The immune mechanisms of abscopal effect in radiation therapy

Radiation, inflammation and the immune response in cancer

Radiation is an important component of cancer treatment with more than half of all patients receive radiotherapy during their cancer experience. While the impact of radiation on tumour morphology is routinely examined in the pre-clinical and clinical setting, the impact of radiation on the tumour microenvironment and more specifically the inflammatory/immune response is less well characterised. Inflammation is a key contributor to short- and long-term cancer eradication, with significant tumour and normal tissue consequences. Therefore, the role of radiation in modulating the inflammatory response is highly topical given the current wave of targeted and immuno-therapeutic treatments for cancer. This review provides a general overview of how radiation modulates the inflammatory and immune response—(i) how radiation induces the inflammatory/immune system, (ii) the cellular changes that take place, (iii) how radiation dose delivery affects the immune response, and (iv) a discussion on research directions to improve patient survival, reduce side effects, improve quality of life, and reduce financial costs in the immediate future. Harnessing the benefits of radiation on the immune response will enhance its maximal therapeutic benefit and reduce radiation-induced toxicity.

Management of Brain Metastases in the New Era of Checkpoint Inhibition

PURPOSE OF THE REVIEW

Brain metastasis is a common complication of advanced malignancies, especially, lung cancer, breast cancer, renal cell carcinoma, and melanoma. Traditionally surgery, when indicated, and radiation therapy, either as whole-brain radiation therapy or stereotactic radiosurgery, constituted the major treatment options for brain metastases. Until recently, most of the systemic chemotherapy agents had limited activity for brain metastases. However, with the advent of small molecule tyrosine kinase inhibitors and immunotherapy agents, there has been renewed interest in using these agents in the management of brain metastases.

RECENT FINDINGS

Immune checkpoint inhibitors have revolutionized the treatment of metastatic melanoma, lung cancer, kidney cancer, and bladder cancer among others. They modulate the immune system to recognize tumor antigens as "non-self" antigens and mount an immune response against them. Initial studies of using immune checkpoint inhibitors in brain metastases have shown promising activity, and several clinical trials are currently underway. Studies are also assessing the combination of radiation therapy and immunotherapy in brain metastases. The results of these ongoing clinical trials have the potential to change the therapeutic paradigm in patients with brain metastases.

Advantages and Limitations in the Use of Combination Therapies with Charged Particle Radiation Therapy

Purpose

Studies are currently underway to help provide basic and clinical evidence for combination particle beam radiation therapy, on which there are few published reports. The purpose of this article is to summarize the current status in the use of particle beams combined with other modalities.

Results

Following from experiences in x-ray radiation therapy, combination therapy with proton beams (PBT) has been attempted, and several clinical studies have reported improved survival rates for patients with non-small cell lung cancer, pancreatic cancers, esophageal cancers, and glioblastomas. Recently, basic studies combining PBT with PARP inhibitors and histone deacetylase inhibitors have also reported promising results. In the area of carbon ion therapy (CIT), there are few clinical reports on combination therapy; however, the number of basic research reports exceeds that for PBT. So far, the combined use of cytotoxic drugs with CIT yields independent additive effects. In addition, it is notable that combination therapy with CIT is effective against radioresistant cancer stem-like cells. Recent evidence also suggests that local radiation therapy can induce an effective antitumor immune response. There has been an increased use of combination immune-modulating agents and cytokines with particle beams, especially CIT. The field of radiation therapy is evolving from a strong reliance on local-regional treatment to a growing reliance on systemic immunotherapy.

Conclusions

The combined use of anticancer agents with particle radiation therapy has a considerable potential effect. Future research in molecular targeting therapy and immunotherapy may help identify the most efficacious approach for combination therapy with protons and carbon ions.

The Integration of Radiotherapy with Immunotherapy for the Treatment of Non-Small Cell Lung Cancer

Five-year survival rates for non-small cell lung cancer (NSCLC) range from 14% to 49% for stage I to stage IIIA disease, and are <5% for stage IIIB/IV disease. Improvements have been made in the outcomes of patients with NSCLC due to advancements in radiotherapy (RT) techniques, the use of concurrent chemotherapy with RT, and the emergence of immunotherapy as first- and second-line treatment in the metastatic setting. RT remains the mainstay treatment in patients with inoperable early-stage NSCLC and is given concurrently or sequentially with chemotherapy in patients with locally advanced unresectable disease. There is emerging evidence that RT not only provides local tumor control but also may influence systemic control. Multiple preclinical studies have demonstrated that RT induces immunomodulatory effects in the local tumor microenvironment, supporting a synergistic combination approach with immunotherapy to improve systemic control. Immunotherapy options that could be combined with RT include programmed cell death-1/programmed cell death ligand-1 blockers, as well as investigational agents such as OX-40 agonists, toll-like receptor agonists, indoleamine 2,3-dioxygenase-1 inhibitors, and cytokines. Here, we describe the rationale for the integration of RT and immunotherapy in patients with NSCLC, present safety and efficacy data that support this combination strategy, review planned and ongoing studies, and highlight unanswered questions and future research needs.

Personalizing Radiation Treatment Delivery in the Management of Breast Cancer

Long-term data establishes the efficacy of radiotherapy in the adjuvant management of breast cancer. New dose and fractionation schemas have evolved and are available, each with unique risks and rewards. Current efforts are ongoing to tailor radiotherapy to the unique biology of breast cancer. In this review, we discuss our efforts to personalize radiotherapy dosing using genomic data and the implications for future clinical trials. We also explore immune mechanisms that may contribute to a tumor's unique radiation sensitivity or resistance.

Using immunotherapy to boost the abscopal effect

More than 60 years ago, the effect whereby radiotherapy at one site may lead to regression of metastatic cancer at distant sites that are not irradiated was described and called the abscopal effect (from 'ab scopus', that is, away from the target). The abscopal effect has been connected to mechanisms involving the immune system. However, the effect is rare because at the time of treatment, established immune-tolerance mechanisms may hamper the development of sufficiently robust abscopal responses. Today, the growing consensus is that combining radiotherapy with immunotherapy provides an opportunity to boost abscopal response rates, extending the use of radiotherapy to treatment of both local and metastatic disease. In this Opinion article, we review evidence for this growing consensus and highlight emerging limitations to boosting the abscopal effect using immunotherapy. This is followed by a perspective on current and potential cross-disciplinary approaches, including the use of smart materials to address these limitations.

The combination of ionizing radiation and proteasomal inhibition by bortezomib enhances the expression of NKG2D ligands in multiple myeloma cells

Bortezomib, which is a potent proteasome inhibitor, has been used as a first-line drugs to treat multiple myeloma for a few decades, and radiotherapy has frequently been applied to manage acute bone lesions in the patients. Therefore, it was necessary to investigate what the benefits might be if the two therapies were applied simultaneously in the treatment of multiple myeloma. Since it was known that radiotherapy and proteasome inhibitors could increase the expression of NKG2D ligands through induction of protein synthesis and suppression of protein degradation of NKG2D ligands, respectively, we supposed that the combined treatment might further enhance the expression of NKG2D ligands. In this study, we analyzed the expression level of NKG2D ligands using multiplex PCR and flow cytometry after treatment of IM-9 and RPMI-8226 myeloma cells with bortezomib and ionizing radiation; we then assayed the susceptibility to NK-92 cells. Although the expression of only some kinds of NKG2D ligands were increased by treatment with bortezomib alone, five kinds of NKG2D ligands that we assayed were further induced at the surface protein level after combined treatment with ionizing radiation and bortezomib. Furthermore, combined treatment made myeloma cells more susceptible to NK-92 cells, compared with treatment with bortezomib alone. In conclusion, the combination therapy of ionizing radiation plus the proteasome inhibitor bortezomib is a promising therapeutical strategy for enhancing NK cell-mediated anticancer immune responses.

Treatment of Canine Oral Melanoma with Nanotechnology-Based Immunotherapy and Radiation

The presence and benefit of a radiation therapy-associated immune reaction is of great interest as the overall interest in cancer immunotherapy expands. The pathological assessment of irradiated tumors rarely demonstrates consistent immune or inflammatory response. More recent information, primarily associated with the "abscopal effect", suggests a subtle radiation-based systemic immune response may be more common and have more therapeutic potential than previously believed. However, to be of consistent value, the immune stimulatory potential of radiation therapy (RT) will clearly need to be supported by combination with other immunotherapy efforts. In this study, using a spontaneous canine oral melanoma model, we have assessed the efficacy and tumor immunopathology of two nanotechnology-based immune adjuvants combined with RT. The immune adjuvants were administered intratumorally, in an approach termed "in situ vaccination", that puts immunostimulatory reagents into a recognized tumor and utilizes the endogenous antigens in the tumor as the antigens in the antigen/adjuvant combination that constitutes a vaccine. The radiation treatment consisted of a local 6 × 6 Gy tumor regimen given over a 12 day period. The immune adjuvants were a plant-based virus-like nanoparticle (VLP) and a 110 nm diameter magnetic iron oxide nanoparticle (mNPH) that was activated with an alternating magnetic field (AMF) to produce moderate heat (43 °C/60 min). The RT was used alone or combined with one or both adjuvants. The VLP (4 × 200 μg) and mNPH (2 × 7.5 mg/gram tumor) were delivered intratumorally respectively during the RT regimen. All patients received a diagnostic biopsy and CT-based 3-D radiation treatment plan prior to initiating therapy. Patients were assessed clinically 14-21 days post-treatment, monthly for 3 months following treatment, and bimonthly, thereafter. Immunohistopathologic assessment of the tumors was performed before and 14-21 days following treatment. Results suggest that addition of VLPs and/or mNPH to a hypofractionated radiation regimen increases the immune cell infiltration in the tumor, extends the tumor control interval, and has important systemic therapeutic potential.

The immunocytokine L19-IL2: An interplay between radiotherapy and long-lasting systemic anti-tumour immune responses

Recently, we have shown that the administration of the tumour-targeted antibody-based immunocytokine L19-IL2 after radiotherapy (RT) resulted in synergistic anti-tumour effect. Here we show that RT and L19-IL2 can activate a curative abscopal effect, with a long-lasting immunological memory. Ionizing radiation (single dose of 15Gy, 5 × 2Gy or 5 × 5Gy) was delivered to primary C51 colon tumour-bearing immunocompetent mice in combination with L19-IL2 and response of secondary non-irradiated C51 or CT26 colon tumours was evaluated. 15Gy + L19-IL2 triggered a curative (20%) abscopal effect, which was T cell dependent. Moreover, 10Gy + L19-IL2 treated and cured mice were re-injected after 150 days with C51 tumour cells and tumour uptake was assessed. Age-matched controls (matrigel injected mice treated with 10Gy + L19-IL2, mice cured after treatment with surgery + L19-IL2 and mice cured after high dose RT 40Gy + vehicle) were included. Several immunological parameters in blood, tumours, lymph nodes and spleens were investigated. Treatment with 10Gy + L19-IL2 resulted in long-lasting immunological memory, associated with CD44⁺CD127⁺ expression on circulating T cells. This combination treatment can induce long-lasting curative abscopal responses, and therefore it has also great potential for treatment of metastatic disease. Preclinical findings have led to the initiation of a phase I clinical trial (NCT02086721) in our institute investigating stereotactic ablative radiotherapy with L19-IL2 in patients with oligometastatic solid tumours.

The gentamicin-collagen implant and the risk of distant metastases of rectal cancer following short-course radiotherapy and curative resection: the long-term outcomes of a randomized study

PURPOSE

A previous randomized study conducted by our group showed that application of gentamicin-collagen implant (GCI) into the pelvic cavity after total mesorectal excision (TME) reduced the incidence of distant metastases. Therefore, we decided to conduct a confirmatory study.

METHODS

Patients with rectal cancer were included in the study if they met the following criteria: adenocarcinoma of the rectum, preoperative short-term radiotherapy (5 × 5 Gy), and WHO performance score 0-1.

RESULTS

One hundred seventy-six patients were randomly assigned either to an experimental group in which GCI was applied (n = 81) or to a control group without GCI (n = 81). Median follow-up was 80 months. Cumulative incidence of distant metastases at 5 years was higher in the control group compared to the experimental group: 23.5 vs 8.6% (HR 2.4 [95% CI 1.1-5.5], P = 0.005). Overall survival (OS), disease-free survival (DFS), and cancer-specific survival (CSS) did not differ between the experimental group and the control group: HR 0.95 [95% CI 0.55-1.70], P = 0.864; HR 0.85 [95% CI 0.50-1.45], P = 0.548, and HR 0.5 [95%CI 0.22-1.22], P = 0.093, respectively. The predefined by the protocol subgroup analysis for yp stage III disease showed better DFS in the experimental group compared to the control group; HR 0.47 [95%CI 0.23-0.97], P = 0.042).

CONCLUSIONS

The results confirmed our previous finding that GCI applied in the pelvis significantly reduced the rate of distant metastases in patients after radical rectal cancer resection.

Abscopal effect of radiation on bone metastases of breast cancer: A case report

The abscopal effect is defined as the clearance of distant tumors after applying localized irradiation to a particular tumor site. It has been proposed that a mechanism for the abscopal effect might be the activation of the immune system, which leads to immunogenic tumor cell death. Here, we describe a woman with advanced breast cancer that received modified ablative radiation therapy that targeted her primary breast tumor. She experienced an apparent regression of metastatic mass in the thoracic spine. This case supported the hypothesis that the abscopal effect might be attributable to an activation of the systemic immune response.

Radiotherapy prolongs the survival of advanced non-small-cell lung cancer patients undergone to an immune-modulating treatment with dose-fractioned cisplatin and metronomic etoposide and bevacizumab (mPEBev)

Radiotherapy (RT), together with a direct cytolytic effect on tumor tissue, also elicits systemic immunological events, which sometimes result in the regression of distant metastases (abscopal effect). We have shown the safety and anti-tumor activity of a novel metronomic chemotherapy (mCH) regimen with dose-fractioned cisplatin, oral etoposide and bevacizumab, a mAb against the vasculo-endothelial-growth-factor (mPEBev regimen), in metastatic non-small-cell-lung cancer (mNSCLC). This regimen, designed on the results of translational studies, showed immune-modulating effects that could trigger and empower the immunological effects associated with tumor irradiation. In order to assess this, we carried out a retrospective analysis in a subset of 69 consecutive patients who received the mPEBev regimen within the BEVA2007 trial. Forty-five of these patients, also received palliative RT of one or more metastatic sites. Statistical analysis (a Log-rank test) revealed a much longer median survival in the group of patients who received RT [mCH vs mCH + RT: 12.1 +/-2.5 (95%CI 3.35-8.6) vs 22.12 +/-4.3 (95%CI 11.9-26.087) months; P=0.015] with no difference in progression-free survival. In particular, their survival correlated with the mPEBev regimen ability to induce the percentage of activated dendritic cells (DCs) (CD3-CD11b+CD15-CD83+CD80+) [Fold to baseline value (FBV) ≤1 vs >1: 4+/-5.389 (95%CI,0- 14.56) vs 56+/-23.05 (95%CI,10.8-101.2) months; P:0.049)] and central-memory- T-cells (CD3+CD8+CD45RA-CCR7+) [FBV ≤ 1 vs >1: 8+/-5.96 (95%CI,0-19.68) vs 31+/-12.3 (95%CI,6.94-55.1) months; P:0.045]. These results suggest that tumor irradiation may prolong the survival of NSCLC patients undergone mPEBev regimen presumably by eliciting an immune-mediated effect and provide the rationale for further perspective clinical studies.

Stereotactic Ablative Radiation Therapy Combined With Immunotherapy for Solid Tumors

Immunotherapy, particularly immune-checkpoint inhibition, is producing encouraging clinical responses and affecting the way numerous cancers are treated. Yet immune-checkpoint therapy is not effective for many patients, and even those who initially respond can experience relapse, fueling interest in finding new processes or tools to improve the effectiveness of these novel therapeutics. One such tool is radiation. Both preclinical and clinical studies have demonstrated that the systemic effects of immunotherapy can be amplified when it is used in combination with radiation and, conversely, that the immunogenic effects of local irradiation can be amplified and extended to distant sites when used with immunotherapy. We review how stereotactic ablative radiation therapy, a technique specifically indicated for tumors treated with immune-checkpoint inhibitors, can potentiate the effects of immune-checkpoint therapy. We further explore how these novel therapeutics may transform radiation, previously considered a local treatment option, into powerful systemic therapy.

Optimizing tumor immune response through combination of radiation and immunotherapy

Radiation therapy and immunotherapy are two highly evolving modalities for the treatment of solid tumors. Immunotherapeutic drugs can either stimulate the immune system via immunogenic pathways or target co-inhibitory checkpoints. An augmented tumor cell recognition by host immune cells can be achieved post-irradiation, as irradiated tissues can release chemical signals which are sensed by the immune system resulting in its activation. Different strategies combining both treatment modalities were tested in order to achieve a better therapeutic response and longer tumor control. Both regimens act synergistically to one another with complimentary mechanisms. In this review, we explore the scientific basis behind such a combination, starting initially with a brief historical overview behind utilizing radiation and immunotherapies for solid tumors, followed by the different types of these two modalities, and the biological concept behind their synergistic effect. We also shed light on the common side effects and toxicities associated with radiation and immunotherapy. Finally, we discuss previous clinical trials tackling this multimodality combination and highlight future ongoing research.

What Combined Measurements From Structures and Imaging Tell Us About DNA Damage Responses

DNA damage outcomes depend upon the efficiency and fidelity of DNA damage responses (DDRs) for different cells and damage. As such, DDRs represent tightly regulated prototypical systems for linking nanoscale biomolecular structure and assembly to the biology of genomic regulation and cell signaling. However, the dynamic and multifunctional nature of DDR assemblies can render elusive the correlation between the structures of DDR factors and specific biological disruptions to the DDR when these structures are altered. In this chapter, we discuss concepts and strategies for combining structural, biophysical, and imaging techniques to investigate DDR recognition and regulation, and thus bridge sequence-level structural biochemistry to quantitative biological outcomes visualized in cells. We focus on representative DDR responses from PARP/PARG/AIF damage signaling in DNA single-strand break repair and nonhomologous end joining complexes in double-strand break repair. Methods with exemplary experimental results are considered with a focus on strategies for probing flexibility, conformational changes, and assembly processes that shape a predictive understanding of DDR mechanisms in a cellular context. Integration of structural and imaging measurements promises to provide foundational knowledge to rationally control and optimize DNA damage outcomes for synthetic lethality and for immune activation with resulting insights for biology and cancer interventions.

Novel Opportunities to Use Radiation Therapy with Immune Checkpoint Inhibitors for Melanoma Management

Immunotherapy has revolutionized the systemic management of numerous malignancies. Nowhere has the proven benefit of these agents in clinical practice been more evident than in the management of advanced melanoma. Numerous preclinical studies have revealed the potential benefit of immune-priming radiotherapy in stimulating tumor-specific immune responses. This signal for immune activation may lead to clinically relevant synergy with immune checkpoint inhibitors against malignant cells. In this review, the authors summarize the current data outlining the role radiation therapy may play in the management of advanced melanoma alongside immune checkpoint inhibitors.

The effect of hypofractionated radiation and magnetic nanoparticle hyperthermia on tumor immunogenicity and overall treatment response

It is now known that many tumors develop molecular signals (immune checkpoint modulators) that inhibit an effective tumor immune response. New information also suggest that even well-known cancer treatment modalities such as radiation and hyperthermia generate potentially beneficial immune responses that have been blocked or mitigated by such immune checkpoints, or similar molecules. The cancer therapy challenge is to; a) identify these treatment-based immune signals (proteins, antigens, etc.); b) the treatment doses or regimens that produce them; and c) the mechanisms that block or have the potential to promote them. The goal of this preliminary study, using the B6 mouse - B16 tumor model, clinically relevant radiation doses and fractionation schemes (including those used clinically in hypofractionated radiation therapy), magnetic nanoparticle hyperthermia (mNPH) and sophisticated protein, immune and tumor growth analysis techniques and modulators, is to determine the effect of specific radiation or hyperthermia alone and combined on overall treatment efficacy and immunologic response mechanisms. Preliminary analysis suggests that radiation dose (10 Gy vs. 2 Gy) significantly alters the mechanism of cell death (apoptosis vs. mitosis vs. necrosis) and the resulting immunogenicity. Our hypothesis and data suggest this difference is protein/antigen and immune recognition-based. Similarly, our evidence suggest that radiation doses larger than the conventional 2 Gy dose and specific hyperthermia doses and techniques (including mNP hyperthermia treatment) can be immunologically different, and potentially superior to, the radiation and heat therapy regimens that are typically used in research and clinical practice.

The Immunoregulatory Potential of Particle Radiation in Cancer Therapy

Cancer treatment, today, consists of surgery, chemotherapy, radiation, and most recently immunotherapy. Combination immunotherapy-radiotherapy (CIR) has experienced a surge in public attention due to numerous clinical publications outlining the reduction or elimination of metastatic disease, following treatment with specifically ipilimumab and radiotherapy. The mechanism behind CIR, however, remains unclear, though it is hypothesized that radiation transforms the tumor into an in situ vaccine which immunotherapy modulates into a larger immune response. To date, the majority of attention has focused on rotating out immunotherapeutics with conventional radiation; however, the unique biological and physical benefits of particle irradiation may prove superior in generation of systemic effect. Here, we review recent advances in CIR, with a particular focus on the usage of charged particles to induce or enhance response to cancerous disease.

Effect of intra-tumoral magnetic nanoparticle hyperthermia and viral nanoparticle immunogenicity on primary and metastatic cancer

Although there is long association of medical hyperthermia and immune stimulation, the relative lack of a quantifiable and reproducible effect has limited the utility and advancement of this relationship in preclinical/clinical cancer and non-cancer settings. Recent cancer-based immune findings (immune checkpoint modulators etc.) including improved mechanistic understanding and biological tools now make it possible to modify and exploit the immune system to benefit conventional cancer treatments such as radiation and hyperthermia. Based on the prior experience of our research group including; cancer-based heat therapy, magnetic nanoparticle (mNP) hyperthermia, radiation biology, cancer immunology and Cowpea Mosaic Virus that has been engineered to over express antigenic proteins without RNA or DNA (eCPMV/VLP). This research was designed to determine if and how the intra-tumoral delivery of mNP hyperthermia and VLP can work together to improve local and systemic tumor treatment efficacy. Using the C3H mouse/MTG-B mammary adenocarcinoma cell model and the C57-B6 mouse/B-16-F10 melanoma cancer cell model, our data suggests the appropriate combination of intra-tumoral mNP heat (e.g. 43°C/30-60 minutes) and VLP (100 μg/200 mm3 tumor) not only result in significant primary tumor regression but the creation a systemic immune reaction that has the potential to retard secondary tumor growth (abscopal effect) and resist tumor rechallenge. Molecular data from these experiments suggest treatment based cell damage and immune signals such as Heat Shock Protein (HSP) 70/90, calreticulin, MTA1 and CD47 are potential targets that can be exploited to enhance the local and systemic (abscopal effect) immune potential of hyperthermia cancer treatment.

Hypo-fractionated Radiation, Magnetic Nanoparticle Hyperthermia and a Viral Immunotherapy Treatment of Spontaneous Canine Cancer

It has recently been shown that cancer treatments such as radiation and hyperthermia, which have conventionally been viewed to have modest immune based anti-cancer effects, may, if used appropriately stimulate a significant and potentially effective local and systemic anti-cancer immune effect (abscopal effect) and improved prognosis. Using eight spontaneous canine cancers (2 oral melanoma, 3 oral amelioblastomas and 1 carcinomas), we have shown that hypofractionated radiation (6 x 6 Gy) and/or magnetic nanoparticle hyperthermia (2 X 43°C / 45 minutes) and/or an immunogenic virus-like nanoparticle (VLP, 2 x 200 μg) are capable of delivering a highly effective cancer treatment that includes an immunogenic component. Two tumors received all three therapeutic modalities, one tumor received radiation and hyperthermia, two tumors received radiation and VLP, and three tumors received only mNP hyperthermia. The treatment regimen is conducted over a 14-day period. All patients tolerated the treatments without complication and have had local and distant tumor responses that significantly exceed responses observed following conventional therapy (surgery and/or radiation). The results suggest that both hypofractionated radiation and hyperthermia have effective immune responses that are enhanced by the intratumoral VLP treatment. Molecular data from these tumors suggest Heat Shock Protein (HSP) 70/90, calreticulin and CD47 are targets that can be exploited to enhance the local and systemic (abscopal effect) immune potential of radiation and hyperthermia cancer treatment.

Successful palliative approach with high-intensity focused ultrasound in a patient with metastatic anaplastic pancreatic carcinoma: a case report

We report a case of a 74-year-old man with a metastatic anaplastic pancreatic carcinoma (APC). After an early tumour progression on first-line chemotherapy with cisplatin and gemcitabine, even though it was badly tolerated, he was treated with a combination of systemic modified FOLFIRI and high-intensity focused ultrasound (HIFU) on the pancreatic mass. A tumour showing partial response with a clinical benefit was obtained. HIFU was preferred to radiotherapy because of its shorter course and minimal side effects, in order to improve the patient's clinical conditions. The patient is currently on chemotherapy, asymptomatic with a good performance status. In referral centres, with specific expertise, HIFU could be safely and successfully combined with systemic chemotherapy for treatment of metastatic pancreatic carcinoma.

Cancer vaccines

Attempts to generate an anticancer immune response in vivo in patients with cancer have taken several forms. Although to date there have been relatively few published studies describing the effects of the approach in hematologic malignancy, that circumstance is expected to change rapidly during the next few years. In solid tumors, it is not known which, if any, of the approaches being explored will be able to produce responses of sufficient effectiveness and duration to be of general clinical value. Despite the documented increase in survival of patients developing an immune response to tumor immunization, no randomized clinical trial has been entirely convincing. As knowledge of the molecular basis of the immune response and of the immune defenses used by cancer cells improves, it is reasonable to expect to see increasing benefits from tumor vaccines, which are likely to complement, long before they replace, conventional therapies.