Serial Analysis of Circulating Tumor Cells in Metastatic Breast Cancer Receiving First-Line Chemotherapy

BACKGROUND: We examined the prognostic significance of circulating tumor cell (CTC) dynamics during treatment in metastatic breast cancer (MBC) patients receiving first-line chemotherapy. METHODS: Serial CTC data from 469 patients (2202 samples) were used to build a novel latent mixture model to identify groups with similar CTC trajectory (tCTC) patterns during the course of treatment. Cox regression was used to estimate hazard ratios for progression-free survival (PFS) and overall survival (OS) in groups based on baseline CTCs, combined CTC status at baseline to the end of cycle 1, and tCTC. Akaike information criterion was used to select the model that best predicted PFS and OS. RESULTS: Latent mixture modeling revealed 4 distinct tCTC patterns: undetectable CTCs (56.9% ), low (23.7%), intermediate (14.5%), or high (4.9%). Patients with low, intermediate, and high tCTC patterns had statistically significant inferior PFS and OS compared with those with undetectable CTCs (P < .001). Akaike Information Criterion indicated that the tCTC model best predicted PFS and OS compared with baseline CTCs and combined CTC status at baseline to the end of cycle 1 models. Validation studies in an independent cohort of 1856 MBC patients confirmed these findings. Further validation using only a single pretreatment CTC measurement confirmed prognostic performance of the tCTC model. CONCLUSIONS: We identified 4 novel prognostic groups in MBC based on similarities in tCTC patterns during chemotherapy. Prognostic groups included patients with very poor outcome (intermediate + high CTCs, 19.4%) who could benefit from more effective treatment. Our novel prognostic classification approach may be used for fine-tuning of CTC-based risk stratification strategies to guide future prospective clinical trials in MBC

Plasma cell-regulated polyadenylation at the Ig gamma 2b secretion-specific poly(A) site.

Abstract We found that the sequences downstream of the Ig gamma 2b secretory-specific (sec) poly(A) site play an important role in the preferential production of sec Ig mRNA during plasma B cell development. The Ig gamma 2b mRNA production in a deletion mutant (delta-Kpn) lacking the Ig sec poly(A) site and downstream consensus element (dsc) has been previously shown to default to the use of the downstream membrane-specific (mb) poly(A) site. In this study restoration of the Ig sec poly(A) site and dsc to the delta-Kpn gene causes a significant increase in the use of the sec poly(A) site vs mb poly(A) site in stable transfectants of plasma but not memory B cell tumors, indicating plasma cell-specific recognition of the Ig sec dsc. Restoration of the poly(A) cleavage site alone to delta-Kpn did not restore regulation. Substitution of an SV40 downstream poly(A) element for the Ig dsc in the delta-Kpn gene also does not restore regulation. The data further indicate that although the Ig dsc is clearly very important in the plasma cell-regulated expression, the difference in the processing ratios of the restored vs the intact Ig gamma 2b gene in plasma cells suggests that there are other yet to be defined sequences that may also play a role in the intact gene. Insertion of a 130-nucleotide segment of the gene containing the Ig sec poly(A) site and dsc into a heterologous, guanosyl phosphotransferase gene resulted in plasma cell-regulated polyadenylation of the sec poly(A) site. Neither the mb nor the SV40 early poly(A) sites and their respective dscs, in similar gpt chimeras, were regulated. Therefore the region downstream of the Ig sec poly(A) site plays an essential role in regulating polyadenylation at the sec poly(A) site in plasma cells but not memory cells. A model involving a plasma cell-specific recognition factor for the Ig sec dsc is presented.</jats:p

Abstract OT3-05-10: A single arm phase II study of palbociclib in combination with tamoxifen as first line therapy for metastatic hormone receptor positive breast cancer

Abstract Background: Hormone receptor positive breast cancer is the most commonly diagnosed subset of breast cancer (60-65%). Endocrine therapy is effective for this subset of breast cancer, in both the adjuvant and metastatic settings. Despite advances in endocrine therapy, many patients relapse during or after completing adjuvant therapy and metastatic breast cancer remains incurable. Palbociclib is a reversible, oral, small molecule inhibitor of cyclin dependent kinases 4 and 6 (CDK4/6). CDK4 and CDK6 together with cyclin D have important roles in regulation of the G1/S transition via regulation of the phosphorylation state of retinoblastomaprotein (Rb). Palbociclib showed significantly improved progression-free survival taken together with endocrine agents in treatment of metastatic breast cancer. Preclinical data showed that in combination with tamoxifen, palbociclib had synergistic growth inhibitory activity as well as efficacy in a model of acquired tamoxifen resistance. Combining palbociclib with tamoxifen in first line treatment of metastatic hormone receptor positive breast cancer may offers an appealing alternative to other endocrine combinations. Methods: This is a non-randomized, open-label, single-arm, multicenter, phase II study of palbociclib in combination with tamoxifen in patients with hormone receptor positive/HER2 negative advanced breast cancer. The primary objective is to determine the objective response rate (complete or partial response) based on RECIST 1.1 or MDA Criteria (for patients with bone only disease). Secondary objectives are: safety and tolerability, progression-free survival, clinical benefit rate, 2-year overall survival. Correlative objectives will explore alterations in circulating tumor DNA and changes in gene expression pattern at the time of progression. Eligibility criteria: women or men with diagnosis of hormone receptor positive/ HER2 negative locally advanced or metastatic breast cancer, not amenable to curative surgery; no prior systemic anti-cancer therapy for advanced hormone receptor positive breast cancer; adequate organ function; pre and post menopausal women are allowed. Drug administration: palbociclib dose will be 125 mg orally once daily on days 1-21 of each 28-day cycle; tamoxifen dose will be 20 mg orally once daily for every day of the 28-day cycle. As of June 2017, the study enrolled 10/71 patients and it is still open to enrollment. NCT 02668666; [email protected] Citation Format: Danciu OC, Hoskins K, Tamkus D, Truica C, Blaes A, Green L, Liu L, Toppmeyer D, Wisinski K. A single arm phase II study of palbociclib in combination with tamoxifen as first line therapy for metastatic hormone receptor positive breast cancer [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr OT3-05-10.</jats:p

Telephone disclosure of <i>BRCA1/2</i> test results? Experience and opinions of genetic counselors and consumers

1510 Background: BRCA1/2 test results have historically been disclosed in person (IPD) by a certified genetic counselor (GC). Greater consumer demand and access to BRCA1/2 testing, and greater prevalence and acceptance of telemedicine, have interested providers in conducting BRCA1/2 testing and disclosing results by telephone (TD) and internet. GC and consumer experiences and opinions about TD have not been well described. Methods: To determine experience, opinions and interest in TD of BRCA1/2 test results we conducted semi-structured interviews with 194 GC recruited via NSGC Cancer Special Interest Group and with 30 consumers (to date) less than 9 months post IPD of BRCA1/2 test results at two cancer centers. Descriptive statistics characterize GC and consumer experiences and opinions. Results: 98% GC had provided TD; 46% rarely. Most frequent reasons for TD: perceived consumer hardship of IPD (n = 190); consumer preference (n = 49) and medical benefit (n = 30). GC comfort with TD varied by test result (true negative [TN] 77%, indeterminate [IND] 49%; mutation carriers [MC] 37%; variant of unknown significance [VUS] 33%). GC cited consumer convenience (n = 132), medical (n = 71) and psychological benefit (n = 42), and greater GC counseling capacity (n = 33) as TD advantages. No nonverbal communication (n = 161), poorer communication/understanding (n = 67), and difficulty explaining complex results (n = 41) were disadvantages GC most frequently reported. 46% post-IPD consumers reported interest in TD; interest varied by test result (VUS 67%; IND, 63%; TN 57%; MC 25%). Consumers’ perceived advantages: convenience (n = 22) and medical benefit (n = 9); and disadvantage to TD; lack of visual and personal connection with GC (n = 18). Conclusions: Results of the ongoing study suggest many consumers of BRCA1/2 testing are interested in, and nearly all GC have conducted, TD. GC and consumers share perceptions of TD convenience, and of challenges of lack of visual cues, however, GC comfort with, and consumer preference for, TD vary differently by test result. Given consumer and provider interest, longitudinal study of TD impact on knowledge, risk perception, communication, and health behaviors, and their mediators will be critical to develop policy and procedures optimizing adaptive responses to TD. No significant financial relationships to disclose. </jats:p

Polymorphic variants in TSC1 and TSC2 and their association with breast cancer phenotypes

TSC1 acts coordinately with TSC2 in a complex to inhibit mTOR, an emerging therapeutic target and known promoter of cell growth and cell cycle progression. Perturbation of the mTOR pathway, through abnormal expression or function of pathway genes, could lead to tumorigenesis. TSC1 and TSC2 expression is reduced in invasive breast cancer as compared with normal mammary epithelium. Because single nucleotide polymorphisms (SNPs) in regulatory genes have been implicated in risk and age at diagnosis of breast cancers, systematic SNP association studies were performed on TSC1 and TSC2 SNPs for their associations with clinical features of breast cancer. TSC1 and TSC2 haplotypes were constructed from genotyping of multiple loci in both genes in healthy volunteers. SNPs were selected for further study using a bioinformatics approach based on SNP associations with drug response in NCI-60 cell lines and evidence of selection bias based on haplotype frequencies. Genotyping for five TSC1 and one TSC2 loci were performed on genomic DNA from 1,137 women with breast cancer. This study found that for TSC1 rs7874234, TT variant carriers had a 9-year later age at diagnosis of estrogen receptor positive (ER+), but not ER-, ductal carcinomas (P = 0.0049). No other SNP locus showed an association with age at diagnosis, nor any other breast cancer phenotype. TSC1 rs7874234 is hypothesized to be functional in ER+ breast cancer because the T allele, but not the C allele, may create an estrogen receptor element (ERE) site, resulting in increased TSC1 transcription and subsequent inhibition of mTOR. © 2010 Springer Science+Business Media, LLC

Understanding Cancer Genetic Risk Assessment Intentions in a Tailored Risk Communication Intervention Randomized Controlled Trial

Background: Pathogenic variants in cancer predisposition genes increase second, hereditary cancer risk among women with breast and/or ovarian cancer, and primary cancers in their relatives. National guidelines recommend cancer genetic risk assessment (CGRA) (genetic counseling and/or genetic testing) for women at increased hereditary breast and ovarian cancer (HBOC) risk. Yet, less than half of high risk women, including rural dwellers and racial minorities have accessed CGRA. Purpose: The Genetic Risk Assessment for Cancer Education and Empowerment Project (GRACE), a superiority trial, addressed this translational gap, testing the efficacy of a targeted print brochure (TP) vs tailored counseling and navigation (TCN) vs usual care (UC) on CGRA intentions. TCN targeted behavioral variables theorized to mediate CGRA intentions. We believe GRACE is the first study of its kind promoting guideline-based CGRA to women at increased HBOC risk. Methods: CGRA-eligible women were recruited from three state cancer registries (N=641), completed a baseline survey, and randomized to TCN, TP or UC. TP and TCN received the mailed educational brochure. TCN also engaged in a telephone-based decision coaching and navigation session using motivational interviewing and tailored materials based on the Extended Parallel Process Model and Health Action Process Approach. Participants completed a follow-up survey at one month. Results: TCN improved CGRA intentions compared to TP (0.64, p&amp;lt;0.001, CI 0.32, 0.97) and UC (0.69, p&amp;lt;0.001, CI 0.37, 1.02). Theoretical targets, perceived risk (0.77, p=0.02, CI 0.11, 1.44) and self-efficacy (0.67, p=0.04, CI 0.05, 1.28) mediated CGRA intentions in TCN. Stratification showed increases in CGRA intentions for TCN vs TP among non-Hispanic Whites, Hispanics, urban dwellers, and women with low health literacy and no family history of breast and/or ovarian cancer (FBOC). In TCN, perceived self-efficacy improved in women with no FBOC. Conclusions: Improvements in CGRA intentions and theorized mediators support use of tailored risk communication interventions in Hispanics and women with low health literacy and no FBOC. Further tailoring may improve CGRA intentions in Blacks, other minorities, rural dwellers, and women with high health literacy and FBOC.</jats:p