The pathogenesis of mycosis fungoides

Targeting histone deacetyalses in the treatment of B- and T-cell malignancies

HDAC inhibitors (HDACI) are now emerging as one of the most promising new classes of drugs for the treatment of select forms of non-Hodgkin’s lymphoma (NHL). They are particularly active in T-cell lymphomas, possibly hodgkin’s lymphoma and indolent B cell lymphomas. Presently, two of these agents, vorinostat and romidepsin, have been approved in the US for the treatment of relapsed and refractory cutaneous T cell lymphomas (CTCL). Initially, these agents were developed with the idea that they affected transcriptional activation and thus gene expression, by modulating chromatin condensation and decondensation. It is now clear that their effects go beyond chromatin and by affecting the acetylation status of histones and other intra-cellular proteins, they modify gene expression and cellular function via multiple pathways. Gene expression profiles and functional genetic analysis has led to further understanding of the various molecular pathways that are affected by these agents including cell cycle regulation, pathways of cellular proliferation, apoptosis and angiogenesis all important in lymphomagenesis. There is also increasing data to support the effects of these agents on T cell receptor and immune function which may explain the high level of activity of these agents in T cell lymphomas and hodgkin’s lymphoma. There is ample evidence of epigenetic dysregulation in lymphomas which may underlie the mechanisms of action of these agents but how these agents work is still not clear. Current HDAC inhibitors can be divided into at least four classes based on their chemical structure. At present several of these HDAC inhibitors are in clinical trials both as single agents and in combination with chemotherapy or other biological agents. They are easy to administer and are generally well tolerated with minimal side effects. Different dosing levels and schedules and the use of isospecific HDAC inhibitors are some of the strategies that are being employed to increase the therapeutic effect of these agents in the treatment of lymphomas. There may also be class differences that translate into specific activity against different lymphoma. HDAC inhibitors will likely be incorporated into combinations of targeted therapies both in the upfront and relapsed setting for lymphomas.

Interleukin-16 as a marker of Sézary syndrome onset and stage

INTRODUCTION

Sézary syndrome is one of the most common forms of cutaneous T cell lymphoma (CTCL). It is characterized by skin infiltration of malignant T cells. We examined interleukin-16, a potent T cell chemoattractant and cell-cycle regulator, as a prospective marker of disease onset and stage.

METHODS

The correlation of total intracellular interleukin-16 and surface CD26 was studied by flow cytometry. Confocal microscopy was performed to determine localization of interleukin-16 at different stages of the disease. The levels of interleukin-16 in plasma and culture supernatants were examined by enzyme-linked immunoassay. Additionally, lymphocytes from stage IB patients were cultured in the presence of interleukin-16 alone and in combination with interleukin-15, and their ability to survive and proliferate was determined by cell counts and [3H]TdR incorporation.

RESULTS

The data indicate that loss of both nuclear and intracellular pro-interleukin-16 highly correspond to disease stage, with a concomitant increase in secreted mature interleukin-16 in both culture supernatants and patients' plasma that peaks at stage IB. Loss of intracellular interleukin-16 strongly corresponded to loss of surface CD26, which has been shown to occur with more advanced stage of CTCL. Nuclear translocation of pro-interleukin-16 was not observed in late stages of Sézary syndrome, indicating this loss is not reversible.

CONCLUSIONS

We propose that it is feasible to use plasma levels of IL-16 as a potential diagnostic marker of Sézary syndrome and to use loss of intracellular IL-16 as a prognostic indicator of disease severity and stage.

Cutaneous T-cell lymphoma: Biologic targets for therapy

Cutaneous T-cell lymphoma (CTCL) is a malignancy derived from a clonal population of mature, skin-homing lymphocytes. In the skin, the CTCL cells are associated with the Langerhans cells and respond to protumor cytokines. In turn, they upregulate T-cell receptor-dependent signaling pathways and subsequently demonstrate stigmata of T-cell activation. As the disease progresses, there appears to be an accumulation of genetic and epigenetic changes that may contribute to the aggressiveness of the disease. Furthermore, the persistence of tumor appears to require escape from cancer immunosurveillance. This process likely requires modulation of the host immune system and skewing of the immune cells away from a cytotoxic phenotype. Each of these steps in disease pathogenesis offers a potential object for targeted therapies. This article reviews the recent research into the design and use of targeted therapies for CTCL.

Thymus and activation-regulated chemokine in different stages of mycosis fungoides: tissue and serum levels

BACKGROUND/OBJECTIVES

Thymus and activation-regulated chemokine (CCL17) is a member of the CC chemokines known to attract T-helper 2 type memory T cells and to participate in different T-helper 2 diseases. The aim of this study is to determine both serum and tissue levels of thymus and activation-regulated chemokine in patients with different stages of mycosis fungoides.

METHODS

Thirty-two patients with different stages of mycosis fungoides and 10 controls were included in the study. Skin biopsies and blood samples were taken to evaluate both tissue and serum levels of thymus and activation-regulated chemokine using the enzyme-linked immunosorbent assay method.

RESULTS

The mean tissue level of thymus and activation-regulated chemokine in 10 tumour-stage patients was significantly higher (P = 0.002) than in the controls. The mean serum level of thymus and activation-regulated chemokine in all stages of mycosis fungoides patients was not significantly elevated (P = 0.131, 0.725 and 0.622) compared with controls. Both tissue and serum levels of thymus and activation-regulated chemokine correlated significantly with both the disease extent and duration in the three different stages of mycosis fungoides.

CONCLUSION

Thymus and activation-regulated chemokine may be a marker for disease activity of mycosis fungoides, and may have a role in monitoring disease progression.

Vorinostat interferes with the signaling transduction pathway of T-cell receptor and synergizes with phosphoinositide-3 kinase inhibitors in cutaneous T-cell lymphoma

BACKGROUND

Vorinostat (suberoylanilide hydroxamic acid, SAHA), an inhibitor of class I and II histone deacetylases, has been approved for the treatment of cutaneous T-cell lymphoma. In spite of emerging information on the effect of vorinostat in many types of cancer, little is yet known about this drug's mechanism of action, which is essential for its proper use in combination therapy. We investigated alterations in gene expression profile over time in cutaneous T-cell lymphoma cells treated with vorinostat. Subsequently, we evaluated inhibitors of PI3K, PIM and HSP90 as potential combination agents in the treatment of cutaneous T-cell lymphoma.

DESIGN AND METHODS

The genes significantly up- or down-regulated by vorinostat over different time periods (2-fold change, false discovery rate corrected P value<0.05) were selected using the short-time series expression miner. Cell viability was assessed in vitro in cutaneous T-cell lymphoma cells through measuring intracellular ATP content. Drug interactions were analyzed by the combination index method with CalcuSyn software.

RESULTS

The functional analysis suggests that vorinostat modifies signaling of T-cell receptor, MAPK, and JAK-STAT pathways. The phosphorylation studies of ZAP70 (Tyr319, Tyr493) and its downstream target AKT (Ser473) revealed that vorinostat inhibits phosphorylation of these kinases. With regards to effects on cutaneous T-cell lymphoma cells, combining vorinostat with PI3K inhibitors resulted in synergy while cytotoxic antagonism was observed when vorinostat was combined with HSP90 inhibitor.

CONCLUSIONS

These results demonstrate the potential targets of vorinostat, underlining the importance of T-cell receptor signaling inhibition following vorinostat treatment. Additionally, we showed that combination therapies involving histone deacetylase inhibitors and inhibitors of PI3K are potentially efficacious for the treatment of cutaneous T-cell lymphoma.

A meta-analysis of patients receiving allogeneic or autologous hematopoietic stem cell transplant in mycosis fungoides and Sézary syndrome

The survival outlook in advanced mycosis fungoides (MF) is poor. Autologous and allogeneic stem cell transplants (SCT) have been shown, in small case series and case reports, to have the potential for long-term remission or to alter disease course. Allogeneic SCT is thought to have a curative potential secondary to a graft-versus-lymphoma (GVL) effect. A patient-level meta-analysis was performed to compare the outcome of allogeneic versus autologous SCT in patients with MF/Sézary syndrome (SS) using 39 cases from the literature. There were a total of 20 allogeneic and 19 autologous transplant cases. The gender, age, and stage distribution was similar between the transplant groups. The allogeneic group received significantly more systemic therapies prior to transplant (P < .0005) and had longer follow-up after transplant. Overall survival (OS) results showed a more favorable outcome of patients who received allogeneic SCT (P = .027). Event-free survival (EFS) demonstrated a more durable response in patients who received allogeneic SCT (P = .002). In the allogeneic group, the majority (70%) of patients experienced persistent graft-versus-host disease (GVHD), mostly with mild to moderate severity, and 2 of 4 deaths were related to GVHD. Meanwhile, the majority of the deaths (8 of 10) in the autologous group were because of progressive disease. These results support the belief that allogeneic SCT offers a better survival and disease-free outcome versus autologous SCT in MF/SS, likely because of a GVL effect.

Differential CCR4 expression and function in cutaneous T-cell lymphoma cell lines

Cutaneous T cell lymphoma (CTCL) is a clonal epidermotropic malignancy of memory T cells primarily involving the skin. However, the mechanisms governing migration of CTCL cells have not been fully clarified. It has been shown that certain chemokine receptors are upregulated in CTCL cells, but it remains unanswered whether these chemokine receptors play a critical role in the migration dynamics of CTCL. Using cell lines originally derived from patients with different subtypes of CTCL, we have shown higher CCR4 expression in the line derived from the mycosis fungoides (MJ), compared with the line derived from Sezary syndrome (Hut78). In specific responses to CCL22 (a CCR4 ligand) treatments, MJ cells showed significant chemotactic migration, enhanced activation and adhesion of certain integrins (CD49d and CD29) in vitro, while the control cells (Hut78, CD4+CD45RO+ memory T cells, and Jurkat cells) did not. Furthermore, compared with Hut78 cells, MJ cells manifested significantly more transendothelial migration in responses to treatments with either CCL22 or conditioned medium from dendritic cells in vitro. These results provide further dynamic evidence, in line with the multistep cascade paradigm for leukocyte transendothelial migration, to support a critical role for CCR4 in CTCL migration.

Ectopic expression of B-lymphoid kinase in cutaneous T-cell lymphoma

B-lymphoid kinase (Blk) is exclusively expressed in B cells and thymocytes. Interestingly, transgenic expression of a constitutively active form of Blk in the T-cell lineage of mice results in the development of T-lymphoid lymphomas. Here, we demonstrate nuclear factor-kappa B (NF-kappaB)-mediated ectopic expression of Blk in malignant T-cell lines established from patients with cutaneous T-cell lymphoma (CTCL). Importantly, Blk is also expressed in situ in lesional tissue specimens from 26 of 31 patients with CTCL. Already in early disease the majority of epidermotropic T cells express Blk, whereas Blk expression is not observed in patients with benign inflammatory skin disorders. In a longitudinal study of an additional 24 patients biopsied for suspected CTCL, Blk expression significantly correlated with a subsequently confirmed diagnosis of CTCL. Blk is constitutively tyrosine phosphorylated in malignant CTCL cell lines and spontaneously active in kinase assays. Furthermore, targeting Blk activity and expression by Src kinase inhibitors and small interfering RNA (siRNA) inhibit the proliferation of the malignant T cells. In conclusion, this is the first report of Blk expression in CTCL, thereby providing new clues to the pathogenesis of the disease.

Cutaneous T-cell lymphoma in skin of color

Over the past three decades, there has been a marked increase in the incidence of cutaneous T-cell lymphoma (CTCL), with significant differences in the rates of CTCL by race and ethnicity. The overall incidence of CTCL has been shown to be higher among blacks than among whites and other racial groups. In addition, CTCL is thought to follow a more aggressive course in black patients. This article highlights the differences in clinical appearance and response to therapy, and discusses the differential diagnosis of CTCL in skin of color in an attempt to ensure earlier diagnosis and better outcomes for these patients.

Low FAS/CD95 expression by CTCL correlates with reduced sensitivity to apoptosis that can be restored by FAS upregulation

FAS expression was generally low in 30 of 31 cutaneous T-cell lymphoma (CTCL) cases (mycosis fungoides/Sezary syndrome, SS) as well as in 5 of 6 large plaque parapsoriasis cases (a CTCL precursor). To investigate this phenomenon, we explored FAS transcript levels, cell-surface FAS protein expression and susceptibility to FAS-mediated apoptosis in four CTCL lines (MyLa, HH, SZ4, and SeAx), freshly isolated leukemic cells from a patient with SS, an acute lymphoblastic leukemia T-cell line (Jurkat), and JFL (a FAS-low variant of Jurkat). Results confirmed low FAS expression by the leukemic SS cells, HH, SZ4, SeAx, and JFL relative to normal peripheral blood mononuclear leukocytes and the other cell lines. There was a direct correlation among FAS transcript level, FAS protein level, and FAS-mediated apoptotic sensitivity in the CTCL samples. When the FAS-deficient cell lines were transfected with a wild-type FAS construct, FAS expression and sensitivity to FAS-mediated apoptosis were restored. In aggregate, these findings provide evidence that like normal T cells, CTCL cells exhibit a mechanistic connection between transcriptional regulation of FAS and sensitivity to FAS-mediated apoptosis, point to the development of FAS deficiency as one molecular mechanism responsible for acquired resistance to apoptosis in CTCL, and indicate that upregulation of FAS expression can restore sensitivity to apoptosis.

Oncogenomic analysis of mycosis fungoides reveals major differences with Sezary syndrome

Mycosis fungoides (MF), the most common cutaneous T-cell lymphoma, is a malignancy of mature, skin-homing T cells. Sézary syndrome (Sz) is often considered to represent a leukemic phase of MF. In this study, the pattern of numerical chromosomal alterations in MF tumor samples was defined using array-based comparative genomic hybridization (CGH); simultaneously, gene expression was analyzed using microarrays. Highly recurrent chromosomal alterations in MF include gain of 7q36, 7q21-7q22 and loss of 5q13 and 9p21. The pattern characteristic of MF differs markedly from chromosomal alterations observed in Sz. Integration of data from array-based CGH and gene-expression analysis yielded several candidate genes with potential relevance in the pathogenesis of MF. We confirmed that the FASTK and SKAP1 genes, residing in loci with recurrent gain, demonstrated increased expression. The RB1 and DLEU1 tumor suppressor genes showed diminished expression associated with loss. In addition, it was found that the presence of chromosomal alterations on 9p21, 8q24, and 1q21-1q22 was associated with poor prognosis in patients with MF. This study provides novel insight into genetic alterations underlying MF. Furthermore, our analysis uncovered genomic differences between MF and Sz, which suggest that the molecular pathogenesis and therefore therapeutic requirements of these cutaneous T-cell lymphomas may be distinct.

CD8+ cutaneous T-cell lymphoma successfully treated with bexarotene: a case report and review of the literature

CD8+ cutaneous T-cell lymphoma (CTCL) is a relatively rare subset of the non-Hodgkins lymphomas. Bexarotene has been FDA-approved for the treatment of CTCL, but previous studies have been conducted on CD4+ CTL and there have been no reports about its use in CD8+ CTCL. Herein, we report on a patient whose CD8+ CTCL completely responded to treatment with bexarotene.

Comparative genomic hybridization identifies 17q11.2 approximately q12 duplication as an early event in cutaneous T-cell lymphomas

Mycosis fungoides (MF) and Sézary syndrome (SS) are primary cutaneous T-cell lymphomas (CTCL), a heterogeneous group of extranodal non-Hodgkin lymphomas. In the three cases of MF and four of SS studied, comparative genomic hybridization detected chromosomal imbalances in all SS cases and in one MF case. In all five abnormal cases, the long arm of chromosome 17 was completely or partially duplicated; in three of these five cases, it was the sole genomic event. Notably, a minimal common duplicated region at 17q11.2 approximately q12, corresponded to the mapping of HER2/neu and STAT family genes. The only recurrent loss involved chromosome 10, with deletion of the entire long arm in one case and deletion of band 10q23 in another. Sporadic imbalances included gains at chromosome arms 1q, 2q, 7p, 7q, and 12p. Genomic duplication at 17q11.2 approximately q12 emerged as a primary karyotypic abnormality common to both MF and SS, which suggests that this is an early clonal event.

Increased malignancy risk in the cutaneous T-cell lymphoma patient population

BACKGROUND

Cutaneous T-cell lymphoma (CTCL) has been associated with increased risk for second malignancies. However, the degree of risk and types of second cancers detected have been inconsistent in previous studies.

PATIENTS AND METHODS

To further characterize the risk for malignancy associated with CTCL, patients treated for CTCL at M. D. Anderson Cancer Center in Houston, Texas, between November 1979 and November 1999 were assessed for the occurrence of additional cancers by analysis of institutional tumor registry data.

RESULTS

Of 672 patients with CTCL, 112 had > or = 1 additional cancer, 37 occurring after the diagnosis of CTCL. This represents a significant elevation in cancer prevalence and incidence, with a 1.79-fold risk (95% CI, 1.22-2.39) for developing cancer after CTCL. An excess of Hodgkin and non-Hodgkin lymphoma, acute myeloid leukemia, and vulvar cancers was seen.

CONCLUSION

These data provide evidence for an increased overall incidence of second malignancy in CTCL, particularly with respect to other lymphoproliferative malignancies. Appropriate monitoring for the early detection of second cancers might be warranted in patients with CTCL.

Emerging drugs in cutaneous T cell lymphoma

BACKGROUND

Mycosis fungoides (MF) represents the most common type of primary cutaneous T cell-lymphomas (CTCL), which are characterized by a clonally proliferation of malignant CD4+ lymphocytes in the skin.

OBJECTIVE

Skin-directed treatment regimens, like phototherapy and corticosteroids, are commonly used in early stages; systemic treatments and chemotherapies are used in advanced stages. Because conventional treatments usually end in a transient remission without curative results, there is a high need for new therapeutic strategies with acceptable side effects.

METHODS

Literature and reference research was done by using the data bank PubMed, and updates of ongoing studies were taken out of ASCO and ASH annual meeting abstracts.

RESULTS/CONCLUSIONS

This article gives an overview of the various medications in current use, with emphasis on emerging drugs with novel therapeutic targets.

An uncommon skin condition illustrates the need for caution when prescribing for friends

PURPOSE

A dual-focused case study written to discuss the legal and medical hazards of informally writing prescriptions for friends or family members and to provide knowledge of early-stage mycosis fungoides (MF), its course, and treatment.

DATA SOURCES

A review of the prescribing practices of clinicians, the cognitive processes needed in diagnosis and treatment, the current ethical guidelines, and a review of MF, its course, and treatments.

CONCLUSIONS

Treating acquaintances and family informally places clinicians at risk for liability and patients at risk for inaccurate diagnosis and treatment. This case illustrates the potential hazard of casually treating a friend for what looks like a benign condition. Resembling atopic dermatitis in its early stages, MF is the most common of a rare group of skin lymphomas. Early diagnosis and treatment are crucial for a better prognosis. Had this clinician complied with the request of her friend, his diagnosis would have been missed and timely treatment delayed.

IMPLICATIONS FOR PRACTICE

No matter what the prior relationship may have been, once a clinician treats a patient, a legally binding relationship begins, requiring the due standard of care. Nurse practitioners (NPs) need to be aware of the potential for error when treating acquaintances. Available NP standards of practice and ethical guidelines should address informal treatment situations.

Atypical fibroxanthoma presenting in a patient with stage III mycosis fungoides

The association of atypical fibroxanthoma (AFX) and mycosis fungoides (MF) has never been reported. We report a 77-year-old female who was referred for Mohs micrographic surgery (MMS) of an AFX on the right hand. At the time of presentation, this patient had stage III MF, with erythroderma and palpable lymph nodes. Our patient's AFX measured 1.5x2.8 cm. The tumor was removed by MMS with clear margins. The pathologic specimen revealed a relatively well-circumscribed neoplasm in the upper dermis composed of atypical spindle cells with pleomorphism, hyperchromatic nuclei, and brisk mitotic activity. Immunohistochemical stains were focally positive for CD68, and negative for S-100, Melan-A, desmin, smooth muscle actin and neurofilament. Perilesional skin revealed epidermal hyperplasia, parakeratosis, and multiple epidermotropic lymphocytes with enlarged and hyperchromatic nuclei. One year after the initial MMS, our patient developed another tumor on the right hand, which measured 4x6 mm. This neoplasm underwent a fusiform excision with clear margins. Histological examination revealed evidence of MF and an AFX. To our knowledge, this is the first report of an AFX arising in a patient with MF.

Immune function abnormalities in peripheral blood mononuclear cell cytokine expression differentiates stages of cutaneous T-cell lymphoma/mycosis fungoides

PURPOSE

Mycosis fungoides (MF) is a cutaneous T-cell lymphoma (CTCL) characterized by neoplastic skin-homing T cells. To better understand the immunopathogenesis of MF, we analyzed the functional ability of peripheral blood mononuclear cells (PBMC) from early and late MF/CTCL patients to express cytokine genes. In late stage MF/CTCL, patients were separated into those with blood involvement (+B) and without blood involvement (-B).

EXPERIMENTAL DESIGN

We analyzed T(H)1 (interleukin 2 (IL-2), IFN-gamma), T(H)2 (IL-4, IL-5, IL-10, IL-13), and T(H)17 (IL-17) cytokine gene expression from activated PBMCs from normal (n = 12), psoriasis (n = 6), early MF/CTCL (n = 11), and late MF/CTCL+B (n = 4) and MF/CTCL-B (n = 3) by quantitative real-time PCR.

RESULTS

PBMCs from early MF/CTCL and psoriasis showed higher induction of IL-2, IL-4, and IFN-gamma genes than those from normal and late MF/CTCL-B and MF/CTCL+B (P < 0.05) in descending order. PBMCs from late MF/CTCL-B exhibited generally the highest level of IL-5, IL-10, IL-13, and IL-17 expression compared with the other groups. PBMCs from early MF/CTCL and late MF/CTCL-B had similarly elevated IL-13 and IL-17. Of all groups, PBMCs from late MF/CTCL+B had the lowest levels of IL-2 (P < 0.05), IL-4, IFN-gamma, IL-13, and IL-17.

CONCLUSIONS

The different pattern of cytokine gene expression suggests a change in immune function in MF/CTCL from early MF/CTCL to late MF/CTCL-B to late MF/CTCL+B. These stages are consistent with localized disease associated with an anti-tumor immune response and late MF/CTCL associated with a loss of immune function mediated by malignant T cells that share regulatory T cell-like properties.

Antitumour effects in mycosis fungoides of the immunomodulatory, tellurium-based compound, AS101

BACKGROUND

The immunomodulator AS101 [ammonium trichloro (dioxoethylene-O,O') tellurate], a nontoxic tellurium (IV) compound, has antitumoral effects which were demonstrated in several preclinical and clinical studies.

OBJECTIVES

To investigate the antitumour activity of AS101 on cutaneous T-cell lymphoma (CTCL), of which mycosis fungoides (MF) is the most frequent disease variant.

METHODS

We used a newly established mouse xenograft model for MF to test the effect of AS101 in vivo and analysed apoptosis induction in vitro.

RESULTS

When injected intratumorally, AS101 delayed tumour growth in a dose-dependent manner. In vitro, AS101 induced a dose-dependent G2/M arrest in the CTCL cell lines Hut78 and MyLa. Moreover, higher concentrations of AS101 induced apoptosis in MyLa cells. Programmed cell death was associated with the loss of mitochondrial transmembrane potential and activation of caspase 9 and caspase 3. AS101 also elevated intracellular reactive oxygen species (ROS) production; the antioxidant, Mn superoxide dismutase, significantly reduced the degree of apoptosis, suggesting that ROS play a key role in apoptosis induction.

CONCLUSIONS

These findings indicate that AS101 may be a promising antitumour drug for CTCL.

Defucosylated anti CC chemokine receptor 4 monoclonal antibody combined with immunomodulatory cytokines: a novel immunotherapy for aggressive/refractory Mycosis fungoides and Sezary syndrome

PURPOSE

Sézary syndrome (SS) and Mycosis fungoides (MF) in the advanced stage have dismal prognoses. Because CC chemokine receptor 4 (CCR4) has an important role in the skin-homing capacity of MF/SS cells, we postulated that anti-CCR4 monoclonal antibody (mAb) could represent a novel therapeutic agent against aggressive/refractory MF/SS.

EXPERIMENTAL DESIGN

The defucosylated next-generation therapeutic mAb KM2760 induces enhanced antibody-dependent cellular cytotoxicity (ADCC). Here, we assessed the therapeutic potential of this antibody against aggressive MF/SS tumor cells in vitro and in animal models in vivo.

RESULTS

KM2760 induced robust ADCC by peripheral blood mononuclear cell (PBMC) from healthy controls against a MF/SS cell line as well as against primary tumor cells from patients with aggressive MF/SS. KM2760 also showed significant antitumor activity in disseminated and nondisseminated MF/SS mouse models. In addition, approximately 30% of autologous MF/SS tumor cells were killed in in vitro assays of KM2760-induced ADCC mediated by patients' PBMC after only 4 h, despite the low numbers of natural killer cells present in these PBMCs. It is also shown that ADCC induced by defucosylated therapeutic mAb can be greatly augmented by the immunomodulatory cytokines interleukin-12, IFN-alpha-2b, and IFN-gamma.

CONCLUSIONS

The present study has encouraged us in the conducting of a phase I clinical trial of a completely defucosylated anti-CCR4 mAb in patients with CCR4-positive T-cell lymphomas, including aggressive MF/SS (ClinicalTrials.gov identifier: NCT00355472). In the near future, the efficacy not only of defucosylated anti-CCR4 mAb single-agent treatment but also of combination therapy with immunomodulatory cytokines will be clinically established to target aggressive/refractory MF/SS.

Cutaneous T-cell lymphoma: overview and nursing perspectives

Cutaneous T-cell lymphoma (CTCL) is an uncommon and complex malignancy of the immune system with a wide range of clinical presentations primarily involving the skin. An extensive menu of skin-directed and/or systemic treatment options exists. Best practices in management involve multidisciplinary collaboration. Nursing care for patients who have CTCL is a critical component in the successful management of the disease and requires special attention to the patient's physical, emotional, and spiritual needs. Nurses can make a significant impact by being accessible, offering emotional support, demonstrating advocacy, and providing ongoing education for the patient and family.

The Spectrum of Histopathologic and Immunohistochemical Findings in Folliculotropic Mycosis Fungoides

BACKGROUND

Since the original designation of folliculotropic mycosis fungoides (FMF) as a distinct entity, there has been an increasing appreciation of the broad clinical and histopathologic spectrum with which this disease can present. However, there have been few large histologic studies characterizing the various histopathologic patterns.

OBJECTIVE

In this study, we attempt to describe the histopathologic and immunohistochemical features of 47 biopsy specimens from 34 patients with FMF.

METHODS

We searched our lymphoma database for patients with FMF in which detailed histopathologic information and slides as well as clinical information was available for review. Additionally, immunohistochemical studies for CD4, CD8, and CD1a were performed in all cases in which the block was available.

RESULTS

In addition to the prototypical pattern of a folliculotropic lypmphoid infiltrate with or without mucinosis, the histologic features of follicular mycosis fungoides may include a granulomatous reaction, cystic and comedonal changes, an eosinophilic folliculitis pattern and basaloid folliculolymphoid hyperplasia as well as pustular changes, interface dermatitis and an interstitial dermatitislike pattern. Unlike conventional mycosis fungoides, eosinophils and plasma cells are conspicuous within the accompanying reactive infiltrate. We have also noted an exceedingly high number of Langerhans cells within the follicular epithelium. The CD4:CD8 ratio frequently is 10:1 or greater and the follicles show abundant CD1a positive cells.

CONCLUSIONS

FMF may present with a broad spectrum of histopathologic changes including interstitial, granulomatous, fibrotic and acneiform reactions that may lack the typical histologic attributes of a cutaneous T-cell lymphoma. Recognition of these myriad of histologic presentations can be of great diagnostic utility.

T-cell/NK-cell lymphomas: A review

T-cell neoplasms are a group of heterogeneous neoplasms that present a challenge in management. Accurate diagnosis and classification are necessary for proper treatment. This dilemma is exemplified by continuous upgrading of classification systems in an effort to better understand these diseases. The spectrum of management varies from observation and monitoring to prompt aggressive multimodality treatment to achieve optimal outcomes. Allogeneic transplant has been successful in a minority of cases with the possibility of cure; however this approach is still largely experimental. Molecular studies such as gene expression profiling are expected to offer exciting insight into the biology of these diseases. Novel therapeutic approaches continue to be explored, however will probably require larger clinical trials to establish their utility over the current standard.

Vorinostat: a new oral histone deacetylase inhibitor approved for cutaneous T-cell lymphoma

Epigenetic regulation of gene transcription by small-molecule inhibitors of histone deacetylases (HDACs) is a novel cancer therapy. Vorinostat (suberoylanilide hydroxamic acid) is the first FDA-approved HDAC inhibitor for the treatment of cutaneous manifestations of cutaneous T-cell lymphoma (CTCL). Vorinostat was active against solid tumors and hematologic malignancies as intravenous and oral preparations in Phase I development. In two Phase II trials, vorinostat 400 mg/day was safe and effective with an overall response rate of 24-30% in refractory advanced patients with CTCL including large cell transformation and Sézary syndrome. The common side effects of vorinostat, which are similar in all studies, include gastrointestinal symptoms, fatigue and thrombocytopenia and the most common serious event was thrombosis.

Pulmonary manifestations in patients with cutaneous T-cell lymphomas

BACKGROUND

Lungs are among the most common organs of extranodal involvement by cutaneous T-cell lymphomas (CTCLs), yet the magnitude of lung involvement is not clear, and only a few case reports have addressed this issue to date. The objective of this study was to present the authors' observations on how to recognize lung involvement by CTCL and evaluate the clinical and radiologic differences between involvement of the lungs by CTCL and by pneumonia.

METHODS

A retrospective analysis was conducted of all 710 patients with confirmed CTCL who presented to The University of Texas M. D. Anderson Cancer Center between January 1996 and January 2005. Demographics, tumor characteristics, respiratory symptoms, thoracic imaging, microbiology, and laboratory studies were reviewed.

RESULTS

During the 9-year period that was studied, 122 patients presented with pulmonary radiologic abnormalities, including 67 patients who also had respiratory symptoms. Pneumonia (n = 27 patients) or lung involvement (n = 6 patients) in patients with CTCL were associated with high mortality rates (hazard ratio, 1.82; 95% confidence interval, 1.08-3.07%; P = .026). The pathogens that were isolated from lower respiratory cultures were Staphylococcus aureus (n = 4 patients), Aspergillus fumigatus (n = 2 patients), Mycobacterium avium-intracellulare (n = 2 patients), Pseudomonas aeruginosa (n = 1 patient), respiratory syncytial virus (n = 1 patient), and Candida parapsilosis (n = 1 patient). Most of the radiologic findings in patients with pneumonia were opacities. Six patients had involvement of lung by CTCL, and most common radiologic pulmonary findings were either a solitary nodule or multiple progressing pulmonary nodules.

CONCLUSIONS

Pneumonia and lung involvement by CTCL are relatively rare but portend poor survival. Thus, patients with CTCL should be evaluated thoroughly with thoracic imaging when they experience respiratory symptoms.

Treatment of mycosis fungoides: overview

BACKGROUND

Mycosis fungoides (MF) is the most common clinicopathologic subtype of primary cutaneous T-cell lymphoma.

OBJECTIVE

The therapy of MF is highlighted in this overview.

RESULTS AND CONCLUSIONS

Skin-directed MF therapies include topical corticosteroids, nitrogen mustard, carmustine (BCNU), topical bexarotene gel, imiquimod cream, radiotherapy, total skin electron beam therapy, and phototherapy. Systemic therapies include extracorporeal photopheresis, interferon, oral bexarotene, denileukin diftitox, monoclonal antibodies and cytokine therapy, and other systemic chemotherapy. Finally, some investigative therapeutic modalities are presented.

Aminolevulinic Acid Photodynamic Therapy for Skin Cancers

Aminolevulinic acid photodynamic therapy (ALA-PDT) is an effective and noninvasive therapy for superficial basal cell carcinoma (BCC) and Bowen's disease. It also may have a role in the treatment of nodular BCC and other cutaneous malignancies, including localized cutaneous lymphomas. ALA-PDT offers multiple advantages over traditional treatments, including little to no scarring, excellent cosmetic results, and the ability to treat multiple lesions simultaneously. It is not an effective therapy for aggressive subtypes of BCC or for invasive squamous cell carcinoma. Finally, ALA-PDT may be a useful way to prevent new skin cancers in certain high-risk patients.

Clinical and laboratory experience of vorinostat (suberoylanilide hydroxamic acid) in the treatment of cutaneous T-cell lymphoma

The most common cutaneous T-cell lymphomas (CTCLs) – mycosis fungoides (MF) and Sézary Syndrome – are characterised by the presence of clonally expanded, skin-homing helper-memory T cells exhibiting abnormal apoptotic control mechanisms. Epigenetic modulation of genes that induce apoptosis and differentiation of malignant T cells may therefore represent an attractive new strategy for targeted therapy for T-cell lymphomas. In vitro studies show that vorinostat (suberoylanilide hydroxamic acid or SAHA), an oral inhibitor of class I and II histone deacetylases, induces selective apoptosis of malignant CTCL cell lines and peripheral blood lymphocytes from CTCL patients at clinically achievable doses. In a Phase IIa clinical trial, vorinostat therapy achieved a meaningful partial response (>50% reduction in disease burden) in eight out of 33 (24%) patients with heavily pretreated, advanced refractory CTCL. The most common major toxicities of oral vorinostat therapy were fatigue and gastrointestinal symptoms (diarrhoea, altered taste, nausea, and dehydration from not eating). Thrombocytopenia was dose limiting in patients receiving oral vorinostat at the higher dose induction levels of 300 mg twice daily for 14 days. These studies suggest that vorinostat represents a promising new agent in the treatment of CTCL patients. Additional studies are underway to define the exact mechanism (s) of by which vorinostat induces selective apoptosis in CTCL cells and to further evaluate the antitumour efficacy of vorinostat in a Phase IIb study in CTCL patients.

Mycosis fungoides associated with B-cell malignancies

BACKGROUND

The coexistence of mycosis fungoides, a peripheral T-cell lymphoma, and B-cell malignancies or Hodgkin's lymphoma in the same patient is unusual. Most descriptions are isolated case reports and case series are strikingly sparse.

OBJECTIVES

To detect cases of mycosis fungoides associated with B-cell malignancies or Hodgkin's lymphoma and to analyse the characteristics of and the interplay between the lymphoproliferative neoplasms.

METHODS

Patients with mycosis fungoides who had B-cell malignancies or Hodgkin's lymphoma were selected from among 398 patients either treated or followed up in two tertiary medical centres during a 7-year period.

RESULTS

Eleven patients with mycosis fungoides and B-cell malignancy were detected (seven of non-Hodgkin's lymphoma, three of chronic lymphocytic leukaemia, one of multiple myeloma). No case of Hodgkin's lymphoma was found. In seven patients the mycosis fungoides preceded the B-cell malignancy whereas in four it was the B-cell malignancy which occurred first. The time elapsed between onset of the two malignancies ranged from 4 to 22 years (average: 12 years). Patients who had mycosis fungoides as the first neoplasm presented with earlier stages of mycosis fungoides (four of seven: IA, three of seven: IB) than those who had mycosis fungoides as their second neoplasm (of four, one: IB, one: folliculotropic, two: IIB). Among the four patients in whom the appearance of mycosis fungoides followed the B-cell malignancy, three had been treated with multiagent chemotherapy. Two patients who presented with early-stage mycosis fungoides (IA) as the first lymphoma developed mycosis fungoides tumours after becoming immunosuppressed. In two patients infiltrates composed of both malignant T- and B-cell populations were found in a single biopsy. One showed two distinct populations of the malignant cells in the skin tumour, thus constituting a classical composite lymphoma of mycosis fungoides and chronic lymphocytic leukaemia, while in the other patient the two malignant populations of marginal B-cell lymphoma and mycosis fungoides (as evidenced by both phenotypic and genotypic findings) were intermingled.

CONCLUSIONS

This case series indicates that while the coexistence of Hodgkin's lymphoma and mycosis fungoides is extremely rare, the association of mycosis fungoides and B-cell malignancies is not as rare as reflected in the literature, with non-Hodgkin's lymphoma constituting the most common associated B-cell malignancy. In this series as well as in the cases reported in the literature mycosis fungoides usually preceded the development of B-cell malignancies, which may be in accordance with previous reports of an increased risk of developing a second haematological neoplasm. The importance of a competent immune system for patients with mycosis fungoides is well demonstrated in these cases. It is suggested that for greater precision the criteria for diagnosis of composite lymphoma of the skin should include both phenotypic and genotypic features.

CCR4 as a novel molecular target for immunotherapy of cancer

Leukocyte trafficking, which is critically regulated by chemokines and their receptors, shares many of the characteristics of tumor cell infiltration and metastasis. Expression of CC chemokine receptor 4 (CCR4) by tumor cells is associated with skin involvement, but CCR4 also has an important role in normal and tumor immunity. In a subset of patients with CCR4(+) T-cell leukemia/lymphoma, the tumor cells themselves function as regulatory T (Treg) cells, contributing to tumor survival in the face of host antitumor immune responses. In other types of cancers, the chemokines TARC/CCL17 and MDC/CCL22, specific ligands for CCR4 that are produced by tumor cells and the tumor microenvironment, attract CCR4(+) Treg cells to the tumor, where they create a favorable environment for tumor escape from host immune responses. A novel humanized anti-CCR4 monoclonal antibody (mAb) has been developed, the Fc region of which is defucosylated to enhance antibody-dependent cellular cytotoxicity by increasing its binding affinity to Fc receptor on effector cells. We are now conducting a phase I clinical trial of this anti-CCR4 mAb in patients with CCR4(+) T-cell leukemia/lymphoma in Japan (clinical trials gov. identifier: NCT00355472). Anti-CCR4 mAb could be an ideal treatment modality for many different cancers, not only to directly kill the CCR4(+) tumor cells, but also to overcome the suppressive effect of CCR4(+) Treg cells on the host immune response to tumor cells.

Mycosis fungoides and sezary syndrome: An update

Mycosis fungoides (MF), and the associated leukemic variant Sezary Syndrome (SS), are the most common group of cutaneous T-cell lymphomas. MF/SS is a non-Hodgkin's lymphoma of mature, skin-homing, clonal, malignant T lymphocytes that initially presents in the skin as patches, plaques, tumors, or generalized erythema (erythroderma) and can involve the lymph nodes and peripheral blood. Much progress has been made in recent years in understanding the origin of the malignant T cell in MF/SS and the pathophysiology and immunology of the disease. This recent work has made a great impact on diagnosis, prognostication, and treatment. In this review, we survey the MF/SS published literature over the past year and highlight some of the important advances.

Fli-1 expression in mycosis fungoides

BACKGROUND

The Fli-1 transcription factor functions in cellular proliferation and tumorigenesis. Its role in various neoplasms and its presence in lymphocytes suggest a link between Fli-1 dysregulation and the pathogenesis of mycosis fungoides (MF). In this study, we further elucidate this possible link.

METHODS

Sections from archived specimens were stained using a polyclonal antibody against Fli-1. The percentage of nuclei showing Fli-1 expression was recorded. These were compared with reactive dermatoses.

RESULTS

All of the tumor stage lesions showed high levels of nuclear Fli-1 expression. Of plaque stage lesions, six of 12 (50%) showed the same intensity, while the remaining six of 12 varied significantly in their Fli-1 expression. The few patch stage lesions also showed varied expression.

CONCLUSION

This study shows diffuse nuclear expression of Fli-1 in all tumor stage MF, whereas expression of this transcription factor varied widely in the early, epidermotropic stages. Although the numbers are too small to draw statistical significance, this study demonstrates an association between increased expression of Fli-1 and progression to tumor stage MF that merits further investigation. Additionally, the mixed expression of Fli-1 in the epidermotropic stages suggests that the role of Fli-1 in MF is related to neoplasia and not epidermotropism.