Management of the primary cutaneous lymphomas

Prognostic significance of the therapeutic targets histone deacetylase 1, 2, 6 and acetylated histone H4 in cutaneous T-cell lymphoma

AIMS

Aberrant histone acetylation has been associated with malignancy and histone deacetylase (HDAC) inhibitors are currently being investigated in numerous clinical trials. So far, the malignancy most sensitive to HDAC inhibitors has been cutaneous T-cell lymphoma (CTCL). The reason for this sensitivity is unclear and studies on HDAC expression and histone acetylation in CTCL are lacking. The aim of this study was to address this issue.

METHODS AND RESULTS

The immunohistochemical expression of HDAC1, HDAC2, HDAC6, and acetylated H4 was examined in 73 CTCLs and the results related to histological subtypes and overall survival. HDAC1 was most abundantly expressed (P < 0.0001), followed by HDAC2; HDAC6 and H4 acetylation were equally expressed. HDAC2 (P = 0.001) and H4 acetylation (P = 0.03) were significantly more common in aggressive than indolent CTCL subtypes. In contrast, no differences were observed for HDAC1 and HDAC6. In a Cox analysis, elevated HDAC6 was the only parameter showing significant influence on survival (P = 0.04).

CONCLUSIONS

High expression of HDAC2 and acetylated H4 is more common in aggressive than indolent CTCL. HDAC6 expression is associated with a favorable outcome independent of the subtype.

Histone deacetylase inhibitor panobinostat induces clinical responses with associated alterations in gene expression profiles in cutaneous T-cell lymphoma

PURPOSE

Histone deacetylase inhibitors can alter gene expression and mediate diverse antitumor activities. Herein, we report the safety and activity of the histone deacetylase inhibitor panobinostat (LBH589) in cutaneous T-cell lymphoma (CTCL) and identify genes commonly regulated by panobinostat.

EXPERIMENTAL DESIGN

Panobinostat was administered orally to patients with CTCL on Monday, Wednesday, and Friday of each week on a 28-day cycle. A dose of 30 mg was considered excessively toxic, and subsequent patients were treated at the expanded maximum tolerated dose of 20 mg. Biopsies from six patients taken 0, 4, 8, and 24 h after administration were subjected to microarray gene expression profiling and real-time quantitative PCR of selected genes.

RESULTS

Patients attained a complete response (n = 2), attained a partial response (n = 4), achieved stable disease with ongoing improvement (n = 1), and progressed on treatment (n = 2). Microarray data showed distinct gene expression response profiles over time following panobinostat treatment, with the majority of genes being repressed. Twenty-three genes were commonly regulated by panobinostat in all patients tested.

CONCLUSIONS

Panobinostat is well tolerated and induces clinical responses in CTCL patients. Microarray analyses of tumor samples indicate that panobinostat induces rapid changes in gene expression, and surprisingly more genes are repressed than are activated. A unique set of genes that can mediate biological responses such as apoptosis, immune regulation, and angiogenesis were commonly regulated in response to panobinostat. These genes are potential molecular biomarkers for panobinostat activity and are strong candidates for the future assessment of their functional role(s) in mediating the antitumor responses of panobinostat.

Prognostic significance of the therapeutic targets histone deacetylase 1, 2, 6 and acetylated histone H4 in cutaneous T-cell lymphoma

AIMS

Aberrant histone acetylation has been associated with malignancy and histone deacetylase (HDAC) inhibitors are currently being investigated in numerous clinical trials. So far, the malignancy most sensitive to HDAC inhibitors has been cutaneous T-cell lymphoma (CTCL). The reason for this sensitivity is unclear and studies on HDAC expression and histone acetylation in CTCL are lacking. The aim of this study was to address this issue.

METHODS AND RESULTS

The immunohistochemical expression of HDAC1, HDAC2, HDAC6, and acetylated H4 was examined in 73 CTCLs and the results related to histological subtypes and overall survival. HDAC1 was most abundantly expressed (P < 0.0001), followed by HDAC2; HDAC6 and H4 acetylation were equally expressed. HDAC2 (P = 0.001) and H4 acetylation (P = 0.03) were significantly more common in aggressive than indolent CTCL subtypes. In contrast, no differences were observed for HDAC1 and HDAC6. In a Cox analysis, elevated HDAC6 was the only parameter showing significant influence on survival (P = 0.04).

CONCLUSIONS

High expression of HDAC2 and acetylated H4 is more common in aggressive than indolent CTCL. HDAC6 expression is associated with a favorable outcome independent of the subtype.

The important role of radiotherapy in patients with non-melanoma skin cancer and other cutaneous entities

Non-melanoma skin cancer is the commonest malignancy worldwide and a significant public health issue. Although most non-melanoma skin cancers are small and easily excised or ablated, a recommendation of definitive radiotherapy is often made in patients where the outcome (cosmetic and/or functional) will probably be better with radiotherapy compared to surgery. The aim of adjuvant radiotherapy is to reduce the risk of loco-regional recurrence and the role of palliative radiotherapy is important in improving the quality of life in patients with advanced and/or incurable disease. The aim of this review article is to broadly discuss the various clinical settings in which a recommendation of radiotherapy may be made and also includes a discussion on less frequently encountered cutaneous entities (e.g. in situ squamous cell carcinoma, keratocanthoma, lentigo maligna, cutaneous lymphomas and malignant fibrous tumours).

Long-term clearance of patch-stage mycosis fungoides with the 308-nm laser

In order to investigate the effectiveness of the 308-nm xenon chloride laser in the treatment of patch-stage mycosis fungoides that is refractory to topical steroids, we conducted a prospective, histologically controlled, open-label pilot study. Eight patients with stage 1A or 1B cutaneous T-cell lymphoma that was unresponsive to application of potent topical steroids received 20 treatments with the laser over 10 weeks and were then followed up for a minimum of 30 months. Three patients had a complete clinical and histological response and remained free of disease after 30 months A further three patients had complete clinical and histological clearance of disease, but experienced relapse within the 30 months follow-up period. One patient withdrew from the study and one had a partial response. Further research to establish the role of the 308-nm laser in the treatment of MF appears justified.

18 F-fluorodeoxyglucose-positron emission tomography in evaluation of primary cutaneous lymphoma

BACKGROUND

The diagnosis of primary cutaneous lymphoma (PCL) is currently based on clinical and histological findings and/or relatively invasive procedures such as bone marrow and fine-needle lymph node biopsies. Although computed tomography (CT) is a noninvasive imaging modality that is widely used for staging in patients with lymphoma, it cannot provide information about malignant cutaneous lesions.

OBJECTIVES

To investigate the usefulness of (18)F-fluorodeoxyglucose (FDG)-positron emission tomography (PET) in the management of PCL.

METHODS

We retrospectively analysed 31 FDG-PET studies in 19 patients with PCL [15 T-cell non-Hodgkin lymphoma (NHL) and four B-cell NHL]. There were 10 men and nine women (age range 23-84 years, mean +/- SD 54 +/- 16). Eleven FDG-PET studies were performed for initial staging and 20 FDG-PET studies were performed for restaging following therapy. Results of FDG-PET were compared with those of CT. Clinical parameters and/or biopsy results of lesions served as reference for the accuracy of PET and CT in evaluating local and metastatic lesions.

RESULTS

For the initial staging, FDG-PET had a sensitivity of 82% for the evaluation of local disease and 80% for the detection of distant metastasis. The corresponding values for CT were 55% and 100%, respectively. For restaging of cutaneous lymphoma, FDG-PET had a sensitivity of 86% and specificity of 92% for local recurrence/residual disease and a sensitivity of 100% and specificity of 100% for distant metastasis. The corresponding values for CT were 50% and 83% for local recurrence/residual disease and 100% and 67% for distant metastasis.

CONCLUSIONS

FDG-PET has a potential value for initial staging and restaging following therapy in patients with PCL. FDG-PET has higher diagnostic value than CT in the detection both of local disease and distant metastasis.

Graft-versus-lymphoma effect in refractory cutaneous T-cell lymphoma after reduced-intensity HLA-matched sibling allogeneic stem cell transplantation

Cutaneous T-cell lymphomas (CTCL) are rare diseases that, in their advanced stages or in transformation, have a poor prognosis. Autologous stem cell transplantation (Au-SCT) after high-dose therapy has yielded disappointing results. Allogeneic transplantation (allo-SCT) provides the potential advantage of an immune-mediated graft-versus-lymphoma (GVL) effect. Reduced-intensity allo-SCT potentially offers a GVL effect, but with diminished toxicity related to the induction regimen; however, published experience with this approach in CTCL is limited. We report a series of three patients (age 35-49) with advanced, refractory (n=2) or transformed (n=1) CTCL who underwent reduced-intensity allo-SCT in the context of active disease. All three survived the peri-transplant period and, despite later having disease relapse, all exhibited evidence of a GVL effect. Relapses of the disease were in the context of immune suppression for graft-versus-host disease (GVHD), and when immune suppression was reduced, responses were regained. A comparison is made of these results to those in a review of the published literature to date. We conclude that while a GVL can be achieved for CTCL with reduced-intensity allogeneic transplantation, the clinical benefits are short lived and novel approaches are required to obtain sustained remissions.