“Two mechanisms were involved in the acquired resistance of EGFR TKI for 1 patient, which was uncommon in our practice and from literature review,” Dr Chen told Cancer Therapy Advisor.

“Recently, noninvasive liquid biopsy has developed very quickly; however, we think that liquid biopsy could not replace tissue biopsy in the clinical management of advanced NSCLC with TKI resistance.”

According to Dr Chen, patients with local progression or recurrence would typically receive local therapy such as stereotactic body radiation therapy, ablation, or surgery combined with systemic treatment. However, in the case of their patient with sarcomatoid carcinoma, these approaches would have failed.

“Sarcomatoid carcinoma is not very sensitive to chemotherapy or radiotherapy, and because the performance status of the patients was good, we chose a complete surgical resection and to continue systemic treatment with EGFR TKI,” Dr Chen said, adding that this case can provide significant insight that 2 or more mechanisms of EGFR-TKI resistance may be occurring simultaneously.

“Tissue re-biopsy could not be replaced by liquid biopsy currently and should be performed after the development of resistance to identify the best treatment option for patients,” Dr Chen said.

References

  1. Morgillo F, Della Corte CM, Fasano M, Cierdiello F, et al. Mechanisms of resistance to EGFR-targeted drugs: lung cancer. ESMO Open. Epub 2016 may 11.
  2. Ulrich SL. NCCN Trends™ Highlights: targeted therapy in non-small cell lung cancer. http://www.nccn.org/about/ news/ebulletin/ebulletindetail.aspx?ebulletinid=449/ Accessed August 20, 2017.
  3. Xu S, Liu X, Liu R, et al. Concurrent epidermal growth factor receptor T790M secondary mutation and epithelial-mesenchymal transition in a lung adenocarcinoma patient with EGFR-TKI drug resistance. Thorac Cancer. Epub 2017 Aug 8.