P84.22 Outcomes of TKI Treatment in Patients with NSCLC Harboring Uncommon EGFR Mutations: A Real-World Study in Argentina

Abstract

and other two new lesions in the right upper lobe. One was a 10mm nodule close to the scar of primary tumor, which had not found at chest CT from three months ago. The other was a 15mm nodule apart from the scar, which existed before the alectinib treatment and had got larger gradually. PET-CT revealed the high fluorodeoxyglucose (FDG) uptake of only two new lesions. We performed complete VATS right upper lobectomy and mediastinal lymph node dissection for treatment and diagnosis. Histopathlogical diagnoses: No residual viable cell was found in the primary lesion. The lesion close to the scar of the primary lesion was adenocarcinoma (ALK-rearranged), which was thought to be a recurrent lesion because of resemblance to brain metastasis in pathological tissue. The lesion apart from the main lesion was pT1bN0M0 StageIB squamous cell carcinoma, which was thought to be primary lung cancer. Alectinib was continued after the operation, and chest CT shows no sign of recurrence so far. Conclusion:We experienced a VATS right upper lobectomy for advanced non-small cell lung cancer after ALK-tyrosine kinase inhibitor administration.

Testing for EGFR Mutations and ALK Rearrangements in Advanced Non-Small-Cell Lung Cancer: Considerations for Countries in Emerging Markets

“…Of all EGFR mutations, uncommon EGFR mutations (excluding L858R and ex19del) are detected in 10-20% of cases. 174 Cobas ® EGFR Mutation Test v2 or Therascreen ® qPCR is commonly used to assess EGFR and BRAF mutations. IHC with the D5F3 Ventana IHC kit is used for the assessment of ALK, whereas ROS1 status is determined using the D4D6 signaling antibody.…”

“…175 When considering uncommon EGFR mutations (other than L858R and exon 19 deletion), distribution of tumors comprised exon 18 G719X (46.7%), exon 21 L861Q (24.4%), exon 20 T790M (20%), exon 20 S768I (11.1%), exon 20 insertion (4.4%), and exon 19 pLys745_Ala750del (2.2%). 174 Among patients included in the database review, the most frequent EGFR TKI regimen received was afatinib, followed by erlotinib/gefitinib, and osimertinib. Overall, 22% of tumors were considered complex, defined as ≥2 coexisting and distinct EGFR mutations, and were associated with a significantly better response to first-line EGFR TKI (ORR 90%) than those with single, non-resistant uncommon EGFR mutations (ORR 52%) (p=0.06).…”

“…Similarly, patients with complex mutations showed a better OS (median not reached versus 20.3 months [95% CI, 8.7-31.9], respectively; p=0.04). 174 Private and academic laboratories have different reimbursement systems. Approximately 90% of all molecular tests conducted by private laboratories are supported by the pharmaceutical industry.…”