Dermatofibrosarcoma protuberans (DFSP) is a rare malignant dermal neoplasm characterized by slow infiltrative growth, little metastatic potential but a high tendency to recur locally after surgical excision. DFSP is associated with a high cure rate. The optimal therapy is complete surgical resection. The recurrence potential of DFSP is directly related to the extent of resection. The need for wide excision margins has been amply documented. Wide local excision is a frequently used practice. Mohs micrographic surgery with continuous histological margin control is further propagated to reduce local recurrence rates. In more than 90% of DFSP, a specific chromosomal aberration is described, involving Chromosomes 17 and 22. It leads to a constitutive activation of the platelet-derived growth factor receptor (PDGFR) followed by continuous stimulation of the tumor cell growth. The use of targeted inhibitors of PDGFR is a good therapeutic option in the treatment strategy of unresectable locally advanced, recurrent or metastatic disease. With Imatinib, a selective PDGFR tyrosin kinase inhibitor, partial and complete remissions of DFSP could be achieved. This article reviews the current opinion and literature about DFSP and resulting therapy strategies.

Thrombospondin-1 (TSP) is a transiently expressed matricellular protein known to promote chemotaxis of leukocytes to inflammatory sites. However, TSP and its receptor CD36 are abundantly expressed in chronically inflamed tissues such as the rheumatoid synovium. Here, we show that TSP provides the costimulatory signal that is necessary for the activation of autoreactive T cells. Data presented reveal that TSP-mediated costimulation is achieved through its independent interaction with CD36 on APCs and with CD47 on T cells. We propose that a CD47-TSP-CD36 trimolecular complex is a novel costimulatory pathway that significantly decreases the threshold of T cell activation. Consistent with the paradigm that lesions in rheumatoid synovitis are sites of antigenic recognition, the characteristic focal expression of TSP on APCs such as macrophages and fibroblast-like synoviocytes suggest a central role of TSP in the expansion of tissue-infiltrating T cells.

SummaryLenalidomide activates the immune system, but the exact immunomodulatory mechanisms of lenalidomide in vivo are poorly defined. In an observational study we assessed the impact of lenalidomide on different populations of immune cells in multiple myeloma patients. Lenalidomide therapy was associated with increased amounts of a CD8 + T cell subset, phenotypically staged between classical central memory T cells (TCM) and effector memory T cells (TEM), consequently termed TCM/TEM. The moderate expression of perforin/granzyme and phenotypical profile of these cells identifies them as not yet terminally differentiated, which makes them promising candidates for the anti-tumour response. In addition, lenalidomide-treated patients showed higher abundance of CD14 + myeloid cells co-expressing CD15. This population was able to inhibit both CD4 + and CD8 + T cell proliferation in vitro and could thus be defined as a so far undescribed novel myeloid-derived suppressor cell (MDSC) subtype. We observed a striking correlation between levels of TCM/TEM, mature regulatory T cells (Tregs) and CD14 + CD15 + MDSCs. In summary, lenalidomide induces both activating and inhibitory components of the immune system, indicating the existence of potential counter-regulatory mechanisms. These findings provide new insights into the immunomodulatory action of lenalidomide.

The phase 3, randomized Frontline Investigation of Revlimid and Dexamethasone Versus Standard Thalidomide (FIRST) trial investigating lenalidomide plus low-dose dexamethasone until disease progression (Rd continuous) vs melphalan, prednisone and thalidomide for 12 cycles (MPT) and Rd for 18 cycles (Rd18) in transplant-ineligible patients with newly diagnosed multiple myeloma (NDMM) showed that Rd continuous prolonged progression-free survival and overall survival compared with MPT. A subanalysis of the FIRST trial was conducted to determine the benefits of Rd continuous in patients with NDMM based on depth of response. Patients randomized 1:1:1 to Rd continuous, Rd18 or MPT were divided into subgroups based on best response: complete response (CR; n=290), ⩾very good partial response (VGPR; n=679), ⩾partial response (PR; n=1 225) or ⩽stable disease (n=299). Over 13% of patients receiving Rd continuous who achieved ⩾VGPR as best response did so beyond 18 months of treatment. Rd continuous reduced the risk of progression or death by 67%, 51% and 35% vs MPT in patients with CR, ⩾VGPR and ⩾PR, respectively. Similarly, Rd continuous reduced the risk of progression or death by 61%, 54% and 38% vs Rd18 in patients with CR, ⩾VGPR and ⩾PR, respectively. In patients with CR, ⩾VGPR or ⩾PR, 4-year survival rates in the Rd continuous arm (81.1%, 73.1% or 64.6%, respectively) were higher vs MPT (70.8%, 59.8% or 57.2%, respectively) and similar vs Rd18 (76.5%, 67.7% and 62.5%, respectively). Rd continuous improved efficacy outcomes in all responding patients, including those with CR, compared with fixed duration treatment.

We assessed the safety and efficacy of bortezomib, cyclophosphamide and dexamethasone (VCD) induction therapy in previously untreated multiple myeloma patients. A total of 414 patients received three 21-day cycles of VCD prior to autologous stem-cell transplantation (ASCT). Most common grade ≥3 adverse events were leucopenia (31·4%) and thrombocytopenia (6·8%). The overall response rate (ORR) by investigator-based assessment was 85·4%. Most patients (74%) underwent successful central laboratory-based molecular cytogenetic analysis. No clinically relevant differences in ORR post-induction were seen between patients with or without high-risk cytogenetic abnormalities (86·2% vs. 84·3%). Further follow-up data are available for 113 patients receiving ASCT who were included in a prospective consolidation trial (median follow-up, 55·5 months); median progression-free survival (PFS) was 35·3 months and median overall survival (OS) was not reached. In patients with high-risk versus standard-risk cytogenetics, median PFS was 19·9 vs. 43·6 months (P < 0·0001), and median OS was 54·7 months versus not reached (P = 0·0022). VCD is an effective and tolerable induction regimen; results suggest that VCD induces high response rates independently of cytogenetic risk status, but after long-term follow-up, cytogenetic high risk is associated with markedly reduced PFS and OS post-ASCT.