Citations

Abstract The most common adverse event (AE) of dabrafenib and trametinib (DT) is pyrexia, which has been reported to occur in up to 71% of patients. Pyrexia resulted in therapy discontinuation in up to 26% of patients who otherwise were benefiting from the treatment. Little is known about the pathogenesis and optimal management of this common AE. We hypothesized that the etiology of pyrexia in patients treated with DT could be extrapolated from DT-related cutaneous adverse effects in which a paradoxical MAPK pathway activation has been identified. We hypothesized that the mechanism of MAPK pathway activation with DT therapy is similar to that reported in patients with familial Mediterranean fever (FMF), a rare, inherited condition characterized by episodes of fever and rash that responds exceedingly well to colchicine-based therapy. Based on this association, our group explored the use of oral colchicine for the treatment of DT-associated pyrexia in five patients with metastatic melanoma. Citation Format: Jesus Vera, Jonas Paludo, Lisa Kottschade, Matthew Block, Yiyi Yan, Charles Loprinzi, Svetomir Markovic. Dabrafenib-trametinib-induced pyrexia successfully treated with colchicine [abstract]. In: Proceedings of the AACR Special Conference on Targeting RAS-Driven Cancers; 2018 Dec 9-12; San Diego, CA. Philadelphia (PA): AACR; Mol Cancer Res 2020;18(5_Suppl):Abstract nr B15.

Background Linear scleroderma is a rare connective tissue disease characterized by thickening of the skin due to excess collagen deposit. It is the most frequent type of localized scleroderma in the pediatric population (40%–70%), and it usually affects the extremities and head. Linear scleroderma can cause growth disturbances, extremity length discrepancy, and debilitating joint contractures. The aim of this study was to describe the surgical outcomes of microsurgical flap reconstruction of linear scleroderma in the pediatric population. Methods A retrospective review of all children with linear scleroderma was performed at our institution. Patients less than 18 years of age with clinical diagnosis of linear scleroderma and who underwent microsurgical flap reconstruction for correction of their scleroderma were included. Fat grafting procedures were excluded. Patient demographics and surgical outcomes were collected. Results A total 7 patients underwent microsurgical flap reconstruction for treatment of their linear scleroderma producing debilitating soft tissue contractures and preventing ambulation or elbow extension. Six patients had scleroderma involving the lower extremity and 1 involving the upper extremity. Three anterolateral thigh and 4 latissimus dorsi flaps were performed. The median age at surgery was 7 years (Q1–Q3, 5–11), and the median body mass index was 21.3 kg/m2 (Q1–Q3, 16.5–22.1). The median follow-up was 121.1 months (Q1–Q3, 43.2–187.4). All flaps survived, and no donor site complications were reported. Perioperative complications included wound infection that required debridement (n = 1), immediate postoperative bleeding requiring surgical intervention (n = 1), intraoperative venous congestion (n = 1), and scleroderma recurrence outside the flap (n = 2). When comparing anterolateral thigh and latissimus dorsi flaps, there was no statistically significant difference in the development of surgical complications, number of surgical revisions per patient [median, 4 (Q1–Q3, 4–7) vs 2.5 (Q1–Q3, 1.3, 3), P = 0.0916], or unplanned surgical interventions [median, 0 (Q1–Q3, 0–1) vs 1 (Q1–Q3, 0–1), P = 0.7228]. The reconstruction was successful in improving range of motion in 6 patients, 5 of which reached full weight-bearing. However, all patients had residual limb deformity, and 4 had remaining extremity length discrepancy. Conclusions Microsurgical flaps are a good option for functional improvement of severe pediatric linear scleroderma affecting the extremities. However, residual limb deformity is common, and patients are often required to undergo additional surgical revisions.

Abstract While combination radiotherapy (RT) and immunotherapy is not novel there is still much to learn about this approach. Some initial pre-clinical and clinical evidence suggests triple therapy with RT and dual immune checkpoint blockade (anti-CTLA-4 + anti-PD-1/PD-L1) is a complimentary technique. We present two cases using the same novel regime of combination RT plus nivolumab and ipilimumab to treat metastatic melanoma. In both cases the burden of disease was significant within a lower extremity. Additionally, in both cases using this treatment plan, we were able establish sustained local disease control with additional systemic benefit which allowed both patients to avoid significant debility from surgical amputation. Given the response and safety we observed, this technique could be used as a potentially safe approach for future patients who are not eligible for traditional RT palliation or clinical trials.

H. pylori is the most common infection in the world and is associated with gastrointestinal and extra-gastrointestinal manifestations, including peptic ulcer disease, gastrointestinal bleeding, and lymphoproliferative disorders. Despite being discovered less than half a century ago, antibiotic resistance, exacerbated by medication non-adherence and inefficacy of proton pump inhibitors, has grown substantially, explaining the rising incidence of refractory H. pylori infection. In this review, we discuss risk factors, treatment options, surveillance and follow-up, as well as emerging therapies for refractory H. pylori.

Irritable bowel syndrome (IBS) remains one of the most common gastrointestinal disorders seen by clinicians in both primary and secondary care. Since publication of the last British Society of Gastroenterology (BSG) guideline in 2007, substantial advances have been made in understanding its complex pathophysiology, resulting in its re-classification as a disorder of gut-brain interaction, rather than a functional gastrointestinal disorder. Moreover, there has been a considerable amount of new evidence published concerning the diagnosis, investigation and management of IBS. The primary aim of this guideline, commissioned by the BSG, is to review and summarise the current evidence to inform and guide clinical practice, by providing a practical framework for evidence-based management of patients. One of the strengths of this guideline is that the recommendations for treatment are based on evidence derived from a comprehensive search of the medical literature, which was used to inform an update of a series of trial-based and network meta-analyses assessing the efficacy of dietary, pharmacological and psychological therapies in treating IBS. Specific recommendations have been made according to the Grading of Recommendations Assessment, Development and Evaluation system, summarising both the strength of the recommendations and the overall quality of evidence. Finally, this guideline identifies novel treatments that are in development, as well as highlighting areas of unmet need for future research.

As a member of the phylum Cnidaria, the body wall of hydra is organized as an epithelium bilayer (ectoderm and endoderm) with an intervening extracellular matrix (ECM). Previous studies have established the general molecular structure of hydra ECM and indicate that it is organized as two subepithelial zones that contain basement membrane components such as laminin and a central fibrous zone that contains interstitial matrix components such as a unique type I fibrillar collagen. Because of its simple structure and high regenerative capacity, hydra has been used as a developmental model to study cell-ECM interaction during epithelial morphogenesis. The current study extends previous studies by focusing on the relationship of ECM biogenesis to epithelial morphogenesis in hydra, as monitored during head regeneration or after simple incision of the epithelium. Histological studies indicated that decapitation or incision of the body column resulted in an immediate retraction of the ECM at the wound site followed by a re-fusion of the bilayer within 1 hour. After changes in the morphology of epithelial cells at the regenerating pole, initiation of de novo biogenesis of an ECM began within hours while full reformation of the mature matrix required approximately 2 days. These processes were monitored using probes to three matrix or matrix-associated components: basement membrane-associated hydra laminin β1 chain (HLM-β1), interstitial matrix-associated hydra fibrillar collagen (Hcol-I) and hydra matrix metalloproteinase (HMMP). While upregulation of mRNA for both HLM-β1 and Hcol-I occurred by 3 hours, expression of the former was restricted to the endoderm and expression of the latter was restricted to the ectoderm. Upregulation of HMMP mRNA was also associated with the endoderm and its expression paralleled that for HLM-β1. As monitored by immunofluorescence, HLM-β1 protein first appeared in each of the two subepithelial zones (basal lamina) at about 7 hours, while Hcol-I protein was first observed in the central fibrous zone (interstitial matrix) between 15 and 24 hours. The same temporal and spatial expression pattern for these matrix and matrix-associated components was observed during incision of the body column, thus indicating that these processes are a common feature of the epithelium in hydra. The correlation of loss of the ECM, cell shape changes and subsequent de novo biogenesis of matrix and matrix-associated components were all functionally coupled by antisense experiments in which translation of HLM-β1 and HMMP was blocked and head regeneration was reversibly inhibited. In addition, inhibition of translation of HLM-β1 caused an inhibition in the appearance of Hcol-I into the ECM, thus suggesting that binding of HLM-β1 to the basal plasma membrane of ectodermal cells signaled the subsequent discharge of Hcol-I from this cell layer into the newly forming matrix. Given the early divergence of hydra, these studies point to the fundamental importance of cell-ECM interactions during epithelial morphogenesis.

Although the immune checkpoint role of programmed death ligand 1 (PD-L1) has been established and targeted in cancer immunotherapy, the tumor-intrinsic role of PD-L1 is less appreciated in tumor biology and therapeutics development, partly because of the incomplete mechanistic understanding. Here we demonstrate a potentially novel mechanism by which PD-L1 promotes the epithelial-mesenchymal transition (EMT) in triple-negative breast cancer (TNBC) cells by suppressing the destruction of the EMT transcription factor Snail. PD-L1 directly binds to and inhibits the tyrosine phosphatase PTP1B, thus preserving p38-MAPK activity that phosphorylates and inhibits glycogen synthase kinase 3β (GSK3β). Via this mechanism, PD-L1 prevents the GSK3β-mediated phosphorylation, ubiquitination, and degradation of Snail and consequently promotes the EMT and metastatic potential of TNBC. Significantly, PD-L1 antibodies that confine the tumor-intrinsic PD-L1/Snail pathway restricted TNBC progression in immunodeficient mice. More importantly, targeting both tumor-intrinsic and tumor-extrinsic functions of PD-L1 showed strong synergistic tumor suppression effect in an immunocompetent TNBC mouse model. Our findings support that PD-L1 intrinsically facilitates TNBC progression by promoting the EMT, and this potentially novel PD-L1 signaling pathway could be targeted for better clinical management of PD-L1–overexpressing TNBCs.