Riess case 1:
A 44-year-old female with relapsed stage IV adenocarcinoma.
- This is a 44-year-old female diagnosed with stage IV adenocarcinoma
- Tissue-based mutation testing showed an EGFR mutation with exon 19 deletion
- She was subsequently treated with afatinib
- After 11 months she became mildly symptomatic with small, nonspecific pulmonary nodules
- Follow up CT scan showed growth of the primary lesion
- The patient reported worsening of her cough
- Cell-free DNA testing was ordered and was negative for both the EGFR driver mutation and for T790M
- Subsequent tissue biopsy showed the presence of T790M
- The patient was switched to osimertinib and continues to respond well to therapy with minimal toxicity