Gary S. Wood

Pivotal Phase III Trial of Two Dose Levels of Denileukin Diftitox for the Treatment of Cutaneous T-Cell Lymphoma

PURPOSE The objective of this phase III study was to determine the efficacy, safety, and pharmacokinetics of denileukin diftitox (DAB389IL-2, Ontak [Ligand Pharmaceuticals Inc, San Diego, CA]) in patients with stage Ib to IVa cutaneous T-cell lymphoma (CTCL) who have previously received other therapeutic interventions. PATIENTS AND METHODS Patients with biopsy-proven CTCL that expressed CD25 on > or = 20% of lymphocytes were assigned to one of two dose levels (9 or 18 microg/kg/d) of denileukin diftitox administered 5 consecutive days every 3 weeks for up to 8 cycles. Patients were monitored for toxicity and clinical efficacy, the latter assessed by changes in disease burden and quality of life measurements. Antibody levels of antidenileukin diftitox and anti-interleukin-2 and serum concentrations of denileukin diftitox were also measured. RESULTS Overall, 30% of the 71 patients with CTCL treated with denileukin diftitox had an objective response (20% partial response; 10% complete response). The response rate and duration of response based on the time of the first dose of study drug for all responders (median of 6.9 months with a range of 2.7 to more than 46.1 months) were not statistically different between the two doses. Adverse events consisted of flu-like symptoms (fever/chills, nausea/vomiting, and myalgias/arthralgias), acute infusion-related events (hypotension, dyspnea, chest pain, and back pain), and a vascular leak syndrome (hypotension, hypoalbuminemia, edema). In addition, 61% of the patients experienced transient elevations of hepatic transaminase levels with 17% grade 3 or 4. Hypoalbuminemia occurred in 79%, including 15% with grade 3 or 4 changes. Tolerability at 9 and 18 microg/kg/d was similar, and there was no evidence of cumulative toxicity. CONCLUSION Denileukin diftitox has been shown to be a useful and important agent in the treatment of patients whose CTCL is persistent or recurrent despite other therapeutic interventions.

Suppression of endogenous avidin-binding activity in tissues and its relevance to biotin-avidin detection systems.

As biotin-avidin systems continue to be developed for applications involving single cells, cell suspensions, and especially tissue sections, the need arises for a method of blocking endogenous avidin-binding activity. One such method is described and its proposed mechanism is discussed. Utilizing this method, endogenous avidin-binding activity was detected and suppressed in selected human and murine tissues, thus facilitating the interpretation of specific immunohistochemical staining utilizing hybridoma monoclonal antibodies in a biotin-avidin-horseradish peroxidase detection system.

Clonal rearrangements of T-cell receptor genes in mycosis fungoides and dermatopathic lymphadenopathy.

Histologic diagnosis of mycosis fungoides may be difficult, especially in lymph nodes that show changes frequently associated with chronic skin disease. As an alternative approach to diagnosis, we have analyzed the configuration of DNA for the beta T-cell receptor genes in biopsy tissues from 14 patients with mycosis fungoides. Clonal rearrangements of these genes were found in each specimen tht contained histologically unambiguous mycosis fungoides. Clonal rearrangements were also found in seven of nine lymph nodes removed from patients with mycosis fungoides and considered histologically to contain only benign lymphadenopathy. Matching rearrangements of beta T-cell receptor genes were detected in benign lymph nodes and histologically involved tissues when paired specimens were available from the same cases. Our findings provide molecular evidence for the clonal T-cell origin of mycosis fungoides and indicate the high incidence of extracutaneous disease in patients with palpable lymphadenopathy. In addition, this study demonstrates that the detection of rearranged T-cell receptor genes can be a sensitive and practical method for the diagnosis and characterization of T-cell neoplasms.

Clonal T-cell populations in lymphomatoid papulosis. Evidence of a lymphoproliferative origin for a clinically benign disease.

Lymphomatoid papulosis is a chronic, clinically benign skin disorder that, when examined histologically, is seen to include numerous large, atypical lymphoid cells that display antigenic markers of T lymphocytes. To investigate the disparity between the clinical behavior of this disease and its malignant histologic appearance, we analyzed the DNA from skin lesions of six patients for rearrangements of beta and gamma T-cell receptor genes. Lesions from five of these patients showed between one and three clonal rearrangements for at least one T-cell receptor gene. Three separate biopsy specimens from a single patient showed different patterns of rearrangements for the beta gene in each specimen. Our results indicate that lymphomatoid papulosis is a clonal T-cell lymphoproliferative process that may possibly be multiclonal in origin. We conclude that this disease has both biologic and histologic features consistent with a malignant T-cell neoplasm despite its indolent course.

Apoptosis and melanoma: molecular mechanisms

Melanoma cells can undergo self‐destruction via programmed cell death, i.e. apoptosis. In these tumours, the molecular components of apoptosis include positive (apoptotic) and negative (anti‐apoptotic) regulators. The former include p53, Bid, Noxa, PUMA, Bax, TNF, TRAIL, Fas/FasL, PITSLRE, interferons, and c‐KIT/SCF. The latter include Bcl‐2, Bcl‐XL, Mcl‐1, NF‐KB, survivin, livin, and ML‐IAP. Alternatively, some molecules such as TRAF‐2, c‐Myc, endothelins, and integrins may have either pro‐ or anti‐apoptotic effects. Some of these molecules are of potential therapeutic use, such as: (1) p53, which influences resistance to chemotherapy; (2) Mcl‐1 and Bcl‐XL, which can override apoptosis; (3) TRAIL, which has selective fatal effects on tumour cells; (4) NF‐KB, which when downregulated sensitizes cells to TRAIL and TNF; (5) the PITSLRE kinases, whose alteration appears to result in Fas resistance; (6) interferons, which sensitize cells to other factors; and (7) survivin and other IAPs that inhibit apoptosis. This review summarizes the state of current knowledge about the key molecular components and mechanisms of apoptosis in melanoma, discusses potential therapeutic ramifications, and provides directions for future research. Copyright

EORTC, ISCL, and USCLC consensus recommendations for the treatment of primary cutaneous CD30-positive lymphoproliferative disorders: lymphomatoid papulosis and primary cutaneous anaplastic large-cell lymphoma

Primary cutaneous CD30(+) lymphoproliferative disorders (CD30(+) LPDs) are the second most common form of cutaneous T-cell lymphomas and include lymphomatoid papulosis and primary cutaneous anaplastic large-cell lymphoma. Despite the anaplastic cytomorphology of tumor cells that suggest an aggressive course, CD30(+) LPDs are characterized by an excellent prognosis. Although a broad spectrum of therapeutic strategies has been reported, these have been limited mostly to small retrospective cohort series or case reports, and only very few prospective controlled or multicenter studies have been performed, which results in a low level of evidence for most therapies. The response rates to treatment, recurrence rates, and outcome have not been analyzed in a systematic review. Moreover, international guidelines for staging and treatment of CD30(+) LPDs have not yet been presented. Based on a literature analysis and discussions, recommendations were elaborated by a multidisciplinary expert panel of the Cutaneous Lymphoma Task Force of the European Organization for Research and Treatment of Cancer, the International Society for Cutaneous Lymphomas, and the United States Cutaneous Lymphoma Consortium. The recommendations represent the state-of-the-art management of CD30(+) LPDs and include definitions for clinical endpoints as well as response criteria for future clinical trials in CD30(+) LPDs.

Anti-proliferative and proapoptotic effects of (-)-epigallocatechin-3-gallate on human melanoma: possible implications for the chemoprevention of melanoma.

Melanoma accounts for only about 4% of all skin cancer cases but most of skin cancer‐related deaths. Standard systemic therapies such as interferon (IFN) have not been adequately effective in the management of melanoma. Therefore, novel approaches are needed for prevention and treatment of this disease. Chemoprevention by naturally occurring agents present in food and beverages has shown benefits in certain cancers including nonmelanoma skin cancers. Here, employing 2 human melanoma cell lines (A‐375 amelanotic malignant melanoma and Hs‐294T metastatic melanoma) and normal human epidermal melanocytes (NHEM), we studied the antiproliferative effects of epigallocatechin‐3‐gallate (EGCG), the major polyphenolic antioxidant present in green tea. EGCG treatment was found to result in a dose‐dependent decrease in the viability and growth of both melanoma cell lines. Interestingly, at similar EGCG concentrations, the normal melanocytes were not affected. EGCG treatment of the melanoma cell lines resulted in decreased cell proliferation (as assessed by Ki‐67 and PCNA protein levels) and induction of apoptosis (as assessed cleavage of PARP, TUNEL assay and JC‐1 assay). EGCG also significantly inhibited the colony formation ability of the melanoma cells studied. EGCG treatment of melanoma cells resulted in a downmodulation of anti‐apoptotic protein Bcl2, upregulation of proapoptotic Bax and activation of caspases ‐3, ‐7 and ‐9. Furthermore, our data demonstrated that EGCG treatment resulted in a significant, dose‐dependent decrease in cyclin D1 and cdk2 protein levels and induction of cyclin kinase inhibitors (ckis) p16INK4a, p21WAF1/CIP1 and p27KIP1. Our data suggest that EGCG causes significant induction of cell cycle arrest and apoptosis of melanoma cells that is mediated via modulations in the cki‐cyclin‐cdk network and Bcl2 family proteins. Thus, EGCG, alone or in conjunction with current therapies, could be useful for the management of melanoma.

Histiocytic malignancies. Morphologic, immunologic, and enzymatic heterogeneity

We have studied 14 hematopoietic malignancies with histologic features of histiocytic differentiation, using frozen section immunologic stains, plastic section enzyme histochemistry, and paraffin section immunocytochemistry. There was morphologic, immunologic, and enzymatic heterogeneity, including findings in seven cases that suggested differentiation toward specialized subsets of histiocytes. Four cases expressed a mature monocyte/macrophage phenotype by frozen section monoclonal antibody staining and three of these had histologic patterns diagnostic of malignant histiocytosis; two other cases had ATPase and S100 protein reactivity and morphologic features consistent with interdigitating (reticulum) cell proliferations; and one case was alkaline phosphatase positive, suggestive of differentiation toward fibroblastic reticulum cells. Four cases had histologic findings consistent with malignant histiocytosis, but weak or unreactive staining patterns and were considered poorly differentiated histiocytic or primitive hematopoietic malignancies. Three other cases, also morphologically consistent with malignant histiocytosis, were identified as probable T-cell lymphomas. The morphologic and phenotypic characteristics of non-neoplastic histiocytes and dendritic cell types and their related neoplasms are discussed. Histiocytic malignancies comprise a diverse group that can be identified and subclassified by immunologic and enzymatic techniques.

CD8-positive tumor-infiltrating lymphocytes influence the long-term survival of patients with mycosis fungoides

BACKGROUND Nonneoplastic mononuclear cells commonly infiltrate lesions of mycosis fungoides. OBJECTIVE We sought to determine the immunophenotypic characteristics of these cells and to determine whether the presence of CD8+ tumor-infiltrating lymphocytes has an impact on prognosis. METHODS Skin biopsy specimens from 78 patients were stained with immunopleroxidase techniques to determine their phenotypic characteristics. The proportion of CD8+ tumor-infiltrating lymphocytes was quantified and compared with stage of disease and survival rate. RESULTS Patients with more limited T-stage disease tended to have a higher proportion of CD8+ cells in their skin biopsy specimens, compared with patients with more advanced T-stage disease. Within each T-stage patients with a larger proportion of CD8+ cells had a better survival rate than those with fewer CD8+ cells (p < 0.05 for T1 and T3). A multivariate analysis confirmed the importance of T stage (p = 0.0006), overall stage (p = 0.0112), and CD8 positivity (p = 0.0335) in this cohort of patients. CONCLUSION CD8+ tumor-infiltrating lymphocytes in mycosis fungoides correlate with improved survival rate and may exert an antitumor effect rather than being mere bystander cells.

Absence of Borrelia burgdorferi DNA in cutaneous B‐cell lymphomas from the United States

Background: An association between Borrelia burgdorferi and cutaneous B‐cell lymphoma (CBCL) has been made in several European countries. The evidence in favor of such an association has recently been based on more definitive tests for the pathogenetic role of B. burgdorferi in CBCL, including positive cultures or polymerase chain reaction (PCR) amplification of borrelial DNA from lesional skin. However, there is only one report of B. burgdorferi in four North American cases of B‐cell lymphoma.