only increases the in vivo half-life, it even increases the content release rate without negative effect on TSL stability at 37 degrees C which has been seen for DSPE-PEG2000/P-lyso-PC containing TSL.

[Clinical impact of locoregional hyperthermia in gynecological oncology]

In the last decade progress in gynecological oncology has been achieved mainly by new cytotoxic drugs and advances in radiation technology. For example, the use of taxanes in the primary therapy of ovarian cancers and of combined radio-chemotherapy in cervical cancer has led to significant prolongations of survival. However, in case of relapse most gynaecological malignancies are associated with very poor prognosis. Efficacy of local and systemic therapy can be increased by combining radiotherapy and/or chemotherapy with locoregional hyperthermia (LRH). Increasing the temperature of the target tissue up to 41-43 degrees C leads to local hyperaemia and the tumor tissue becomes more responsive to cytotoxic interventions. In several prospective randomized studies the combination between LRH and radiotherapy was superior to radiotherapy alone in terms of local control (e. g. chest wall recurrence in breast cancer) and has led to longer overall survival in advanced cervical cancer. Platinum derivatives and other cytotoxic drugs have shown synergistic effects with LRH and the combination of both has elicited high response rates in recurrent cervical cancer. In phase-II-clinical trials the newly developed liposomal anthracyclines demonstrated synergistic effects with LRH in patients with refractory ovarian cancer. Our own experience has shown that adding LRH to radio- and/or chemotherapy is well tolerated by the patients. Despite of the fact, that the available data are still preliminary, the inclusion of LRH into multimodal cancer therapy concepts appears to be very promising. Well-designed comparative studies are still needed to evaluate the role of hyperthermia as an adjunct to conventional cancer therapy.

High-risk soft tissue sarcoma: clinical trial and hyperthermia combined chemotherapy

For high-risk soft tissue sarcomas (HR-STS) of adults, new treatment strategies are needed to improve outcome with regard to local control and overall survival. Systemic chemotherapy has been integrated either after (adjuvant) or before (neoadjuvant) optimal local treatment by surgery and radiotherapy in HR-STS. This short overview summarizes the results of the combination with regional hyperthermia as a new treatment strategy to open a new therapeutic window.

The role of hyperthermia in combined treatment in the management of soft tissue sarcoma

For high-risk soft tissue sarcomas (HR-STS) of adults, new treatment strategies are needed to improve outcome with regard to local control and overall survival. Systemic chemotherapy has been integrated either after (adjuvant) or before (neoadjuvant) optimal local treatment by surgery and radiotherapy in HR-STS. This short overview summarizes the results of the combination with regional hyperthermia as a new treatment strategy to open a new therapeutic window.

Ferrite-enhanced MRI monitoring in hyperthermia

In an MRI hyperthermia hybrid system, T1 changes are investigated for monitoring thermal therapy at 0.2 T. The water bolus, which is needed for power transmission and cooling of the skin, limits MR image quality by signal compression and artifacts. Superparamagnetic ferrofluid in different concentration was investigated with MR relaxometry and MRI methods. We found that using ferrofluid in a low concentration of 70-90 ppm magnetite the water signal can be suppressed without susceptibility artifacts. With our method of signal suppression, a significant improvement of spatial and temporal resolution is possible. The ferrofluid is stable and allows RF heating at 100 MHz. This method of signal extinction may also be useful for other experimental setups where suppression of water is necessary.

Emerging treatments for soft tissue sarcoma of adults

Soft tissue sarcomas are a heterogeneous group of malignancies arising from mesenchymal tissues. Patients can present with a localised tumour (primary or local recurrence) at different sites (e.g., extremity, abdomen) or metastatic disease, which may require different treatment strategies. Is the surgical resection of a localised sarcoma enough or is it better to give an additional treatment like adjuvant and/or preoperative radiotherapy and/or chemotherapy? Which chemotherapy should be selected in the first or second line situation? Do new treatment options exist, such as targeted therapies? This review provides answers to some of these questions. To decide on consecutive treatment steps, it is important to know as many relevant factors as possible at first presentation. Therefore, the first part of this review discusses the specific characteristics and prognostic factors of importance for treatment planning. A short summary of current therapy strategies and existing standards is then given. The main body of the review summarises information on new and emerging clinical compounds for patients with soft tissue sarcoma of adults, including recent developments of targeted therapy.

Novel temperature-sensitive liposomes with prolonged circulation time

Hyperthermia increases the efficiency of various chemotherapeutic drugs and is administered as an adjunct to chemotherapy for the treatment of cancer patients. The temperature-dependent effect can be strongly increased by the use of temperature-sensitive liposomes in combination with regional hyperthermia, which specifically releases the entrapped drug in the heated tumor tissue. The novel lipid 1.2-dipalmitoyl-sn-glycero-3-phosphoglyceroglycerol (DPPGOG), which is closely related to the naturally occurring 1.2-dipalmitoyl-sn-glycero-3-phosphoglycerol, in combination with 1.2-dipalmitoyl-sn-glycero-3-phosphocholine and 1.2-distearoyl-sn-glycero-3-phosphocholine provides long-circulating temperature-sensitive liposomes with favorable properties under mildly hyperthermic conditions (41-42 degrees C). DPPGOG facilitates temperature-triggered drug release from these liposomes (diameter, 175 nm) and leads to a substantially prolonged plasma half-life for the encapsulated drug with t(1/2) = 9.6 h in hamsters and t(1/2) = 5.0 h in rats. Quantitative fluorescence microscopy of amelanotic melanoma grown in the transparent dorsal skin fold chamber of hamsters demonstrated a favorable drug accumulation in heated tissue after i.v. application of these liposomes (42 degrees C for 1 h). The mean area under the curve for tissue drug concentration was increased by more than sixfold by application of the new liposomes compared with nonliposomal drug delivery. In summary, we present a new DPPGOG-based liposomal formulation enabling long circulation time combined with fast and efficient drug release under mild hyperthermia. This adds positively to the results with lipid-grafted polyethylenglycol used thus far in temperature sensitive liposomes and widens the possibilities for clinical applications.

[Principles, technology and indication of hyperthermia and part body hyperthermia]

Clinical hyperthermia with controlled alteration of temperature (40 to 44 degrees C) in the target area is used in interdisciplinary treatment concepts for tumor treatment in combination with radiation and/or radiotherapy. Besides the direct cytotoxic power of hyperthermia there is an immunomodulatory effect and a radiation and chemotherapy sensitizing effect in the heated tissue. Clinical hyperthermia is an invasive or non-invasive supply of energy to the body of the patient, which leads to an artificial heating of the tumor and the surrounded tissue. The clinical hyperthermic procedures should take into account the oncologic disease and its pattern of organ involvement. There are three different types of hyperthermia: local hyperthermia (LHT), regional hyperthermia (RHT) and part body hyperthermia (PBH). PBH is used to heat regions of the body in case of metastatic disease, e. g. to the abdomen. I and phase II trials could show that the effects of radiation and chemotherapy can be altered by the simultaneous addition of hyperthermia. Data of trials involving skin metastasis in malignant melanoma, local relapse in breast cancer, tumors of the head and neck with regional lymph node metastasis, as well as trials in colorectal tumors, bladder cancer, pancreatic cancer, cervical cancer and sarcoma are presented. The results shows, that response to treatment can be improved by hyperthermia.

Ifosfamide with regional hyperthermia in soft-tissue sarcomas

For high-risk soft tissue sarcomas (HR-STS) of adults, new treatment strategies are needed to improve outcome with regard to local control and overall survival. Therefore, systemic chemotherapy has been integrated either after (adjuvant) or before (neoadjuvant) optimal local treatment by surgery and radiotherapy in HR-STS. The combination with regional hyperthermia as a new treatment strategy seems to open a new therapeutic window.

Ifosfamide impairs the allostimulatory capacity of human dendritic cells by intracellular glutathione depletion

Ifosfamide, a clinically potent chemotherapeutic agent, causes the depletion of intracellular glutathione (GSH) levels in various cell types. GSH is the major intracellular reductant against oxidative stress. 4-Hydroxyifosfamide (4-OH-IF), the activated form of ifosfamide, depletes GSH levels in T cells and natural killer (NK) cells; this is accompanied by a decrease in T-cell and NK-cell function. Here we demonstrate for the first time that human monocyte-derived dendritic cells (DCs) express higher constitutive levels of GSH and are less sensitive to 4-OH-IF-induced GSH depletion than T cells and NK cells. Treatment of DCs with 4-OH-IF significantly reduced their ability to stimulate allogeneic T-cell proliferation and interferon-gamma (IFN-gamma) production. Ifosfamide also decreased DC interleukin-12p70 (IL-12p70) production after stimulation with lipopolysaccharide (LPS) and IFN-gamma. The decrease in allostimulatory capacity and in IFN-gamma and IL-12 production correlated with a decrease in intracellular GSH in the DCs. The responses could be restored by reconstituting DC GSH levels with glutathione monoethyl ester (GSH-OEt). 4-OH-IF had no inhibitory effect on the ability of DCs to present exogenously added tyrosinase peptide to tyrosinase-specific cytotoxic T lymphocytes (CTLs). These studies suggest that in cancer patients treated with ifosfamide, protection strategies based on glutathione reconstitution may enhance DC function.

Feasibility and morbidity of combined hyperthermia and radiochemotherapy in recurrent rectal cancer--preliminary results

BACKGROUND

The local recurrence rate of colorectal cancer has been significantly reduced due to the use of combined radiochemotherapy. Despite this improvement regarding locally advanced tumour recurrences, the treatment strategy for pre-treated patients remains difficult and unresolved.

PATIENTS AND METHODS

We analysed treatment and follow-up data of 14 patients with local recurrence of rectal cancer who were treated with radiation therapy (RT), chemotherapy (CT) and regional hyperthermia (RHT) from November 1997 to December 2001. Nine of these patients had received irradiation and CT (= pre-treated patients) in the past. For this group, 30.6-39.6 Gy RT, 5-fluorouracil (5-FU) as a continuous infusion over 5 days per week (350 mg/m(2)/24 h) combined with RHT twice a week was given. The 5 remaining patients (= not pre-treated) received conformal irradiation of 45 Gy with a boost between 9 and 14.4 Gy, combined with continuous infusion of 5-FU on days 1-4, and 29-33 (500 mg/m(2)/ 24 h), and RHT twice a week. Response to therapy was evaluated by means of computed tomography (CT) or magnetic resonance imaging (MRI) and by clinical follow-up.

RESULTS

Among 13 evaluated cases, the overall objective response rate was 54% (5 complete responses, 2 partial responses). At mean follow-up of 13.9 months (range 5-32 months) 7 patients were alive.

CONCLUSION

The therapeutic regimen appears to be active in the treatment of local recurrences of rectal cancer. Larger-scaled studies are needed to evaluate the potency of hyperthermia in this therapeutic strategy.

Tumor-derived heat shock protein 70 peptide complexes are cross-presented by human dendritic cells

Our study demonstrates that tumor-derived heat shock protein (HSP)70 chaperones a tyrosinase peptide and mediates its transfer to human immature dendritic cells (DCs) by receptor-dependent uptake. Human tumor-derived HSP70 peptide complexes (HSP70-PC) thus have the immunogenic potential to instruct DCs to cross-present endogenously expressed, nonmutated, and tumor antigenic peptides that are shared among tumors of the melanocytic lineage for T cell recognition. T cell stimulation by HSP70-instructed DCs is dependent on the Ag bound to HSP70 in that only DCs incubated with HSP70-PC purified from tyrosinase-positive (HSP70-PC/tyr(+)) but not from tyrosinase-negative (HSP70-PC/tyr(-)) melanoma cells resulted in the specific activation of the HLA-A*0201-restricted tyrosinase peptide-specific cytotoxic T cell clone. HSP70-PC-mediated T cell stimulation is very efficient, delivering the tyrosinase peptide at concentrations as low as 30 ng/ml of HSP70-PC for T cell recognition. Receptor-dependent binding of HSP70-PC and active cell metabolism are prerequisites for MHC class I-restricted cross-presentation and T cell stimulation. T cell stimulation does not require external DC maturation signals (e.g., exogenously added TNF-alpha), suggesting that signaling DC maturation is an intrinsic property of the HSP70-PC itself and related to receptor-mediated binding. The cross-presentation of a shared human tumor Ag together with the exquisite efficacy are important new aspects for HSP70-based immunotherapy in clinical anti-cancer vaccination strategies, and suggest a potential extension of HSP70-based vaccination protocols from a patient-individual treatment modality to its use in an allogeneic setting.

Heat shock protein 70: role in antigen presentation and immune stimulation

Heat shock proteins (HSP) when released into the extracellular milieu can act simultaneously as a source of antigen due to their ability to chaperone peptides and as a maturation signal for dendritic cells, thereby inducing DCs to cross-present antigens to CD8+ T-cells. HSP can also act independently from associated peptides, stimulating the innate immune system. Previous results regarding the activation of NK cells by HSP70 cell surface expression on tumour cells and soluble HSP70 will be further covered elsewhere within this issue. For cross-presentation, HSP70-peptide complexes (HSP70-PC) were used from two human melanoma cell lines that differ in the expression of the tumour-associated antigen tyrosinase. Purified HSP70-PC consists of both the constitutively expressed HSC70 and the inducible HSP70. HSP70-peptide complexes purified from tyrosinase positive (HSP70-PC/tyr+) human melanoma cells, incubated with immature DCs, results in the activation of HLA-*A0201-restricted tyrosinase peptide-specific T-cells. Receptor-mediated uptake of HSP70-PC by DCs and intracellular transport are required for efficient MHC class I restricted cross-presentation of chaperoned peptides. Demonstration of HSP70-PC mediated cross-presentation of such non-mutated naturally expressed tumour antigens is of special clinical interest with regard to hyperthermia. Tumour regression and improved local control have been shown within clinical phase II/III trials integrating regional hyperthermia combined with radiation and/or chemotherapy in multimodal treatment strategies. According to the proposed concept, local necrosis induced by hyperthermic treatment induces the release of HSPs, followed by uptake, processing and presentation of associated peptides by DCs. By acting as chaperone and a signal for DC maturation, HSP70-PC might efficiently prime circulating T-cells. Therefore, upregulating HSP70 and causing local necrosis in tumour tissue by hyperthermia offers great potential as a new approach to directly activate the immune system.

Response to neoadjuvant chemotherapy combined with regional hyperthermia predicts long-term survival for adult patients with retroperitoneal and visceral high-risk soft tissue sarcomas

PURPOSE

To determine the efficacy of neoadjuvant chemotherapy combined with regional hyperthermia (RHT) for local tumor control and overall survival (OS) in adult patients with retroperitoneal or visceral (RP/V) high-risk soft tissue sarcomas (HR-STS).

PATIENTS AND METHODS

From 1991 to 1997, 58 patients with HR-STS at RP/V sites were prospectively treated with four cycles of etoposide, ifosfamide, and doxorubicin combined with RHT followed by surgery, adjuvant chemotherapy, and radiation.

RESULTS

Objective response rate assessable in 40 patients was 13% (five partial responses). Including minor responses (n = 8), the radiographic response rate was 33%. The pathologic response rate assessable in 26 patients after surgical resection was 42%. Median OS was 31 months. At a median observation time of 74 months, 5-year probability of local failure-free survival (LFFS), distant metastasis-free survival, event-free survival, and OS were 25%, 51%, 20%, and 32%, respectively. Averaged minimum temperatures (T(min)) and time-averaged temperatures achieved in 50% (T(50)) and 90% (T(90)) of all measured tumor sites differed significantly between responders and nonresponders (T(min), 39.3 degrees C v 38.0 degrees C; P =.002; T(50), 40.9 degrees C v 40.3 degrees C; P =.038; T(90), 40.1 degrees C v 39.3 degrees C; P =.017). At 5-year follow-up, probability of LFFS (59% v 0%; P <.001) and OS (60% v 10%; P <.001) was significantly in favor of patients responding to neoadjuvant thermochemotherapy.

CONCLUSION

Response to neoadjuvant chemotherapy combined with RHT is predictive for an improved local tumor control resulting in a long-term survival benefit for patients with HR-STS at unfavorable RP/V sites; however, the impact of RHT has to be defined in a randomized phase III trial.