Treatment of AIDS-related cutaneous Kaposi's sarcoma with topical alitretinoin (9-cis-retinoic acid) gel. Panretin Gel North American Study Group

Inverse agonists of retinoic acid receptor/retinoid X receptor signaling as lineage-specific antitumor agents against human adenoid cystic carcinoma

BACKGROUND

Adenoid cystic carcinoma (ACC) is a lethal malignancy of exocrine glands, characterized by the coexistence within tumor tissues of 2 distinct populations of cancer cells, phenotypically similar to the myoepithelial and ductal lineages of normal salivary epithelia. The developmental relationship linking these 2 cell types, and their differential vulnerability to antitumor treatments, remains unknown.

METHODS

Using single-cell RNA sequencing, we identified cell-surface markers (CD49f, KIT) that enabled the differential purification of myoepithelial-like (CD49fhigh/KITneg) and ductal-like (CD49flow/KIT+) cells from patient-derived xenografts (PDXs) of human ACCs. Using prospective xenotransplantation experiments, we compared the tumor-initiating capacity of the 2 cell types and tested whether one could differentiate into the other. Finally, we searched for signaling pathways with differential activation between the 2 cell types and tested their role as lineage-specific therapeutic targets.

RESULTS

Myoepithelial-like cells displayed higher tumorigenicity than ductal-like cells and acted as their progenitors. Myoepithelial-like and ductal-like cells displayed differential expression of genes encoding for suppressors and activators of retinoic acid signaling, respectively. Agonists of retinoic acid receptor (RAR) or retinoid X receptor (RXR) signaling (all-trans retinoic acid, bexarotene) promoted myoepithelial-to-ductal differentiation, whereas suppression of RAR/RXR signaling with a dominant-negative RAR construct abrogated it. Inverse agonists of RAR/RXR signaling (BMS493, AGN193109) displayed selective toxicity against ductal-like cells and in vivo antitumor activity against PDX models of human ACC.

CONCLUSIONS

In human ACCs, myoepithelial-like cells act as progenitors of ductal-like cells, and myoepithelial-to-ductal differentiation is promoted by RAR/RXR signaling. Suppression of RAR/RXR signaling is lethal to ductal-like cells and represents a new therapeutic approach against human ACCs.

Efficacy of immunotherapy with combination of cryotherapy and topical imiquimod for treatment of Kaposi sarcoma

Multiple treatment modalities for Kaposi sarcoma (KS) have been reported, including chemotherapy, radiation therapy, surgical excision, electrochemotherapy, and cryotherapy. Common topical treatments include timolol, imiquimod, and alitretinoin. We searched our institutional database for patients with ICD-9 or 10 codes for KS seen by a dermatologist with experience in KS management from July 1, 2004 to January 1, 2022. We screened patient charts to include patients who received combination therapy of cryotherapy followed by topical imiquimod three times a week for 2 months (n = 9). Patients were followed in the clinic every 3 months. Time to resolution was assessed by photographic evidence of resolution as determined by a dermatologist and corroborated with clinical documentation in patient charts. Median age (IQR) at KS diagnosis was 58 (27.5) years. All patients were male (n = 9, 100%). Majority were white (n = 7, 78%) and non-Hispanic (n = 8, 89%). Five (56%) had classic KS, one (11%) had HIV-associated KS, and three (33%) were HIV-negative men who have sex with men. Median time to resolution was 30.5 weeks, with a median of two treatments. In our study, 93% (n = 42/45) of lesions and 89% (n = 8/9) of patients experienced complete resolution during a median (range) duration of follow-up of 58 (13-209) weeks. Side effects were limited to pain during cryotherapy, occasional blister formation after cryotherapy, and mild inflammation due to imiquimod. No infections were observed. Combination therapy of cryotherapy and topical imiquimod may be an efficacious and comparatively low-risk treatment for limited, cutaneous KS.

The Use of Retinoids for the Prevention and Treatment of Skin Cancers: An Updated Review

Retinoids are natural and synthetic vitamin A derivatives that are effective for the prevention and the treatment of non-melanoma skin cancers (NMSC). NMSCs constitute a heterogenous group of non-melanocyte-derived skin cancers that impose substantial burdens on patients and healthcare systems. They include entities such as basal cell carcinoma and cutaneous squamous cell carcinoma (collectively called keratinocyte carcinomas), cutaneous lymphomas and Kaposi’s sarcoma among others. The retinoid signaling pathway plays influential roles in skin physiology and pathology. These compounds regulate diverse biological processes within the skin, including proliferation, differentiation, angiogenesis and immune regulation. Collectively, retinoids can suppress skin carcinogenesis. Both topical and systemic retinoids have been investigated in clinical trials as NMSC prophylactics and treatments. Desirable efficacy and tolerability in clinical trials have prompted health regulatory bodies to approve the use of retinoids for NMSC management. Acceptable off-label uses of these compounds as drugs for skin cancers are also described. This review is a comprehensive outline on the biochemistry of retinoids, their activities in the skin, their effects on cancer cells and their adoption in clinical practice.

Small-molecule inhibitors, immune checkpoint inhibitors, and more: FDA-approved novel therapeutic drugs for solid tumors from 1991 to 2021

The United States Food and Drug Administration (US FDA) has always been a forerunner in drug evaluation and supervision. Over the past 31 years, 1050 drugs (excluding vaccines, cell-based therapies, and gene therapy products) have been approved as new molecular entities (NMEs) or biologics license applications (BLAs). A total of 228 of these 1050 drugs were identified as cancer therapeutics or cancer-related drugs, and 120 of them were classified as therapeutic drugs for solid tumors according to their initial indications. These drugs have evolved from small molecules with broad-spectrum antitumor properties in the early stage to monoclonal antibodies (mAbs) and antibody‒drug conjugates (ADCs) with a more precise targeting effect during the most recent decade. These drugs have extended indications for other malignancies, constituting a cancer treatment system for monotherapy or combined therapy. However, the available targets are still mainly limited to receptor tyrosine kinases (RTKs), restricting the development of antitumor drugs. In this review, these 120 drugs are summarized and classified according to the initial indications, characteristics, or functions. Additionally, RTK-targeted therapies and immune checkpoint-based immunotherapies are also discussed. Our analysis of existing challenges and potential opportunities in drug development may advance solid tumor treatment in the future.

Treatments for AIDS/HIV-related Kaposi sarcoma: A systematic review of the literature

BACKGROUND

Treatment guidelines are not well established in AIDS-related Kaposi sarcoma (KS).

OBJECTIVE

We aim to review the evidence on efficacy of treatments for AIDS-related Kaposi sarcoma.

METHODS

We searched the Cochrane Library, PubMed, and Embase Database from date of database inception till July 2020. Randomized controlled trials reporting intervention consisting of any type of treatment compared to control/placebo to a different treatment modality or different combination of treatment/treatment doses with a diagnosis of AIDS-related KS are selected.

MAIN OUTCOMES AND MEASURES

Primary outcomes were response rates defined as complete response (CR), partial response (PR), stable disease (SD), or progressive disease (PD). Secondary outcomes were cosmesis and adverse outcomes such as pain and erythema.

RESULTS

Thirteen out of 536 articles met our eligibility criteria. Three studies reported the efficacy of chemotherapy, two studies looked at different doses of radiotherapy regimes, and three studies compared different antiretroviral therapy (ART) and chemotherapy regimens. Other studies reported topical therapies such as alitretinoin gel, IM862, and bHCG injection which showed varied efficacies.

LIMITATIONS

Lack of standardization classification of disease activity and clinical outcomes and treatment modalities precluded meaningful comparison of studies.

CONCLUSION

The evidence of efficacy of any particular intervention is overall varied and there was insufficient evidence to recommend any particular intervention. We have provided an overview of treatments for KS but larger studies need to be carried out to verify the efficacy of treatment options reported in the literature.

Topical treatments for Kaposi sarcoma: A systematic review

Background

While treatment options exist for solitary or disseminated Kaposi sarcoma (KS) disease, there are currently no standardized clinical treatment guidelines for cutaneous KS.

Objective

This systematic review seeks to identify safe and effective topical treatments for cutaneous KS lesions.

Methods

We conducted a systematic review using peer-reviewed articles from January 1970 to September 2021 published in the PubMed/MEDLINE and EMBASE databases.

Results

From the initial search that yielded 590 studies, 34 met the inclusion criteria and were selected. Of the 34 studies, seven were clinical trials, 26 were case reports/series and one was a multicentre study. A total of 634 patients were included in our review. The three most common topical treatments used for cutaneous KS were imiquimod, alitretinoin and timolol. Topical alitretinoin was used in three case reports and three clinical trials. Topical imiquimod was used in eight case reports, one prospective phase II cohort study and one comparative single-blinded non-controlled clinical study. Topical timolol was used in nine case reports/series. Our review also identified reports of less widely used topical treatments for cutaneous KS. These include topical diphencyprone (DPCP), all-trans-retinoic-acid, rapamycin and bleomycin-dimethylsulfoxide (BLM-DMSO) which achieved variable response rates but have not been widely studied.

Conclusion

Topical alitretinoin, imiquimod and timolol demonstrated positive responses for cutaneous KS and the treatments were well tolerated. These three topical treatment modalities could be considered by clinicians when treating cutaneous KS.

HIV-Associated Cutaneous Kaposi's Sarcoma

Kaposi's sarcoma (KS) is a vascular tumor that originates from the endothelial and immune cells. Lesions usually appear on the skin and oral mucosa, but they may also extend to involve lymph nodes and visceral organs. Patients typically present with multiple painless purplish spots on the face, oral mucosa, and genitalia.

We report a case of cutaneous KS in a 31-year-old male with an unknown positive HIV status. Clinical presentation and investigations were both toward KS. Therefore, our patient was treated immediately after diagnosis but could not tolerate the antiretroviral therapy and had unfortunate consequences.

AIDS-Related Kaposi Sarcoma, Version 2.2019, NCCN Clinical Practice Guidelines in Oncology

As treatment of HIV has improved, people living with HIV (PLWH) have experienced a decreased risk of AIDS and AIDS-defining cancers (non-Hodgkin's lymphoma, Kaposi sarcoma, and cervical cancer), but the risk of Kaposi sarcoma in PLWH is still elevated about 500-fold compared with the general population in the United States. The NCCN Clinical Practice Guidelines in Oncology (NCCN Guidelines) for AIDS-Related Kaposi Sarcoma provide diagnosis, treatment, and surveillance recommendations for PLWH who develop limited cutaneous Kaposi sarcoma and for those with advanced cutaneous, oral, visceral, or nodal disease.

AIDS-Related Kaposi Sarcoma in a Tertiary University Hospital in Manila, Philippines: A Report of Six Cases

We report six cases of Kaposi sarcoma (KS) seen at the University of the Philippines–Philippine General Hospital, a tertiary university hospital with a 1,500-bed capacity in Manila, from 2017 to February 2020. All cases involved males (21–47 years old) infected with human immunodeficiency virus (HIV). Majority came from Metro Manila and had opportunistic infections at the time of KS diagnosis, most commonly pulmonary tuberculosis. Four patients presented with multiple hyperpigmented cutaneous patches. One patient had both cutaneous lesions and necrotic gingival mass. One patient presented with a gastrointestinal mass. One patient underwent systemic chemotherapy (liposomal doxorubicin) but was eventually lost to follow-up. Although considered the most common tumor arising from HIV-infected persons, KS is considered rare in the Philippines. No studies have been undertaken to determine its incidence. However, the incidence may be expected to rise due to the increasing number of Filipinos diagnosed with HIV daily.

Non-genomic effects of nuclear receptors: insights from the anucleate platelet

Nuclear receptors (NRs) have the ability to elicit two different kinds of responses, genomic and non-genomic. Although genomic responses control gene expression by influencing the rate of transcription, non-genomic effects occur rapidly and independently of transcriptional regulation. Due to their anucleate nature and mechanistically well-characterized and rapid responses, platelets provide a model system for the study of any non-genomic effects of the NRs. Several NRs have been found to be present in human platelets, and multiple NR agonists have been shown to elicit anti-platelet effects by a variety of mechanisms. The non-genomic functions of NRs vary, including the regulation of kinase and phosphatase activity, ion channel function, intracellular calcium levels, and production of second messengers. Recently, the characterization of mechanisms and identification of novel binding partners of NRs have further strengthened the prospects of developing their ligands into potential therapeutics that offer cardio-protective properties in addition to their other defined genomic effects.

HIV-Related Skin Disease in the Era of Antiretroviral Therapy: Recognition and Management

Antiretroviral therapy (ART) has revolutionized the treatment and prognosis of people living with HIV (PLHIV). With increased survival and improved overall health, PLHIV are experiencing dermatologic issues both specific to HIV and common to the general population. In this new era of ART, it is crucial for dermatologists to have a strong understanding of the broad range of cutaneous disease and treatment options in this unique population. In this review, we outline the most common skin diseases in PLHIV, including HIV-associated malignancies, inflammatory conditions, and infections, and focus on the role of ART in altering epidemiology, clinical features, diagnosis, and treatment of cutaneous conditions.

Pathologic Angiogenesis of Malignant Vascular Sarcomas: Implications for Treatment

Angiosarcoma, epithelioid hemangioendothelioma, and Kaposi sarcoma are classified according to the line of differentiation that these neoplastic cells most closely resemble: the endothelial cell. Although these malignant vascular sarcomas demonstrate immunohistochemical and ultrastructural features typical of this lineage, they vary dramatically in presentation and behavior, reflecting oncologic mechanisms unique to each. Antineoplastic therapies offer significant benefit, but because of the rarity of these cancers, novel therapies are slow to develop, and treatment options for these cancers remain limited. Antiangiogenic approaches that have shown benefit in other malignancies have not fully realized their promise in vascular tumors, suggesting that these tumors do not depend entirely on either angiogenic growth factors or on neighboring endothelia that are affected by these agents. Nonetheless, translational studies have begun to unravel these distinct pathologies, identifying novel translocation products, targets of oncogenic virulence factors, and genomic mutations that hijack angiogenic signaling and drive malignant growth. Concurrently, an elaborate and highly regulated model of angiogenesis and lymphangiogenesis involving vascular endothelial growth factor–receptor tyrosine kinase and TGF-β and Notch pathways has emerged that informs treatment of these tumors as well as cancer in general. This review summarizes the literature on malignant vascular sarcomas in the context of current models of angiogenesis and, in light of recent clinical trial data, could help clinician-scientists generate novel therapeutic approaches.

HIV-associated Kaposi sarcoma and related diseases

: The search for the etiologic agent for Kaposi sarcoma led to the discovery of Kaposi sarcoma-associated herpesvirus (KSHV) in 1994. KSHV, also called human herpesvirus-8, has since been shown to be the etiologic agent for several other tumors and diseases, including primary effusion lymphoma (PEL), an extracavitary variant of PEL, KSHV-associated diffuse large B-cell lymphoma, a form of multicentric Castleman disease, and KSHV inflammatory cytokine syndrome. KSHV encodes several genes that interfere with innate and specific immunity, thwart apoptosis, enhance cell proliferation and cytokine production, and promote angiogenesis, and these play important roles in disease pathogenesis. HIV is an important cofactor in Kaposi sarcoma pathogenesis, and widespread use of antiretroviral therapy has reduced Kaposi sarcoma incidence. However, Kaposi sarcoma remains the second most frequent tumor arising in HIV-infected patients in the United States and is particularly common in sub-Saharan Africa. KSHV prevalence varies substantially in different populations. KSHV is secreted in saliva, and public health measures to reduce its spread may help reduce the incidence of KSHV-associated diseases. Although there have been advances in the treatment of Kaposi sarcoma, KSHV-multicentric Castleman disease, and PEL, improved therapies are needed, especially those that are appropriate for Kaposi sarcoma in resource-poor regions.

RXR Ligands Negatively Regulate Thrombosis and Hemostasis

Supplemental Digital Content is available in the text.

Objective—

Platelets have been found to express intracellular nuclear receptors including the retinoid X receptors (RXRα and RXRβ). Treatment of platelets with ligands of RXR has been shown to inhibit platelet responses to ADP and thromboxane A2; however, the effects on responses to other platelet agonists and the underlying mechanism have not been fully characterized.

Approach and Results—

The effect of 9-cis-retinoic acid, docosahexaenoic acid and methoprene acid on collagen receptor (glycoprotein VI [GPVI]) agonists and thrombin-stimulated platelet function; including aggregation, granule secretion, integrin activation, calcium mobilization, integrin αIIbβ3 outside-in signaling and thrombus formation in vitro and in vivo were determined. Treatment of platelets with RXR ligands resulted in attenuation of platelet functional responses after stimulation by GPVI agonists or thrombin and inhibition of integrin αIIbβ3 outside-in signaling. Treatment with 9-cis-retinoic acid caused inhibition of thrombus formation in vitro and an impairment of thrombosis and hemostasis in vivo. Both RXR ligands stimulated protein kinase A activation, measured by VASP S157 phosphorylation, that was found to be dependent on both cAMP and nuclear factor κ-light-chain-enhancer of activated B cell activity.

Conclusions—

This study identifies a widespread, negative regulatory role for RXR in the regulation of platelet functional responses and thrombus formation and describes novel events that lead to the upregulation of protein kinase A, a known negative regulator of many aspects of platelet function. This mechanism may offer a possible explanation for the cardioprotective effects described in vivo after treatment with RXR ligands.

Use of retinoic acid/aldehyde dehydrogenase pathway as potential targeted therapy against cancer stem cells

A large number of studies have investigated possible drug resistance mechanisms of cancer cells and suggested strategies to overcome it. In this review, we outline the role and function of aldehyde dehydrogenase (ALDH) activity in multiple cellular functions and in cancer stem cells (CSCs) and focus on the role of retinoic acid (RA), one of the products of ALDH isozymes. We discuss our observation that ATRA and other RAs can suppress ALDH activity and decrease different ALDH isozyme proteins and result in detrimental effects on cell proliferation, invasion and chemotherapy sensitivity. We review the known uses of different RAs in the treatment of cancers. We review the use of RAs in combination with chemo-/radiotherapy and the major signaling pathways affected in different tumor types. We provide follow-up on studies that may have used our prior observation with the aim of targeting the CSCs. We conclude with summary of the findings and potential impact of published studies on future use of RAs in the targeting of CSCs and drug resistance.

New insights in the biology of ABC transporters ABCC2 and ABCC3: impact on drug disposition

INTRODUCTION

For the elimination of environmental chemicals and metabolic waste products, the body is equipped with a range of broad specificity transporters that are present in excretory organs as well as in several epithelial blood-tissue barriers.

AREAS COVERED

ABCC2 and ABCC3 (also known as MRP2 and MRP3) mediate the transport of various conjugated organic anions, including many drugs, toxicants and endogenous compounds. This review focuses on the physiology of these transporters, their roles in drug disposition and how they affect drug sensitivity and toxicity. It also examines how ABCC2 and ABCC3 are coordinately regulated at the transcriptional level by members of the nuclear receptor (NR) family of ligand-modulated transcription factors and how this can be therapeutically exploited.

EXPERT OPINION

Mutations in both ABCC2 and ABCC3 have been associated with changes in drug disposition, sensitivity and toxicity. A defect in ABCC2 is associated with Dubin-Johnson syndrome, a recessively inherited disorder characterized by conjugated hyperbilirubinemia. Pharmacological manipulation of the activity of these transporters can potentially improve the pharmacokinetics and thus therapeutic activity of substrate drugs but also affect the physiological function of these transporters and consequently ameliorate associated disease states.

Treatment of severe or progressive Kaposi's sarcoma in HIV-infected adults

BACKGROUND

Kaposi's sarcoma remains the most common cancer in Sub-Saharan Africa and the second most common cancer in HIV-infected patients worldwide. Since the introduction of highly active antiretroviral therapy (HAART), there has been a decline in its incidence.However, Kaposi's sarcoma continues to be diagnosed in HIV-infected patients.

OBJECTIVES

To assess the added advantage of chemotherapy plus HAART compared to HAART alone; and the advantages of different chemotherapy regimens in HAART and HAART naive HIV infected adults with severe or progressive Kaposi's sarcoma.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE and , GATEWAY, the WHO Clinical Trials Registry Platform and the US National Institutes of Health's ClinicalTrials.gov for ongoing trials and the Aegis archive of HIV/AIDS for conference abstracts. An updated search was conducted in July 2014.

SELECTION CRITERIA

Randomised trials and observational studies evaluating the effects of any chemotherapeutic regimen in combination with HAART compared to HAART alone, chemotherapy versus HAART, and comparisons between different chemotherapy regimens.

DATA COLLECTION AND ANALYSIS

Two review authors assessed the studies independently and extracted outcome data.We used the risk ratio (RR) with a 95% confidence interval (CI) as the measure of effect.We did not conduct meta-analysis as none of the included trials assessed identical chemotherapy regimens.

MAIN RESULTS

We included six randomised trials and three observational studies involving 792 HIV-infected adults with severe Kaposi's sarcoma.Seven studies included patients with a mix of mild to moderate (T0) and severe (T1) Kaposi's sarcoma. However, this review was restricted to the subset of participants with severe Kaposi's sarcoma disease.Studies comparing HAART plus chemotherapy to HAART alone showed the following: one trial comparing HAART plus doxorubicin,bleomycin and vincristine (ABV) to HAART alone showed a significant reduction in disease progression in the HAART plus ABV group (RR 0.10; 95% CI 0.01 to 0.75, 100 participants); there was no statistically significant reduction in mortality and no difference in adverse events. A cohort study comparing liposomal anthracyclines plus HAART to HAART alone showed a non-statistically significant reduction in Kaposi's sarcoma immune reconstitution inflammatory syndrome in patients that received HAART plus liposomal anthracyclines (RR 0.49; 95% CI 0.16 to 1.55, 129 participants).Studies comparing HAART plus chemotherapy to HAART plus a different chemotherapy regimen showed the following: one trial involving 49 participants and comparing paclitaxel versus pegylated liposomal doxorubicin in patients on HAART showed no difference in disease progression. Another trial involving 46 patients and comparing pegylated liposomal doxorubicin versus liposomal daunorubicin showed no participants with progressive Kaposi's sarcoma disease in either group.Studies comparing different chemotherapy regimens in patients from the pre-HAART era showed the following: in the single RCT comparing liposomal daunorubicin to ABV, there was no significant difference with the use of liposomal daunorubicin compared to ABV in disease progression (RR 0.78; 95% CI 0.34 to 1.82, 227 participants) and overall response rate. Another trial involving 178 participants and comparing oral etoposide versus ABV demonstrated no difference in mortality in either group. A non-randomised trial comparing bleomycin alone to ABV demonstrated a higher median survival time in the ABV group; there was also a non-statistically significant reduction in adverse events and disease progression in the ABV group (RR 11; 95% CI 0.67 to 179.29, 24 participants).An additional non-randomised study showed a non-statistically significant overall mortality benefit from liposomal doxorubicin as compared to conservative management consisting of either bleomycin plus vinblastine, vincristine or single-agent antiretroviral therapy alone (RR 0.93; 95% CI 0.75 to 1.15, 29 participants). The overall quality of evidence can be described as moderate quality. The quality of evidence was downgraded due to the small size of many of the included studies and small number of events.

AUTHORS' CONCLUSIONS

The findings from this review suggest that HAART plus chemotherapy may be beneficial in reducing disease progression compared to HAART alone in patients with severe or progressive Kaposi's sarcoma. For patients on HAART, when choosing from different chemotherapy regimens, there was no observed difference between liposomal doxorubicin, liposomal daunorubicin and paclitaxel.

An evidence-based systematic review of vitamin A by the natural standard research collaboration

An evidence-based systematic review of vitamin A by the Natural Standard Research Collaboration consolidates the safety and efficacy data available in the scientific literature using a validated and reproducible grading rationale. This paper includes written and statistical analysis of clinical trials, plus a compilation of expert opinion, folkloric precedent, history, pharmacology, kinetics/dynamics, interactions, adverse effects, toxicology, and dosing.

Non AIDS Kaposi's Sarcoma Leading to Lower Extremities Wounds, Case Presentations and Discussion

Kaposi's sarcoma (KS) is a rare malignancy that with the onset of the AIDS epidemic suggests a link between the development of disease and a transmissible agent. It is a low-grade vascular tumor associated with infection with the human herpes virus 8 (HHV-8). The first case presents a non-HIV patient with Kaposi's sarcoma of the left foot and the second case is a kidney transplant patient on immunosuppressive medications with wounds on the right leg due to non-HIV Kaposi's sarcoma.

Ongoing change in the treatment of HIV-associated malignancies in the HAART era

Implementation of highly active antiretroviral therapy (HAART) has changed the epidemiology, clinical outcome and therapeutic approach of HIV-associated malignancies. Whereas Kaposi sarcoma and primary CNS non-Hodgkin lymphoma have decreased dramatically, systemic non-Hodgkin lymphoma incidence seems unchanged, perhaps increasing as with other tumor incidence. Owing to HAART-induced immune function preservation, response rates to chemotherapy and survival times in patients with HIV-associated malignancies have neared those observed in their HIV-negative counterparts. Hence, intensive regimens have been more and more extensively used with promising results. This may also apply to other therapeutic options, such as biotherapy, and procedures, such as stem cell rescue following high-dose chemotherapy or heterologous stem cell transplant, which have so far been precluded to HIV-infected subjects as a matter of fact. A trend toward a full assimilation of HIV-infected people with cancer and the general population with the same pathology is ongoing.

Alitretinoin: a comprehensive review

BACKGROUND

Alitretinoin (9-cis-retinoic acid) is a unique panagonist retinoid, capable of binding to all six known retinoid receptors (RAR-alpha, -beta, -gamma, and RXR-alpha, -beta, -gamma). Studies are being carried out to determine how best to utilize this characteristic in treatments for conditions such as chronic hand dermatitis.

OBJECTIVE

To review the literature on alitretinoin.

METHODS

The scope of the review encompasses ways that alitretinoin is currently and may potentially be utilized.

RESULTS/CONCLUSIONS

Orally administered alitretinoin is a safe and effective treatment for chronic hand dermatitis. Topical treatment with alitretinoin can be expanded into other areas such as photoaged skin and cutaneous T-cell lymphoma. Despite these benefits, oral alitretinoin will face a difficult path attaining approval for use in the US.

Radiotherapy of classic and human immunodeficiency virus-related Kaposi's sarcoma: results in 1482 lesions

BACKGROUND

The lesions of the various forms of Kaposi's sarcoma (KS), which are relatively radiosensitive, have been treated with different modalities of radiotherapy, with heterogeneous aims and results.

OBJECTIVE

To verify the effectiveness and safety of radiotherapy on a large number of lesions endowed (classic KS) with a prolonged follow-up.

METHODS

A retrospective study was done on 711 lesions of classic KS and 771 lesions of human immunodeficiency virus (HIV)-related KS, treated with traditional X-ray therapy.

RESULTS

In classic KS, a cure rate of 98.7% resulted after 13.5 years from the end of radiotherapy. In three lesions (0.42%) in the same patient, an acute radiodermatitis occurred after traumatic action. In HIV-related KS, a complete remission was obtained in 91.43% of the lesions, partial remission in 6.74% and non-response in 0.51% at 1 to 46 months from the end of radiotherapy.

CONCLUSION

Radiotherapy showed to be a safe and effective method, with relevant importance in the therapeutic strategy of KS.

Retinoic Acid Analogues Inhibit Human Herpesvirus 8 Replication

Background

Retinoids have a pronounced antiviral effect against several viruses. In this study we aimed to investigate the effect of retinoids on human herpesvirus 8 (HHV-8).

Methods

A panel of retinoic acid compounds were tested for their antiviral activity against HHV-8 in human umbilical vascular endothelial cells (HUVECs) and in a human epithelial cell line. The presence, transcription and antigen expression of HHV-8 in infected cells – in the presence or absence of retinoic acid compounds – were evaluated by PCR, reverse transcriptase PCR and immunofluorescence assays; HHV-8 viral load was determined by real-time quantitative PCR. Angiogenesis induced by HHV-8 was also assessed using Cultrex® basement membrane extract.

Results

The compounds tested specifically inhibited viral promoters, during the early and late phases of infection in both cell systems tested, and resulted in up to 100fold reduction of viral titre and release of progeny virus. The inhibition of viral replication induced by retinoids in endothelial cells, the primary target of HHV-8-driven transformation in Kaposi's Sarcoma, prevented endothelial cells from developing spindle morphology and in vitro tube formation, characteristic changes associated with HHV-8 infection and transformation.

Conclusions

We show that retinoids inhibit HHV-8 replication and identify new retinoid compounds with a strong antiviral effect. Selective retinoids, particularly those with retinoic acid receptor agonist activity, may be good candidates for the development of antiviral drugs.

A vitamin A deficient diet enhances proinflammatory cytokine, Mu opioid receptor, and HIV-1 expression in the HIV-1 transgenic rat

The HIV-1 (HIV) transgenic (Tg) rat develops several immune abnormalities in association with clinical impairments that are similar to what are seen with HIV infection in humans. In HIV infection, retinoids and opioids can have separate and potentially combined effects on the clinical course of HIV disease. In these studies, the effects of a vitamin A deficient diet on T cell proinflammatory cytokine and mu opioid receptor (MOR) expression were examined in the Tg and in wild-type (WT) rats. The effects of the diet on HIV gene expression were also analyzed in the Tg rats. Phytohemagglutinin-stimulated T cells from WT rats on the vitamin A diet and from Tg rats on either diet were more likely to either produce increased percentages of T cells expressing intracytoplasmic IFN-gamma, secrete higher levels of TNF-alpha, and express higher levels of MOR mRNA and surface MOR. Mitogen stimulation also increased Tg rat HIV env, tat, and nef mRNA expression with even higher env and nef mRNA produced in association with the vitamin A deficient diet. All together, these data suggest that a vitamin A deficient diet can result in cellular effects that increase T cell proinflammatory responses and HIV expression, which may alter the course of disease in the HIV Tg rat model.

Management of AIDS-related Kaposi's sarcoma

The advent of highly active antiretroviral therapy (HAART) has lead to a substantial reduction in the prevalence, morbidity, and mortality associated with AIDS-related Kaposi's sarcoma. Similarly, concomitant advances in chemotherapy and supportive-care protocols have allowed for Kaposi's sarcoma to be managed more effectively in comparison with the pre-HAART era. Furthermore, developments in our understanding of the pathogenesis of Kaposi's sarcoma have identified several molecular targets that can potentially provide new therapeutic strategies. This Review discusses the role of conventional chemotherapeutic and immunomodulatory agents in the treatment of Kaposi's sarcoma and summarises the current status and future prospects of novel molecularly targeted agents in the treatment of this disease.

HIV-associated Kaposi's sarcoma

Kaposi's sarcoma (KS) is a multifocal vascular tumor that occurs most commonly in patients who have immunosuppression caused by HIV. KS-associated herpes virus (human herpes virus 8, KSHV) has been identified as the causative agent. There are marked geographic differences in the prevalence of both KS and seropositivity to KSHV. The incidence of the tumor has shown a marked decline in first-world countries with the widespread use of effective antiretroviral therapy. The most effective anthracycline is pegylated liposomal doxorubicin; however, few developing countries, where KS prevalence is highest, can afford to use these agents.

AIDS-related malignancies: emerging challenges in the era of highly active antiretroviral therapy

Human immunodeficiency virus (HIV)-infected patients are at increased risk of developing cancer, particularly in the later stages of acquired immune deficiency syndrome (AIDS). Despite the advent of highly active anti-retroviral therapy (HAART), malignancy in this population is a leading cause of morbidity and mortality. Kaposi's sarcoma (KS) and AIDS-related non-Hodgkin's lymphoma (ARL) are the most common AIDS-defining malignancies. AIDS-related KS varies from minimal to fulminant disease. Treatment decisions for AIDS-related KS are guided largely by the presence and extent of symptomatic disease. In addition to HAART, excellent treatments exist for both localized disease (topical gel, radiotherapy, and intralesional therapy) and advanced disease (liposomal anthracyclines, paclitaxel). Novel therapies that have become available to treat AIDS-related KS include angiogenesis inhibitors and antiviral agents. ARL comprises a heterogeneous group of malignancies. With the immune restoration afforded by HAART, standard-dose chemotherapies now can be safely administered to treat ARL with curative intent. The role of analogous treatments used in HIV-negative patients, including monoclonal antibodies and autologous stem cell transplantation, requires further clarification in HIV-positive patients. HIV-infected patients also appear to be at increased risk for developing certain non-AIDS-defining cancers, such as Hodgkin's lymphoma and multiple myeloma. Although the optimal treatment of these neoplasms is at present uncertain, recent advances in chemotherapy, antiretroviral drugs, and supportive care protocols are allowing for more aggressive management of many of the AIDS-related cancers. This article provides an up-to-date review of the epidemiology, pathogenesis, clinical features, and treatment of various AIDS-related malignancies that are likely to be encountered by an oncologist practicing in the current HAART era.

Therapy insight: AIDS-related malignancies--the influence of antiviral therapy on pathogenesis and management

Patients with HIV infection are at an increased risk of a number of malignancies, including Kaposi's sarcoma (KS) and certain B-cell lymphomas. Most of these tumors are caused by oncogenic DNA viruses, including KS-associated herpesvirus and Epstein-Barr virus. HIV contributes to the development of these tumors through several mechanisms, including immunodeficiency, immunodysregulation, and the effects of HIV proteins such as Tat. The development of highly active antiretroviral therapy (HAART) has reduced the incidence of many HIV-associated tumors and has generally improved their responsiveness to therapy. However, the number of people living with AIDS is increasing, and it is possible that the number of AIDS-associated malignancies will rise and the pattern of tumors will change as more people live longer with HIV infection. The goal of KS therapy is long-term tumor control with minimal toxicity. HAART is an important component of this therapy, and some patients do not require other KS-specific therapies. By contrast, the goal of AIDS-related lymphoma therapy in most cases is the attainment of a complete response with curative intent, and the benefits of administering HAART during therapy must be weighed against possible disadvantages. The past decade has seen substantial improvements in the treatment of AIDS-related lymphoma, which is attributed partially to a shift in tumor type and more effective regimens. There is currently an interest in developing new therapies for HIV-associated malignancies, based on viral, vascular or other pathogenesis-based targets.

AIDS-related cancer in the era of highly active antiretroviral therapy (HAART): a model of the interplay of the immune system, virus, and cancer. "On the offensive--the Trojan Horse is being destroyed"--Part A: Kaposi's sarcoma

The introduction of highly active antiretroviral therapy (HAART), aimed at controlling human immunodeficiency virus (HIV), has been associated with a dramatic decrease in the incidence of acquired immunodeficiency syndrome-Kaposi's sarcoma (AIDS-KS) and the clinical manifestations of KS appear to be less aggressive. The pathogenesis of AIDS-related KS is related to a system of cytokines (e.g., interleukin-6) driven by autocrine and paracrine loops. More recently, human herpesvirus 8 (HHV-8), was discovered to be the putative etiological agent of this disease. This virus encodes several unique open reading frames that are homologs of human cellular proteins involved in cellular regulations, cell proliferation, apoptosis, and immune regulation. The treatment of this disease depends on whether it is "limited" disease or "extensive" disease. For "limited" disease, local therapy or non-bone marrow suppressive agents should be used. For "extensive" disease, new chemotherapeutic agents, such as liposomal anthracycline, which are active and have little adverse reactions, are indicated. The control of HIV infection continues to be essential. Knowledge of the pathogenesis of the disease has led to the development of novel treatment strategies, aimed at the inflammatory or angiogenesis cytokines necessary for growth or at HHV-8 as the target of therapy.

Therapeutic options for human herpesvirus-8/Kaposi's sarcoma-associated herpesvirus-related disorders

Human herpesvirus-8/Kaposi's sarcoma-associated herpesvirus infection is associated with three proliferative disorders in immunocompromised patients - Kaposi's sarcoma, primary effusion lymphoma and multicentric Castleman's disease. These disorders often develop in patients with advanced AIDS who present a number of therapeutic challenges, underscoring the importance of continuing efforts dedicated to basic and clinical research in this field. In the era of highly active antiretroviral therapy, the incidence of AIDS and Kaposi's sarcoma has considerably decreased, presumably due to enhanced anti-Kaposi's sarcoma-associated herpesvirus immune responses, whereas the situation with primary effusion lymphoma and multicentric Castleman's disease is more complex. Based on advances in the understanding of Kaposi's sarcoma-associated herpesvirus-related disorders and availability of antiretroviral agents, current and future therapeutic approaches will be discussed.

Application of retinoids in the treatment of renal cell carcinoma–a futile effort?

The therapeutic benefit of adding retinoids such as all-trans retinoic acid (RA), 9-cis-RA or 13-cis-RA to established single-agent or combination immuno/chemotherapy regimens for the treatment of metastatic renal cell carcinoma (RCC) has been extensively investigated during the last decade. However, at present results are contradictory and their application controversial. Moreover, recent studies indicated a significantly higher incidence of toxic side-effects in patients treated with retinoids in addition to established bio/chemotherapy. This Commentary summarizes preclinical and clinical trials investigating efficacy and toxicity of retinoids in the treatment of RCC.

Topical acne drugs: review of clinical properties, systemic exposure, and safety

This review examines the commonly available topical acne agents and factors that determine their percutaneous absorption. Reported and theoretical adverse effects from systemic exposure are detailed. The topical retinoid class, which includes tretinoin, adapalene and tazarotene, and the topical antibacterials, clindamycin and erythromycin, are regulated by prescription in most countries. Used appropriately, the above-mentioned drugs deliver, at most, miniscule amounts of active ingredient into the circulation. Clear-cut links to systemic toxicity in humans are practically nonexistent, except in the case of topical clindamycin, which has been associated with diarrhea rarely, and there have been 2 cases of pseudomembranous colitis reported. Birth defects have occurred in two patients treated with tretinoin and one patient treated with adapalene, but causation was not proven. Another prescription drug, 20% azelaic acid, is associated with relatively high systemic exposure, which is presumed innocuous because it is a normal dietary constituent whose endogenous levels are not altered by topical use. Benzoyl peroxide, salicylic acid, sulfur, and sodium sulfacetamide are available in concentrations of 2% or more in over-the-counter acne treatments and some prescription products. All of these agents are known to exhibit some degree of percutaneous absorption. They remain largely unregulated because, other than skin irritation, only local allergic contact dermatitis from benzoyl peroxide in about 2.5% of patients and rare local and systemic hypersensitivity reactions from sodium sulfacetamide have been reported. Salicylism has occurred using methyl salicylate ointments and high concentrations of salicylic acid on widespread areas of hyperkeratotic skin, but there are no known cases resulting from salicylic acid acne products. Caution is advised in special circumstances, such as during childhood, pregnancy, lactation and concomitant therapy with other drugs, because relevant studies are lacking. Animal data support avoidance of many topical agents, particularly known teratogens such as retinoids and salicylic acid, in pregnant women. Salicylate avoidance is advised during lactation, because aspirin use carries the risk of bleeding disorders in nursing infants.

Update on Kaposi's Sarcoma: A Gammaherpesvirus- induced Malignancy

Since the beginning of the AIDS epidemic, Kaposi's sarcoma (KS) has been one of the most visible manifestations of this disease and one of the most distressing for affected patients. The discovery in 1994 of a new gammaherpesvirus, called Kaposi's sarcoma-associated herpesvirus, has led to increased understanding of the pathogenesis of this disease and the potential for new specific therapy. In addition, the development of highly active antiretroviral therapy has had a substantial impact on the incidence of KS in countries where it is available and on the course of established disease. Finally, recent advances in our understanding of angiogenesis have the potential of leading to new KS therapies. In this article we review some of the recent advances in the epidemiology and pathogenesis of KS, review the current treatment of this disease, and discuss several therapeutic approaches that are now under development.

Treatment of Kaposi's sarcoma in HIV-1 infected individuals with emphasis on resource poor settings

BACKGROUND

In many countries, Kaposi's sarcoma (KS) is the commonest malignancy among individuals infected with the human immunodeficiency virus-1 (HIV) and is a cause of substantial morbidity and mortality.

OBJECTIVES

The aim of this review was to assess the effectiveness of current therapeutic regimens for the treatment of HIV associated KS, with a focus on options that may be available in resource poor settings.

SEARCH STRATEGY

We searched Cochrane HIV/AIDS Group trials register, Cochrane Central Register of Controlled Trials (The Cochrane Library Issue 1, 2002), MEDLINE, EMBASE, AIDSLINE, CINAHL, CANCER LIT, AIDSDRUGS, AIDSTRIALS, African index medicus, physicians data query protocols, United Kingdom Co-ordinating committee on Cancer Research Register of Cancer trials, proceedings and abstracts from AIDS and cancer conferences. The search was conducted between 1st October 2001 and completed 14th December 2002. We also contacted experts in the field of cancer.

SELECTION CRITERIA

Randomised trials of therapy for KS in HIV infected adults.

DATA COLLECTION AND ANALYSIS

All reviewers assessed trial quality and extracted data. We contacted study authors for additional information.

MAIN RESULTS

Five trials involving 915 people were included. Two trials involving 499 people compared pegylated liposomal doxorubicin (PLD) to a standard regimen among patients with advanced KS were analysed together. There was no difference in mortality between the two regimens RR1.26 (95% confidence interval (CI) 0.83 to 1.91). The response to PLD was superior to that of the control regimen RR 2.16, (95% CI 1.68 to 2.78). Two other trials involving 402 people demonstrated that topical alitretinoin was effective treatment compared to placebo among patients with cutaneous Kaposi's sarcoma. The results were analysed separately due to heterogeneity; (1) the relative risk (RR) was 5.34 (95%CI 2.16 to 13.21) and (2) RR 1.96, 95% CI 1.27 to 3.01). The final trial compared different radiotherapy regimens for treatment of cutaneous KS. The initial complete response of lesions to 20Gy given in 10 fractions or 40Gy in 20 fractions was similar and slightly superior to that of lesions treated with 8Gy as a single fraction, RR 1.58, (95% CI 1.01 to 2.48) and RR 1.65, (95% CI 1.06 to 2.57) respectively.

REVIEWER'S CONCLUSIONS

Alitretinoin gel is effective in treating cutaneous KS, PLD is effective treatment for advanced KS and radiotherapy appears effective in treating cutaneous lesions. Apart from the trial of radiotherapy no trials applicable to developing settings were identified.

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.

Alitretinoin

Alitretinoin is a retinoid receptor pan-agonist, which has been investigated in the treatment of Kaposi's sarcoma (KS). Binding with high affinity to all known retinoid receptors, alitretinoin is thought to regulate proliferation, differentiation, and apoptosis of KS cells. Significantly more patients experienced complete or partial responses [according to the AIDS Clinical Trials Group (ACTG) criteria for topical treatment of cutaneous KS] with alitretinoin 0.1% gel 2 to 4 times daily than with vehicle gel in 2 phase III, multicenter, 12-week, randomized, double-blind clinical trials of patients with AIDS-related KS (35 vs 18%, p = 0.002 and 37 vs 7%, p = 0.00003, respectively). Responses were also observed in patients refractory to prior systemic or topical anti-KS therapies. In an intent-to-treat analysis in a phase II trial, 37% of patients with AIDS-related KS receiving alitretinoin capsules 60 to 100 mg/m2/day demonstrated either complete or partial responses (determined by ACTG criteria). The majority of adverse events associated with alitretinoin 0.1% gel were classified as either mild or moderate, occurred at the site of application and were reversible. In both phase III trials, rash was the most common adverse event. The most common adverse events in patients taking alitretinoin capsules included headache, dry skin, rash, alopecia, exfoliative dermatitis, and hyperlipidemia.