Invasive lobular carcinoma (ILC) is the second most common subtype of breast cancer after invasive breast cancer of no special type (IBC-NST). This retrospective analysis of the MINDACT trial investig Show more
Invasive lobular carcinoma (ILC) is the second most common subtype of breast cancer after invasive breast cancer of no special type (IBC-NST). This retrospective analysis of the MINDACT trial investigated transcriptomic differences between estrogen receptor-positive/HER2-negative (ER+/HER2-) ILC versus ER+/HER2- IBC-NST, classic and non-classic ER+/HER2- ILC, and, recurring and non-recurring ER+/HER2- ILC in patients with a low genomic risk and either a low (cL/gL) or high clinical risk (cH/gL). We analyzed 4261 ER+/HER2- tumors (63.7%, 464 ILC, 3798 IBC-NST) with central pathology review. Differential gene expression analysis was adjusted for age and grade, followed by gene set enrichment analysis. Adjusted regression models evaluated associations of transcriptomic profiles with disease-free (DFS) and distant recurrence-free survival (DRFS). An increased expression of CDH1 (E-cadherin) in IBC-NST compared to ILC was observed. ILC showed more uptake of extracellular lipid sources (LPL, CD36, LEP, LEPR), while IBC-NST favored lipid synthesis (FASN). Decreased ER-signaling, increased PI3K/Akt-signaling, and differences related to the extracellular matrix was also observed in ILC. Classic and non-classic ILC differed subtly, notably in cell cycle regulation. In ER+/HER2- ILC patients with a cL/gL risk, enrichment of apoptosis, inflammatory response, hypoxia and oncogenic signaling (PI3K/Akt, Ras, c-Myc) was associated with worse survival. In contrast, in the cH/gL group, associations between ILC transcriptomic features and survival were more subtle. This represents the largest transcriptomic dataset for ILC from a clinical trial with central histology review. Findings may provide insights to refine treatment and relapse risk assessment for ILC patients. Show less
As dual-specificity phosphatase (DUSP) expression has been correlated to sensitivity to MEK inhibitors, DUSP expression levels may indicate activation of the mitogen-activated protein kinase (MAPK) pa Show more
As dual-specificity phosphatase (DUSP) expression has been correlated to sensitivity to MEK inhibitors, DUSP expression levels may indicate activation of the mitogen-activated protein kinase (MAPK) pathway in many tumor types. In this study, we investigate if DUSP levels can indicate different levels of MAPK activation within colorectal cancer (CRC) patients. In three different CRC patient microarray datasets, we analyzed the expression of DUSP1. DUSP4 and DUSP6 according to mutational status, their correlation with survival and their association with different clinical characteristics. DUSP4 was significantly differentially expressed between all mutational subgroups with the highest expression in BRAF mutated tumors. Moreover, high DUSP4 expression was associated with a worse overall survival and with clinical characteristics typical for BRAF mutant patients. The use of DUSP expression as a predictive biomarker towards MAPK targeted therapy in CRC patients needs further investigation. Show less