A case of advanced biliary tract cancer with EGFR amplification that
responded to Necitumumab and post-treatment resistance changes detected
by liquid biopsy
Abstract
Background: Recent advances in cancer genome analysis and the
practice of precision medicine have made it possible to identify
fractions with rare genetic alterations. EGFR-amplified cancers
are known to be rare fractions across organs and have a poor prognosis.
The use of anti-EGFR antibody for EGFR-amplified cancers has been
promising, but the evidence is not yet clear. Case: In this
report, we describe the case of a 48-year-old man diagnosed with
advanced gallbladder cancer. The patient was administered Gemcitabine
plus Cisplatin, followed by S-1 monotherapy; however, disease
progression was observed after two cycles of each regimen. Comprehensive
genomic profiling test revealed EGFR-amplification, and the
patient was treated with combination therapy with the anti-EGFR antibody
Necitumumab, Gemcitabine, and Cisplatin. After two cycles of treatment,
showed a reduction in tumor size, and the treatment response was
evaluated as partial response. On day 90, after five cycles of
treatment, tumor progression was confirmed. In addition, after disease
progression, liquid biopsy revealed acquired pathogenic gene alterations
suggesting anti-EGFR antibody resistance. Conclusions: This
report supports the clinical benefit of anti-EGFR antibody for
EGFR-amplified biliary tract cancers and the importance of
genomic analysis in personalized therapy and drug resistance research.