BACKGROUND Although common in lung cancer,somatic epidermal growth factor receptor(EGFR)mutations are rarely found in colorectal cancer,occurring in approximately 3%of cases.Treatment with anti-EGFR antibodies is comm...BACKGROUND Although common in lung cancer,somatic epidermal growth factor receptor(EGFR)mutations are rarely found in colorectal cancer,occurring in approximately 3%of cases.Treatment with anti-EGFR antibodies is commonplace,but EGFR tyrosine kinase inhibitors are not standard treatments in colorectal cancer.Here we report a case of sustained response to osimertinib in a colorectal cancer patient with an EGFR T790M mutation on cell-free DNA analysis.CASE SUMMARY A 72-year old woman with a past medical history of post-polio syndrome confined to a wheelchair,scoliosis and hypothyroidism presented with metastatic sigmoid colon adenocarcinoma with hepatic metastases.Next generation sequencing revealed a RAS/RAF wild-type,microsatellite stable,PD-L1 negative malignancy.Mutations in TP3 and APC were also identified,as well as EGFR amplification.Cell-free DNA analysis revealed an EGFR T790M mutation.She was unable to tolerate first-line treatment with panitumumab,5-fluorouracil and leucovorin,progressed on second-line treatment with trifluridine/tipiracil plus bevacizumab,and was unable to tolerate third-line treatment with regorafenib.She was started on fourth-line treatment with off-label osimertinib,with clinical response–decrease in size of hepatic metastases and a pericardial effusion.She remained on treatment with osimertinib for seven months.CONCLUSION This case shows the benefit of multi-gene sequencing assays to identify potential therapeutic options in patients with refractory disease.展开更多
文摘BACKGROUND Although common in lung cancer,somatic epidermal growth factor receptor(EGFR)mutations are rarely found in colorectal cancer,occurring in approximately 3%of cases.Treatment with anti-EGFR antibodies is commonplace,but EGFR tyrosine kinase inhibitors are not standard treatments in colorectal cancer.Here we report a case of sustained response to osimertinib in a colorectal cancer patient with an EGFR T790M mutation on cell-free DNA analysis.CASE SUMMARY A 72-year old woman with a past medical history of post-polio syndrome confined to a wheelchair,scoliosis and hypothyroidism presented with metastatic sigmoid colon adenocarcinoma with hepatic metastases.Next generation sequencing revealed a RAS/RAF wild-type,microsatellite stable,PD-L1 negative malignancy.Mutations in TP3 and APC were also identified,as well as EGFR amplification.Cell-free DNA analysis revealed an EGFR T790M mutation.She was unable to tolerate first-line treatment with panitumumab,5-fluorouracil and leucovorin,progressed on second-line treatment with trifluridine/tipiracil plus bevacizumab,and was unable to tolerate third-line treatment with regorafenib.She was started on fourth-line treatment with off-label osimertinib,with clinical response–decrease in size of hepatic metastases and a pericardial effusion.She remained on treatment with osimertinib for seven months.CONCLUSION This case shows the benefit of multi-gene sequencing assays to identify potential therapeutic options in patients with refractory disease.
