Cancer discovery
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The antibody-drug conjugate T-DM1 spurs immune cells to infiltrate HER2-positive breast tumors in patients. Treating mice that carry breast tumors with T-DM1 improves survival, but the tumors suppress the infiltrating lymphocytes. Combining T-DM1 with checkpoint inhibitors that block CTLA-4 and PD-1 overcomes this effect, eliminating breast tumors from 95% of the mice.
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In the phase II TOPARP-A clinical trial, patients with metastatic castrate-resistant prostate cancer who were treated with the PARP inhibitor olaparib lived nearly three times longer without their cancer worsening if their tumors had mutations in at least one of 12 DNA repair genes. However, physicians say that a larger trial is needed to confirm olaparib's effectiveness against the disease before they start routinely sequencing tumors and prescribing the drug.
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A phase II study indicates that sacituzumab govitecan (IMMU-132), a Trop-2-specific antibody linked to the irinotecan metabolite SN-38, prolongs the progression-free survival of patients with advanced triple-negative breast cancer. IMMU-132 is well tolerated, causing fewer and more manageable side effects than irinotecan.
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Patients with pancreatic and biliary carcinomas lack personalized treatment options, in part because biopsies are often inadequate for molecular characterization. Cell-free DNA (cfDNA) sequencing may enable a precision oncology approach in this setting. We attempted to prospectively analyze 54 genes in tumor and cfDNA for 26 patients. Tumor sequencing failed in 9 patients (35%). In the remaining 17, 90.3% (95% confidence interval, 73.1%-97.5%) of mutations detected in tumor biopsies were also detected in cfDNA. The diagnostic accuracy of cfDNA sequencing was 97.7%, with 92.3% average sensitivity and 100% specificity across five informative genes. Changes in cfDNA correlated well with tumor marker dynamics in serial sampling (r = 0.93). We demonstrate that cfDNA sequencing is feasible, accurate, and sensitive in identifying tumor-derived mutations without prior knowledge of tumor genotype or the abundance of circulating tumor DNA. cfDNA sequencing should be considered in pancreatobiliary cancer trials where tissue sampling is unsafe, infeasible, or otherwise unsuccessful. ⋯ Precision medicine efforts in biliary and pancreatic cancers have been frustrated by difficulties in obtaining adequate tumor tissue for next-generation sequencing. cfDNA sequencing reliably and accurately detects tumor-derived mutations, paving the way for precision oncology approaches in these deadly diseases.
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The BTK inhibitor ibrutinib is preferentially effective in patients with the ABC subtype of DLBCL.