| LUNG CANCER HARB ORING HER2 MUTATION :EPIDE MIOLOGI CAL CHARACTE RISTICS AND  Z7 V! }& j( P* g) i; | THERAPE UTIC PERSPECTIVES6 ^9 }* `7 E! s+ O  a2 g
 J. Mazieres, S. Peters  _" k$ m; d2 }/ X
 Introduction: HER2 oncogene is a memb er of the EGFR family, encoding atransmembrane receptor that drives and regulates cell proliferation. HER2 mutations are identified in about 2% of non small cell lung cancer (NSCLC) , mainly located in exon 20, and appear to be critical for lung cancer carcinogenesis . Very scarce data are available to define a clinical profile of the patients harboring HER2 mutated NSCLC. We aimed to study clinic opatholog ical characteristics an d therapeutic; r0 z, x$ Q2 S1 }* z0 d, ?+ _- N
 outcomes of patients harboring HER2 mutation in a large European series. Result s:We retrospec tively ide ntified 46 NSCLC patients diagn osed with HER2 exon 20 mut ation. HER2 mutation was mainly exclusive as only one concomitan t KRas mutation was des cribed. Our population was characterized by a median age of 60 yr (31 to 86 yr), a high proportion of women (30 vs. 16 men, 65% ), and of never smokers (24, 52%). All tumors were adenoc arcinomas (two with lepidic features). Half of the patients had stage IV dise ase at the time of diagnosis. HER2 targeted7 I; E/ M4 f( r' I- @9 f
 treatment was delivered after convention al chemothe rapy. A total of 20 anti-Her2
 : R9 `" i$ @% }! y; u+ q9 Etreatments were eval uable. We observed 4 progressive dise ases, 7 disease stabilizations0 p! n; l* z8 S, u$ q0 G
 and 9 partial resp onses according to RECIST 1.1 (overall response rate ORR = 45% ;: p5 @/ ?& |1 O2 ^7 C2 T  J& P
 disease control rate DCR = 80%). Specifica lly, we obse rved a DCR of 92% for
 2 S) v2 l" {7 ?4 Xtrastuzum ab-based therapie s (n = 14), 100 % for afatinib (n = 3) but no response to: |1 f3 C4 m- X$ e8 x- {
 lapatinib (n = 2) and to a multiTKI (n = 1). Median survival was of 68.2 months and1 {  j* M5 k: q" _! ?. u& O
 22.9 months for respectively early stage and stag e IV patients.
 5 ?8 }. {" e' V) t0 NConclusion: This study, the largest to date dedic ated to HER2 mutated NSCLC,
 ( L& R% W' _& U% S: U. g8 preinforces the importance of an HER2 screening strategy in lung adenoc arcinomas .
 5 L7 c, V2 s. a4 V. ]: BHER2-target ed drugs shou ld be tested further, ide ally withi n large collaborative# |5 C1 [( e& M" }0 B% r; F
 clinicaltrials.
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