Resistance to trastuzumab in patients with HER2-overexpressing breast cancer is associated with higher risk of progression or cancer death, and might be related to activation of PI3K/AKT/mTOR and Ras/Raf/MAPK signaling cascades and a decreased level of their inhibitor (PTEN). HER2-overexpressing breast cancer patients (n = 75) treated with radical local therapy and trastuzumab in adjuvant setting were included into the study. Deoxyribonucleic acid isolated from paraffin sections was used to assess mutational status of the PIK3CA gene (p.H1047R and p.E545K mutations) by the quantitative polymerase chain reaction technique. Expression of selected proteins (ER, PgR, AR, Ki-67, EGFR) was assessed using immunohistochemistry. In the studied group we found significantly higher Ki-67LI in EGFR-positive carcinomas (p = 0.048). Moreover, EGFR immunonegativity was observed more frequently in low-grade (G1/G2) carcinomas as well as in estrogen/progesterone and androgen receptor immunopositive tumors (p = 0.042, p = 0.016, p = 0.044, respectively). Favorable metastasis-free survival was observed in patients with pN0 and pN1 (vs. pN2+3) stage (p = 0.040) and with tumors characterized by low Ki-67LI (≤ 50% vs. > 50%) (p = 0.014). Patients with tumor androgen receptor immunonegativity (weak or lack of expression) or strong PTEN expression survived 3 years without metastases (p = 0.007). The results of our study suggest that androgen receptor and PTEN status might be considered as indicators of trastuzumab sensitivity.
BackgroundThe aim of the study was to investigate if parameters associated with human epidermal growth factor receptor type 2 (HER2) status (HER2 gene copy number, HER2/CEP17 ratio or polysomy of chromosome 17) are related to various biological features potentially responsible for trastuzumab resistance (PTEN, IGF-1R, MUC4, EGFR, HER3, HER4, and mutation status of PIK3CA) as well as their influence on survival of HER2-positive breast cancer patients treated with adjuvant chemotherapy and trastuzumab.Patients and methodsThe investigated group consisted of 117 patients with invasive ductal breast cancer (T≥1, N≥0, M0) with overexpression of HER2, who underwent radical surgery between 2007 and 2014. Status of ER, PR, and HER2 expression was retrieved from patients’ files. HER2 gene copy number was investigated by fluorescence in situ hybridization using PathVysion HER-2 DNA Probe Kit II. Expression of PTEN, IGF-1R, MUC4, EGFR, HER3, and HER4 was assessed immunohistochemically on formalin-fixed paraffin-embedded tissue sections. PIK3C mutation status was determined by qPCR analysis.ResultsOverexpression of HER2 protein (IHC 3+) and ER negativity corresponded to higher HER22 copy number and HER2/CEP17 ratio (.<0.001). Tumors with polysomy were characterized by higher HER22 gene copy number but lower HER2/CEP17p ratio (p<0.026, p<0.001). Patients with tumors featuring HER3 immunonegativity or low HER2/CEP17 ratio (#4) were characterized by 100% metastasis-free survival (.=0.018, p=0.062).ConclusionPresence of both unfavorable factors, ie, HER3 expression and high HER2/CEP17 ratio, allowed to distinguish a group of patients with worse prognosis (.=0.001).
Aim: Resistance to trastuzumab (which is a standard therapy for breast cancer patients with HER2 overexpression) is associated with higher risk of progression or cancer death, and might be related to activation of signalling cascades (PI3K/AKT/mTOR, Ras/Raf/MAPK) and decreased level of their inhibitors.Material and methods: Formalin-fixed paraffin-embedded tumour specimens from 118 HER2-overexpressing breast cancer patients treated with radical local therapy and trastuzumab in adjuvant setting were used for the assessment of: (1) PIK3CA gene mutations (p.H1047R and p.E545K) by qPCR, and (2) expression of Ki-67, EGFR, MUC4, HER3 and PTEN by immunohistochemistry.Results: Lower Ki-67LI was observed in EGFR-immunonegative and in PTEN-immunopositive tumours. MUC4-immunonegative tumours more frequently were PTEN- and HER3-immunonegative. Favourable metastasis-free survival was observed in patients with tumours characterized by Ki-67LI≤50% (p=0.027), HER3 immunonegativity or PTEN immunopositivity (vs. tumours with HER3 expression and lack of PTEN expression, p=0.043), additionally, the trend was observed for patients with pN0+pN1 pathological tumour stage (vs. pN2+pN3) (p=0.086). Cox model revealed that independent negative prognostic factors were: (i) Ki-67LI>50% (p=0.014, RR=4.6, 95% CI 1.4-15.4), (ii) HER3 immunopositivity together with PTEN immunonegativity (p=0.034, RR=3.7, 95% CI 1.1-12.5).Conclusion: The results of our study suggest that combined analysis of HER3 and PTEN expression might bring information on trastuzumab sensitivity in the group of HER2-positive breast cancer patients treated with trastuzumab in adjuvant setting.
BackgroundRarity and heterogeneity of liposarcomas (LPS) make their diagnosis difficult even for sarcoma-experts pathologists. The molecular mechanism underlying the development and progression of liposarcomas (LPS) remains only partially known. In order to identify and compare the genomic profiles, we analyzed array-based comparative genomic hybridization (array-CGH) profiles of 66 liposarcomas, including well-differentiated (WDLPS), dedifferentiated (DDLPS) and myxoid (MLPS) subtypes.ResultsCopy number aberrations (CNAs) were identified in 98% of WDLPS and DDLPS and in 95% of MLPS cases. The minimal common region of amplification at 12q14.1q21.1 was observed in 96% of WDLPS and DDLPS cases. Four regions of CNAs, including losses of chromosome 6, 11 and 13 and gains of chromosome 14 were classified as recurrent in DDLPS; at least one was identified in 74% of DDLPS tumors. The DDLPS-associated losses were much more common in tumors with increased genomic complexity. In MLPS, the most frequent CNAs were losses of chromosome 6 (40%) and gains of chromosome 1 (30%), with the minimal overlapping regions 6q14.1q22.31 and 1q25.1q32.2, respectively.ConclusionsOur findings show that the application of array-CGH allows to delineate clearly the genomic profiles of WDLPS, DDLPS and MLPS that reflect biological differences between these tumors. Although CNAs varied widely, the subtypes of tumors have characteristic genomic profiles that could facilitate the differential diagnosis of LPS subtypes, especially between WDLPS and DDLPS.Electronic supplementary materialThe online version of this article (doi:10.1186/s13039-017-0309-5) contains supplementary material, which is available to authorized users.
INI1 antigen is a product of the INI-1/SMARCB1 gene localized on chromosome 22q. It is well known that INI1 gene inactivation or loss of INI1 antigen expression is observed in epithelioid sarcomas; however, there are only few reports concerning specificity and sensitivity of immunohistochemical INI1 labeling as a marker of this neoplasm. That is why we decided to test 99 soft tissue sarcomas for the presence of the INI1 gene product. More specifically, the analyzed group consisted of 33 synovial sarcomas, 14 fibrosarcomas, 8 desmoid tumors, 8 DFSPs, 5 MPNSTs, 9 epithelioid sarcomas, 11 Ewing sarcomas/PNETs, 9 rhabdomyosarcomas and 2 clear cell sarcomas. Additionally, 7 malignant melanomas and 9 adenocarcinomas were included into the study. Positive staining with an antibody against the INI-1 gene product was observed in all studied cases of MPNST, Ewing sarcoma/PNET, rhabdomyosarcoma, malignant melanoma, clear cell sarcoma, and adenocarcinoma. On the contrary, none of 9 epithelioid sarcomas was labeled. The loss of INI1 expression was also detected in 7 (21.2%) synovial sarcomas, confirmed cytogenetically or by FISH. Considering the lack of reaction with INI-1 antibody as a diagnostic test for epithelioid sarcoma we estimated that its sensitivity reached 100% and specificity -83.5% (p < 0.0001).
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.