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A solitary bone plasmacytoma is a rare tumor. Intrahepatic cholangiocarcinoma is the second most common primary liver cancer after hepatocellular carcinoma. We present the case of a 48-year-old female patient who consulted for recent back pain, with a final diagnosis of T10 solitary plasmacytoma and synchronous intrahepatic cholangiocarcinoma. Imaging suggested cholangiocarcinoma with bone metastasis. The patient underwent neurosurgical management with laminectomy, arthrodesis, and arthrectomy, with biopsies revealing monotypic kappa plasmacytic proliferation. Liver biopsies revealed an adenocarcinoma with expression of cytokeratin 19, cytokeratin 7, N-cadherin, and high expression of carbonic anydrase IX. The plasmacytoma was treated with external radiotherapy. The cholangiocarcinoma was treated with selective internal radiation therapy and concomitant systemic treatment with combinations of cisplatin and durvalumab, with capecitabine during radiotherapy, switched for gemcitabine after completion of irradiation. One year after initial management, imaging revealed a partial metabolic response of the intrahepatic cholangiocarcinoma, and a complete metabolic response of the plasmacytoma. This case illustrates the importance of not ignoring two primary tumors and the management of two concomitant treatments exploiting potential therapeutic synergies and limiting expected toxicities. [ABSTRACT FROM AUTHOR]

Bladder cancer aggressiveness is correlated with abnormal N-cadherin transmembrane glycoprotein expression. This protein is cleaved by the metalloprotease ADAM10 and the γ-secretase complex releasing a pro-angiogenic N-terminal fragment (NTF) and a proliferation-activating soluble C-terminal fragment (CTF2). Tetraspanin 15 (Tspan15) is identified as an ADAM10-interacting protein to induce selective N-cadherin cleavage. We first demonstrated, in invasive T24 bladder cancer cells, that N-cadherin was cleaved by ADAM10 generating NTF in the extracellular environment and leaving a membrane-anchored CTF1 fragment and that Tspan15 is required for ADAM10 to induce the selective N-cadherin cleavage. Targeting N-cadherin function in cancer is relevant to preventing tumor progression and metastases. For antitumor molecules to inhibit N-cadherin function, they should be complete and not cleaved. We first showed that the GW501516, an agonist of the nuclear receptor PPARβ/δ, decreased Tspan15 and prevented N-cadherin cleavage thus decreasing NTF. Interestingly, the drug did not modify ADAM10 expression, which was important because it could limit side effects since ADAM10 cleaves numerous substrates. By targeting Tspan15 to block ADAM10 activity on N-cadherin, GW501516 could prevent NTF pro-tumoral effects and be a promising molecule to treat bladder cancer. More interestingly, it could optimize the effects of the N-cadherin antagonists those such as ADH-1 that target the N-cadherin ectodomain. [ABSTRACT FROM AUTHOR]

Personalized medicine represents a major goal in oncology. It has its underpinning in the identification of biomarkers with diagnostic, prognostic, or predictive values. Nowadays, the concept of biomarker no longer necessarily corresponds to biological characteristics measured ex vivo but includes complex physiological characteristics acquired by different technologies. Positron-emission-tomography (PET) imaging is an integral part of this approach by enabling the fine characterization of tumor heterogeneity in vivo in a non-invasive way. It can effectively be assessed by exploring the heterogeneous distribution and uptake of a tracer such as 18F-fluoro-deoxyglucose (FDG) or by using multiple radiopharmaceuticals, each providing different information. These two approaches represent two avenues of development for the research of new biomarkers in oncology. In this article, we review the existing evidence that the measurement of tumor heterogeneity with PET imaging provide essential information in clinical practice for treatment decision-making strategy, to better select patients with poor prognosis for more intensive therapy or those eligible for targeted therapy. [ABSTRACT FROM AUTHOR]