Introduction: PD-L1 immunohistochemistry (IHC) is being used as a predictive marker of the benefit derived from immunotherapy in several cancer types, including breast cancer. However, the insight gleaned of the prognostic and predictive value of PD-L1 status and its correlation with molecular characteristics during breast cancer progression remains limited.
Methods: We performed an PD-L1 (22C3) assay in pre-treatment primary and metastatic tumor sections from 33 patients with breast carcinoma, matched for post neoadjuvant chemotherapy (p-NACT).
Purpose: The International Ki67 Working Group (IKWG) has developed training for immunohistochemistry (IHC) scoring reproducibility and recommends cut points of ≤ 5% and ≥ 30% for prognosis in ER+, HER2-, stage I/II breast cancer. We examined scoring reproducibility following IKWG training and evaluated these cut points for selecting patients for further testing with the 21-gene Recurrence Score (RS) assay.
Methods: We included 307 women aged 50+ years with node-negative, ER+PR+HER2- breast cancer and with available RS results.
Cnk1 (connector enhancer of kinase suppressor of Ras 1) is a pleckstrin homology (PH) domain-containing scaffold protein that increases the efficiency of Ras signaling pathways, imparting efficiency and specificity to the response of cell proliferation, survival, and migration. Mutated KRAS (mut-KRAS) is the most common proto-oncogenic event, occurring in approximately 25% of human cancers and has no effective treatment. In this study, we show that selective inhibition of Cnk1 blocks growth and Raf/Mek/Erk, Rho and RalA/B signaling in mut-KRAS lung and colon cancer cells with little effect on wild-type (wt)-KRAS cells.
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