PIK3CA mutations in primary HER2-positive and triple negative breast cancer.

2013 ◽  
Vol 31 (15_suppl) ◽  
pp. 11061-11061
Author(s):  
Sibylle Loibl ◽  
Carsten Denkert ◽  
Sherene Loi ◽  
Fabrice Andre ◽  
Berit Mueller ◽  
...  

11061 Background: Phosphatidylinositol 3-kinase (PI3K)/AKT pathway aberrations are common in breast cancer (BC), PIK3CA mutations being the most common. Mutations are frequently found in hot-spots located in the helical and kinase domains (exons 9 and 20). Reported data is discrepant with regard to prognostic or predictive value of PIK3CA mutations especially in HER2+ve BC. We therefore investigated the frequency and prognostic associations of PIK3CA mutations in HER2+ve and triple negative (TN) primary BC by treated with neoadjuvant therapy. Methods: We prospectively evaluated PIK3CA mutations in the 595 participants of the neoadjuvant Geparsixto study (NCT01426880). The study investigates the effect of adding carboplatin to a liposomal doxorubicin/taxane combination for the treatment of patients with HER2+ve and TN primary BC. All HER2+ve patients received trastuzumab and lapatinib, the TN patients received bevacizumab. HER2, hormone receptors (HR), and Ki67 were centrally assessed. PIK3CAwas genotyped in tumor material from formalin-fixed, paraffin embedded core biopsies taken before therapy using classical Sanger sequencing of exon 9 and 20. Results: From 09/2011 to 11/2012, 595 patients with HER2+ve or TN primary BC have been randomized in the Geparsixto study. Median age was 47 years (range 21-78); most tumors were cT2 (65%); cN0 (57%); ductal invasive (93%), grade 3 (65%); within the HER2+ve group 28% were HR positive. So far, PIK3CA genotype was evaluated in 395 randomized patients - 176 with HER2+ve and 219 with TN disease. Overall, 11.1% were found to have at least one mutation, in HER2+ve: 18.2% and TN BC: 5.5%. An exon 9 mutation was detected in 6.3% of the HER2+ve and 2.7% of the TNBC cases and an exon 20 mutation in 11.9% of the HER2+ve and 3.6% of the TN cases. A mutation in both exons was detected in 2 TN cases. PIK3CAmutations were more frequent in the HER2+ve/HR+ve compared to the HER2+ve/HR-ve group: 22.8% vs 10.6% respectively (p=0.047). Conclusions: PIK3CAmutations are more frequent in HER2+ve then in TN BC which is in line with previous reports. Results on all 595 patients and the correlation with response to therapy (pCR) will be presented at the meeting. The project has been funded within the EU-FP7 project RESPONSIFY No 278659. Clinical trial information: NCT01426880.

2013 ◽  
Vol 31 (15_suppl) ◽  
pp. 11019-11019 ◽  
Author(s):  
Julia A. Beaver ◽  
Sasidharan Balukrishna ◽  
Danijela Jelovac ◽  
Michaela Jane Higgins ◽  
Stacie Jeter ◽  
...  

11019 Background: PIK3CA is mutated in up to 30% of breast cancers. Classically somatic mutations are identified by Sanger sequencing of the primary tumor specimen. However third generation droplet digital PCR technologies offer a novel platform for quantitative mutation detection with improved sensitivity. Methods: Thirty stage I-III breast cancer patients were consented on an IRB-approved prospective repository study at Johns Hopkins for collection of their primary breast tumor specimen. Formalin-fixed paraffin embedded (FFPE) samples were analyzed by standard sequencing for three PIK3CA hotspot mutations. The DNA from these samples was then analyzed using the RainDrop digital PCR platform with TaqMan probes in a triplex format to simultaneously detect and quantitate hotspot mutations and genome equivalents. Results are expressed as a percentage of mutant to wild-type PIK3CA molecules for each sample. Results: Standard sequencing of all tumors (n=30) identified seven PIK3CA Exon 20 mutations (H1047R) and three Exon 9 mutations (E545K). Samples were scored as PIK3CA mutation positive by digital PCR if the tumor DNA contained at least 5% mutant molecules. All ten mutations identified by sequencing were verified by digital PCR with quantities of mutant molecules ranging from 20.3-55.6% in a given sample. Digital PCR identified additional PIK3CA mutations that were wild type by standard sequencing including three mutant Exon 20 samples, two mutant Exon 9 samples and one sample with an Exon 20 and Exon 9 mutation. Quantities of mutant molecules in these additional samples ranged from 5-28.9%. Conclusions: RainDrop digital PCR offers improved sensitivity and quantification for detecting PIK3CA mutations in FFPE samples using nanograms of DNA. Additional mutations identified by digital PCR may reflect genetic heterogeneity or possibly tissue contamination. The clinical utility of identifying a small proportion of mutations is unknown but may impact eligibility for targeted therapies and clinical trials. Ongoing studies will also address whether the identification of solid tumor mutations in circulating cell-free plasma DNA by digital PCR can improve diagnostics and aid in therapeutic decisions.


2020 ◽  
Vol 52 (3) ◽  
pp. 689-696 ◽  
Author(s):  
Sanxing Guo ◽  
Sibylle Loibl ◽  
Gunter von Minckwitz ◽  
Silvia Darb-Esfahani ◽  
Bianca Lederer ◽  
...  

Purpose<i>PIK3CA</i>, encoding for subunit p110a of phosphatidylinositol 3 kinase, is frequently mutated in breast cancer. <i>PIK3CA</i>mutation was predictive for pathological complete response (pCR) in human epidermal growth factor 2 positive breast cancer. This study explores the association of <i>PIK3CA</i> mutation and pCR in triple-negative breast cancer (TNBC) treated with neoadjuvant chemotherapy.Materials and MethodsA total of 92 patients with TNBC derived from a prospectively randomized phase II trial GeparSixto study (NCT01426880). Exon 9 and exon 20 of <i>PIK3CA</i> mutations were evaluated by using classical Sanger method with formalin-fixed paraffin-embedded tumor tissues.ResultsSeven of 90 tumors (7.8%) were detectable with a <i>PIK3CA</i> H1047R mutation. Overall, <i>PIK3CA</i> H1047R mutation was significantly associated with a lower pCR rate (14.3% vs. 56.6%; odds ratio, 0.128; 95% confidence interval [CI], 0.015 to 1.108; p=0.047). In carboplatin- containing treatment patients, H1047R mutation trended to predict a lower pCR rate (20% vs. 62.5%; p=0.146). In a multivariable analysis, H1047R mutation trended to predict a lower pCR rate (hazard ratio, 0.1; 95% CI, 0.01 to 1; p=0.056).ConclusionTNBC with a <i>PIK3CA</i> H1047R mutation was less likely to achieve pCR after anthracyclinebased neoadjuvant chemotherapy. Development of H1047R mutant selective inhibitors might be helpful to conquer this subtype of breast cancer.


Cancers ◽  
2021 ◽  
Vol 13 (15) ◽  
pp. 3691
Author(s):  
Giulia Cosentino ◽  
Ilaria Plantamura ◽  
Elda Tagliabue ◽  
Marilena V. Iorio ◽  
Alessandra Cataldo

The clinical management of breast cancer reaches new frontiers every day. However, the number of drug resistant cases is still high, and, currently, this constitutes one of the major challenges that cancer research has to face. For instance, 50% of women affected with HER2 positive breast cancer presents or acquires resistance to trastuzumab. Moreover, for patients affected with triple negative breast cancer, standard chemotherapy is still the fist-line therapy, and often patients become resistant to treatments. Tumor microenvironment plays a crucial role in this context. Indeed, cancer-associated stromal cells deliver oncogenic cues to the tumor and vice versa to escape exogenous insults. It is well known that microRNAs are among the molecules exploited in this aberrant crosstalk. Indeed, microRNAs play a crucial function both in the induction of pro-tumoral traits in stromal cells and in the stroma-mediated fueling of tumor aggressiveness. Here, we summarize the most recent literature regarding the involvement of miRNAs in the crosstalk between tumor and stromal cells and their capability to modulate tumor microenvironment characteristics. All up-to-date findings suggest that microRNAs in the TME could serve both to reverse malignant phenotype of stromal cells, modulating response to therapy, and as predictive/prognostic biomarkers.


2021 ◽  
Vol 107 (1_suppl) ◽  
pp. 12-12
Author(s):  
D Aissaoui ◽  
M Bohli ◽  
R Ben Amor ◽  
J Yahyaoui ◽  
A Hamdoun ◽  
...  

Introduction: Inflammatory Breast Cancer (IBC) is a rare and very aggressive breast cancer with poor prognosis. The prevalence is different from a country to another. In Tunisia, it is about 5 to 7% of breast cancer. The aim of this study is to describe the epidemiological and histopathological features of patients with inflammatory breast cancer and to evaluate the treatment response according to the molecular subtypes. Methods: This retrospective review identified 31 patients with no metastatic IBC treated in our radiotherapy department between December 2019 and November 2020. IBC was confirmed using the clinical criteria. Baseline clinic-pathological and treatment information was retrieved from medical records. Statistical analysis was performed with IBM SPSS V.20. Results: Median age was 51.3 years [27-68]. 48% of tumors were grade 3. The average tumor size was 36mm [10-90]. The histological type was ductal carcinoma in 97%. Vascular invasion was noted in 24 patients (77%). Thirty patients were classified as stage IIIB and one patient was IIIC. 74% were hormone receptor positive and 45% were HER2 positive. Luminal B was the predominant subtype (52%) followed by Her2 positive (32%), Luminal A (23%), and triple negative (3%) All patients had chemotherapy: neoadjuvant for 26 patients (84%) and adjuvant for 5 patients (16%). Nine patients (29%) had tumor pathological complete response (pCR). Partial response was observed in 18 patients (58%). Lymph node pCR was noted in 16% of cases (n=5). Endocrine therapy and trastuzumab were given to 76% and 45% of patients, respectively. The influence of the molecular subtype was not statistically significant on the response to neoadjuvant treatment. The highest rate of pCR were 43% for Her2positive, then 27%, 21% and 9% for Luminal B, Luminal A and Triple negative, respectively (p=0.2). Conclusion: Our study showed a high percentage of hormone receptor and Her2+ (74% and 45% respectively) in IBC. Luminal B was the most frequent subtype. Anthracycline-based chemotherapy and trastuzumab improved the pCR rate: 44% for Her2positive. Triple negative showed poorer pCR than other breast cancer subtype without a significant difference. A larger study is warranted to confirm our findings.


Author(s):  
Rupert Bartsch

SummaryOne year into the severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2) pandemic, the 2020 San Antonio Breast Cancer Symposium (SABCS) was another large congress held in a virtual format. Despite these circumstances, clinically relevant data were presented, and this short review focuses on developments in the fields of triple-negative breast cancer (TNBC) and metastatic HER2-positive breast cancer. A quality-of-life (QoL) analysis from IMPassion031 showed that adding atezolizumab to neoadjuvant chemotherapy was not associated with a detrimental effect on QoL, while the burden of treatment-induced side effects increased with each cycle of neoadjuvant therapy in both treatment arms. KEYNOTE-355 evaluated the addition of pembrolizumab to chemotherapy as first-line treatment in metastatic TNBC (mTNBC); a significant improvement of progression-free survival (PFS) was reported in the pembrolizumab arm. At the 2020 SABCS, results with respect to different chemotherapy backbones were reported and the benefit of pembrolizumab was maintained irrespective of the type of taxane. Disappointingly, the phase III IPATunity130 study could not confirm a PFS improvement with the AKT inhibitor ipatasertib when added to paclitaxel as first-line treatment in mTNBC. A biomarker analysis from the phase III ASCENT study showed that the antibody–drug conjugate sacituzumab govitecan was superior to chemotherapy by investigator’s choice independent of Trop‑2 expression and BRCA mutation status. In HER2-positive breast cancer, the PRECIOUS trial suggested a small albeit significant benefit with reinduction of pertuzumab in later treatment lines in patients progressing on prior dual HER2-blockade in the first- or second-line setting. The HER2-specific tyrosine kinase inhibitor tucatinib when added to trastuzumab and capecitabine was shown to improve PFS and overall survival (OS) over trastuzumab and capecitabine alone in pretreated patients in the randomized HER2CLIMB trial; this benefit was apparently independent of hormone-receptor expression. An update from the DESTINY-Breast01 trial reported a median PFS of 19.4 months with trastuzumab deruxtecan in heavily pretreated patients. Finally, an analysis from the PERTAIN trial with > 6 years median follow-up showed excellent OS in patients with luminal B/HER2-positive receiving first-line trastuzumab/pertuzumab in combination with endocrine therapy suggesting that chemotherapy-free treatment is an option in highly selected patients.


2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Fangfang Liu ◽  
Thomas Hardiman ◽  
Kailiang Wu ◽  
Jelmar Quist ◽  
Patrycja Gazinska ◽  
...  

AbstractThe level of stromal tumor-infiltrating lymphocytes (sTILs) in triple-negative (TNBC) and HER2-positive breast cancers convey prognostic information. The importance of systemic immunity to local immunity is unknown in breast cancer. We previously demonstrated that histological alterations in axillary lymph nodes (LNs) carry clinical relevance. Here, we capture local immune responses by scoring TILs at the primary tumor and systemic immune responses by recording the formation of secondary follicles, also known as germinal centers, in 2,857 cancer-free and involved axillary LNs on haematoxylin and eosin (H&E) stained sections from a retrospective cohort of 161 LN-positive triple-negative and HER2-positive breast cancer patients. Our data demonstrate that the number of germinal center formations across all cancer-free LNs, similar to high levels of TILs, is associated with a good prognosis in low TILs TNBC. This highlights the importance of assessing both primary and LN immune responses for prognostication and for future breast cancer research.


Diagnostics ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 416
Author(s):  
Woo Young Sun ◽  
Jina Lee ◽  
Bong Kyun Kim ◽  
Jong Ok Kim ◽  
Joonhong Park

This study aimed to clarify the genetic difference between Korean triple-negative breast cancer (TNBC) and other breast cancer (BC) subtypes. TNBC was defined as the absence of hormonal receptors and human epidermal growth factor receptor 2 (HER2) amplification. DNA panel of the Ion Torrent Oncomine Comprehensive Assay (OCA) v3 was performed to identify somatic alteration in 48 specimens. In a total of 102 alterations (37 nonsense, 35 missense, 8 frameshift and 22 amplifications), 30 nucleotide alterations (24 nonsense, 1 missense, and 5 frameshift) were newly identified. The eight most commonly altered genes were PIK3CA, TP53, ERBB2, BRCA2, FANCD2, AKT1, BRCA1, and FANCA. TNBC had significantly lower mutation frequency in PIK3CA (TNBC vs. hormone receptor-positive and HER2-negative BC [HRPBC], p = 0.009), but higher mutation frequency in TP53 (TNBC vs. HRPBC, p = 0.036; TNBC vs. hormone receptor-positive and HER2- positive BC [HHPBC], p = 0.004). TNBC showed frequently higher Ki-67 expression than any positive BC (p = 0.004) due to HRPBC (p < 0.001). TNBC with high Ki-67/unmutated PIK3CA/mutated TP53 appears at a younger age (52.2 ± 7.6 years), compared to other subtypes (63.7 ± 11.0 years). TNBC with high Ki-67/unmutated PIK3CA/mutated TP53 may be related to relatively early onset BCThese findings demonstrate the genomic heterogeneity between TNBC and other BC subtypes and could present a new approach for molecular targeted therapy in TNBC patients.


2021 ◽  
Vol 14 (7) ◽  
pp. 628
Author(s):  
Shoghag Panjarian ◽  
Jean-Pierre J. Issa

Triple-negative breast cancers (TNBCs) are very heterogenous, molecularly diverse, and are characterized by a high propensity to relapse or metastasize. Clinically, TNBC remains a diagnosis of exclusion by the lack of hormone receptors (Estrogen Receptor (ER) and Progesterone Receptor (PR)) as well as the absence of overexpression and/or amplification of HER2. DNA methylation plays an important role in breast cancer carcinogenesis and TNBCs have a distinct DNA methylation profile characterized by marked hypomethylation and lower gains of methylations compared to all other subtypes. DNA methylation is regulated by the balance of DNA methylases (DNMTs) and DNA demethylases (TETs). Here, we review the roles of TETs as context-dependent tumor-suppressor genes and/or oncogenes in solid tumors, and we discuss the current understandings of the oncogenic role of TET1 and its therapeutic implications in TNBCs.


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