Breast cancer Flashcards
HER2 path
HER2-PI3K-AKT-mTOR-ER
ER-positive mutations
PI3K (36%), AKT, HER2, ESR1, FGFR1 (11%)
PI3K
36% of Breast ca (65% have one of the classic aberrations PI3K, AKT, ESR1, etc.)
Pertuzumab mechanism
Binds to HER2 preventing dimerization of HER3
CLEOPATRA study
first line pertuz/tras/doce v. tras/doce –> 6.1mo improvement in PFS, 15.7mo improvement in OS (median 56.5mo). If you remove PI3K mutants, survival doubles
T-DM1 mechanism
binding, internalization, release of emtansine, block microtubules
EMILIA study
T-DM1 v. lapatinib/cape, n=991, OS 30.9 v. 25 mo
TH3RESA study
3rd line T-DM1 v. Tras+chemo–>, PFS 6.2 v 3.2 mo
MARIANNE study
T-DM1 v +pertuz v. tras/taxane for first line–> NONINFERIOR
Mechanisms of ER-resistance
ERa mutations–>increased to 22%, make receptors ligand-independent
Fulvestrant mechanism
ER binding and degradation. however residual receptor found in 38% of patients
SERD
selective estrogen receptor degrader (ARN-810/GDC-0810) with complete receptor silencing.
mTOR signaling
cross-talk with ER.
everolimus
not very active in PI3Ka mutants (36% of pts)
PI3K subtypes
alpha-specific-breast (BYL719, GDC-0032); delta/gamma-important for lymphoid
PI3Ka blocking
when you block, ERa signaling is reactivated, therefore you may have to combine with fulvestrant
ERBB2 mutations
neratinib,
CDK4 signaling
regulates cells into S-phase, important for ER-positive; pablociclib + letrozole v. letrozole–> 20 v. 10 month PFS (randomized non-blinded phase 2)
luminal A
50%, bone/soft tissue, indolent, endocine
luminal B
HER+ER+’s, or high Ki67, visceral