Colorectal cancer (CRC) is the third most commonly diagnosed cancer worldwide and clinical outcome has improved substantially during the last two decades with targeted therapies. The immune system has a major role in cancers, especially the CD8 + T cells specific to tumor antigens. However, tumors can escape immune response by different mechanisms including upregulation of inhibitory immune checkpoint receptors, such as well-known Programmed cell Death protein-1 (PD-1)/Programmed cell Death Ligand 1 (PD-L1) interaction, leading CD8 + T cells to a state of anergy. Immunotherapy, with the so-called immune checkpoint inhibitors (CPIs), has recently been approved in treatment of multiple cancers due to its prolonged disease control and acceptable toxicities. The recent groundbreaking success involving anti-PD-1 CPIs in metastatic CRC with deficient mismatch repair system (dMMR) is promising, with several trials ongoing. Major challenges are ahead in order to determine how, when and for which patients we should use these CPIs in CRC. Areas covered: This review highlights some promises and challenges concerning personalized immunotherapy in CRC. First results and ongoing breakthrough trials are presented. The crucial role of biomarkers in selecting patient is also discussed. Expert opinion: As of now, dMMR and POLE mutations (DNA polymerase ε) with ultramutator phenotype are the most powerful predictive biomarkers of CPI efficacy. The most challenging issue is pMMR mCRC and determination of how to convert a 'nonimmunogenic' neoplasm into an 'immunogenic' neoplasm, a combination of CPIs with radiation or MEK inhibitor probably being the most relevant strategy. Next-generation sequencing (NGS) assays to quantify mutational load could be more reliable predictive biomarkers of CPIs efficacy than PD-L1 expression or immune scores.

Background: Colorectal cancers (CRC) with brain metastases (BM) are scarcely described. The main objective of this study was to determine the molecular profile of CRC with BM. Methods: We included 82 CRC patients with BM. KRAS, NRAS, BRAF and mismatch repair (MMR) status were investigated on primary tumors (n = 82) and BM (n = 38). ALK, ROS1, cMET, HER-2, PD-1, PD-L1, CD3 and CD8 status were evaluated by immunohistochemistry, and when recommended, by fluorescence in situ hybridization. Results: In primary tumors, KRAS, NRAS and BRAF mutations were observed in 56%, 6%, and 6% of cases, respectively. No ROS1, ALK and cMET rearrangement was detected. Only one tumor presented HER-2 amplification. Molecular profiles were mostly concordant between BM and paired primary tumors, except for 9% of discordances for RAS mutation. CD3, CD8, PD-1 and PD-L1 expressions presented some discordance between primary tumors and BM. In multivariate analysis, multiple BM, lung metastases and PD-L1+ tumor were predictive of poor overall survival. Conclusions: CRCs with BM are associated with high frequency of RAS mutations and significant discordance for RAS mutational status between BM and paired primary tumors. Multiple BM, lung metastases and PD-L1+ have been identified as prognostic factors and can guide therapeutic decisions for CRC patients with BM.

No abstract

Desmoplastic small round-cell tumor is a rare but highly aggressive tumor occurring mainly in adolescents and young adults. Prolonged progression-free survival has been documented in patients who have undergone aggressive multimodality therapy - that is, multiagent intensive chemotherapy, debulking surgery, and radiation therapy. Eribulin is a microtubule-dynamics inhibitor, and it has recently been shown to be active in liposarcomas. In preclinical models, eribulin activities have also been shown to occur in Ewing's sarcoma cell lines, rhabdomyosarcomas and osteosarcomas. In this study, we report three cases of male patients suffering from desmoplastic small round-cell tumor and the clinical response to eribulin in two of them.