Management of Kaposi sarcoma: the role of interferon and thalidomide

Phase II Trial of Lenalidomide in HIV-Infected Patients with Previously Treated Kaposi's Sarcoma: Results of the ANRS 154 Lenakap Trial

Lenalidomide, an oral immunomodulating agent, has shown promising activity in HIV-infected individuals with Kaposi's sarcoma (KS). This single-arm, multicenter, open-label, Gehan's two-stage phase II trial evaluated the efficacy and safety of lenalidomide in HIV-infected patients with progressive KS despite previous chemotherapy (NCT01282047, ANRS 154 Lenakap trial). The primary endpoint was the rate of partial response (PR) or complete response (CR) at week 24, evaluated by both the study investigators and the patients using the Physical Global Assessment (PGA). AIDS Clinical Trials Group (ACTG) criteria for KS treatment evaluation were used as a secondary endpoint. The data and safety monitoring board recommended that enrollments be halted on April 24, 2013, because of lack of responses. We enrolled 12 antiretroviral-treated HIV-infected men with progressive KS despite previous chemotherapy. Their HIV plasma viral load was <50 copies/ml and their median CD4 cell count 444/mm³. One patient stopped taking lenalidomide because of hives at week 1 and a second patient died at week 7. The remaining 10 patients were assessable at week 24, when none had PGA-defined CR or PR and one had ACTG-defined PR. There were no additional PGA responses at week 48, but an additional three patients had ACTG responses, for a total of four patients with ACTG PR at week 48 (40%; 95% confidence interval: 12.2-73.8). Fourteen grade 3-4 adverse events were considered at least possibly related to lenalidomide during a total of 101 cycles. Lenalidomide was well tolerated in antiretroviral experienced patients with progressive KS previously treated with chemotherapy. The ACTG-defined response rate at week 48 was 40%, while it was 0% using PGA criteria.

Thalidomide plus chemotherapy exhibit enhanced efficacy in the clinical treatment of T-cell non-Hodgkin's lymphoma: A prospective study of 46 cases

The treatment of T-cell non-Hodgkin's lymphoma (T-NHL) remains challenging. There is currently no standard regimen for the treatment of T-NHL in the first- or second-line setting. Thalidomide was previously shown to exert antitumor effects through inhibiting angiogenesis, promoting apoptosis and immunomodulatory activity. However, all the previous studies on the treatment of lymphoma with thalidomide included patient samples of limited size. In the present study, 46 cases of eligible T-NHL patients were randomized into i) the control group (conventional combined chemotherapy, n=22) and ii) the thalidomide group (thalidomide plus combined chemotherapy, n=24). The median dose of thalidomide was 200 mg (range, 150-400 mg) every night, without reported severe side effects. The clinical response to treatment was as follows: Complete response (CR) in 12 cases, partial response (PR) in 7, stable disease (SD) in 1 and progressive disease (PD) in 4 cases in the thalidomide group; and CR in 8 cases, PR in 6, SD in 3 and PD in 5 cases in the control group. The CR rate was 50.0 and 36.4% in the thalidomide and the control groups, respectively (P<0.05). The median progression-free and overall survival were 12 and undefined months, respectively, in the thalidomide group and 6 and 17 months, respectively, in the control group. The toxicity profile was considered acceptable in both groups. Our results indicated that thalidomide plus combined chemotherapy may exhibit enhanced efficacy in the clinical treatment of T-NHL. In addition, this type of treatment may reduce the frequency of adverse gastrointestinal reactions and help alleviate fear of chemotherapy. Therefore, thalidomide plus combined chemotherapy may be a viable option for the clinical treatment of T-NHL.

Angiogenesis in cutaneous disease: part II

This review will discuss the role of angiogenesis in specific cutaneous diseases. Scientific evidence now points to the role of angiogenesis in tumor development and many other cutaneous disorders. Angiogenesis is a complex process that involves angiogenic growth factors and inhibitors, many of which could be a potential target for pharmacologic intervention. Antiangiogenic agents have recently been applied to dermatologic diseases with promising efficacy.

LEARNING OBJECTIVES

After completing this learning activity, participants should be able to recognize cutaneous diseases where angiogenesis is likely to be an important factor, recognize scenarios where angiogenic therapy may be useful in conjunction with traditional therapies, and be able to use angiogenic-mediating agents in the treatment of dermatologic disease.

Oral complications of HIV disease

Oral lesions are among the early signs of HIV infection and can predict its progression to acquired immunodeficiency syndrome (AIDS). A better understanding of the oral manifestations of AIDS in both adults and children has implications for all health care professionals. The knowledge of such alterations would allow for early recognition of HIV-infected patients. The present paper reviews epidemiology, relevant aspects of HIV infection related to the mouth in both adults and children, as well as current trends in antiretroviral therapy and its connection with orofacial manifestations related to AIDS.

Pattern of head and neck malignant neoplasms in HIV-infected patients in Kenya

HIV-infected patients face a greater risk of developing malignant disease. The most commonly reported neoplasms of the head and neck region include Kaposi's sarcoma (KS) and non-Hodgkin's lymphoma (NHL). There is also an increased risk of oral squamous cell carcinoma (SCC). A descriptive cross-sectional study including HIV-infected patients with neoplastic and non-neoplastic lesions was conducted. Of the 200 participants, 116 (58%) were male and 84 (42%) female with an age range of 18-61 years (mean 37 years). The females were significantly younger (mean 33 years) than the males (mean 37 years) (t test; 2.57; P<0.05 [0.001]). The prevalence of neoplastic lesions in this study was 27%; 37 (68%) patients had KS, 9 (17%) had SCC, 7 (13%) had NHL and 1 (2%) had Burkitt's lymphoma. More females than males presented with lesions of KS and SCC compared with NHL. The youngest patient presented with SCC at 18 years (mean 35.7 years), followed by KS at 23 years (mean 36.3 years) and NHL at 33 years (mean 43.9 years). Most study participants (97%) were in stage III/IV of the disease and the remaining 3% in stage II. In this study, the most common malignant neoplasms were KS, SCC and NHL, manifesting in a younger age group than in the non-HIV group of patients.

Kaposi sarcoma: a continuing conundrum

Kaposi sarcoma (KS) remains a challenge. Its classic or Mediterranean form tends to be benign. In transplant recipients it may be less so. As part of the AIDS pandemic, of which it was an original defining component, it may be life-threatening. It is due to human herpesvirus-8, which is necessary but not sufficient to produce the disease. KS has a low prevalence in the general population of the United States and United Kingdom, with an intermediate rate in Italy and Greece, and a high one in parts of Africa. In Italy, hot spots include its southern regions, the Po River Valley, and Sardinia, possibly related to a high density of blood-sucking insects. An important challenge is to treat KS patients without immunocompromising them. The potential of effective anti-herpes virus therapy and the use of sirolimus in transplantation recipients have added new opportunities for KS prevention.

LEARNING OBJECTIVES

At the conclusion of this learning activity, participants should be able to provide the most recent information about Kaposi sarcoma in the context in which it occurs. Its classic or Mediterranean form, its pattern in transplant recipients and others iatrogenically immunosuppressed, and its occurrence as a potentially life-threatening part of the AIDS pandemic will be stressed. Its etiology and transmission will be discussed in detail to facilitate understanding of Kaposi sarcoma and of human herpesvirus-8 infection in the general population of the United States and United Kingdom, in Italy and Greece, and in certain parts of Africa. Its therapy, including the concept of doing it without immunocompromising the patient, will be stressed. New opportunities for Kaposi sarcoma prevention will also be discussed.

Characterization of thalidomide using Raman spectroscopy

Thalidomide is a potent anticancer therapeutic drug whose mechanism of action has not yet been elucidated. In this report, experimental Raman spectroscopy is used to determine and characterize the vibrational frequencies of the drug. These normal modes are then compared to their quantum mechanical counterparts, which have been computed using density functional theory. Upon analysis of the spectra, we found that there was a high level of agreement between the wavenumbers. As such, this spectroscopic technique may be a viable tool for examining the way in which this drug interacts with its target molecules.

Thalidomide in the treatment of Kaposi's sarcoma

BACKGROUND

Kaposi's sarcoma (KS) is a lymphangioproliferative tumour. Therapy of KS depends on the characteristics of the disease, especially area and growth rate of lesions, and patient condition. Currently symptomatic resectable lesions are excised, whereas more advanced disease and unresectable lesions are treated with radiotherapy. If a large area or internal organs are affected or other treatments fail, chemotherapy is used. Recently some authors have reported their encouraging experience in the use of thalidomide in patients with AIDS-related KS.

OBJECTIVE

To evaluate the efficacy of thalidomide in 3 patients with non-AIDS-related KS.

METHODS

Two patients with classic widespread cutaneous and 1 with iatrogenic cutaneous and visceral KS were treated with thalidomide (100 mg/day) for 12 months.

RESULTS

In all 3 patients partial remission was evident after 4 months of thalidomide therapy; in 2 out of 3 complete remission was achieved after 12 months of treatment.

CONCLUSIONS

Our results seem to confirm the utility of thalidomide in the treatment of non-AIDS-related KS.

Soft Tissue Tumors of the Hand. 2. Malignant

Soft tissue tumors of the hand arise from skin, subcutaneous tissue, tendons, nerve, and blood vessels. Many of these lesions occur on other parts of the body; however, the hand remains a unique site because these tumors have symptoms, appearances, treatments, and prognoses that may be quite different than when on other parts of the body. Their characteristics and the severity of symptoms vary markedly depending on the exact location, size, and type of tumor-and many of these tumors can have multiple forms of presentation. Two articles are intended to provide an overview of benign (previous article) and malignant tumors (this article) of the hand. The rarer and more deleterious tumors are discussed in detail while the common tumors and epidermal lesions with which practitioners are familiar are briefly overviewed. At the completion of these review articles, participants should be able to identify and diagnose various benign and malignant hand tumors as well as understand the accepted current treatment of these growths.

Systemic treatment of AIDS-related Kaposi sarcoma: current status and perspectives

Kaposi's sarcoma (KS) is the most frequent type of cancer in patients with Acquired Immune Deficiency Syndrome (AIDS). In the western world, its incidence decreased dramatically in the era of highly active anti-retroviral therapy (HAART). In contrast, the incidence of KS has been steadily climbing in parallel with the AIDS epidemic in Africa over the past 10-15 years, being the most common cancer in adult men in countries like Uganda and Zimbabwe. AIDS-KS can be diagnosed at any stage of HIV infection, although it more commonly occurs in the setting of severe immune suppression, especially with an elevated viral load. Up to now, AIDS-KS is still an incurable disease. Its clinical course is variable, ranging from very indolent cases, requiring no or minimal therapy, to a rapidly progressive disease. Various local therapies are available to control small and asymptomatic lesions, while cytotoxic, immunological and biological therapies can be considered for more aggressive disease. The primary goal of therapy in most of the cases is to provide safe and effective palliation, in order to quality of life. Optimal anti-retroviral therapy is a key component of AIDS-KS management. There are still many questions to be answered in the management of patients with AIDS-KS, such as (1) What are the therapeutic agents that should be used in this disease, and in which sequence? and (2) What are the benefits and risks expected with each treatment option? The aim of this review is to discuss the systemic management of AIDS-KS, with special focus on the above mentioned questions.

Cutaneous malignancy and human immunodeficiency virus disease

Certain skin cancers occur with increased frequency or altered course in patients infected with HIV. Malignant melanoma and squamous cell carcinoma are examples of cutaneous malignancies that have a more aggressive course in patients with HIV. Others, such as basal cell carcinoma, appear more frequently in this population but do not appear to be more aggressive. The incidence of HIV-associated Kapsosi's sarcoma has markedly decreased since the advent of HIV antiretroviral therapy. Our understanding of the pathogenesis of this malignancy and its unique management issues are fully reviewed. Cutaneous T-cell lymphoma (CTCL) is rare in this population. Other types of cutaneous lymphoma and HIV-associated pseudo-CTCL are discussed. This article addresses prevention, treatment, and follow-up strategies for this at-risk population.

LEARNING OBJECTIVE

At the completion of this learning activity, participants should be familiar with the unique epidemiology, clinical course, and management of cutaneous malignancy in patients infected with HIV.

AIDS-related Kaposi's sarcoma: epidemiological, diagnostic, treatment and control aspects in sub-Saharan Africa

Until the 1980s, little attention had been accorded to endemic Kaposi's sarcoma (KS), a neoplasm noted in several parts of Southern Europe and the African continent but with relatively slow progression, except in children and young adults. Furthermore, therapeutic approaches based on surgery, radiation and topical treatment were of limited efficacy, mostly used to overcome the disabling and stigmatizing effects of the disease. With the emergence of the HIV/AIDS epidemic, and the profound impact of KS on AIDS-related mortality, the pathogenesis of KS has been better studied, and the realisation that a virus (KS-associated Herpesvirus or Human Herpesvirus 8, or KSHV/HHV-8), combined with immunosuppression and cytokine-induced growth, was responsible for the development of this disease has led to novel therapeutic approaches. These are unfortunately still highly toxic, require careful monitoring, and are expensive, thus limiting their use in most parts of Africa. However, the use of highly active antiretroviral therapy (HAART), which has led to a considerable decline in KS incidence in populations of industrialized countries, constitutes the best hope for the control of this stigmatizing and lethal disease in Africa. Trials comparing different regimens of antiretroviral drugs in combination with systemic chemotherapeutic agents are urgently needed.

Current trends of HIV disease of the mouth

HIV infection affects residents of all countries of the world, but the greater majority of affected individuals reside in the developing world. In the past decade there have been substantial changes in the management of HIV disease, particularly the introduction of highly active antiretroviral therapy (HAART). Such agents have reduced significantly the morbidity and mortality associated with HIV disease, however, they are not available for most HIV-infected individuals in the developing world. There is now considerable understanding of the molecular epidemiology, transmission and therapy of the common opportunistic oral infections of HIV disease, and as a consequence of improved anti-HIV strategies, the frequency and severity of oral disease associated with HIV infection have reduced considerably, although HAART may predispose to human papilloma virus infection of the mouth and potentially increase the risk of later oral squamous cell carcinoma. Despite advances in clinical care the majority of individuals with HIV disease worldwide will continue to develop oral disease, as they are resident in the developing world and do not have ready access to even simple therapies.

Thalidomide Downregulates Angiogenic Genes in Bone Marrow Endothelial Cells of Patients With Active Multiple Myeloma

Purpose

To study the antiangiogenic effect of thalidomide.

Patients and Methods

The expression of key angiogenic genes was studied in bone marrow endothelial cells (ECs) of patients with active and nonactive multiple myeloma (MM), monoclonal gammopathies unattributed/unassociated (MG[u]), diffuse large B-cell non-Hodgkin's lymphoma, in a Kaposi's sarcoma (KS) cell line, and in healthy human umbilical vein ECs (HUVECs) following exposure to therapeutic doses of thalidomide.

Results

Thalidomide markedly downregulates the genes in a dose-dependent fashion in active MMECs and KS cell line, but upregulates them or is ineffective in nonactive MMECs, MG(u)ECs, NHL-ECs, and in HUVECs. Secretion of vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF) and hepatocyte growth factor also diminishes according to the dose in culture conditioned media (CM) of active MMECs and KS, whereas it does not change in the other CM.

Conclusion

Inhibition by thalidomide is probably confined to the genes of active MMECs and KS. This would account for its higher efficacy in these diseases.

Approach to the treatment of cutaneous malignancy in HIV-infected patients

Patients infected with human immunodeficiency virus (HIV) have an increased risk of developing skin cancers. These at-risk patients may have atypical presentations and/or altered clinical courses. This article will review and discuss management issues for the following malignancies: lymphomas, malignant melanoma, basal cell carcinoma, squamous cell carcinoma, and Kaposi's sarcoma.

Evaluating antiangiogenesis agents in the clinic: the Eastern Cooperative Oncology Group Portfolio of Clinical Trials

Recent evidence indicates that treatment with a humanized monoclonal antibody (bevacizumab) directed at vascular endothelial growth factor improves response and survival in metastatic colorectal cancer when added to standard chemotherapy, validating angiogenesis as a therapeutic target. Investigators from the Eastern Cooperative Oncology Group (ECOG) have initiated a number of Phase III studies that will help further define the role of antiangiogenic agents for the treatment of breast, colon, lung, renal, and head and neck cancer, as well as melanoma and myeloma. The agents being evaluated target various biological functions involved in angiogenesis, including vascular endothelial growth factor (bevacizumab), endothelial cell proliferation (thalidomide, IFN-alpha), and matrix metalloproteinases (marimastat). These clinical trials include correlative laboratory studies aimed at elucidating how these agents may exert their clinical effects. The portfolio of Eastern Cooperative Oncology Group studies will serve to further define the role of this therapeutic strategy for patients with advanced cancer.

Vogt-Koyanagi-Harada disease associated with interferon alpha-2b/ribavirin combination therapy

The complex immunological effects of interferon and ribavirin therapy (IFN/R) in hepatitis C virus (HCV) may also exacerbate or trigger the de novo development of autoimmunity. We report the first case of IFN/R therapy associated with Vogt-Koyanagi-Harada disease, a T-cell-mediated autoimmune response to melanocytes. This condition, which has characteristic ocular, neurological and integumentary findings, elicits a systemic prodrome that may mimic side-effect profile and delay of IFN or mask its recognition. We discuss this disease in the context of the known immunomodulatory effects of IFN-alpha and ribavirin and suggest potential mechanistic explanations for the association.

HIV protease inhibitors as new treatment options for Kaposi's sarcoma

A reduced incidence and regression of Kaposi's sarcoma (KS) and other tumours has been reported in Acquired Immune Deficiency Syndrome (AIDS) patients treated with antiretroviral combination therapies containing Human Immunodeficiency Virus (HIV) protease inhibitors (PIs) such as indinavir or saquinavir. Indeed, evidence indicates that although PIs were designed to selectively inhibit the HIV protease activity, they can interfere with several cellular pathways and can inhibit tumour growth. In particular, our recent results indicate that doses of indinavir or saquinavir similar to those employed to treat AIDS patients can induce regression of experimental KS by directly blocking two fundamental steps of KS initiation and progression: new blood vessel formation (angiogenesis) and KS tumour cell invasion. This is because indinavir or saquinavir inhibit the activation of matrix metalloproteinase-2 (MMP-2), a basement membrane-degrading enzyme, which is required for the progression of most tumours. Based on these results, a multicentre clinical trial is now starting in Italy, which will assess PI effects on the progression of KS in HIV-uninfected individuals (classical KS).

Stimulation of primary human endothelial cell proliferation by IFN

The IFN family of cytokines has pleiotropic roles in immunity and development. In this study, we provide evidence that IFN can stimulate the proliferation of primary human endothelial cells. This is in contrast to the growth-suppressive effects of IFN observed on transformed human cells, thereby underscoring the distinctive responses of primary human cells. The growth-stimulatory effect of IFN was determined by an increase in DNA synthesis assessed with [(3)H]thymidine incorporation, an increase in G(2) and M cell cycle phases assessed with flow cytometric analysis, and an increase in cell number. Distinct cell types, including primary human fibroblast and smooth muscle cells, were also growth stimulated by IFN. Neutralizing Abs to IFN were used to demonstrate the growth response was mediated specifically by the IFN cytokine. The signaling pathway of type I IFNs activates STAT1 and STAT2. In primary endothelial cells, we demonstrate that STAT3 and STAT5 are also activated, and these STATs may contribute to cellular proliferation. To evaluate possible effectors of positive growth, DNA microarray analyses were performed to assess gene induction in response to IFN. These results reveal changes in the RNA levels of genes in endothelial cells that encode proteins involved in cellular proliferation.

Molecular genetics of Kaposi's sarcoma-associated herpesvirus (human herpesvirus-8) epidemiology and pathogenesis

Kaposi's sarcoma had been recognized as unique human cancer for a century before it manifested as an AIDS-defining illness with a suspected infectious etiology. The discovery of Kaposi's sarcoma-associated herpesvirus (KSHV), also known as human herpesvirus-8, in 1994 by using representational difference analysis, a subtractive method previously employed for cloning differences in human genomic DNA, was a fitting harbinger for the powerful bioinformatic approaches since employed to understand its pathogenesis in KS. Indeed, the discovery of KSHV was rapidly followed by publication of its complete sequence, which revealed that the virus had coopted a wide armamentarium of human genes; in the short time since then, the functions of many of these viral gene variants in cell growth control, signaling apoptosis, angiogenesis, and immunomodulation have been characterized. This critical literature review explores the pathogenic potential of these genes within the framework of current knowledge of the basic herpesvirology of KSHV, including the relationships between viral genotypic variation and the four clinicoepidemiologic forms of Kaposi's sarcoma, current viral detection methods and their utility, primary infection by KSHV, tissue culture and animal models of latent- and lytic-cycle gene expression and pathogenesis, and viral reactivation from latency. Recent advances in models of de novo endothelial infection, microarray analyses of the host response to infection, receptor identification, and cloning of full-length, infectious KSHV genomic DNA promise to reveal key molecular mechanisms of the candidate pathogeneic genes when expressed in the context of viral infection.

Therapy of AIDS-associated Kaposi's sarcoma: targeting pathogenetic mechanisms

Only a small number of the many agents with the potential to inhibit factors known to stimulate KS growth have been tested clinically, and many were investigated at a time when treatment options for HIV infection were relatively ineffective. The failure of some of these agents to induce KS regression may not signify failure to achieve a relevant biologic effect in all cases, but may simply mean that in a neoplasm that expresses a broad array of growth factors, inhibition of a single factor may be insufficient to achieve tumor regression. Moreover, agents that inhibit angiogenesis may be expected to stabilize tumors rather then eradicate them, but tumor stabilization is a difficult endpoint to quantify. In fact, given the redundancy of growth factors believed to be involved in KS development, it is perhaps remarkable that members of several classes of agents (eg, a synthetic retinoid, an MMPI, thalidomide, IL-12) have induced KS regression in a substantial minority of patients. It is likely, however, that drug combinations that target several pathogenetic mechanisms will be more effective than will single drugs in suppressing KS growth. A particular need. especially in the early evaluation of therapies aimed at specific pathogenic targets, is the development of assays to measure specific biologic effects (eg, changes in the activity of signal transduction pathways within tumor biopsy specimens) related to the agent's putative mechanism of action. Greater availability and clinical application of these types of markers of biologic efficacy may speed the identification of potentially active agents that could then be "fast tracked" into larger efficacy trials and combination studies.

Potential of interferon-alpha in solid tumours: part 2

The second part of this review examines the use of recombinant interferon-alpha (rIFNalpha) in the following solid tumours: superficial bladder cancer, Kaposi's sarcoma, head and neck cancer, gastrointestinal cancers, lung cancer, mesothelioma and ovarian, breast and cervical malignancies. In superficial bladder cancer, intravesical rIFNalpha has a promising role as second-line therapy in patients resistant or intolerant to intravesical bacille Calmette-Guérin (BCG). In HIV-associated Kaposi's sarcoma, rIFNalpha is active as monotherapy and in combination with antiretroviral agents, especially in patients with CD4 counts >200/mm(3), no prior opportunistic infections and nonvisceral disease. rIFNalpha has shown encouraging results when used in combination with retinoids in the chemoprevention of head and neck squamous cell cancers. It is effective in the chemoprevention of hepatocellular cancer in hepatitis C-seropositive patients. In neuroendocrine tumours, including carcinoid tumour, low-dosage (</=3 MU) or intermediate-dosage (5 to 10 MU) rIFNalpha is indicated as second-line treatment, either with octreotide or alone in patients resistant to somatostatin analogues. Intracavitary IFNalpha may be useful in malignant pleural effusions from mesothelioma. Similarly, intraperitoneal IFNalpha may have a role in the treatment of minimal residual disease in ovarian cancer. In breast cancer, the only possible role for IFNalpha appears to be intralesional administration for resistant disease. IFNalpha may have a role as a radiosensitising agent for the treatment of cervical cancer; however, this requires confirmation in randomised trials. On the basis of current evidence, the routine use of rIFNalpha is not recommended in the therapy of head and neck squamous cell cancers, upper gastrointestinal tract, colorectal and lung cancers, or mesothelioma. Pegylated IFNalpha (peginterferon-alpha) is an exciting development that offers theoretical advantages of increased efficacy, reduced toxicity and improved compliance. Further data from randomised studies in solid tumours are needed where rIFNalpha has activity, such as neuroendocrine tumours, minimal residual disease in ovarian cancer, and cervical cancer. A better understanding of the biological mechanisms that determine response to rIFNalpha is needed. Studies of IFNalpha-stimulated gene expression, which are now feasible, should help to identify molecular predictors of response and allow us to target therapy more selectively to patients with solid tumours responsive to IFNalpha.

Infection and cancer: the common vein

The role of infectious agents in the development of cancer is well documented. The pathogenesis of various human neoplasms ranging from non-Hodgkin lymphoma (NHL) to cervical carcinoma frequently involves a chronic, most often viral, infection. At the same time, there is compelling evidence that certain acute infections result in the inhibition of neoplastic growth. The basis for this phenomenon is often thought to be concomitant anti-tumor immunity. Yet, experimental data supporting this hypothesis are scarce, and other non-immune anti-tumor factors could be involved. For instance, since virtually all aggressive tumors outstrip their blood supply, development of new vessels, or angiogenesis, is a limiting factor during neoplastic growth. In this review, we will discuss recent studies that implicate anti-angiogenesis in infection-mediated tumor suppression and suggest that this mechanism could also complement cytotoxic immunity arising from the use of cancer vaccines.

Treatment of Kaposi's sarcoma--an update

Kaposi's sarcoma (KS) is an angioproliferative disease of multifactorial origin arising in different clinic-epidemiologic forms, which show the same histopathological features. It generally starts as a hyperplastic reactive-inflammatory and angiogenic process, which may evolve into monomorphic nodules of KS cells that can be clonal (late-stage lesions) and resemble a true sarcoma. Infection with the human herpesvirus 8, cytokine- and angiogenic factor-induced growth together with an immuno-dysregulated state represent fundamental conditions for the development of this tumor. Several local therapies are used to eradicate early and confined skin lesions, whereas widely disseminated, progressive or symptomatic disease requires a more aggressive treatment. Although different chemotherapeutic agents have been used to treat aggressive KS, the growing understanding of the pathogenetic factors participating in KS development has provided a strong rationale for using less- or non-cytotoxic agents that block the mechanisms involved in KS pathogenesis. The angiogenic nature of KS makes it particularly suitable for using therapies based on anti-angiogenic agents. Of note on this goal, recent studies indicate that the highly active anti-retroviral therapy, including at least one human immunodeficiency virus (HIV) protease inhibitor (PI), is associated with a dramatic decrease in the incidence of AIDS-KS and with a regression of KS in treated individuals. Consistent with this, results from preclinical studies indicate that PIs have potent and direct anti-angiogenic and anti-KS activities, suggesting that they should be further investigated, alone or combined with other therapies, as a novel treatment for KS in both HIV seropositive or seronegative individuals.

Thalidomide in cancer treatment: a potential role in the elderly?

There is increased interest in the treatment of cancer with thalidomide because of its antiangiogenic, immunomodulating and sedative effects. In animal models, the antitumour activity of thalidomide is dependent on the species, route of administration and coadministration of other drugs. For example, thalidomide has shown antitumour effects as a single agent in rabbits, but not in mice. In addition, the antitumour effects of the conventional cytotoxic drug cyclophosphamide and the tumour necrosis factor inducer 5,6-dimethylxanthenone-4-acetic acid (DMXAA) were found to be potentiated by thalidomide in mice bearing colon 38 adenocarcinoma tumours. Further studies have revealed that thalidomide upregulates intratumoral production of tumour necrosis factor-alpha 10-fold over that induced by DMXAA alone. Coadministration of thalidomide also significantly reduced the plasma clearance of DMXAA and cyclophosphamide. All these effects of thalidomide may contribute to the enhanced antitumour activity. Recent clinical trials of thalidomide have indicated that it has minimal anticancer activity for most patients with solid tumours when used as a single agent, although it was well tolerated. However, improved responses have been reported in patients with multiple myeloma. Palliative effects of thalidomide on cancer-related symptoms have also been observed, especially for geriatric patients with prostate cancer. Thalidomide also eliminates the dose-limiting gastrointestinal toxic effects of irinotecan. There is preliminary evidence indicating that the clearance of thalidomide may be reduced in the elderly. The exact role of thalidomide in the treatment of cancer and cancer cachexia in the elderly remains to be elucidated. However, it may have some value as part of a multimodality anticancer therapy, rather than as a single agent.

Update on Kaposi's sarcoma and other HHV8 associated diseases. Part 1: epidemiology, environmental predispositions, clinical manifestations, and therapy

Kaposi's sarcoma (KS) is a mesenchymal tumour involving blood and lymphatic vessels. Only recently has the pathogenesis of this extraordinary neoplasm been elucidated. Viral oncogenesis and cytokine-induced growth together with some state of immunocompromise represent important conditions for this tumour to develop. In 1994, a novel virus was discovered and termed human herpesvirus 8 (HHV8), also known as Kaposi's sarcoma-associated herpes virus, which can be found in all types of KS, whether related to HIV or not. In the era of highly active antiretroviral therapy (HAART), the incidence of AIDS-KS has considerably declined, probably due to enhanced immune reconstitution and anti-HHV8-specific immune responses. If HAART is able to prevent spreading of KS, local therapy of KS may become an essential component of patient management. Part 1 of the review covers the epidemiology, environmental predispositions, clinical manifestations, and therapy of KS. Newer treatments such as pegylated liposomal anthracyclines and experimental strategies are discussed. We also present rationales and graduated treatment algorithms for local and systemic therapy in patients with KS to appropriately meet the challenges of this extraordinary neoplasm. Part 2, to be published next month, will summarise recent insights in the pathogenesis of KS and will discuss other HHV8-related diseases such as Castleman's disease and primary effusion lymphoma.