Metastatic triple-negative breast cancer patient with TP53 tumor mutation experienced 11 months progression-free survival on bortezomib monotherapy without adverse events after ending standard treatments with grade 3 adverse events.

Authors:
Tobias Meißner, Adam Mark, Casey Williams, Wolfgang E Berdel, Stephanie Wiebe, Andrea Kerkhoff, Eva Wardelmann, Timo Gaiser, Carsten Müller-Tidow, Philip Rosenstiel, Norbert Arnold, Brian Leyland-Jones, Andre Franke, Martin Stanulla, Michael Forster
Year of publication:
2017
Volume:
3
Issue:
4
Issn:
2373-2873
Journal title abbreviated:
Cold Spring Harb Mol Case Stud
Journal title long:
Cold Spring Harbor molecular case studies
Abstract:
A triple-negative breast cancer patient had no hereditary BRCA1, BRCA2, or TP53 risk variants. After exhaustion of standard treatments, she underwent experimental treatments and whole-exome sequencing of tumor, blood, and a metastasis. Well-tolerated experimental bortezomib monotherapy was administered for a progression-free period of 11 mo. After progression, treatments were changed and the exome data were evaluated, expanded with RNA and exome sequencing of a late-stage metastasis. In the final stage, eribulin alone and in combination with anthracyclines were administered. While suffering from grade 3 adverse events, skin metastases progressed. She lived 51 mo after initial diagnosis.Toxicity from anthracyclines and cisplatin may have been due to associated germline variants CBR3 C4Y and V224M and GSTP1 I105V, respectively. Somatic mutations predicted or reported as pathogenic were detected in 38 genes in tumor tissues. All tumor samples harbored the heterozygous TP53 Y220C variant, known to destabilize p53 and down-regulate p53-mediated apoptosis. The success of bortezomib may be explained by the previously reported up-regulation of caspase-mediated apoptosis, which is p53-independent. Phylogenetic analysis of blood, primary tumor, and two metastases inferred an ancestral tumor cell with 12 expressed tumor mutations from which all three tumors may have evolved.Although our first urgent analysis could only include 40 genes, postmortem analysis uncovered the aggressiveness and suggested experimental therapies including 16 actionable targets, partly validated by immunohistochemistry. Exome and transcriptome analyses yielded comprehensive therapy-relevant information and should be considered for patients at first diagnosis.