18F-FDG Dedicated Breast PET Complementary to Breast MRI for Evaluating Early Response to Neoadjuvant Chemotherapy

Purpose To compare quantitative measures of tumor metabolism and perfusion using fluorine 18 (18F) fluorodeoxyglucose (FDG) dedicated breast PET (dbPET) and breast dynamic contrast-enhanced (DCE) MRI during early treatment with neoadjuvant chemotherapy (NAC). Materials and Methods Prospectively collected DCE MRI and 18F-FDG dbPET examinations were analyzed at baseline (T0) and after 3 weeks (T1) of NAC in 20 participants with 22 invasive breast cancers. FDG dbPET-derived standardized uptake value (SUV), metabolic tumor volume, and total lesion glycolysis (TLG) and MRI-derived percent enhancement (PE), signal enhancement ratio (SER), and functional tumor volume (FTV) were calculated at both time points. Differences between FDG dbPET and MRI parameters were evaluated after stratifying by receptor status, Ki-67 index, and residual cancer burden. Parameters were compared using Wilcoxon signed rank and Mann-Whitney U tests. Results High Ki-67 tumors had higher baseline SUVmean (difference, 5.1; P = .01) and SUVpeak (difference, 5.5; P = .04). At T1, decreases were observed in FDG dbPET measures (pseudo-median difference T0 minus T1 value [95% CI]) of SUVmax (-6.2 [-10.2, -2.6]; P < .001), SUVmean (-2.6 [-4.9, -1.3]; P < .001), SUVpeak (-4.2 [-6.9, -2.3]; P < .001), and TLG (-29.1 mL3 [-71.4, -6.8]; P = .005) and MRI measures of SERpeak (-1.0 [-1.3, -0.2]; P = .02) and FTV (-11.6 mL3 [-22.2, -1.7]; P = .009). Relative to nonresponsive tumors, responsive tumors showed a difference (95% CI) in percent change in SUVmax of -34.3% (-55.9%, 1.5%; P = .06) and in PEpeak of -42.4% (95% CI: -110.5%, 8.5%; P = .08). Conclusion 18F-FDG dbPET was sensitive to early changes during NAC and provided complementary information to DCE MRI that may be useful for treatment response evaluation. Keywords: Breast, PET, Dynamic Contrast-enhanced MRI Clinical trial registration no. NCT01042379 Supplemental material is available for this article. © RSNA, 2024.

Abstract P5-07-03: The Association Between Symptom Severity and Physical Function among Participants in I-SPY2

Background. Patient-reported outcomes (PROs) are increasingly recognized as a valuable component to understand treatment tolerability and toxicity among patients on clinical trials. We have implemented a system for monitoring patient reported outcomes (PROs), symptoms, and quality of life (QOL) using electronic PRO (ePRO) instruments for patients enrolled in the I-SPY2 trial. I-SPY2 is a phase II multi-site clinical trial evaluating the effect of novel neoadjuvant therapies for locally advanced breast cancer. We correlated patient demographic factors with symptoms, investigated the trajectory of symptoms throughout treatment, and sought to characterize symptoms associated with decline in physical function (PF). Methods. Our study population included 259 I-SPY2 patients that completed surveys on one of 9 study arms (including novel oral taxane/immunotherapy combinations, IV paclitaxel, checkpoint inhibitor+/- LAG3 inhibitor, and control IV paclitaxel +/- trastuzumab/pertuzumab). After the 12 week period of investigational agents, most patients received standard adriamycin and cyclophosphamide (AC). Symptom severity, frequency, and interference was assessed weekly using 33 items from the PRO-CTCAE item bank. PF was assessed using the NIH PROMIS instrument and was evaluated at baseline, inter-regimen (after 12 weeks of treatment), pre-surgery, and 1 and 6 months at follow-up. An odds ratio was used to assess univariate associations between age and race, and symptoms. Regularized multi-variate regression was used to evaluate early symptoms (prior to week 6) predictive of a clinically significant (&gt;5 point T-score) decline in PF from baseline to post-treatment follow-up among all races and age groups. Results. Of 259 patients (mean age (SD) = 46.8 (13.6)), 160 (58%) were White, 13 (5%) were Asian, 26 (10%) were African American (AA), 25 (9.3%) were Hispanic, and 35 (13.5%) self-reported “Other”. At baseline, AA patients had a higher severity of joint pain than White patients (OR = 14.9, P &lt; 0.05). During study treatment with paclitaxel and/or novel agent within the first 12 weeks of treatment, AA patients and non-white (NW) patients were more likely to report severe vomiting than White patients (OR =13.22 and 12.72, P&lt; 0.05 and P&lt; 0.03 respectively). During treatment with AC, NW patients were more likely to report higher severity of neuropathy than White patients (OR = 5.43, P&lt; 0.03). Among all patients, in analysis of early symptoms predictive of a clinically significant decline in PF between baseline and 1 month post treatment, predictors included high frequency of diarrhea, severity of itching, and severity of joint pain. Further analysis of symptom trajectories revealed that frequency of diarrhea reported rose sharply between baseline and Cycle 2 with 9 patients (7%) reporting occasional or frequent diarrhea to 39 patients (28%) reporting occasional to almost constant diarrhea and remained stable at that proportion for the remainder of treatment. Frequency of diarrhea declined slightly during AC (17%) and dropped to baseline levels by follow-up. In contrast, severity of joint pain persisted post-treatment, rising consistently from baseline through follow- up with 3 patients (2%) reporting moderate to severe joint pain at baseline to 18 patients (35%) reporting moderate to severe joint pain at follow-up. Conclusion. Among I-SPY2 participants, when higher grade of diarrhea is persistent (or uncontrolled), it impacts physical function even after end of therapy. In some cases, race was also a determinant in symptom trajectory, although a higher enrollment of AA and NW patients will enable more robust estimates to be computed. While some of these early symptom predictors are transient and resolve by the time of follow-up, others persist long-term and contribute more directly towards impaired physical function at follow-up.

Citation Format: Amrita Basu, Saumya Umashankar, Kaylee Blevins, Anna Northrop, Anika Christofferson, Ebunoluwa Olunuga, Jaeyoon Cha, Ananya Mittal, Julissa Molina-Vega, Laura Sit, Thelma Brown, Bev Parker, Diane Heditsian, Susie Brain, Carol Simmons, Alessandra Taboada, Tina J. Hieken, Kathryn Ruddy, Carolina Salvador, Candace Mainor, Anosheh Afghahi, Sarah Tevis, Anne Blaes, Irene M. Kang, Jane Perlmutter, Hope Rugo, Sai Kanaparthi, Garry Peterson, Lisa T. Weiss, Adam Asare, Laura J. Esserman, Michelle Melisko, Dawn Hershman. The Association Between Symptom Severity and Physical Function among Participants in I-SPY2 [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr P5-07-03.

Patient perspectives on window of opportunity clinical trials in early-stage breast cancer

PURPOSE

Window of opportunity trials (WOT) are increasingly common in oncology research. In WOT participants receive a drug between diagnosis and anti-cancer treatment, usually for the purpose of investigating that drugs effect on cancer biology. This qualitative study aimed to understand patient perspectives on WOT.

METHODS

We recruited adults diagnosed with early-stage breast cancer awaiting definitive therapy at a single-academic medical center to participate in semi-structured interviews. Thematic and content analyses were performed to identify attitudes and factors that would influence decisions about WOT participation.

RESULTS

We interviewed 25 women diagnosed with early-stage breast cancer. The most common positive attitudes toward trial participation were a desire to contribute to research and a hope for personal benefit, while the most common concerns were the potential for side effects and how they might impact fitness for planned treatment. Participants indicated family would be an important normative factor in decision-making and, during the COVID-19 pandemic, deemed the absence of family members during clinic visits a barrier to enrollment. Factors that could hinder participation included delay in standard treatment and the requirement for additional visits or procedures. Ultimately, most interviewees stated they would participate in a WOT if offered (N = 17/25).

CONCLUSION

In this qualitative study, interviewees weighed altruism and hypothetical personal benefit against the possibility of side effect from a WOT. In-person family presence during trial discussion, challenging during COVID-19, was important for many. Our results may inform trial design and communication approaches in future window of opportunity efforts.

Abstract P3-02-02: FES-dedicated breast PET uptake in early-stage ER+ breast cancers

BACKGROUND: Patients with ER+ breast cancer may have a recurrence risk of aggressive disease. While clinical evidence suggests that ER+ tumors are responsive to endocrine therapy, up to one-third of patients with early-stage ER+ disease may not respond to endocrine therapy. Tumor biologic factors such as ER functionality, cell proliferation, and molecular traits may influence endocrine treatment responsiveness and long-term recurrence risk. More comprehensive tools are needed to depict the primary breast tumor. [18F]fluoroestradiol (FES) is a radiotracer developed for positron emission tomography (PET) imaging of ER status. We used FES with a high-resolution dedicated breast PET (dbPET) to quantify ER expression in primary ER+ tumors and assessed the relationship between FES uptake and tumor characteristics. METHODS: With IRB approval, patients with biopsy-proven ER+/HER2- breast cancer were imaged using dbPET with 5 mCi of FES before treatment. FES uptake (SUVmax, SUVmean, and SUVpeak), background parenchymal uptake (BPU), tumor uptake volume (TUV), and tumor to background ratio (TBR) were calculated. Background values (SUVbkg) were obtained from the normal region of the ipsilateral breast. Lesions with background-corrected SUVmax 2 times higher than SUVbkg were considered FES avid. Tumor size (longest diameter) was measured by MRI. The histologic subtype, ER expression, tumor grade, and Ki67 were obtained from core biopsies before treatment. Ki67 was dichotomized to low and high using a 20% cutoff. Spearman’s rank correlation was used to assess the correlation between FES uptake and tumor size. Differences between FES uptake, histologic subtype, and Ki67 were compared using a Wilcoxon rank-sum test. RESULTS: 19 treatment-naïve patients were included in this analysis as part of an ongoing study. Patient and tumor characteristics are listed in Table 1. While all patients had ER positivity &gt;90% by immunohistochemistry (IHC), we observed varying FES avidity in ER+ breast cancers, with 14 FES avid and 5 non-FES avid lesions. There was a statistically significant difference between FES avid vs. non-avid lesions measured by all uptake metrics except BPU. FES uptake in invasive ductal carcinoma was similar to invasive lobular carcinoma. FES uptake correlated with tumor size, with the highest correlation ρ = 0.58, 95% CI (0.17, 0.84), p=0.012, detected in TUV. FES uptake was associated with Ki67, with all uptake metrics except BPU showing a statistically significant difference between high and low Ki67 expression (Table 2). CONCLUSION: We found that not all lesions that were highly ER+ by IHC were FES avid. FES-dbPET captures information from the entire tumor, providing a more comprehensive assessment of functional ER status than IHC of a limited tumor sample. Moreover, FES uptake correlates with tumor size and cell proliferation. This is an ongoing study; additional data may help to guide endocrine therapy decisions. Future studies with a larger cohort are planned to assess the relationship between FES uptake and tumor grade and molecular risk profiles.

Table 1.Patient and tumor characteristicsCharacteristicsNo. of patientsTotal N=19Age (median (IQR))56.0 (21.5)Pre-menopausal7Post-menopausal12Histologic subtypeInvasive ductal carcinoma (IDC)6Invasive lobular carcinoma (ILC)13Tumor size (N=18) (MRI LD (cm), median (IQR))3.2 (4.1)Tumor grade1421332Ki67Low12High6Unknown1FESNon-avid5Avid14

Table 2.Summary of baseline FES uptake valuesTumor Size (cm)FES AvidityHistologic SubtypeKi67Spearman CorrelationAvid vs. Non-avidILC vs. IDCHigh vs. Lowρ (95%CI)P-valueMedian Diff (95%CI)P-valueMedian Diff (95%CI)P-valueMedian Diff (95%CI)P-valueSUVmax0.51 (0.054, 0.79)0.0318.02 (3.55, 11.9)0.0010.187 (-8.04, 6.32)0.976.38 (2.36, 11.6)0.017SUVmean0.31 (-0.18, 0.68)0.2042.42 (1.47, 3.49)0.001-0.477 (-1.96, 1.37)0.571.61 (0.81, 2.77)0.028SUVpeak0.46 (-0.0053, 0.76)0.0533.16 (1.42, 5.2)0.003-0.583 (-3.76, 2.61)0.633.16 (1.32, 4.66)0.013BPU-0.09 (-0.53, 0.39)0.723-0.33 (-1.25, 0.46)0.3790.226 (-0.58, 1.19)0.40-0.49 (-1.49, 0.28)0.122TUV (cm3)0.58 (0.15, 0.82)0.0125.45 (1.09, 12.5)0.005-2.82 (-12.5, 4.06)0.405.9 (0.98, 12.66)0.021TBR0.5 (0.047, 0.79)0.0333.48 (2.2, 13.5)0.001-0.295 (-11.9, 7.42)0.9010.2 (1.47, 13.49)0.028

Citation Format: Ella F. Jones, Deep K. Hathi, Julissa Molina-Vega, David C. Newitt, Courtney Lawhn-Heath, Kimberly M. Ray, Bonnie N. Joe, Diane Heditsian, Susie Brain, Rita A. Mukhtar, A. Jo Chien, Hope S. Rugo, I-SPY 2 TRIAL Consortium, I-SPY 2 TRIAL Imaging Working Group, Laura J. Esserman, Nola M. Hylton. FES-dedicated breast PET uptake in early-stage ER+ breast cancers [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr P3-02-02.

Abstract P3-02-01: Initial experience of FES-dedicated breast PET imaging of early-stage ER+ invasive lobular carcinoma

BACKGROUND: Invasive lobular carcinoma (ILC) is the second most common histological subtype of breast cancer, representing 15% of all invasive breast cancers. Most ILC tumors are estrogen receptor-positive (ER+) and may respond to endocrine therapy. However, tumor biologic factors such as ER functionality, cell proliferation, and molecular traits may influence endocrine treatment response and long-term recurrence risk, thus necessitating a comprehensive approach to characterize the primary breast tumor. [18F]fluoroestradiol (FES) is a radiotracer developed for positron emission tomography (PET) imaging of ER status. For this work, we studied the utility of imaging FES uptake in early-stage primary ER+ ILC lesions, using high-resolution dedicated breast PET (dbPET) to assess the relationship between FES uptake and tumor characteristics. METHODS: With institutional review board approval, patients with biopsy-proven ER+/HER2- ILC were prospectively imaged using dbPET with 5 mCi of FES before treatment. FES uptake (SUVmax, SUVmean, and SUVpeak), tumor uptake volume (TUV), and background parenchymal uptake (BPU) values were calculated. Background values (SUVbkg) were obtained from the normal region of the ipsilateral breast. Lesions with background-corrected SUVmax 2 times higher than SUVbkg were considered FES-avid. Tumor grade, Ki67 cell proliferation index, and ER expression were obtained from core biopsies before treatment. Ki67 was dichotomized to low and high using a 20% cutoff1. Tumor size (longest diameter) was measured by magnetic resonance imaging (MRI). Spearman rank correlation was used to assess the relationship between FES uptake and tumor size. Differences between FES uptake at high and low Ki67 were compared using a Wilcoxon rank-sum test. RESULTS: 13 treatment-naïve ILC patients aged 32-82 years were included in this analysis (Table 1). Despite all lesions exhibiting strongly positive ER expression &gt;90% by immunohistochemistry (IHC), we observed varying FES avidity with 9 FES avid and 4 FES non-avid ILC lesions. SUVmax, TUV, and TBR had substantial median differences between Ki67 high and low lesions (5.9, 4.3, and 9.6, respectively), but the difference did not achieve statistical significance. FES tumor uptake also correlated with tumor size, with the highest correlation observed for SUVpeak (ρ = 0.71 (95% CI: 0.22, 0.91), p=0.010) (Table 2). CONCLUSION: We found that not all highly ER expressing ILC by IHC were FES-avid. As FES-dbPET captures information from the entire tumor, it provides a more comprehensive assessment of functional ER status than IHC of a limited tumor sample. FES uptake in ILC also relates to tumor size and Ki67. This is an ongoing study; additional data may help to guide endocrine therapy decisions. Future studies with a larger cohort are planned to assess the relationship between FES uptake and tumor grade and molecular risk profiles. 1. Acs, B. et al. Ki-67 as a controversial predictive and prognostic marker in breast cancer patients treated with neoadjuvant chemotherapy. Diagn Pathol 12, 20, doi:10.1186/s13000-017-0608-5 (2017).

Patient and tumor characteristicsCharacteristicsNumber of patients (Total N=13)Age (median (range))56.0 (32-80)Pre-menopausal3Post-menopausal10MRI tumor size (median (interquartile range)4.1 (2.4-6.8)Tumor grade132931Ki6712Low/High3/9FES13Avid/Non-avid9/4

Summary of FES uptake values and correlation coefficients.FES avidity (N=13)Ki67 (N=12)MRI tumor size (N=12)Avid vs Non-avidHigh vs LowSpearman rank correlationMedian Difference (95% CI)P-valueMedian Difference (95% CI)P-valueSpearman ρ (95% CI)P-valueSUVmax8.68 (2.86, 12)0.0075.9 (-19.5, 11.6)0.140.67 (0.16, 0.9)0.017SUVmean2.56 (1.43, 4.86)0.0071.34 (-4.14, 3.1)0.200.6 (0.042, 0.87)0.039SUVpeak2.86 (1.14, 4.59)0.0112.15 (-14.4, 3.72)0.190.71 (0.22, 0.91)0.01BPU-0.31 (-1.89, 1.02)0.82-0.73 (-2.34, 0.28)0.0960.01 (-0.57, 0.58)0.98TUV (cm3)5.45 (1.04, 10)0.014.3 (-185, 10)0.190.70 (0.21, 0.91)0.011TBR3.61 (2.2, 13)0.0079.57 (-19.6, 12.4)0.0640.66 (0.13, 0.89)0.02

Citation Format: Ella F Jones, Deep K Hathi, Natalia Konovalova, Julissa Molina-Vega, David C Newitt, Courtney Lawhn-Heath, Kimberly M Ray, Bonnie N Joe, Diane Heditsian, Susie Brain, I-SPY 2 TRIAL Imaging Working Group, I-SPY 2 TRIAL Consortium, A. Jo Chien, Laura J Esserman, Nola M Hylton, Rita A Mukhtar. Initial experience of FES-dedicated breast PET imaging of early-stage ER+ invasive lobular carcinoma [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr P3-02-01.

Abstract P5-19-04: The WISDOM study: Reducing sequential steps and implementing parallel workflows in pragmatic trials

Background:The WISDOM Study is a preference-tolerant pragmatic study, comparing annual mammograms to a risk-based screening. Eligibility includes women ages 40-74 years with no history of breast cancer or DCIS. Participants are enrolled to one study arm: annual screening or risk-based screening (includes genetic testing). Pragmatic trials often involve gathering real-time data over multiple time points. Collecting real-time data sequentially can limit enrollment, delay study assignments, and reduce participant engagement. The WISDOM Study has identified such bottlenecks and has implemented parallel workflows, reducing the overall wait time for participants to complete required study steps. These data highlight how moving participants through the study more efficiently can improve enrollment and retention and inform other pragmatic trials. Methods: WISDOM participants have the option to either choose their study arm or be randomized into one as part of the preference tolerant randomized trial design. Participants then complete breast health questionnaires and genetic testing (if in the risk-based arm). This information is analyzed by the WISDOM breast cancer risk assessment algorithm, the result of which is then communicated to the participant through a screening assignment letter (SAL). Specific data elements, such as breast density found participants’ mammogram reports and genetic testing results are required for study randomization process and risk assessment calculations, respectively. The WISDOM randomization algorithm is stratified by several factors, including breast cancer risk estimated using the Breast Cancer Surveillance Consortium (BCSC) model, which uses mammographic density as a key input variable. The study team changed the workflow to allow participants to proceed to randomization without specific information by imputing both density and risk. Additionally, a parallel workflow improvement process was implemented to obtain mammogram reports while genetic testing was being completed. Results: Before the weighted BCSC and imputed density algorithms were introduced, it took an average of 47 days to randomize participants after completion of the baseline enrollment questionnaires. Now, participants are randomized immediately which has reduced delays by 100%. Prior to implementing the parallel workflow for genetic testing and mammogram ascertainment, genetic testing kits were sent only after mammogram reports were collected and validated. The expected turnaround time for genetic testing results was 30-60 days and on average, results were returned to participants in 42 days. Streamlining the study design to obtain mammogram reports while participants complete their genetic testing has shortened the time for participants to receive their screening assignment letters (SALs) from an average of 160 days to 78 days, a reduction by 49%. In comparison, participants in the annual arm of the study who do not complete genetic testing, receive their SALs after an average of 38 days from enrollment. This is due to long wait times to obtain mammographic densities from outside medical facilities. Conclusions: Creating parallel data ascertainment workflows and reducing sequential steps in the study process has increased completion of individual enrollment activities. Participants now are randomized immediately upon joining the study and have access to their SALs and genetic results more rapidly. This approach eliminated randomization wait times and improved efficiency of the early in the enrollment process. We are evaluating the impact on participant retention going forward. Workflow efficiency is critical to improve the patient experience, and our learnings can inform future trial design, particularly for studies requiring data from outside sources.

Citation Format: Tomiyuri Lewis, Stephanie Flores, Leah Sabacan, Patricia Choy, Halle Thannickal, Yiwey Shieh, Jeffrey Tice, Elad Ziv, Lisa Madlensky, Martin Eklund, Christina Yau, Amie Blanco, Barry Tong, Deborah Goodman, Nancy Anderson, Heather Harvey, Steele Fors, Hannah L Park, Samrrah Raouf, Skye Stewart, Janet Wernisch, Barbara Koenig, Celia Kaplan, Robert Hiatt, Neil Wenger, Vivian Lee, Diane Heditsian, Susie Brain, Dolores Moorehead, Barbara A Parker, Alexander Borowsky, Hoda Anton-Culver, Arash Naeim, Andrea Kaster, Laura van ‘t Veer, Andrea Z LaCroix, Olufunmilayo I Olopade, Deepa Sheth, Agustin Garcia, Rachel Lancaster, Michael Plaza, Wisdom Study, Athena Breast Health Network Investigators, Advocate Partners, Allison S Fiscalini, Laura Esserman. The WISDOM study: Reducing sequential steps and implementing parallel workflows in pragmatic trials [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr P5-19-04.

Abstract P5-19-01: The impact of streamlined processes and patient-directed messaging to improve enrollment in a remote, pragmatic clinical trial

Background Recent advances in technology have made it possible to conduct remote clinical trials that allow individuals to participate from home with comfort, privacy, and ease. Despite these advances, challenges persist in running remote trials, such as survey question redundancies, lack of patient-initiated data-sharing tools, and unclear patient communication around critical enrollment steps. The Women Informed to Screen Depending on Measures of risk (WISDOM) Study is a pragmatic, preference-tolerant randomized control breast cancer screening trial comparing personalized risk-based screening to traditional, annual screening. The study population includes women ages 40-74 without a history of breast cancer or DCIS. Since 2016, study enrollment has been available to all women in the U.S. who meet study eligibility criteria. Since October 2020, WISDOM has implemented multiple strategies to improve participant experience: participant-initiated data-sharing tools and clear participant messaging. This abstract presents the efficacy of these interventions as they relate to increasing patient enrollment in remote, pragmatic clinical trials. Methods The WISDOM Study online enrollment process includes registration, participant study arm selection or randomization, online consent, and enrollment (submission of multiple study surveys over a secure, online platform). Barriers to online enrollment were uncovered through an internally-conducted needs assessment of participants who enrolled between 2019-2020, and participant feedback obtained through phone interviews conducted by WISDOM’s embedded ethics study. Improvements to our online enrollment procedures were executed in October 2020 and included: improving the clarity of study arm selection options, streamlining data collection surveys, and enacting a secure, patient-initiated online data-sharing tool and an online portal feature with auto-launch of critical information. Study metrics were obtained through Google Analytics and Salesforce. Results Prior to the end of 2020, only 62% of the 30,046 participants who registered for the WISDOM Study completed study enrollment. After improving the enrollment process, of the 5,334 participants registered for the study between Jan-June 2021, 69% completed the enrollment process finishing both the online consent and survey forms. Conversion from consent to enrollment went from 78% in January 2020 to 93% in June 2021. Currently, 56% participants complete enrollment in one day. Streamlining online patient questionnaires led to an increase in completion rates, with 75% of participants completing their yearly surveys, compared to 59% prior to April 2021. A secure patient upload feature for data sharing led to 1,054 participants successfully sharing their mammogram reports with WISDOM between March - June 2021. Previously, mammogram reports were missing for 20% of enrolled participants. This feature has enabled WISDOM to process 300 additional mammogram reports per month. Integration of an auto-launch feature in the participant’s portal in Feb 2021 has led to a 17% increase in participants viewing their screening recommendations in Yr 1. Prior to auto-launch, only 59% (n=6328) of Yr 1 screening recommendations and 61% (n=3681) of genetic testing reports were viewed by participants. Since implementation, the numbers increased to 78% (n=8406) and 85% (n=5160), respectively. Conclusions. Streamlining data to the most essential elements, and minimizing the steps required to share clinical documents, complete questionnaires and open key study notification is essential to improving enrollment rates in virtual, pragmatic trials. Patient-initiated data-sharing tools such as the ability for participants to share documents through secure, online portals is one example of success.

Citation Format: Patricia Choy, Tomiyuri Lewis, Stephanie Flores, Leah Sabacan, Halle Thannickal, Steffanie Goodman, Yiwey Shieh, Lisa Madlensky, Jeffrey A. Tice, Elad Ziv, Martin Eklund, Amie Blanco, Barry Tong, Deborah Goodman, Nancy Anderson, Heather Harvey, Steele Fors, Hannah Lui Park, Antonia Petruse, Skye Stewart, Samrrah Raouf, Janet Wernisch, Barbara Koenig, Celia Kaplan, Robert Hiatt, Neil Wenger, Vivian Lee, Diane Heditsian, Susie Brain, Dolores Moorehead, Barbara A Parker, Alexander Borowsky, Hoda Anton-Culver, Arash Naeim, Andrea Kaster, Laura van 't Veer, Andrea Z LaCroix, Olufunmilayo I. Olopade, Deepa Sheth, Agustin Garcia, Rachel Lancaster, Jennifer James, Galen Joseph, Wisdom Study, Athena Breast Health Network Investigators and Advocates, Allison Stover Fiscallini, Laura Esserman. The impact of streamlined processes and patient-directed messaging to improve enrollment in a remote, pragmatic clinical trial [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr P5-19-01.

Abstract P4-12-02: Improving patient-reported outcome data capture for clinical research: ePRO in ISPY 2, a phase 2 breast cancer study

Introduction: Advances in technology and internet capability have provided an opportunity for efficient collection of Patient Reported Outcomes (PRO) during medical treatment. Here we describe the development and implementation of a system for monitoring patient reported adverse events (AEs) and quality of life (QoL) using electronic PRO (ePRO) instruments for patients enrolled on the Investigation of Serial studies to Predict Your Therapeutic Response with Imaging And moLecular analysis (I-SPY 2 TRIAL), a phase II adaptive platform clinical trial for locally advanced breast cancer. Methods: We designed an ePRO system to increase the accuracy of patient-reported QoL and AE data collection with the intent to act on symptoms in real time. Using the OpenClinica electronic data capture system, we developed rules-based logic to build automated ePRO surveys, customized to the I-SPY 2 treatment schedule. Weekly surveys contained a maximum of 126 validated, branching logic questions from the Patient Reported Outcomes Measurement Information System (PROMIS®) Health Measures and the National Cancer Institute’s Patient Reported Outcomes - Common Terminology Criteria for Adverse Events (PRO-CTCAE™) instruments. We piloted ePROs at the University of California, San Francisco (UCSF) to evaluate compatibility with a variety of I-SPY 2 patient scenarios (e.g., dose delays). We then staggered rollout of the ePRO system to 22 I-SPY 2 sites to ensure technological feasibility. In order to improve accuracy of data collection, we utilized real-time tracking and developed a Clinical Research Coordinator (CRC) training manual, which integrated workflow diagrams with technical solutions. CRCs were trained using remote video sessions. Results: The UCSF ePRO pilot began in September of 2020. Over 9-months, we accrued 43 I-SPY 2 patients (average age of 43.8 years), whose interactions with the ePRO system informed design improvements. Of the patients who received a baseline ePRO survey, the completion rate was 75.9% (average age of 44.2 years). This represents an increase from the 15-20% baseline completion rate for the 360 UCSF I-SPY 2 patients who received paper-based PRO surveys between May 2012 - January 2019. As of June 2021, the ePRO system was operational at all 22 I-SPY 2 sites. The UCSF pilot revealed that engagement with patients at critical timepoints improved survey completion. CRCs facilitated patient participation by sending instructional emails and communicating with patients weekly. We tracked data completeness using a Patient Tracking report, which displayed each patient’s survey completion history. This real-time tool enabled CRCs to identify patients who had not completed ePRO surveys prior to their visit, so they could be provided a tablet computer to complete the survey in the clinic. After introducing tablets into the workflow at UCSF, patient completion of the baseline survey increased from 75.9% to 80%. Conclusion: The transition from paper to electronic QOL and AE data collection improves the ability of patients to complete PRO surveys, but the process must also be optimized and integrated into clinical workflow and trial conduct. In the future, we will present additional results highlighting the feasibility of multilingual ePRO integration into I-SPY 2. ePRO also provides a new opportunity for data analysis, as well as the potential to reduce high grade toxicity through early intervention. It will allow us to assess QoL and AE data by drug regimen, site, provider, and study treatment. The creation of clinician-facing reports also enables access to patient responses in real-time. By implementing ePRO within I-SPY 2, we not only increase efficiency and accuracy of patient-reported data collection, but also improve quality of care and patient safety.

Citation Format: Anna Northrop, Anika Christofferson, Michelle Melisko, Laura Sit, Ebunoluwa Olunuga, Ananya Mittal, Adi Goldman, Thelma Brown, Diane Heditsian, Bev Parker, Susie Brain, Carol Simmons, Alessandra Taboada, Kathryn J Ruddy, Tina Hieken, Mara Piltin, Kiri Cook, Carolina Salvador, Candace Mainor, Anosheh Afghahi, Sarah Tevis, Anne Blaes, Irene Kang, Susan Melin, Laura Esserman, Adam Asare, Dawn L Hershman, Amrita Basu. Improving patient-reported outcome data capture for clinical research: ePRO in ISPY 2, a phase 2 breast cancer study [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr P4-12-02.

Abstract OT-21-01: Personalized breast cancer screening in a population-based study: Women informed to screen depending on measures of risk (WISDOM)

Background: WISDOM is a 100,000 healthy women preference-tolerant, pragmatic study comparing traditional annual screening to personalized risk-based breast screening. The novelty of WISDOM personalized screening is the integration of previously validated genetic and clinical risk factors (age, family history, breast biopsy results, ethnicity, mammographic density) into a single risk assessment model that directs the starting age, timing, and frequency of screening. The goal of WISDOM is to determine if personalized screening, compared to annual screening, is as safe, less morbid, enables prevention, and is more accepted by women. The study is registered on ClinicalTrials.gov, NCT02620852. Methods: Women aged 40-74 years with no history of breast cancer, DCIS or previous double mastectomy can join the study online at wisdomstudy.org. Participants can either elect randomization or self-select a study arm. Then, they provide electronic consent and sign the Release for Medical Information via DocuSign. For all participants, 5-year risk of developing breast cancer is calculated according to the Breast Cancer Surveillance Consortium (BCSC) model. Participants in the personalized arm undergo panel-based mutation testing (BRCA1, BRCA2, TP53, PTEN, STK11, CDH1, ATM, PALB2, and CHEK2), and their 5-year risk is calculated using the BCSC score combined with a Polygenic Risk Score (BCSC-PRS) that includes 229 single nucleotide polymorphisms (SNPs) known to increase breast cancer risk. The SNPs and mutations are assessed by saliva-based testing through Color Genomics. Five-year risk level thresholds are used to stratify participants as low-, moderate- and high risk. Risk stratification determines age to start, stop, and frequency of screening in the personalized arm. Accrual: As of July 2020 the WISDOM Study is open to all eligible women in the United States. To date, 38,762 eligible women have registered, and 28,706 women have consented to participate in the trial. The median age is 56 years. Seventy-seven percent of participants are Caucasian, 2% African-American, 5% Asian, and 8% of self-reported Hispanic ethnicity. WISDOM is partnering with Blue Cross Blue Shield Association for regional plan opt-in coverage, self-insured companies (Salesforce, Genentech, Qualcomm, CalPERS) and Medi-Cal (Inland Empire Health Plan) using a coverage with evidence progression approach. Accrual expansion and diversity: To ensure that resulting data are meaningful and potentially practice-changing for all populations of women, the WISDOM Study is enhancing the diversity of our participant population by establishing WISDOM sites in diverse areas with large African-American (Alabama, Louisiana, Illinois) and Latina (Florida) populations. These new recruitment sites, intentionally selected for the diverse communities they serve, have established partnerships with community organizations and outreach navigators. Additionally, we have translated the WISDOM Study to Spanish to facilitate access by Latina communities. With the engagement of patient advocates and community partnerships, expanding diversity in the study population will strengthen our scientific knowledge of breast cancer risk and improve access to personalized breast cancer screening recommendations for all women. Enrollment will continue through 2022. Conclusions: Results of 5 years follow-up will enable us to demonstrate whether personalized screening improves outcomes for future patients and it improves healthcare value by reducing screen volumes and costs without jeopardizing outcomes.

Citation Format: Irene Acerbi, Allison Stover Fiscalini, Mandy Che, Yiwey Shieh, Lisa Madlensky, Jeffrey Tice, Elad Ziv, Martin Eklund, Amie Blanco, Barry Tong, Deborah Goodman, Lamees Nassereddine, Nancy Anderson, Heather Harvey, Steele Fors, Hannah L Park, Antonia Petruse, Skye Stewart, Janet Wernisch, Larissa Risty, Ian Hurley, Barbara Koenig, Celia Kaplan, Robert Hiatt, Neil Wenger, Vivian Lee, Diane Heditsian, Susie Brain, Leah Sabacan, Tianyi Wang, Barbara A Parker, Alexander Borowsky, Hoda Anton-Culver, Arash Naeim, Andrea Kaster, Melinda Talley, Laura van 't Veer, Andrea Z LaCroix, Olufunmilayo I Olopade, Deepa Sheth, Augustin Garcia, Rachel Lancaster, Wisdom Study and Athena Breast Health Network Investigators and Advocate Partners, Laura Esserman. Personalized breast cancer screening in a population-based study: Women informed to screen depending on measures of risk (WISDOM) [abstract]. In: Proceedings of the 2020 San Antonio Breast Cancer Virtual Symposium; 2020 Dec 8-11; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2021;81(4 Suppl):Abstract nr OT-21-01.

Abstract PS13-50: Relationship of dedicated breast PET and MRI features in breast cancer patients receiving neoadjuvant chemotherapy

Introduction: Dedicated breast positron emission tomography (dbPET) is an emerging imaging technique with the spatial resolution needed to assess functionality and intra-tumor heterogeneity in primary breast lesions. Breast cancer patients may benefit from dbPET imaging combined with molecularly targeted agents to non-invasively assess and predict response to targeted therapy in the neoadjuvant treatment setting. We have previously observed that [18F]-fluorodeoxyglucose (FDG) PET provides tumor metabolic information complementary to the angiogenic properties reflected by dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) for characterizing triple-negative breast cancers (TNBC) (1). In this study, we examined the relationship between FDG-dbPET and MRI features in a cohort of breast cancer patients receiving neoadjuvant chemotherapy (NAC).

Methods: With institutional review board approval, patients with biopsy-proven locally-advanced breast cancer were imaged with breast MRI and dbPET before (T0) and after three weeks (T1) of NAC. Standard DCE-MRI was obtained using a dedicated breast coil. Patients also underwent dbPET with 5 mCi of FDG at 45 minutes post-injection. Functional tumor volumes (FTV) were calculated from DCE-MRI by summing all voxels with an early percent enhancement (PE) exceeding 70% within a manually defined volume of interest (VOI). Maximum and mean PE (PEMax, PEMean) values within the VOI were also computed for analyses. Tumors were segmented in dbPET images using semi-automated threshold-driven methods. Body weight-corrected maximum and mean standardized uptake values (SUVMax, SUVMean), total lesion glycolysis (TLG), and metabolic tumor volume (MTV) were calculated for FDG-dbPET. Percent change relative to T0 (Δ = 100*(T1 - T0)/T0) was calculated for each feature. Spearman’s correlation coefficient was used to evaluate the relationship between MRI and dbPET features.

Results: Of the 16 patients enrolled in this study, 13 patients (N = 15 unique tumors) with MRI and dbPET at T0 and T1 were included in the analysis. 46% (6/13) of the patients had TNBC. Our initial findings indicated that ΔPEMax and ΔSUVMax had the highest correlation (ρ = 0.59, p = 0.022). FTV and TLG at T1 were also correlated (ρ = 0.56, p = 0.032). Among all imaging features, ΔMTV showed the largest post-treatment difference between TNBC (-54.5%) and non-TNBC (-6.06%) groups. Among MRI features, ΔFTV exhibited the largest difference between the groups: -70.4% in TNBC and -43.1% in non-TNBC. ΔSUVMax and ΔTLG were additional dbPET features with large differences between TNBC and non-TNBC patients (Table 1).

Conclusion: This exploratory study suggests that post-treatment ΔSUVMax and TLG provide complementary metabolic information to angiogenic properties (ΔPEMax and FTV, respectively) reflected by MRI. Other dbPET features may provide independent information adjunct to MRI for describing primary breast tumors. Patients with TNBC exhibited larger reductions in FDG uptake values and metabolic volume than non-TNBC patients. These observed reductions may improve early treatment response in patients with TNBC, enabling more precise treatment guidance. Further studies in larger cohorts are needed to validate these initial observations.

1. Bolouri MS, et al. Triple-Negative and Non-Triple-Negative Invasive Breast Cancer: Association between MR and Fluorine 18 Fluorodeoxyglucose PET Imaging. Radiology 2013;269:354-61

Comparison of ΔMRI and ΔFDG-dbPET in TNBC vs non-TNBC patientsAll Tumors (N = 15 tumors) Median(IQR)TNBC (N = 6 tumors) Median(IQR)non-TNBC (N = 9 tumors) Median(IQR)DCE-MRIΔFTV (%)-66.1 (-77.6, -19.1)-70.4 (-79.0, -62.1)-43.1 (-72.5, -2.95)ΔPEMax (%)-9.91 (-31.5, 19.5)-10.3 (-26.3, 24.2)-9.91 (-31.8, 8.42)ΔPEMean (%)-10.7 (-22.4, 2.77)-9.57 (-12.8, 0.29)-17.0 (-26.0, 2.33)FDG-dbPETΔSUVMax (%)-31.6 (-53.9, -20.6)-47.3 (-55.7, -41.1)-23.1 (-31.6, 1.13)ΔSUVMean (%)-34.1 (-65.4, -14.2)-48.5 (-74.6, -9.74)-34.1 (-44.5, -14.8)ΔMTV (%)-6.18 (-57.0, 38.5)-54.5 (-75.4, 15.3)-6.06 (-47.2, 38.9)ΔTLG (%)-64.9 (-75.2, 23.3)-75.2 (-84.0, -60.0)-47.9 (-65.2, 31.1)

Citation Format: Deep K Hathi, Ella F Jones, Wen Li, David C Newitt, Ruby Guo, Youngho Seo, Robert R Flavell, Bonnie N Joe, Diane Heditsian, Susie Brain, ISPY-2 Imaging Working Group, ISPY-2 Consortium, Laura J Esserman, Nola M Hylton. Relationship of dedicated breast PET and MRI features in breast cancer patients receiving neoadjuvant chemotherapy [abstract]. In: Proceedings of the 2020 San Antonio Breast Cancer Virtual Symposium; 2020 Dec 8-11; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2021;81(4 Suppl):Abstract nr PS13-50.

Abstract OT-22-01: Opportunities and lessons learned in using electronic health record patient portal (MyChart) for recruitment to the population-based WISDOM study

Background: WISDOM is a preference-tolerant, pragmatic study comparing annual mammogram screening to personalized, risk-based breast screening in healthy women with a target accrual of 100,000. This sizable recruitment goal requires creative and broad-based strategies that are not typical for traditional clinical research. One of the recruitment methods is use of an electronic health record patient portal (Epic’s MyChart) to invite patients to participate in research. We tested various MyChart implementation strategies across WISDOM recruitment sites and report response rates, barriers and lessons learned. The study is registered on ClinicalTrials.gov, NCT02620852. Methods: Women aged 40-74 years with no history of breast cancer, DCIS, or double mastectomy can join the WISDOM Study online at wisdomstudy.org. Participants either elect to be randomized or self-select one of the study arms, the control (annual mammogram screening) arm or the treatment (personalized, risk-based breast screening) arm. All study steps can be completed electronically, with no requirement to travel to a study site. University of California, Los Angeles (UCLA) was the first WISDOM site to gain approval to use MyChart as a recruitment tool as part of the Clinical Translational Science Institute pilot in Spring 2018. The pilot was designed to demonstrate feasibility, patient response, and recruitment metrics. Following UCLA’s pilot, additional WISDOM sites received approval to use MyChart; however, implementation differed across sites based on local medical center leadership decisions. MyChart Implementation: As of July 2020, use of MyChart is ongoing at five of WISDOM’s six initial recruitment sites (UCLA, Sanford Health, UCSF, UCSD, UCI). Three sites (UCLA, Stanford, and UCSF) implemented MyChart broadly, and two sites (UCI and UCSD) are phasing in MyChart recruitment. UCLA and Sanford Health implemented MyChart recruitment through a centralized approach targeting all eligible patients and sending a MyChart invitation with a link to the study’s enrollment website. UCSF was approved to send WISDOM information on the MyChart portal, but the patients must opt in to learn more by outreach from a research coordinator. UCSD and UCI approaches are more limited requiring departmental or primary care provider approval for communications to be sent to patients. Results: MyChart enabled direct communication to a large number of potential study participants at UCLA and Sanford Health (UCLA 107,829, Sanford Health 86,684) during a 12-month period. The experiences of both sites were similar in that 50% of individuals read the MyChart message, 2.5-5% registered for additional information, and 1.5-2.5% consented to participate. UCSF’s implementation approach was similar with 8005 individuals invited, 6.6% indicating interest to participate, and 2.4% consenting. Although the number of consented participants represented a small portion of the total women consented to join the study to date, the recruitment rates from using MyChart were 2.5-10X higher compared to sites that did not use it or were in pilot phase. Participating sites saw 30%-50% increased recruitment rates during periods when MyChart messages were in use. Implementations at the departmental (UCSD) and primary care provider level (UCI) demonstrated similar trends (3.8% and 3% consented respectively), albeit with smaller samples. Conclusions: Use of electronic health record patient portal (MyChart) recruitment for the WISDOM Study increased enrollment rate by site and is a cost-effective approach to recruiting for large scale trials with broad eligibility criteria like the WISDOM Study.

Citation Format: Antonio Petruse, Alyssa Rocha, Liliana Johansen, Neil Wenger, Mandy Che, Steele Fors, Hannah L Park, Janet Wernisch, Irene Acerbi, Allison S Fiscalini, Jasmin Hassam, Andrea LaCroix, Barbara Parker, Lisa Madlensky, Laura Van't Veer, Celia Kaplan, Hoda Anton-Culver, Andrea Kaster, Skye Stewart, Samrrah Rouf, Alexander Borowsky, Ian Hurley, Robert Hiatt, Vivian Lee, Diane Heditsian, Susie Brain, Olufunmilayo Olopade, Deepa Sheth, Laura Esserman, Wisdom Study and Athena Breast Health Network Investigators and Advocate Partners, Arash Naeim. Opportunities and lessons learned in using electronic health record patient portal (MyChart) for recruitment to the population-based WISDOM study [abstract]. In: Proceedings of the 2020 San Antonio Breast Cancer Virtual Symposium; 2020 Dec 8-11; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2021;81(4 Suppl):Abstract nr OT-22-01.

Understanding patient perspectives on window of opportunity clinical trials

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Background: In “window of opportunity” (WOO) clinical trials, people with newly diagnosed early-stage cancer are exposed to an experimental drug during the period of time between diagnosis and definitive anti-cancer treatment. These trials allow investigators to study drug efficacy in untreated disease, which can expedite drug development. However, for trial participants, the WOO approach requires them to decide about an altruistic clinical trial during an intense time immediately after cancer diagnosis. This qualitative study aimed to understand patient perspectives on WOO clinical trials. Methods: We recruited adults newly diagnosed with early-stage breast cancer who were awaiting definitive therapy at a single academic medical center. We developed an interview guide grounded in the theoretical framework, the Theory of Planned Behavior (TPB). TBP is a well-validated decision-making model with three domains that guide behavior: (1) attitudes (2) normative factors and (3) perceived difficulty of a behavior. We conducted one-on-one semi-structured interviews that were audio-recorded and transcribed. Transcripts were analyzed to ensure interrater reliability and content analysis was performed to assess themes that emerged. Results: We interviewed 15 women (age 32-72) with early-stage breast cancer, and the majority were White (n = 12, 80%) and at least college educated (n = 12, 80%). Key themes that emerged included favorable attitudes towards participating in a WOO trial that were altruistic, including the desire to contribute to science (n = 10, 67%) and to help future breast cancer patients (n = 5, 33%). Several individuals also identified a potential benefit to themselves (n = 10, 67%), including access to a targeted drug (n = 4, 27%) and adding meaning to their diagnosis (n = 3, 20%). However, most interviewees reported concerns about drug side effects (n = 12, 80%) and whether side effects would impact other planned treatments (n = 10, 67%). Interviewees also expressed family would be an important normative factor in decision-making (n = 8, 53%). A key theme that emerged as a difficulty was the potential delay in standard treatment (n = 14, 93%). Despite this concern, at the end of the interviews, most interviewees stated they would participate in a WOO trial if offered (n = 10, 67%). Conclusions: WOO trials are becoming increasingly common in oncology research. In this qualitative study, interviewees weighed altruism against the possibility delaying or impacting other treatments. Our results may inform trial design and communication approaches in future WOO efforts.

Abstract OT3-19-02: Introducing an electronic platform to collect patient reported outcomes in the I-SPY 2 trial, a neoadjuvant clinical trial

Background: While the side effects of anthracycline and taxane based chemotherapy are well characterized, introduction of experimental agents and immunotherapy in the neoadjuvant and adjuvant setting may significantly alter the toxicity profiles of these regimens, resulting in short and long-term changes in patient quality of life (QOL).

Trial Design: I-SPY 2 is a phase 2 trial investigating novel targeted therapies and immunotherapy in combination with standard chemotherapy in the neoadjuvant setting for Mammaprint high-risk stage 2 and 3 breast cancers. A QOL sub-study was introduced into the I-SPY 2 trial platform in 2012. All patients who consent to screen for the I-SPY 2 trial receive a baseline QOL questionnaire. Patients who consent to the treatment phase of I-SPY 2 also complete questionnaires on the first day of treatment, mid-way through neoadjuvant treatment, prior to surgery, and then 1, 6, 12 and 24 months post-surgery. Instruments have included the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire (EORTC) QLQ C30 and BR23, as well as NCI Patient-Reported Outcomes Measurement Information System (PROMIS) measures, the National Comprehensive Cancer Network (NCCN) Distress Thermometer, and a Fear of Recurrence (FOR) instrument. We are currently implementing an electronic platform for survey collection and modifying the survey instruments to incorporate 31 items from the Patient Reported Outcomes-Common Terminology Criteria for Adverse Events (PRO-CTCAE) measurement system along with previously included PROMIS items in domains of physical, psychological, cognitive, and sexual function, the Distress Thermometer, and the FOR instrument. During neoadjuvant treatment, patients will also complete weekly abbreviated surveys containing PRO-CTCAE items only. We are using the data from these measures to generate a Clinical Benefit Index (CBI), a single composite score that integrates a PROMIS Preference (PROPr) score with a clinical efficacy assessment (residual cancer burden- RCB index) to provide new insight into the overall impact that therapeutic agents in I-SPY2 have on cancer recurrence risk, general health, and QOL.

Specific Aims: The primary objective of the QOL study is to evaluate the short- and long-term impact on QOL of novel agents added to standard treatment in high-risk breast cancer patients receiving neoadjuvant therapy. Factors including patient age, hormone receptor and HER2 status, and response to treatment by residual cancer burden will be evaluated to understand their impact on a patients’ QOL trajectory over time. A secondary objective is to compare patient reported toxicities (using PRO-CTCAE measures) with clinician-reported adverse events.

Accrual: The I-SPY 2 trial has registered 2729 patients to date and there are 18 sites open across the US. Since the initiation of the QOL study, at least one QOL survey has been collected from 1066 patients. Given the adaptive design, enrollment for each agent varies based on patient outcomes, but collection of PRO measures on all patients will continue as new agents enter the trial. Clinical trial information: NCT01042379.

Citation Format: Hila Ghersin, Aheli Chattopadhyay, Anne Blaes, Tara Sanft, Dawn Hershman, Amrita Basu, Ruby Singhrao, Susie Brain, Diane Heditsian, Hope S Rugo, Laura Esserman, Michelle Melisko. Introducing an electronic platform to collect patient reported outcomes in the I-SPY 2 trial, a neoadjuvant clinical trial [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr OT3-19-02.

Abstract OT3-03-02: Personalized breast cancer screening in a population-based study: Women informed to screen depending on measures of risk (WISDOM)

Background: WISDOM is a 100,000 healthy women preference-tolerant, pragmatic study comparing traditional annual screening to personalized risk-based breast screening. The novelty of WISDOM personalized screening is the integration of previously validated genetic and clinical risk factors (age, family history, breast biopsy results, ethnicity, mammographic density) into a single risk assessment model that directs the starting age, timing, and frequency of screening. The goal of WISDOM is to determine if personalized screening, compared to annual screening, is as safe, less morbid, enables prevention, and is more accepted by women. The study is registered on ClinicalTrials.gov, NCT02620852.

Methods: Women aged 40-74 years with no history of breast cancer or DCIS, and no previous double mastectomy can join the study online at wisdomstudy.org. Participants can either elect randomization or self-select a study arm. Then, they can provide electronic consent and sign the Release for Medical Information via DocuSign. For all participants, 5-year risk of developing breast cancer is calculated according to the Breast Cancer Screening Consortium (BCSC) model. Participants in the personalized arm undergo panel-based mutation testing (BRCA1, BRCA2, TP53, PTEN, STK11, CDH1, ATM, PALB2, and CHEK2), and their 5-year risk is calculated using the BCSC score combined with a Polygenic Risk Score (BCSC-PRS) that includes 75 single nucleotide polymorphisms (SNPs) known to increase breast cancer risk (will increase to 229). The SNPs and mutations are assessed by saliva-based testing through Color Genomics. 5-year risk level thresholds are used to stratify for low-, moderate- and high risk. Risk stratification determines age to start, stop, and frequency of screening.

Accrual: As of July 2019, the WISDOM study is open to all eligible women in California, North Dakota, South Dakota, Minnesota, Iowa, Illinois, and New Jersey. To date, 30,392 eligible women have registered, and 21,392 women have consented to participate in the trial. The median age was 56 years. 85% of participants were Caucasian, 2% African-American, and 5% Asian. 6% self-reported Hispanic ethnicity. WISDOM is actively partnering with Blue Cross Blue Shield Association for national coverage, self-insured companies (Salesforce, Genentech, Qualcomm, CalPERS) and Medi-Cal (Inland Empire Health Plan) using a coverage with evidence progression approach.

Accrual expansion and diversity: To strengthen generalizability, the WISDOM Study is enhancing the diversity of our potential participant population by expanding to other states (Alabama, Louisiana), and partnering with other health insurers and self-insured companies. Future expansion regions include Texas, Florida, South Carolina, Oklahoma, Montana, and New Mexico. Additionally, we have translated the whole study experience to Spanish to further reach Spanish-speaking communities. With the engagement of patient advocates and community partnerships, expanding diversity recruitment will strengthen our scientific knowledge of breast cancer risk and increase access to personalized breast cancer screening recommendations for all women. WISDOM enrollment will continue through 2020.

Conclusions: Results at 5 years will enable us to demonstrate that personalized screening improves healthcare value by reducing screen volumes and costs without jeopardizing outcomes.

Citation Format: Mandy Che, Allison Stover Fiscallini, Irene Acerbi, Yiweh Shieh, Lisa Madlensky, Jeffrey Tice, Elad Ziv, Martin Eklund, Amie Blanco, Barry Tong, Deborah Goodman, Lamees Nassereddine, Nancy Anderson, Heather Harvey, Steele Fors, Hannah L Park, Antonia Petruse, Skye Stewart, Janet Wernisch, Larissa Risty, Ian Hurley, Barbara Koenig, Celia Kaplan, Robert Hiatt, Neil Wenger, Vivian Lee, Diane Heditsian, Susie Brain, Leah Sabacan, Barbara Parker, Alexander Borowsky, Hoda Anton-Culver, Hoda Anton-Culver, Arash Naeim, Andrea Kaster, Melinda Talley, Laura van't Veer, Andrea LaCroix, Olufunmilayo I Olopade, Deepa Sheth, WISDOM Study and Athena Breast Health Network Investigators and Advocate Partners and Laura Esserman. Personalized breast cancer screening in a population-based study: Women informed to screen depending on measures of risk (WISDOM) [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr OT3-03-02.

Abstract 2830: Breast cancer and the human oral and gut microbiomes

The human body harbors ten times more bacterial cells than human cells - a stunning figure that suggests a likely dynamic between our bodies and the bacteria we carry, both in health and disease. In this study, we characterized and compared the gut and oral microbiota from women with invasive breast cancer, women with ductal carcinoma in situ (DCIS), and healthy women. Samples were collected prior to any systemic therapy to avoid therapy-associated effects on the microbiomes studied. Kits for collecting oral and stool swab samples were distributed to patients for self-collection. DNA was isolated from these samples and bacterial 16S rRNA was PCR amplified and sequenced. Based on the sequencing results, bacterial taxa present in the samples were enumerated. The gut microbiota of women with breast cancer demonstrated significantly lower alpha-diversity compared to the gut microbiomes of healthy women. In contrast, there was no difference in gut microbiota alpha-diversity of women with DCIS compared to healthy women. There were no differences in alpha-diversity of the oral microbiota between any of the cohorts. Discriminant analysis of principal components (DAPC) at the genus level of both the gut and oral microbiota demonstrated distinct clustering of the DCIS, breast cancer, and healthy cohorts. LEfSe analyses were performed to detect differences in relative abundance of bacterial taxa across the gut and oral samples. The genus Bacteroides was significantly enriched in breast cancer compared to healthy samples, as were the related taxa Bacteroidetes (phylum), Bacteroidia (class), Bacteroidales (order), and Bacteroidaceae (family). The genera Fusicatenibacter and Butyrivibrio, both from the phylum Firmicutes, class Clostridia, order Clostridiales, family Lachnospiraceae, were more abundant in the healthy cohort. Only 2 genera, Fusicatenibacter and Clostridium were differentially abundant between the DCIS and healthy gut samples, both being enriched in the healthy samples. Numerous taxa in the oral microbiota were found to be differentially abundant between cohorts. In particular, 7 genera (Bacteroides, Blautia, Faecalibacterium, Roseburia, Pseudobutyrivibrio, Anaerostipes, and Subdoligranulum) were all significantly enriched in the healthy oral samples compared to the DCIS and breast cancer oral samples. To determine whether the taxonomic differences we observed between the cohorts’ gut and oral microbiota corresponded to functional differences, we performed a predictive functional analysis using Piphillin which identified 35 KEGG pathways differentially present in the gut microbiota and 8 pathways differentially present in the oral samples. Understanding how gut and oral microbiomes relate to breast cancer may open up new opportunities for the development of novel markers for early detection (or markers of susceptibility) as well as new strategies for prevention and/or treatment.

Citation Format: Michael J. Campbell, Emma McCune, Breanna Johnson, Tess O'Meara, Diane Heditsian, Susie Brain, Laura Esserman. Breast cancer and the human oral and gut microbiomes [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 2830.

Abstract OT2-08-01: Personalized breast cancer screening in a population based study: Women Informed to Screen Depending On Measures of risk (WISDOM)

Background: WISDOM is a 100,000 healthy women preference-tolerant, pragmatic study comparing annual to personalized risk-based breast screening. The novelty of WISDOM personalized screening is the integration of previously validated genetic and clinical risk factors (age, family history, breast biopsy results, ethnicity, mammographic density) into a single risk assessment model that directs the starting age, timing, and frequency of screening. The goal of WISDOM is to determine if personalized screening, compared to annual screening, is as safe, less morbid, enables prevention, and is preferred by women. The study is registered on ClinicalTrials.gov, NCT02620852.

Methods: Women aged 40-74 years with no history of breast cancer or DCIS, and no previous double mastectomy can join the study online at wisdomstudy.org. Participants can elect randomization or self-select a study arm, and provide electronic consent and Release for Medical Information using DocuSign. For all participants, 5-year risk of developing breast cancer is calculated according to the Breast Cancer Screening Consortium (BCSC) model. Participants in the personalized arm undergo panel-based mutation testing, and their 5-year risk is calculated using the BCSC score combined with a Polygenic Risk Score (BCSC-PRS) that includes 75 single nucleotide polymorphisms (SNPs, increase to 229) known to increase breast cancer risk. SNPs and mutations (BRCA1, BRCA2, TP53, PTEN, STK11, CDH1, ATM, PALB2, and CHEK2) are assessed by saliva-based testing through Color Genomics. 5-year risk level thresholds are used to stratify for low-, moderate- and high risk. Risk stratification determines age to start, stop, and frequency of screening.

Enrollment: As of July 2018, the WISDOM study is open to all eligible women in California, North Dakota, South Dakota, Minnesota and Iowa. To date, 23,329 eligible women have registered and 14,393 women have consented to participate in the trial. We analyzed 3,255 participants who have completed risk assessment in the personalized arm. The median age was 56 years. 82% were Caucasian, 1% African-American, and 6% Asian. 9% self-reported as Hispanic. We are partnering with health insurers and self-insured companies using coverage with evidence progression. To strengthen generalizability, we are expanding to other states. WISDOM enrollment will continue past 2019.

Feasibility: To evaluate the addition of PRS, we used paired statistical tests (McNemar) to compare the distributions of BCSC, and BCSC-PRS risk estimates around low-risk (&lt;1.3%), and very-high risk (&gt;6%) thresholds, the latter corresponding to 5-year risk of a BRCA mutation carrier. The median 5-year risk was 1.5% (IQR 1.0-2.1%) using the BCSC model, and 1.4% (IQR 0.8-2.5%) using the BCSC-PRS model. The BCSC-PRS model classified more women into the low (&lt;1%) and very high (≥6%) risk categories compared to the BCSC model (p &lt; 0.001).

Conclusions: Our findings demonstrate that incorporating genetic variants into a validated clinical model is feasible and impacts risk classification compared to a model without genetic risk factors. Results at 5 years will reveal if this classification improves healthcare value by reducing screen volumes and costs without jeopardizing outcomes.

Citation Format: Acerbi I, Shieh Y, Madlensky L, Tice J, Ziv E, Eklund M, Blanco A, DeRosa D, Tong B, Goodman D, Nassereddine L, Anderson N, Harvey H, Layton T, Park HL, Petruse A, Stewart S, Wernisch J, Risty L, Koenig B, Sarrafan S, Firouzian R, Kaplan C, Hiatt R, Parker BA, Wenger N, Lee V, Heditsian D, Brain S, Stover Fiscalini A, Borowsky AD, Anton-Culver H, Naeim A, Kaster A, Talley M, van 't Veer LJ, LaCroix A, Wisdom Study and Athena Breast Health Network Investigators and Advocate Partners, Esserman LJ. Personalized breast cancer screening in a population based study: Women Informed to Screen Depending On Measures of risk (WISDOM) [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr OT2-08-01.

Abstract P1-05-01: Breast cancer and the human microbiome

The human body harbors ten times more bacterial cells than human cells – a stunning figure that suggests a likely dynamic between our bodies and the bacteria we carry, both in health and disease. In this study, we characterized and compared the gut, oral, and breast tissue microbiomes from women with invasive breast cancer, women with ductal carcinoma in situ (DCIS), and healthy women. Samples were collected prior to any systemic therapy to avoid therapy-associated effects on the microbiomes studied. Kits containing materials for collecting oral and stool swab samples were distributed to patients for self-collection. DNA was isolated from these samples and bacterial 16S rRNA was PCR amplified and sequenced. Based on the sequencing results, bacterial taxa present in the samples were enumerated. In our analyses, we looked at microbial diversity and differential relative abundance of bacterial taxa across the three cohorts. Oral and gut microbial diversity at various taxa levels were assessed using Shannon and Simpson diversity indices. The oral microbiome did not show any significant difference in microbial diversity across the three cohorts. In the gut microbiome, the invasive cohort showed a significant decrease in microbial diversity when compared to the healthy cohort. Differences in phylogenetic and relative abundance of bacterial taxa across the three cohorts were measured using a T-test analysis with a p value less than 0.05 considered significant. In the oral microbiome, there were no significant differences in the relative abundance of bacteria across the three cohorts. In the gut microbiome, there were significant differences in the relative abundance of bacteria within each cohort on the phylum, family, and genus levels. The genus Fusicanterbacter (associated with the Lachnospiracaea family and Firmicutes phylum) was significantly overabundant in gut microbiomes of healthy women when compared to the gut microbiomes of women with DCIS or invasive breast cancer. Meanwhile, the genus Bacteriodes (associated with the Bacteroidaceae family and Bacteriodetes phylum) was significantly overabundant in the gut microbiomes of women with invasive breast cancer when compared to the gut microbiomes of healthy women. Although tissues are often thought of as sterile, there is emerging data indicating that different tissues may harbor their own unique microbiomes. We obtained breast tissue microbiome data from a small subset of our breast cancer and DCIS cohorts, as well as healthy breast tissue from reduction mammaplasty specimens. At the genus level, we observed an enrichment of Lactococcus, Lactobacillus, and Halomonas in healthy breast tissues compared to breast cancer tissues and an enrichment of Hyphomicrobium in breast cancer tissues compared to healthy breast tissues. Understanding how gut, oral, and tissue microbiomes relate to breast cancer may open up new opportunities for the development of novel markers for early detection (or markers of susceptibility) as well as new strategies for prevention and/or treatment.

Citation Format: McCune E, Johnson B, O'Meara T, Theiner S, Campos M, Heditsian D, Brain S, Esserman L, Campbell M. Breast cancer and the human microbiome [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 P1-05-01.

Abstract OT3-03-01: Preference-Tolerant randomized trial of risk-based vs. annual breast cancer screening: WISDOM study in progress

Purpose: Women Informed to Screen Depending on Measures of risk (WISDOM) trial is a pragmatic study comparing two real world approaches to clinical care for breast screening: annual screening versus personalized screening. The novelty of the personalized arm of the study is that we are combining known risk factors (age, family history, history of breast disease, ethnicity, BIRADS breast density, and genetics) into a single risk assessment model. All components of the model have been tested and established, but have never been used jointly.

The goal of the WISDOM study is to examine the effectiveness of personalized breast cancer screening and to bring objective recommendations to the current mammography screening debate.

Methods: The WISDOM trial will enroll 100,000 women with a preference-tolerant design that will determine if risk-based screening vs. annual screening, is as safe, less morbid, enables prevention, and is preferred by women. Women 40 - 74 years of age with no history of breast cancer or DCIS, and no previous double mastectomy can join the study from the WISDOM Study website (wisdomstudy.org). All participants sign up, elect randomization or self-select the study arm, provide electronic consent using DocuSign (eConsent), and sign a Medical Release Form. For all participants, 5-year risk of developing breast cancer is calculated according to the Breast Cancer Screening Consortium (BCSC) model. For participants in the personalized arm, the overall 5-year risk BCSC score is combined with a Polygenic Risk Score, based on a genetic test including mutations in 9 genes (BRCA1, BRCA2, TP53, PTEN, STK11, CDH1, ATM, PALB2, and CHEK2) and a panel of 75 common single nucleotide polymorphisms known to increase breast cancer risk. Risk stratification will determine frequency of screening. The study is registered on ClinicalTrials.gov as NCT02620852.

Results: As of June 12th 2017, the WISDOM study is live at all UC medical centers and recruitment is open to all eligible women in California. Up to date 4,769 eligible women registered at all sites. 2,823 women have consented in the trial. 64% were randomized and 36% chose their screening arm. A pilot was conducted to test the logistics of online participation and examine the acceptance of the study design and approach. We are partnering with health insurance companies and self-insured companies to reach our recruitment goal.

Conclusions: Enrollment will be completed by end of 2018.

Acknowledgment: support by the Patient-Centered Outcomes Research Institute (PCORI), PCS-1402-10749 to L.J.E.

(*) Authors equally contributed to this work.

Citation Format: Acerbi I, Abihider K, Ling J, Layton T, DeRosa D, Madlensky L, Tice J, Shieh Y, Ziv E, Sarrafan S, Firouzian R, Tong B, Blanco A, Lee V, Heditsian D, Brain S, Kaplan C, Borowsky A, Anton-Culver H, Naeim A, Cink T, Stover Fiscalini A, Parker B, van 't Veer L, Wisdom Study and Athena Breast Health Network Investigators and Advocate Partners, LaCroix A, Esserman L. Preference-Tolerant randomized trial of risk-based vs. annual breast cancer screening: WISDOM study in progress [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 OT3-03-01.

Heterogeneous drug penetrance of veliparib and carboplatin measured in triple negative breast tumors

BACKGROUND

Poly(ADP-ribose) polymerase inhibitors (PARPi), coupled to a DNA damaging agent is a promising approach to treating triple negative breast cancer (TNBC). However, not all patients respond; we hypothesize that non-response in some patients may be due to insufficient drug penetration. As a first step to testing this hypothesis, we quantified and visualized veliparib and carboplatin penetration in mouse xenograft TNBCs and patient blood samples.

METHODS

MDA-MB-231, HCC70 or MDA-MB-436 human TNBC cells were implanted in 41 beige SCID mice. Low dose (20 mg/kg) or high dose (60 mg/kg) veliparib was given three times daily for three days, with carboplatin (60 mg/kg) administered twice. In addition, blood samples were analyzed from 19 patients from a phase 1 study of carboplatin + PARPi talazoparib. Veliparib and carboplatin was quantified using liquid chromatography-mass spectrometry (LC-MS). Veliparib tissue penetration was visualized using matrix-assisted laser desorption/ionization mass spectrometric imaging (MALDI-MSI) and platinum adducts (covalent nuclear DNA-binding) were quantified using inductively coupled plasma-mass spectrometry (ICP-MS). Pharmacokinetic modeling and Pearson's correlation were used to explore associations between concentrations in plasma, tumor cells and peripheral blood mononuclear cells (PBMCs).

RESULTS

Veliparib penetration in xenograft tumors was highly heterogeneous between and within tumors. Only 35% (CI 95% 26-44%), 74% (40-97%) and 46% (9-37%) of veliparib observed in plasma penetrated into MDA-MB-231, HCC70 and MDA-MB-436 cell-based xenografts, respectively. Within tumors, penetration heterogeneity was larger with the 60 mg/kg compared to the 20 mg/kg dose (RSD 155% versus 255%, P = 0.001). These tumor concentrations were predicted similar to clinical dosing levels, but predicted tumor concentrations were below half maximal concentration values as threshold of response. Xenograft veliparib concentrations correlated positively with platinum adduct formation (R 2 = 0.657), but no PARPi-platinum interaction was observed in patients' PBMCs. Platinum adduct formation was significantly higher in five gBRCA carriers (ratio of platinum in DNA in PBMCs/plasma 0.64% (IQR 0.60-1.16%) compared to nine non-carriers (ratio 0.29% (IQR 0.21-0.66%, P < 0.0001).

CONCLUSIONS

PARPi/platinum tumor penetration can be measured by MALDI-MSI and ICP-MS in PBMCs and fresh frozen, OCT embedded core needle biopsies. Large variability in platinum adduct formation and spatial heterogeneity in veliparib distribution may lead to insufficient drug exposure in select cell populations.

Abstract C61: Non-homogeneous drug penetrance of veliparib measured in triple negative breast tumors

Background: Veliparib, an inhibitor of Poly(ADP-ribose) polymerase (PARPi), in combination with carboplatin showed efficacy in triple negative breast cancer (TNBC) patients in the I-SPY 2 TRIAL. However ∼42% of TNBC did not achieve pathologic complete response. Insufficient uptake of drug in TNBC may lead to inadequate response to PARPi. As a first step toward testing this hypothesis in patients, we quantified veliparib penetration in mouse xenograft models of TNBC.

Methods: MDA-MB-231, HCC70 or MDA-MB-436 human TNBC cells were implanted in 41 beige SCID mice. Veliparib at low dose (20mg/kg) or high dose (60mg/kg) and carboplatin (60mg/kg) was given three times daily for three days. MR images were taken at day 1. Plasma, fresh frozen and OCT embedded tissues were analyzed using Matrix-assisted laser desorption/ionization mass spectrometric imaging (MALDI) Liquid chromatography–mass spectrometry (LC-MS). Drug penetration was compared among doses and cell lines.

Results: Ex vivo veliparib concentrations quantified by LC-MS differed significantly among the tumors derived from the three cell lines. Liver and plasma concentrations were uniformly high in all mice compared to tumor and muscle tissues. Plasma pharmacokinetics in mice exhibited non-linear clearance resulting in prolonged high plasma levels at higher doses, while tumor and plasma concentrations were linearly correlated. MALDI-MSI images of tumor and muscle in 12 mice showed higher veliparib concentrations in necrotic areas compared to areas with viable tumor cells (P = 0.126, Table) and higher concentrations at the rim then in the center of the tumor (P = 0.046). Lower concentrations were found in MDA-MB-231 than in other cell lines (0.008). Contrast agent and veliparib accumulated near the rim of the tumors and a fast elimination of the contrast agent from the tumor correlated with relatively low veliparib tumor concentrations.

Conclusions: The spatial distribution of veliparib in TNBC depends on the dose and tumor cell biology. We demonstrated that MALDI-MSI can be used to measure veliparib penetration tumor samples, which may have potential to monitor response to PARPi therapies.

Table: Veliparib concentrations by LC-MS and its spatial distribution by MALDI varies by tissue, drug dose and TNBC cell line of origin.

TissueNMedian conc. (mg/L)RSEPMethodPlasma low/high dose9/60.19 / 0.8610%/11%0.001 (low/high dose)LC-MSTNBC xenograft tissue19/170.05 / 0.3356% / 12%0.322 (tumor/plasma)LC-MSMuscle5/60.12 / 0.4770% / 47%0.882 (muscle/plasma)LC-MSLiver6/60.47 / 1.7720% / 14%&lt;0.001 (liver/plasmaLC-MSnecrotic tissue/ cellular tumor tissue19/191.63 / 1.0170% / 85%0.126MALDIrim/ center19/191.54 / 1.1389% / 87%0.046MALDIHCC70 / MDA-MB-231 / MDA-MB-4366/7/60.31/ 0.12/0.1418% / 22% / 49%0.008LC-MS

Citation Format: Imke H. Bartelink, Brendan Prideaux, Gregor Krings, Lisa Wilmes, Pei R.E. Lee, Byron Hann, Jean-Philippe Coppé, Diane Heditsian, Lamorna Swigart-Brown, Ella F. Jones, Sergey Magnitsky, Ron Keizer, Laura Esserman, Weiming Ruan, Alan Wu, Douglas Yee, Veronique Dartois, Denise Wolf, Rada Savic, Laura vantVeer. Non-homogeneous drug penetrance of veliparib measured in triple negative breast tumors. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2015 Nov 5-9; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2015;14(12 Suppl 2):Abstract nr C61.