Systematic tissue collection during clinical breast biopsy is feasible, safe and enables high-content translational analyses

Systematic collection of fresh tissues for research at the time of diagnostic image-guided breast biopsy has the potential to fuel a wide variety of innovative studies. Here we report the initial experience, including safety, feasibility, and laboratory proof-of-principle, with the collection and analysis of research specimens obtained via breast core needle biopsy immediately following routine clinical biopsy at a single institution over a 14-month period. Patients underwent one or two additional core biopsies following collection of all necessary clinical specimens. In total, 395 patients were approached and 270 consented to the research study, yielding a 68.4% consent rate. Among consenting patients, 238 lesions were biopsied for research, resulting in 446 research specimens collected. No immediate complications were observed. Representative research core specimens showed high diagnostic concordance with clinical core biopsies. Flow cytometry demonstrated consistent recovery of hundreds to thousands of viable cells per research core. Among a group of HER2 + tumor research specimens, HER2 assessment by flow cytometry correlated highly with immunohistochemistry (IHC) staining, and in addition revealed extensive inter- and intra-tumoral variation in HER2 levels of potential clinical relevance. Suitability for single-cell transcriptomic analysis was demonstrated for a triple-negative tumor core biopsy, revealing substantial cellular diversity in the tumor immune microenvironment, including a prognostically relevant T cell subpopulation. Thus, collection of fresh tissues for research purposes at the time of diagnostic breast biopsy is safe, feasible and efficient, and may provide a high-yield mechanism to generate a rich tissue repository for a wide variety of cross-disciplinary research.

Retrospective comparisons of nanoparticle albumin-bound paclitaxel and docetaxel neoadjuvant regimens for breast cancer

Aim: To compare the efficacy and safety of 2-weekly nanoparticle albumin-bound paclitaxel (nP) and 3-weekly docetaxel regimens as neoadjuvant systemic therapy (NST) for breast cancer. Materials & methods: Patients (n = 201) received NST comprising either dose-dense epirubicin and cyclophosphamide followed by 2-weekly nP (n = 104) or 3-weekly courses of epirubicin and cyclophosphamide followed by docetaxel (n = 97). Results: Higher pathological complete response rates were achieved by the nP group. Subgroup analysis showed that the nP-based regimen achieved higher pathological complete response rates in patients with triple-negative tumor cells and high Ki67 levels. However, grades 3–4 peripheral sensory neuropathies were more frequent in the nP group. Conclusion: The 2-weekly nP-based regimen might be a better choice of NST for patients with breast cancer.

PROSPECTS FOR INCREASING THE EFFICIENCY OF TREATMENT OF PATIENTS HEAVING OF LOCALLY- DISTRIBUTED BREAST CANCER

Improving the efficiency of treatment of locally distributed forms of breast cancer (BC) patients is relevant. The aim of the study: to determine the possibility of increasing the efficiency of treatment of patients with locally distributed BC by supplementing it with the determination of the expression of TOP2 alpha and beta-tubulin III genes in the primary tumor during various chemotherapy regimens. Method. 139 patients with locally distributed BC were examined. Patients received 2-4 courses of neoadjuvant chemotherapy (NAChT) according to the TC (docetaxel + cyclophosphamide) and TAC (docetaxel + doxorubicin + cyclophosphamide) regimens, subsequent surgical intervention and 2–4 courses of AchT according to the FAC regimen. Immunohistochemical (IHCh) study of the levels of estrogen receptors (ER), progesterone (PR), epidermal growth factor (HER2) in tumors was conducted. The expression of TOP2 alpha and beta-tubulin class III genes was determined using PCR. Statistical data processing was performed using the program Stastistica for Windows 6. 0, Excel. Results. In the third cycle of chemotherapy, patients were transferred from the TC scheme to the TAC scheme. The frequency of the FPR increased 4 times in the group of patients with a triple negative tumor subtype compared with patients with luminal B. A combination of low expression of the class III beta-tubulin gene with high expression of TOP2 alpha in tumor tissue was found in 64.5 % of patients treated according to the TAC + cross over regimen and in 56.3 % of cases according to the TC regimen. A change in the receptor status of MLN after NAChT was detected in some cases. Conclusions. The combination of high expression of TOP2 alpha with low expression of class III beta-tubulins can be considered as a predictive sign of full pathomorphological response when using taxane-containing locally distributed BC. These markers can be recommended for determination in MLN (along with definition of ER, PR, HER2) in order to increase the effectiveness of AchT.

REVIEW ON POTENTIAL TARGETED THERAPY FOR TRIPLE NEGATIVE BREAST CANCER

Triple negative breast cancer (TNBC) is a very aggressive type of cancer. TNBC is not just a single type of disease to be cured, but it consists of 6 subtypes which are basal-like 1 and 2, immunomodulatory, mesenchymal, mesenchymal stem- like and luminar androgen receptor. These subtypes has diverse characteristics, which hold potential opportunity for targeted treatment. Lack of molecular targets for triple negative tumor lead to limited targeted therapies for TNBC. Therefore, effective targeted therapies are urgently needed for TNBC. This paper will highlight on the potential targets in TNBC and treatment options that are currently under clinical application.

Development of a drug repressible β-catenin mutant mouse to examine effect of activated β-catenin signaling on long-term maintenance of mammary tumor growth

Stabilized β-catenin expression is a well described initiator of mammary tumorigenesis in the mouse and elevated nuclear expression of this protein has been observed in human triple-negative tumor samples. However, the importance of stabilized β-catenin to continued tumor growth after initiation, and in the context of other driver mutations, has yet to be elucidated. To ascertain the importance of stabilized β-catenin after tumor initiation, we generated a novel transgenic mouse model, utilizing the tet-off system, to control expression of a stabilized mutant of β-catenin. Pups from early litters carrying one allele of regulatable stabilized β-catenin at the Rosa26 locus, but not targeted by Cre, were smaller in size compared with wildtype littermates and also developed skin lesions, requiring euthanasia. Maintenance of breeding cages on doxycycline chow allowed for healthy transgenic pups to survive past 3 weeks of age and 6 animal cohorts were established. We used two different mammary Cre strains, WAP-Cre and MMTV-NLST-Cre, crossed with regulatable, stabilized β-catenin (bcatFL) animals, as well as animals expressing mutated p53-R270H. While mammary tumors developed in animals expressing Cre-targeted regulatable bcatFL, the penetrance and growth kinetics were lower than observed with other mammary mouse models expressing stabilized β-catenin. Since fewer animals developed tumors, we focused analysis on the effect of turning off stabilized β-catenin expression following tumor initiation. In the animals examined, a delay in tumor growth, but not regression, was observed in animals expressing Cretargeted bcatFL as well as those expressing both bcatFL and p53-R270H. These results indicate that in a less aggressive β-catenin model, additional mutations likely provide independence from the initiating event.

Prognosis of pT1a,bN0 breast cancer: Perception from the French oncology community—Results from the EURISTIC survey.

e11607 Background: Although most early-stage breast tumors have a favourable outcome, some subgroups carry a higher recurrence risk. The objective of the EURISTIC Survey was to evaluate the perception French physicians have of the prognostic risk associated with the biopathological characteristics of tumors in pT1a,b N0 breast cancer. Methods: This 38 item postal survey was developed by an expert panel. 2,000 physicians involved in breast cancer treatment were contacted. Specialities involved were medical and radiation oncologists, surgeons, radiologists and pathologists. Results: The survey was conducted between September and December 2012. A total of 663 physicians responded (response rate = 33%). They stated treating an average of 50 breast cancer patients per month. 58% of physicians reported that tumour size was not considered a major parameter in this clinical setting. In the absence of an adjuvant treatment, the prognosis of T1a,bN0 carcinoma was perceived better if HR-positive rather than HER2-positive or triple-negative with a "positive" prognosis perception rated by 83%, 21% and 8% of physicians respectively. For pT1a,bN0 tumors, the criteria with the highest perceived prognostic risk were ranked as follows: HER2+ (29%), HR- (20%) elevated tumor grade (20%) and triple negative tumor (14%). The average size threshold for a "negative" prognostic rated tumor was 18 mm. This threshold was scaled up for HR-positive carcinoma (22 mm) and scaled down for HER2-positive (10mm) or triple negative carcinoma (7mm). Between 4 and 17 mm, there was a linear correlation between tumor size and perceived risk of recurrence with HER2-positive tumors always carrying a worse prognostic than HR-positive tumor (Table). Conclusions: French physicians have the perception that HER2-positivity and triple negative tumor biology strongly impact the prognosis of pT1a,b N0 carcinoma, independent of tumor size. [Table: see text]

MYC pathway activation in triple-negative breast cancer is synthetic lethal with CDK inhibition

Estrogen, progesterone, and HER2 receptor-negative triple-negative breast cancers encompass the most clinically challenging subtype for which targeted therapeutics are lacking. We find that triple-negative tumors exhibit elevated MYC expression, as well as altered expression of MYC regulatory genes, resulting in increased activity of the MYC pathway. In primary breast tumors, MYC signaling did not predict response to neoadjuvant chemotherapy but was associated with poor prognosis. We exploit the increased MYC expression found in triple-negative breast cancers by using a synthetic-lethal approach dependent on cyclin-dependent kinase (CDK) inhibition. CDK inhibition effectively induced tumor regression in triple-negative tumor xenografts. The proapoptotic BCL-2 family member BIM is up-regulated after CDK inhibition and contributes to this synthetic-lethal mechanism. These results indicate that aggressive breast tumors with elevated MYC are uniquely sensitive to CDK inhibitors.