Abstract P5-15-01: The use of 18F-FDG PET/CT as an initial staging procedure for stage II-III breast cancer reduces false positives, costs, and time to treatment: A multicenter value analysis in the I-SPY2 trial

Introduction: Diagnostic metastatic staging imaging (SI) for asymptomatic stage I-II patients (pts) is not routinely recommended, but is warranted in stage II-III pts with high risk biological subtypes, where previous trials have shown up to a 15% rate of de novo metastatic disease. NCCN guidelines endorse CT CAP and bone scan (STD) for stage III pts, but not PET/CT, and PET/CT is not covered in most parts of the country. We present data on the performance and value of PET/CT.

Methods: Data were available for 799 high risk clinical stage II-III pts screened for I-SPY2 at UCSF, Uminn, UAB, and Georgetown. Of these, 564 pts ranging in age from 25-81 (median = 48) had complete records that were retrospectively reviewed for SI and potential false positives (FP), defined as incidental findings on SI proven benign by subsequent workup. Economic evaluation was conducted from the payer perspective using the mean national 2018 Medicare Physician Fee Schedule and representative costs from the UCSF billing department. The incremental cost effectiveness ratio (ICER) measured the cost of using PET/CT per percent patient (pt) who avoided a FP.

Results: The rate of de novo metastatic disease was 4.8% (38/799), range 3.6-6.4%. Of the 564 pts with complete records, diagnostic SI varied significantly among the four sites (p < 0.0001). STD was used for most pts at UAB (92.8%, 141/152) and Georgetown (85.7%, 54/63), while PET/CT was used for most pts at UCSF (86.6%, 226/261) and Uminn (63.6%, 56/88). Chest X-ray was used for 29.5% (26/88) at Uminn. There were significantly more pts with FP in the group that received STD (22.1%, 51/231) vs. PET/CT (11.1%, 33/298) (p < 0.05). Mean time between incidental finding on SI to determination of FP was 10.8 days. When controlling for institution, mean time from cancer diagnosis to initiation of neoadjuvant chemotherapy was significantly different between STD (44.3 days) and PET/CT (37.5 days) groups (p < 0.05). When aggregating the four sites using mean costs from the 2018 Medicare Physician Fee Schedule, the mean cost/pt was $1132 for STD vs. $1477 for PET/CT. The mean increase in price from baseline SI costs due to FP workup was $216 (23.6%) for STD vs. $65 (4.6%) for PET/CT. The ICER was $31 per percent pt who avoided a FP. When analyzing UCSF pts alone using representative reimbursements from Medicare, the mean cost/pt was $1236 for STD vs. $1081 for PET/CT; using representative reimbursements from Anthem Blue Cross, the mean cost/pt was $3080 for STD vs. $1662 for PET/CT. The ICERs were -$10 and -$95 per percent pt who avoided a FP, respectively.

Conclusion: As compared to STD metastatic staging workup, PET/CT added value by decreasing FP two-fold. This reduced direct costs of FP workup procedures that took a mean time of 10.8 days to resolve. PET/CT also accelerated treatment start. Reducing the chance of FP workup for metastatic disease is of enormous value to pts. Our data establish the value of PET/CT for staging in our high risk clinical stage II-III trial population and highlight the need for alignment between hospital pricing strategies and payer coverage policies in order to deliver high value care to pts.

Citation Format: Hyland CJ, Varghese F, Yau C, Beckwith H, Khoury K, Varnado W, Hirst G, Chien J, Yee D, Isaacs C, Forero-Torres A, Esserman L, Melisko M, I-SPY2 Consortium. The use of 18F-FDG PET/CT as an initial staging procedure for stage II-III breast cancer reduces false positives, costs, and time to treatment: A multicenter value analysis in the I-SPY2 trial [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 P5-15-01.

Abstract P1-11-18: Measuring severe anxiety in patients with metastatic breast cancer: Living up to the PROMIS

Purpose/Objective(s):

Symptom burden in the advanced cancer patient can be substantial. PROMIS (Patient Reported Outcome Measurement Information System) is a powerful PRO symptom assessment tool that is increasingly being utilized at the point of care through patient-facing electronic health record (EHR) systems. However, the PROMIS threshold (T-score) for detecting severe anxiety has not been previously validated for patients with advanced breast cancer. The sensitivity/specificity of current expert derive threshold T-score of >/=75 in this specific population is not known. In this study, we compared PROMIS scores with the PRO-CTCAE anxiety instrument—a standard PRO tool used in the setting of clinical trials that assesses anxiety frequency, severity, and interference with usual activities—to examine the best T-score to use for PROMIS to guide management in advanced breast cancer care.

Materials/Methods:

A total of 84 unique visits of 74 English speaking patients on active cancer treatment for metastatic breast cancer were assessed using electronic PROMIS CAT (Computer Adaptive Test) and PRO-CTCAE at the UCSF Carol Buck Breast Cancer Center. Assessment forms were displayed on a touch screen tablet and completed by the patient at check-in for weekly treatment visits. PRO-CTCAE anxiety questions were graded on a scale of 1 (none) to 5 (disabling). Any score of grade >/=4 (severe to disabling) for frequency, severity or interference was defined as severe anxiety.

Results:

There was a strong correlation of PROMIS T-score and maximum PRO-CTCAE grade (highest grade of frequency, severity, or interference); Spearman correlation coefficient = 0.77 (P= <0.001). No patients reached the expert derived severe threshold of PROMIS T-score 75. Highest PROMIS T-score was 69 (range, 33-69). 11 patients reported severe or disabling anxiety by PRO-CTCAE at one visit. Area under the ROC analysis identified a cutoff that maximizes Youden's index at 55.05—sensitivity = 100% (95% CI) and specificity = 63% (95% CI).

Conclusion:

Electronic systems with integrated patient reported outcomes (PROs) along with validated thresholds to identify severe anxiety will allow for systematic identification of symptoms at point of care and the opportunity to respond rapidly to those symptoms most distressing to patients.

Citation Format: Marquez C, Li Y, Huang C-Y, Rugo H, Rabow M, Melisko M, Esserman L. Measuring severe anxiety in patients with metastatic breast cancer: Living up to the PROMIS [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 P1-11-18.

Abstract P1-15-02: Withdrawn

This abstract was withdrawn by the authors.

Citation Format: Schwab R, Clark A, Yau C, Wolf D, Chien AJ, Majure M, Ewing C, Wallace A, Roesch E, Helsten T, Forero A, Stringer-Reasor E, Vaklavas C, Nanda R, Jaskowiak N, Boughey J, Haddad T, Han H, Lee C, Albain K, Isaacs C, Elias A, Ellis E, Shah P, Lang J, Lu J, Tripathy D, Kemmer K, Yee D, Haley B, Korde L, Edmiston K, Northfelt D, Viscusi R, Khan Q, I-SPY 2 Consortium, Symmans WF, Perlmutter J, Hylton N, Rugo H, Melisko M, Wilson A, Singhrao R, Asare S, van't Veer L, DeMichele A, Berry D, Esserman L. Withdrawn [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 P1-15-02.

Abstract P6-09-03: Gene expression patterns in younger versus older HR+ breast cancer patients: An age-related analysis of HoxB13/IL17BR (H/I), proliferation status, and quantitative hormone receptor expression

Background: HR+ breast cancer in younger vs older patients may have distinct biological features. The Breast Cancer Index (BCI) is a gene expression-based assay that includes two component biomarkers: the HoxB13/IL17BR (H/I ratio), an endocrine response biomarker; and the molecular grade index (MGI), a set of proliferation-related genes. The objective of this study was to assess age-related associations with endocrine sensitivity (H/I), proliferative status (MGI), and quantitative expression of ER and PR.

Methods: Data were extracted from the BCI Clinical Database for Correlative Studies, an IRB-approved de-identified database containing clinicopathologic and molecular variables from clinical cases submitted for BCI testing. Molecular results from H/I, MGI, and quantitative (qPCR–based) ER and PR were analyzed across age groups. Chi-squared tests and ANOVA were used to compare the results between age groups (<40y, 40-49y, 50-59y, 60-69y, and ≥70y).

Results: Analyses included 19,126 patients (median age at diagnosis 58.6y; 4.5% <40y, 20.6% 40-49y, 28.9% 50-59y, 32.5% 60-69y, and 13.6% ≥70y). Proliferation status (MGI) was significantly higher in patients <40y and 40-49y compared to older groups (P<.0001).H/I analysis indicated a similar distribution of high versus low endocrine responsiveness across all groups (P=.94), except the 40-49y group, in which fewer patients had high H/I (44.2% in <40y, 39.4% in 40-49y, 43.7% in 50-59y, 43.7% in 60-69y, and 43.1% in ≥70y; P=.0001). Median qER increased with age (P<0.0001), while qPR was similar across all age groups except for the 40-49y group (P=.57), in which expression was higher (P<.0001).

Conclusion: Results from >19,000 patients with early-stage HR+ breast cancer and BCI testing showed a broad distribution in all variables. Tumors from the youngest patients (<40y) had the highest expression of proliferative genes and the lowest quantitative ER expression. However, endocrine response, according to the H/I biomarker, does not appear to be strongly linked to age.

Citation Format: Melisko M, Chien AJ, Poage GM, Salganik M, Schnabel CA, Ruddy KJ, Blackwell K. Gene expression patterns in younger versus older HR+ breast cancer patients: An age-related analysis of HoxB13/IL17BR (H/I), proliferation status, and quantitative hormone receptor expression [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 P6-09-03.

The value of embedding: integrated palliative care for patients with metastatic breast cancer

PURPOSE

The American Society of Clinical Oncology recommends concurrent palliative care (PC) for patients with metastatic cancer. Recent data show benefits of early PC (at least 90 days before death). However, little is known about PC among patients who die from metastatic breast cancer.

METHODS

Patients with metastatic breast cancer at a comprehensive cancer center. Analysis of medical records and clinician and patient surveys. Assess referral patterns and value to patients at the end of life (EOL) of a specialty PC service embedded in a breast oncology program; compare to a prior period of stand-alone PC.

RESULTS

In the 18-month study period, oncologists referred for palliative care 105 of their 515 (20.4%) patients; 59 (11.5%) patients were seen by the PC physician. Of the 38 referred patients who died, 23 (60.5%) were seen by embedded PC and all 23 received PC within 90 days of death; 0 of 18 decedents with data available for analysis had ICU stays within 30 days of death. In an earlier 24-month period of stand-alone PC, 43 patients died after receiving PC, but only 11 (25.5%) received PC within 90 days of death (p < 0.01) and 7 of 43 had ICU stays within 30 days of death (p = 0.074).

CONCLUSIONS

Embedded PC was well-received by patients and oncologists, increased early PC referrals, and improved EOL care. Avoidable, unnecessary health care utilization at the end of life, such as ICU stays in the last month of life, represent an important potential reduction in patient suffering and system costs.

Abstract P5-11-17: Body image in women with breast cancer using a scalp cooling system to reduce chemotherapy induced alopecia

Background: Most women consider hair to be an important part of body image. Alopecia is an emotionally traumatic side effect for breast cancer patients undergoing adjuvant chemotherapy. The DigniCap™ Scalp Cooling System is the first scalp cooling system cleared by the US Food and Drug Administration to reduce the likelihood of chemotherapy induced alopecia.

Methods: Quality of Life (QOL) data were collected as part of a prospective clinical trial evaluating the clinical performance of scalp cooling in women with early stage BC receiving adjuvant chemotherapy.

The study's primary endpoint was hair loss as evaluated by patient self-assessment. Treatment success was defined as ≤ 50% hair loss. QOL was evaluated by the EORTC-QLQ-BR23 (BR23) administered at baseline, last chemotherapy cycle, and one month later. For BR23, 4 response categories were collapsed to 2 categories (Not at all/A little bit and Quite a bit/Very much) for analysis. QOL was compared between those with success vs. failure of scalp cooling.

Results: 101 patients were evaluable for the primary endpoint: Success was seen in 67 (66.3%) pts. QOL at study entry was comparable between pts with scalp cooling success or failure for each item in the BR23 questionnaire. Results reported as percentages of patients in each group who answered either quite a bit or very much to body image-related questions on the BR23 questionnaire are displayed in Table 1.

BR23 results (% quite a bit/very much) one month after chemotherapyBR23 ItemsTreatment Success % (95% CI)Treatment Failure % (95% CI)Felt physically less attractive18.5% (9.0%, 27.9%)52.2% (31.8%, 72.6%)Felt less feminine15.4% (6.6%, 24.2%)29.1% (19.2%, 59.1%)Found it difficult to see themselves naked13.8% (5.5%, 22.2%)21.7% (4.9%, 38.6%)Felt dissatisfied with their body12.3% (4.3%, 20.3%)26.1% (8.1%, 44.0%)

Conclusions: Women with breast cancer using scalp cooling during chemotherapy who had hair preservation experienced improved quality of life, according to self-assessment of body image, compared to women who had significant hair loss.

Citation Format: Cigler T, Melin SA, Klein P, Hurvitz SA, Melisko M, Moore A, Park GD, Bageman E, Ver Hoeve ES, Rugo HS. Body image in women with breast cancer using a scalp cooling system to reduce chemotherapy induced alopecia [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P5-11-17.

Abstract OT1-03-15: The METRIC trial: A randomized international study of the antibody-drug conjugate glembatumumab vedotin (GV or CDX-011) in patients with metastatic gpNMB-overexpressing triple-negative breast cancer (TNBC)

Background

Glycoprotein NMB (gpNMB) is an internalizable transmembrane protein overexpressed in approximately 20% of breast cancer (BC), including approximately 40% of TNBC. gpNMB is a poor prognostic marker in BC (Rose CCR 2010) and preclinically has been implicated in tumor invasion, metastasis, and angiogenesis. GV is a novel antibody-drug conjugate targeting the potent cytotoxin monomethylauristatin E (MMAE) to gpNMB overexpressing cancer cells.

In a Phase I/II study and the Phase II "EMERGE" study, GV demonstrated promising activity with TNBC patients (pts) deriving the greatest benefit and exhibiting the highest degree of gpNMB overexpression. GV was well-tolerated with the most frequent treatment-related toxicities consisting of rash, neutropenia, and neuropathy. In subset analyses of the EMERGE trial, objective response rate (ORR) was 30% (7/23) for GV vs. 9% (1/11) for investigator's choice in tumors with gpNMB overexpression (&gt;25% of tumor epithelium); 18% (5/28) vs. 0% (0/11) in TNBC; and 40% (4/10) vs. 0% (0/6) in gpNMB-overexpressing TNBC for GV and IC respectively, with apparent improvements in progression-free survival (PFS; hazard ratio (HR) = 0.11) and overall survival (OS; HR = 0.14).

Trial design

The METRIC Trial (NCT#01997333) is an international (USA, CA, Aus), two-arm phase II study. Pts are randomized 2:1 to GV (1.88 mg/kg IV q 21 days) or capecitabine, a current standard of care for this population (2,500 mg/m2 daily for d1-14, q21 days) until progression or intolerance. Crossover is not permitted.

Eligibility criteria

Key eligibility criteria include: &gt;25% of tumor epithelium gpNMB+ by central immunohistochemistry (IHC) screening of archival tissue; estrogen receptor and progesterone receptor &lt;10% and HER2 negative [0-1+ IHC, or ISH copy number &lt;4.0/ratio &lt;2.0] by local assessment; ECOG 0-1; taxane resistance; anthracycline exposure (if indicated); &lt;2 chemotherapy regimens for advanced BC; measurable disease; no persistent Grade &gt;2 toxicity.

Specific aims

The primary endpoint is PFS per independent, blinded central review committee according to RECIST 1.1. Secondary endpoints are ORR, duration of response, OS, safety, pharmacokinetics and pharmacodynamics. Exploratory endpoints are quality of life and/or cancer-related pain.

Statistical methods and target accrual

The trial has 85% power to detect a PFS HR of 0.64 with two sided α = 0.05. The hypothesized median PFS is 4.0 months for capecitabine and 6.25 months for GV. Target accrual is open for 300 pts.

Citation Format: Melisko M, Yardley DA, Blackwell K, Forero A, Ma C, Montero A, Daniel BR, Wright G, Fehrenbacher L, Chew H, Ferrario C, Nanda R, Seiler Jr M, Guthrie T, Vance K, Ouellette G, He Y, Bagley RG, Zhang J, Vahdat LT. The METRIC trial: A randomized international study of the antibody-drug conjugate glembatumumab vedotin (GV or CDX-011) in patients with metastatic gpNMB-overexpressing triple-negative breast cancer (TNBC). [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr OT1-03-15.

The symptom phenotype of oncology outpatients remains relatively stable from prior to through 1 week following chemotherapy

Some oncology outpatients experience a higher number of and more severe symptoms during chemotherapy (CTX). However, little is known about whether this high risk phenotype persists over time. Latent transition analysis (LTA) was used to examine the probability that patients remained in the same symptom class when assessed prior to the administration of and following their next dose of CTX. For the patients whose class membership remained consistent, differences in demographic and clinical characteristics, and quality of life (QOL) were evaluated. The Memorial Symptom Assessment Scale (MSAS) was used to evaluate symptom burden. LTA was used to identify subgroups of patients with distinct symptom experiences based on the occurrence of the MSAS symptoms. Of the 906 patients evaluated, 83.9% were classified in the same symptom occurrence class at both assessments. Of these 760 patients, 25.0% were classified as Low-Low, 44.1% as Moderate-Moderate and 30.9% as High-High. Compared to the Low-Low class, the other two classes were younger, more likely to be women and to report child care responsibilities, and had a lower functional status and a higher comorbidity scores. The two higher classes reported lower QOL scores. The use of LTA could assist clinicians to identify higher risk patients and initiate more aggressive interventions.

Abstract P3-08-18: Association of tamoxifen use and ovarian aging in patients with invasive or pre-invasive breast cancer

Background: The use of tamoxifen has been shown to delay the recovery of chemotherapy-induced amenorrhea, however the independent impact of long-term endocrine therapy on ovarian aging is not known, and to our knowledge, has never been directly investigated. Understanding the effect of endocrine therapy on ovarian aging will help breast cancer patients of reproductive age make more informed and empowered decisions regarding their treatment. The aim of this study is to explore the relationship between tamoxifen therapy and age onset of menopause.

Methods: We conducted a retrospective cohort study using patients identified through the UCSF Cancer Registry and UCSF SPORE database. Women who were diagnosed with Stage 1-3 invasive or in situ breast cancer between 1985 and 2011, who were premenopausal at the time of diagnosis and who did not receive systemic chemotherapy were included. Patients with recurrent disease and prior ovarian surgery were excluded. Eligibility was confirmed by telephone, and online or paper surveys were distributed to eligible subjects only. Age onset of menopause was the primary endpoint of the study and was defined as the age at which a woman had her last period and no menses for 12 months. Age onset of menopause was assessed through surveys. The primary analysis compared age onset of menopause between subjects who received tamoxifen for any duration and control subjects who never received tamoxifen. Secondary analyses were performed using a Cox proportional hazards model to determine whether duration of tamoxifen exposure and age of tamoxifen initiation impacted age onset of menopause in subjects treated with tamoxifen.

Results: A total of 1137 potential subjects believed to meet eligibility criteria were identified and called, and 649 subjects were reached. Eligibility was confirmed by phone in 340 subjects. A total of 336 subjects consented to participate in the study, and 262 (78%) completed and returned the survey. 227 subjects were included in the primary analysis of which 110 subjects received prior tamoxifen, and 117 subjects received no prior tamoxifen. At the time of the survey, 16.3% vs. 20.2% of patients under age 50 that were exposed and not exposed to tamoxifen entered menopause, respectively. The median age onset of menopause was 50.94 and 51.34 for the tamoxifen and no tamoxifen groups, respectively. The hazard ratio between these groups was 1.077 which was not statistically significant (p = 0.6917). No association (p = 0.55) was found between the duration of tamoxifen use and the age onset of menopause. When controlling for tamoxifen duration, there was no significant difference (p = 0.93) in age onset of menopause between subjects who initiated tamoxifen prior to age 45 and those who initiated at age 45 or older.

Conclusion: These data suggest that tamoxifen alone is not associated with an earlier age onset of menopause, and that tamoxifen use, in the absence of systemic chemotherapy, is unlikely to significantly accelerate ovarian aging.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P3-08-18.

Abstract P1-02-07: Discordance for low and intermediate levels (1+ or 2+ by IHC) of HER2 protein expression in the phase III PRESENT trial

Background

Significant discordance has been described between different laboratories and between testing methodologies for HER2 overexpression and gene amplification. Concern has focused on missing patients who might benefit from treatment with HER2 targeted therapy. Concordance rates between local and central testing for tumors selected for HER2 0-2+ is not well described. We describe discordance rates between local and central testing performed to identify tumors with 1 and 2+ HER2 expression.

Methods

The PRESENT study is a multicenter, multinational, prospective, randomized, double-blind, controlled Phase 3 study assessing efficacy and safety of the peptide vaccine NeuVax, in HLA-A2 and/or A3 positive patients with early stage, node positive breast cancer expressing low and intermediate levels (1/2+ by IHC) of HER2 protein. PRESENT 2-step screening includes HLA testing followed by central lab confirmation of HER2 1 or 2+ expression using the DAKO HercepTest.

Results

215 patients underwent central IHC testing for HER2. Discordance between local and central testing was seen in 54% (117/215); 34% (65/192) of those eligible by local results were ineligible on central testing, and 48% (11/23) of those not eligible by local results were eligible on central testing.

Local testingCentral testing (IHC (%))IHC (n)01+2+3+0 (15)5 (33%)7 (47%3 (20%)—1+ (127)39 (31%)68 (53%)15 (12%)5 (4%)2+ (65)11 (17%)23 (35%)21 (32%)10 (16%)3+ (8)3 (38%)—1 (12%)4 (50%)

Of those with 1 or 2+ local results, 8% (15/192) were found to be 3+ on central testing. Discordant rates varied by geographic location with higher rates seen in Eastern Europe and Russia.

Conclusion

Significant discordance exists between local and central laboratory test results for HER2 expression by IHC even at lower levels of expression, and current tests are defined by their ability to determine 3+ positivity. In order to improve accuracy of testing and to develop a companion diagnostic for NeuVax, the Leica Bond Oracle HER2 IHC System will be incorporated into future HER2 screening for the PRESENT trial.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P1-02-07.

Clinical Phase II Study of Vorinostat, a Hydroxamic Type Histone Deacetylase Inhibitor, in Combination with Tamoxifen To Reverse Acquired Hormone Resistance in Breast Cancer Patients Who Progressed on Hormone Therapy

Background: Primary or acquired resistance to hormonal therapy remains a major clinical challenge in patients with breast cancer. The most commonly used approach to modulate estrogen receptor signaling includes the use of a selective estrogen receptor modulator or down-regulator, or an aromatase inhibitor. Recently, inhibition of histone deacetylases (HDAC) has emerged as a novel strategy to modulate the estrogen and progesterone receptors by a different mechanism. This study seeks to test whether the addition of an HDAC inhibitor to tamoxifen may reverse acquired hormone resistance.Methods: Patients with estrogen receptor (ER) positive metastatic breast cancer who progressed on prior hormonal therapy with one or two aromatase inhibitors, and up to three chemotherapy regimens for metastatic cancer were treated with 400 mg vorinostat daily for 21 of 28 days and 20 mg tamoxifen daily, continuously. Patients previously treated with tamoxifen in the adjuvant, but not in the metastatic setting, were eligible. Bone only disease was permissible if at least one lesion measured 1 cm by MRI.Results: The study enrolled 43 female patients with a median age of 56 years (range 34-71). To date 42 patients with ER-positive breast cancer completed at least 1 cycle of therapy with a median number of 4 (1-24) cycles and a median duration of response of 8 months. Prior hormonal therapy included at least one aromatase inhibitor in 41 (98%) patients and two aromatase inhibitors in 22 (52%) of the patients; 21 (50%) of the patients received at least one chemotherapy regimen for metastatic disease, and 22 (52%) patients had received adjuvant tamoxifen. Of the 34 patients evaluable for response to date, 7 (21%) had a confirmed partial response and one additional patient with bone only disease had a response by PET/CT, another 4 (12%) patients had stable disease for ≥ 6 months. Dose reductions from 400 mg to 300 mg vorinostat were required in 30% of patients and to 200 mg in 18%. Major grade 3/4 toxicities included fatigue (5 pts, 12%), anorexia/weight loss (2 pts, 5%), nausea/vomiting (2 pts, 5%), hypokalemia (1 pt, 2%), liver enzyme elevations (1 pt, 2%), lymphopenia (7 pts, 16%), thrombocytopenia (3 pts, 7%) and neutropenia (6 pts, 14%). Pulmonary emboli were observed in 2 (5%) patients. Common grade 2 toxicities were fatigue (14%), nausea/vomiting/diarrhea (21%), hyperglycemia (19%), anorexia (12%), and myelosuppression (19%). Histone H3 and H4 acetylation was seen at day 8 suggesting adequate vorinostat plasma levels in the majority of patients.Conclusions: These findings suggest that the addition of the HDAC inhibitor, vorinostat to tamoxifen in patients who have progressed on prior hormonal therapy and including prior adjuvant tamoxifen is tolerable and demonstrates efficacy.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 6100.

The Prognostic Significance of Functional Limitations among Women with Breast Cancer

Background:With the aging of the population, functional limitations are a growing burden among women with breast cancer. The prognostic impact of functional status among breast cancer survivors is not well understood.Methods:A total of 2270 women diagnosed with breast cancer between 1997 and 2000, and followed in the prospective cohort study, Life after Cancer Epidemiology (LACE) were included. Information on functional limitations, health behaviors, anthropometric and demographic factors was self-reported by participants at enrollment. Tumor characteristics, treatment and outcomes were ascertained from medical records.Associations between functional limitations and survival from all causes, breast cancer specific causes and competing causes were analyzed with delayed entry Cox proportional hazards regression.Results:Thirty-nine percent of the cohort reported one or more limitations at study entry. Compared to women without functional limitations (n=1,345), those with one or more limitations (n = 857) were proportionately more likely to be elderly, less educated and more obese (all p&lt;.0001). Over a mean follow-up of 7 years, breast cancer survivors with functional limitations had higher overall crude mortality than their counterparts with no limitations [137 (50.9%) versus 132 (49.1%) respectively, p&lt;.0001]. When covariates were taken into account, the presence of functional limitations was associated with deaths from all causes [hazard ratio (HR)=1.39, 95% confidence intervals (CI) 1.06-1.83] and those from competing causes (HR=2.60, 95%CI 1.69-3.98) but not with breast cancer specific deaths (HR=.90, 95%CI .71-1.14).Conclusion:More breast cancer cases with functional limitations die of competing causes than of breast cancer. Interventions aimed at regaining physical function should lead to improvements in life expectancy in this population.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 2067.

A phase I dose-escalation study of 5-day intermittent oral lapatinib therapy with biomarker analysis in patients with HER-2–overexpressing breast cancer

e14530

Background: Although current HER2 targeting agents have made measurable impact on the treatment of HER2overexpressing breast cancer, their effects have been modest. Recent evidence has redefined the target of interest as the HER2-HER3 signaling dimer and identified inherent signal buffering capacity that protects it against partial inhibitors of HER2 function. In preclinical studies, HER2 catalytic function and HER2-HER3 signaling can be suppressed, but this requires higher fully inactivating doses of HER- family tyrosine kinase inhibitors (TKIs) leading to apoptotic tumor cell death. We hypothesize that TKIs may be much more clinically effective if used at much higher and fully inactivating doses. Such high dosing may only be tolerable if given intermittently rather than continuously. Methods: To test this hypothesis clinically, we conducted a phase 1 dose-escalation study of a 5-day course of lapatinib (Lp) in women with advanced HER2-overexpressing breast cancer. Lp was administered on days 1–5 of a 14 day cycle. Starting Lp dose was 1750 mg/day and was escalated in cohorts of 3 until the maximum tolerated dose (MTD) was defined. The first cycle of Lp therapy was bracketed by tumor fine needle aspirations and serologic studies, performed at baseline and on day 5. Functional signaling pathway biomarker analysis was performed on tumor lysates using Reverse Phase Protein Microarrays to assay the inactivation of HER2-HER3 signaling. Plasma Lp concentration was assayed at all dose levels and cardiac function was rigorously monitored. Tumor core biopsies were performed on a subset of patients at the MTD to determine tissue Lp levels. Results: 17 patients have been treated to date. No grade 4 or serious adverse events (AEs) attributable to Lp have been noted. 1 patient experienced dose-limiting toxicity at dose level 6 (7000 mg/day) consisting of grade 3 diarrhea despite maximal anti-diarrheal support. There have been no cardiac AEs. The most common AEs include grade 2 diarrhea, nausea, vomiting, acne. Conclusions: The MTD and systemic exposure of Lp can be considerably increased throsugh intermittent dosing.

[Table: see text]

Phase II trial of the histone deacetylase inhibitor, vorinostat, to restore hormone sensitivity to the antiestrogen tamoxifen in patients with advanced breast cancer who progressed on prior hormone therapy

1075

Background: Modulation of estrogen receptor signaling is one of the most successful modalities in the treatment of estrogen receptor (ER) positive breast cancers. However, hormone therapy resistance remains a challenging problem. Histone deacetylases (HDAC) have emerged as a recent strategy to interfere with hormone receptor signaling by modulating the estrogen and progesterone receptor. Here we report the findings from a phase II trial evaluating the HDAC inhibitor, vorinostat and the anti-estrogen, tamoxifen, placed in context with correlative studies. Methods: Patients with ER-positive metastatic breast cancer who progressed on prior hormonal therapy and up to three chemotherapy regimens were treated with 400 mg vorinostat daily for three of four weeks and 20 mg tamoxifen daily, continuously. Histone acetylation was evaluated in peripheral blood mononuclear cells. Results: To date, 29 patients [median age 53 years (34–71)] have been treated with the combination. Pulmonary emboli were observed in 2/29 (7%) patients. Other grade 3/4 toxicities included fatigue (5/29, 17%), anorexia (2/29, 7%), diarrhea (1/29, 3%), nausea/vomiting (3/29, 10%), hypokalemia (1/29, 3%), liver enzyme elevation (1/29, 3%), lymphopenia (5/29, 17%) and leukopenia (4/29, 13%). Predominant grade 2 toxicities included fatigue, nausea/vomiting/diarrhea, hyperglycemia, anorexia, and myelosuppression. Six (21%) patients had an objective response, and 3/29 (10%) additional patients had disease stabilization for >6 months; 13/29 (45%) patients had at least one prior chemotherapy regimen for metastatic disease, 28/29 (92%) patients had progressed after exposure to at least one and 16/29 (55%) patients after two aromatase inhibitors, and 18/29 (62%) patients had received prior adjuvant tamoxifen. H3 and H4 histone acetylation was seen at day 8 suggesting adequate vorinostat plasma levels. Histone acetylation and baseline HDAC expression will be presented. Conclusions: These findings suggest that the addition of an HDAC inhibitor to tamoxifen in patients who have progressed on prior hormonal therapy and/or adjuvant tamoxifen may restore hormone sensitivity.

No significant financial relationships to disclose.

Circulating tumor cell and endothelial cell data from a phase II evaluation of lapatinib and bevacizumab in HER2-overexpressing metastatic breast cancer

Abstract #3154

Background: Overexpression of both HER2 and VEGF is associated with worse outcome than overexpression of either receptor alone. In preclinical models, combination anti-HER2 and anti-VEGF therapy has been shown to be more effective than either treatment alone. Bevacizumab (B) plus trastuzumab and lapatinib (L) plus pazopanib have shown activity in patients (pts) with HER2+ MBC. We evaluated the combination of L+B in a phase 2 trial in HER2+ MBC pts. To explore new biomarkers of treatment effect, we measured circulating tumor cells (CTCs) with two different methods of CTC enumeration: CellSearch (Veridex LLC), and immunomagnetic enrichment followed by flow cytometry (IE/FC), as well as circulating endothelial cells (CECs) in pts receiving study treatment.&#x2028; Methods: This study evaluated L (1500 mg PO daily) plus B (10 mg/kg IV q2wk) in 50 HER2+ MBC pts. The primary endpoint is crude progression-free survival (PFS) at 12 wks. Serial evaluation of CTC and CEC was performed. Blood was obtained from consenting pts at baseline, weeks 2, 6 then every 12 weeks until end of study. CellSearch assay was performed as previously described using 7.5 cc blood in a CellSave tube and the CellSpotter analyzer. For IE/FC, 20 ml of blood was subjected to IE using anti-EpCAM ferrofluid, followed by FC for EpCAM, CD45, and nucleic acid content. CTC data were correlated with assay method and with best response. CECs were defined as CD34/31+, CD45-, or CD34/146+, CD45-, and were assayed by FC.&#x2028; Results: Enrollment to this study ended in March 2008 (n=52). Clinical data is presented at this meeting (Dickler et al). 47 patients have evaluable CTC and CEC data at baseline and/or first follow-up; 32 patients have response data. CTC determined by CellSearch or IE/FC showed significant correlation at baseline (R=0.58; P=0.012). CTC by CellSearch at first followup correlated with treatment response (P=0.01) with levels above 5 CTC/sample associated with progression; there was no correlation with baseline values. There were too few positive IE/FC values to evaluate correlation with outcome. The change in CEC/CD146 from baseline to first followup for is of borderline significance in this preliminary analysis (P=0.07) between PR (N=2, Mean Change Score/MCS=-4.345) and SD/PD (N=18, MCS=0.8); a decrease of CEC/CD146 from baseline to first followup suggests greater likelihood of response.&#x2028; Conclusions: L+B is an active regimen in pts with MBC. CTC measurements correlated between two separate methodologies, and for the CellSearch assay predicted response to therapy. A decrease in CEC from baseline to first followup correlated with response to this combined targeted therapy, consistent with our previous results with other B-based therapy. PFS and response correlations for the full study cohort will be presented.

Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 3154.

Adjuvant therapy for early stage breast cancer (EBC): Distant disease-free survival (DDFS) as a predictor of overall survival (OS)

583

Background: OS advantages are often difficult to demonstrate in trials evaluating treatment for EBC, as this requires long follow-up (FU) and large trials. Results are also confounded by factors such as further treatment. DFS, the primary endpoint in many adjuvant trials, is not a consistent predictor of OS and lack of standard definitions renders its interpretation difficult. A better, quicker endpoint is needed as a surrogate for OS. Distant metastases (DM), the most common type of recurrence, are responsible for the initial peak of relapse seen at 2 years post surgery and are associated with the highest risk of death compared to locoregional and contralateral events. DDFS may be a better short-term OS predictor. Methods: The impact of common adjuvant therapies (chemotherapy [CT], tamoxifen [TAM], and aromatase inhibitors [AIs]) on DM risk and OS was examined. Results: CT trials show that improvements in DDFS often precede subsequent improvements in OS. In NSABP B14, TAM significantly improved DDFS at 4 years and OS at 10 years. In ATAC and BIG 1–98, over half of EBC recurrences are DM, but OS differences are limited by short FU. BIG 1–98 showed a significant reduction in DM risk with letrozole versus TAM, but ATAC showed no significant reduction in DM risk with anastrozole in hormone receptor-positive patients. The reason for this difference is unclear. IES initially showed a significant reduction in DM risk, which was later followed by a borderline significant OS benefit in estrogen receptor-positive/unknown patients, favoring exemestane. Conclusion: Data from several adjuvant trials show that improvements in DDFS often precede significant improvements in OS. AIs show superiority over TAM in reducing DM risk (IES, BIG 1–98). DDFS may be a better, more achievable endpoint than OS for women with EBC and could quicken the development of future adjuvant breast cancer therapies.

[Table: see text]

No significant financial relationships to disclose.