Anti-CTLA-4 therapy broadens the melanoma-reactive CD8+ T cell response.

Anti-CTLA-4 treatment improves the survival of patients with advanced-stage melanoma. However, although the anti-CTLA-4 antibody ipilimumab is now an approved treatment for patients with metastatic disease, it remains unknown by which mechanism it boosts tumor-specific T cell activity. In particular, it is unclear whether treatment amplifies previously induced T cell responses or whether it induces new tumor-specific T cell reactivities. Using a combination ultraviolet (UV)-induced peptide exchange and peptide-major histocompatibility complex (pMHC) combinatorial coding, we monitored immune reactivity against a panel of 145 melanoma-associated epitopes in a cohort of patients receiving anti-CTLA-4 treatment. Comparison of pre- and posttreatment T cell reactivities in peripheral blood mononuclear cell samples of 40 melanoma patients demonstrated that anti-CTLA-4 treatment induces a significant increase in the number of detectable melanoma-specific CD8 T cell responses (P = 0.0009). In striking contrast, the magnitude of both virus-specific and melanoma-specific T cell responses that were already detected before start of therapy remained unaltered by treatment (P = 0.74). The observation that anti-CTLA-4 treatment induces a significant number of newly detected T cell responses-but only infrequently boosts preexisting immune responses-provides strong evidence for anti-CTLA-4 therapy-enhanced T cell priming as a component of the clinical mode of action.

Mélanome: une nouvette ère thérapeutique [Melanoma: a new therapeutic era].

Melanoma is the cancer with the fastest incidence increase in Switzerland. 30% of the cases arise before the age of 50 years. Once metastatic, the median survival under current systemic therapies is about 8 months, with less than 5% of patients alive at 5 years. Many efforts in the understanding of cellular biology, intracellular signaling pathways, as well as the role of cellular immunity have been made in the recent years. This has resulted in the development of novel and very promising therapies. In this review, we will cover the results obtained with targeted therapies such as "tyrosin kinase inhibitors" (TKI), as well as those obtained with a monoclonal antibody directed against the CTLA-4 receptor of lymphocytes.

Type I signal peptidase from Leishmania is a target of the immune response in human cutaneous and visceral leishmaniasis.

The gene encoding type I signal peptidase (Lmjsp) has been cloned from Leishmania major. Lmjsp encodes a protein of 180 amino residues with a predicted molecular mass of 20.5 kDa. Comparison of the protein sequence with those of known type I signal peptidases indicates homology in five conserved domains A-E which are known to be important, or essential, for catalytic activity. Southern blot hybridisation analysis indicates that there is a single copy of the Lmjsp gene. A recombinant SPase protein and a synthetic peptide of the L. major signal peptidase were used to examine the presence of specific antibodies in sera from either recovered or active individuals of both cutaneous and visceral leishmaniasis. This evaluation demonstrated that sera from cutaneous and visceral forms of leishmaniasis are highly reactive to both the recombinant and synthetic signal peptidase antigens. Therefore, the Leishmania signal peptidase, albeit localised intracellularly, is a significant target of the Leishmania specific immune response and highlights its potential use for serodiagnosis of cutaneous and visceral leishmaniasis.

Clinical activity of ipilimumab for metastatic uveal melanoma: a retrospective review of the Dana-Farber Cancer Institute, Massachusetts General Hospital, Memorial Sloan-Kettering Cancer Center, and University Hospital of Lausanne experience.

BACKGROUND: Uveal melanoma exhibits a high incidence of metastases; and, to date, there is no systemic therapy that clearly improves outcomes. The anticytotoxic T-lymphocyte-associated protein 4 (anti-CTLA-4) antibody ipilimumab is a standard of care for metastatic melanoma; however, the clinical activity of CTLA-4 inhibition in patients with metastatic uveal melanoma is poorly defined. METHODS: To assess ipilimumab in this setting, the authors performed a multicenter, retrospective analysis of 4 hospitals in the United States and Europe. Clinical characteristics, toxicities, and radiographic disease burden, as determined by central, blinded radiology review, were evaluated. RESULTS: Thirty-nine patients with uveal melanoma were identified, including 34 patients who received 3 mg/kg ipilimumab and 5 who received 10 mg/kg ipilimumab. Immune-related response criteria and modified World Health Organization criteria were used to assess the response rate (RR) and the combined response plus stable disease (SD) rate after 12 weeks, after 23 weeks, and overall (median follow-up, 50.4 weeks [12.6 months]). At week 12, the RR was 2.6%, and the response plus SD rate was 46.%; at week 23, the RR was 2.6%, and the response plus SD rate was 28.2%. There was 1 complete response and 1 late partial response (at 100 weeks after initial SD) for an immune-related RR of 5.1%. Immune-related adverse events were observed in 28 patients (71.8%) and included 7 (17.9%) grade 3 and 4 events. Immune-related adverse events were more frequent in patients who received 10 mg/kg ipilimumab than in those who received 3 mg/kg ipilimumab. The median overall survival from the first dose of ipilimumab was 9.6 months (95% confidence interval, 6.3-13.4 months; range, 1.6-41.6 months). Performance status, lactate dehydrogenase level, and an absolute lymphocyte count ≥ 1000 cells/μL at week 7 were associated significantly with survival. CONCLUSIONS: In this multicenter, retrospective analysis of 4 hospitals in the United States and Europe of patients with uveal melanoma, durable responses to ipilimumab and manageable toxicity were observed.

Skin cancer in survivors of childhood and adolescent cancer.

The incidence of basal cell carcinoma (BCC) has been related to ionizing radiation, particularly for exposure occurring at young age. In this study, we considered the incidence of second skin neoplasms in long-term survivors from childhood cancer. We considered second primary cancers occurring among 776 subjects (436 males, 340 females) with first primary cancer diagnosed before age 20 years, between 1974 and 2001, in the Swiss Cantons of Vaud and Neuchâtel (786,000 inhabitants). Five BCC were observed versus 0.43 expected (standardized incidence ratio: 11.6, 95% confidence interval: 3.7-27.1). No case of cutaneous squamous cell carcinoma, nor of malignant melanoma was observed. The estimated radiation doses at 1mm through the skin ranged between 7 and 27 Sv. These data confirm that BCC are strongly related to ionizing radiation exposure in childhood. All the BCC were located within the radiation field, thus indicating that ionizing radiation is the key aetiological factor, even in the absence of any meaningful interaction with UV.

EBV+ cutaneous B-cell lymphoproliferation of the leg in an elderly patient with mycosis fungoides and methotrexate treatment.

A 77-year-old man with a 5-year history of mycosis fungoides (MF) who had received several lines of therapy, including intravenous courses of Methotrexate (MTX) for the past 2 years, went on to develop several ulcerated cutaneous nodules on the left leg. Biopsy revealed diffuse sheets of EBV-positive large B cells (CD20+ CD30 ± IgM Lambda), with an angiocentric distribution and a monoclonal IGH gene rearrangement. Although the pathological features were diagnostic for an EBV-positive diffuse large B-cell lymphoma (DLBCL), several possibilities could be considered for assignment to a specific entity: EBV-positive DLBCL of the elderly, methotrexate-induced lymphoproliferative disorder (LPD), lymphomatoid granulomatosis, or the more recently described EBV-positive mucocutaneous ulcer. The development of EBV+ lymphoproliferations has been reported in two other patients with MF under MTX, and occurred as skin lesions of the leg in one of these and in the current case, which may question the relatedness to primary cutaneous DLCBL, leg-type.

Tumor-reactive, SSX-2-specific CD8+ T cells are selectively expanded during immune responses to antigen-expressing tumors in melanoma patients.

The SSX-2 gene encodes a tumor-specific antigen expressed in neoplasms of various histological types. By analyzing a tumor-infiltrated lymph node of a melanoma patient bearing an SSX-2-expressing tumor, we have recently identified the first SSX-2-derived CD8(+) T-cell epitope, that corresponds to peptide SSX-2(41-49), and is recognized by specific CTL in an HLA-A2 restricted fashion. Here, we have used fluorescent HLA-A2/SSX-2(41-49) peptide multimeric complexes to analyze the response to SSX-2(41-49) in melanoma patients and healthy donors. Multimer(+) CD8(+) T cells were readily detected in the majority of patients bearing SSX-2-expressing tumors and, at lower proportions, in patients with nonexpressing tumors and healthy donors. Importantly, isolated A2/SSX-2(41-49) multimer(+) CD8(+) T cells exhibited a large functional heterogeneity in terms of antigen recognition and tumor reactivity. SSX-2-specific CTLs isolated from tumor-infiltrated lymph node of antigen-expressing patients as well as from the corresponding peripheral blood mononuclear cells exhibited high functional avidity of antigen recognition and efficiently recognized antigen-expressing tumors. In contrast, SSX-2-specific CTLs isolated from patients with undetectable responses in the tumor-infiltrated lymph node, as well as from healthy donors, recognized the antigen with decreased functional avidity and were not tumor reactive. Together, these data indicate that CD8(+) T-cell responses to SSX-2(41-49) frequently occur in SSX-2-expressing melanoma patients and suggest that SSX-2(41-49)-specific CTLs of high avidity and tumor reactivity are selectively expanded during immune responses to SSX-2-expressing tumors in vivo.

Exome sequencing identifies recurrent somatic MAP2K1 and MAP2K2 mutations in melanoma.

We performed exome sequencing to detect somatic mutations in protein-coding regions in seven melanoma cell lines and donor-matched germline cells. All melanoma samples had high numbers of somatic mutations, which showed the hallmark of UV-induced DNA repair. Such a hallmark was absent in tumor sample-specific mutations in two metastases derived from the same individual. Two melanomas with non-canonical BRAF mutations harbored gain-of-function MAP2K1 and MAP2K2 (MEK1 and MEK2, respectively) mutations, resulting in constitutive ERK phosphorylation and higher resistance to MEK inhibitors. Screening a larger cohort of individuals with melanoma revealed the presence of recurring somatic MAP2K1 and MAP2K2 mutations, which occurred at an overall frequency of 8%. Furthermore, missense and nonsense somatic mutations were frequently found in three candidate melanoma genes, FAT4, LRP1B and DSC1.

Osteosarcoma metastasis causing ileo-ileal intussusception.

Osteosarcoma metastasis causing intussusception is a very rare entity, with a pejorative prognosis. Based on a case, we performed a literature review in order to better assess this situation. We conclude that, in patients with a history of osteosarcoma lung metastasis, echographic and/or computed tomography scan evidence of a small bowel obstruction with intussusception should lead to an open surgical procedure if the laparoscopic approach does not allow to accurately explore and resect the lesion, in order to prevent misdiagnosis and to avoid further delay in the management.

Sistema informàtic d’ajut a la detecció i al seguiment del melanoma

Mitjançant les tècniques de visió per computador aquest projecte pretén desenvolupar una aplicació capaç de segmentar la pell, detectar nevus (pigues i altres taques) i poder comparar imatges de pacients amb risc de contreure melanoma preses en moments diferents. Aquest projecte pretén oferir diferents eines informàtiques als dermatòlegs per a propòsits relacionats amb la investigació. L’ objectiu principal d’ aquest projecte és desenvolupar un sistema informàtic que proporcioni als dermatòlegs agilitat a l’hora de gestionar les dades dels pacients amb les sevesimatges corresponents, ajudar-los en la realització de deteccions dels nevus d’aquestes imatges, i ajudar-los en la comparació d’exploracions (amb les deteccions realitzades)de diferents èpoques d’un mateix pacient

Selective tumor localization of radiolabeled anti-human melanoma monoclonal antibody fragment demonstrated in the nude mouse model.

Monoclonal antibodies (Mab) directed against distinct epitopes of the human 240 kD melanoma-associated antigen have been evaluated for their capacity to localize in human melanoma grafted into nude mice. A favorable tumor to normal tissue ratio of 13 was obtained with intact 131I-labeled MAb Me1-14. This ratio was further increased to 43 and 23 by the use of F(ab')2 and Fab fragments, respectively. The specificity of tumor localization was demonstrated by the simultaneous injection of F(ab')2 fragments from MAb Me1-14 and anti-CEA MAb 35, each labeled with a different iodine isotope, into nude mice grafted with a melanoma and colon carcinoma. The fragments from both MAb localized with perfect selectivity in their relevant tumor as shown by differential whole body scanning and by direct measurement of the two isotopes in tumors and normal tissues. These in vivo experimental results suggest that the F(ab')2 fragment from MAb Me1-14 is suitable for melanoma detection by immunoscintigraphy in patients.

Identification of a new oncofoetal antigen associated with several types of human carcinomas.

In experimental animals, oncofoetal antigens1 have been found to be associated with both chemical-2 and virus-induced tumours3. In man the two best known oncofoetal antigens are the α-foetoprotein (AFP) described by both Abelev4 and Tatarinov5 and the carcinoembryonic antigen (CEA) of the human digestive system identified by Gold and Freedman6. We describe here a different human oncofoetal antigen, common to several types of carcinomas and various foetal organs. This antigen has been identified by rabbit antisera raised against semipurified fractions of colon carcinoma soluble extracts. Because of its β-immunoelectrophoretic mobility, this antigen will be referred to as β-oncofoetal antigen (BOFA).

Concepts of metastasis in flux: the stromal progression model.

The ability of tumor cells to leave a primary tumor, to disseminate through the body, and to ultimately seed new secondary tumors is universally agreed to be the basis for metastasis formation. An accurate description of the cellular and molecular mechanisms that underlie this multistep process would greatly facilitate the rational development of therapies that effectively allow metastatic disease to be controlled and treated. A number of disparate and sometimes conflicting hypotheses and models have been suggested to explain various aspects of the process, and no single concept explains the mechanism of metastasis in its entirety or encompasses all observations and experimental findings. The exciting progress made in metastasis research in recent years has refined existing ideas, as well as giving rise to new ones. In this review we survey some of the main theories that currently exist in the field, and show that significant convergence is emerging, allowing a synthesis of several models to give a more comprehensive overview of the process of metastasis. As a result we postulate a stromal progression model of metastasis. In this model, progressive modification of the tumor microenvironment is equally as important as genetic and epigenetic changes in tumor cells during primary tumor progression. Mutual regulatory interactions between stroma and tumor cells modify the stemness of the cells that drive tumor growth, in a manner that involves epithelial-mesenchymal and mesenchymal-epithelial-like transitions. Similar interactions need to be recapitulated at secondary sites for metastases to grow. Early disseminating tumor cells can progress at the secondary site in parallel to the primary tumor, both in terms of genetic changes, as well as progressive development of a metastatic stroma. Although this model brings together many ideas in the field, there remain nevertheless a number of major open questions, underscoring the need for further research to fully understand metastasis, and thereby identify new and effective ways of treating metastatic disease.

Primary cutaneous posttransplant lymphoproliferative disorders in solid organ transplant recipients: a multicenter European case series.

Primary cutaneous posttransplant lymphoproliferative disorders (PTLD) are rare. This retrospective, multicenter study of 35 cases aimed to better describe this entity. Cases were (re)-classified according to the WHO-EORTC or the WHO 2008 classifications of lymphomas. Median interval between first transplantation and diagnosis was 85 months. Fifty-seven percent of patients had a kidney transplant. Twenty-four cases (68.6%) were classified as primary cutaneous T cell lymphoma (CTCL) and 11 (31.4%) as primary cutaneous B cell PTLD. Mycosis fungoides (MF) was the most common (50%) CTCL subtype. Ten (90.9%) cutaneous B cell PTLD cases were classified as EBV-associated B cell lymphoproliferations (including one plasmablastic lymphoma and one lymphomatoid granulomatosis) and one as diffuse large B cell lymphoma, other, that was EBV-negative. Sixteen (45.7%) patients died after a median follow-up of 19.5 months (11 [68.8%] with CTCL [6 of whom had CD30(+) lymphoproliferative disorders (LPD)] and 5 [31.2%] with cutaneous B cell PTLD. Median survival times for all patients, CTCL and cutaneous B cell PTLD subgroups were 93, 93, and 112 months, respectively. Survival rates for MF were higher than those for CD30(+) LPD. The spectrum of primary CTCL in organ transplant recipients (OTR) is similar to that in the general population. The prognosis of posttransplant primary cutaneous CD30(+) LPD is worse than posttransplant MF and than its counterpart in the immunocompetent population. EBV-associated cutaneous B cell LPD predominates in OTR.