Fragmentomic analysis of circulating tumor DNA-targeted cancer panels

BACKGROUND

The isolation of cell-free DNA (cfDNA) from the bloodstream can be used to detect and analyze somatic alterations in circulating tumor DNA (ctDNA), and multiple cfDNA-targeted sequencing panels are now commercially available for Food and Drug Administration (FDA)-approved biomarker indications to guide treatment. More recently, cfDNA fragmentation patterns have emerged as a tool to infer epigenomic and transcriptomic information. However, most of these analyses used whole-genome sequencing, which is insufficient to identify FDA-approved biomarker indications in a cost-effective manner.

PATIENTS AND METHODS

We used machine learning models of fragmentation patterns at the first coding exon in standard targeted cancer gene cfDNA sequencing panels to distinguish between cancer and non-cancer patients, as well as the specific tumor type and subtype. We assessed this approach in two independent cohorts: a published cohort from GRAIL (breast, lung, and prostate cancers, non-cancer, n = 198) and an institutional cohort from the University of Wisconsin (UW; breast, lung, prostate, bladder cancers, n = 320). Each cohort was split 70%/30% into training and validation sets.

RESULTS

In the UW cohort, training cross-validated accuracy was 82.1%, and accuracy in the independent validation cohort was 86.6% despite a median ctDNA fraction of only 0.06. In the GRAIL cohort, to assess how this approach performs in very low ctDNA fractions, training and independent validation were split based on ctDNA fraction. Training cross-validated accuracy was 80.6%, and accuracy in the independent validation cohort was 76.3%. In the validation cohort where the ctDNA fractions were all <0.05 and as low as 0.0003, the cancer versus non-cancer area under the curve was 0.99.

CONCLUSIONS

To our knowledge, this is the first study to demonstrate that sequencing from targeted cfDNA panels can be utilized to analyze fragmentation patterns to classify cancer types, dramatically expanding the potential capabilities of existing clinically used panels at minimal additional cost.

The impact of service user's suicide on mental health professionals

OBJECTIVES

Our principle objective was to examine the personal and professional impact of service user (SU) suicide on mental health professionals (MHPs). We also wished to explore putative demographic or clinical factors relating to SUs or MPHs that could influence the impact of SU suicide for MHPs and explore factors MHPs report as helpful in reducing distress following SU suicide.

METHODS

A mixed-method questionnaire with quantitative and thematic analysis was utilised.

RESULTS

Quantitative data indicated SU suicide was associated with personal and professional distress with sadness (79.5%), shock (74.5%) and surprise (68.7%) particularly evident with these phenomena lasting less than a year for more than 90% of MHPs. MHPs also reported guilt, reduced self-confidence and a fear of negative publicity. Thematic analysis indicated that some MHPs had greater expertise when addressing SU suicidal ideation and in supporting colleagues after experiencing a SU suicide. Only 17.7% of MHPs were offered formal support following SU suicide.

CONCLUSION

SU suicide impacts MHPs personally and professionally in both a positive and negative fashion. A culture and clear pathway of formal support for MHPs to ascertain the most appropriate individualised support dependent on the distress they experience following SU suicide would be optimal.

Abstract OT1-05-01: A phase I/II, single arm, non-randomized study of ribociclib (LEE011), a CDK 4/6 inhibitor, in combination with bicalutamide, an androgen receptor (AR) inhibitor, in advanced AR+ triple-negative breast cancer

Background: Triple negative breast cancer (TNBC) is a heterogeneous disease encompassing distinct intrinsic molecular subtypes, including a luminal androgen receptor (AR) subtype, characteristically dependent on AR signaling. The AR is expressed in more than 50% of TNBCs. Bicalutamide is an oral, non-steroidal, AR antagonist, which has been studied in metastatic TNBC with a clinical benefit rate of 19% at 24 weeks. In preclinical models, cyclin dependant kinase (CDK) 4/6 inhibition has been shown to restore sensitivity to AR inhibition, and may thus be an important resistance mechanism. Ribociclib is an orally bioavailable, highly specific CDK4/6 inhibitor that induces cell cycle arrest, already approved in endocrine receptor positive breast cancers. We hypothesize that inhibition of CDK inhibition can enhance the activity of anti-androgen therapy in TNBC that express AR.

Methods: We designed a phase I/II, single arm, non-randomized, open label study of the combination of bicalutamide with ribociclib in women with advanced AR-positive TNBC. The primary objective of the phase I component is to determine the maximum tolerated dose of the combination, and of the phase II component to assess the clinical benefit rate at 16 weeks. Secondary objectives include progression free and overall survival, objective response rates, and safety and tolerability. Exploratory objectives will be to assess AR quantification, localization and splice variants in circulating tumor cells, as well as quantification of pan and phospho proteins of Rb. Eligible patients must have measurable metastatic or unresectable AR-positive TNBC and have had no more than 1 line of systemic therapy for metastatic disease. The phase I study will be conducted using a 3+3 dose escalation schema, 12 to 18 patients are expected to enroll. The phase II component will utilize a Simon's two stage design, enrolling 24 patients for the first stage. At least 5 subjects must have clinical benefit by 16 weeks to proceed onto the second stage, which would enroll an additional 22 subjects for a total of 46 patients. The study will be powered to detect a clinical benefit rate of 40% with a power of 80% and a type I error rate of 10%. Contact dmusapatika@hoosiercancer.org for more information about the study.

Citation Format: Santa-Maria CA, Rampurwala M, Wisinski K, Toppmeyer D, O'Regan R. A phase I/II, single arm, non-randomized study of ribociclib (LEE011), a CDK 4/6 inhibitor, in combination with bicalutamide, an androgen receptor (AR) inhibitor, in advanced AR+ triple-negative breast cancer [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr OT1-05-01.

Abstract OT1-03-06: Phase IB/II clinical trial to evaluate safety and efficacy of tucatinib in combination with palbociclib and letrozole in patients with hormone receptor positive and HER2-positive metastatic breast cancer

Breast cancers overexpressing HER2-oncogene and hormone receptors (HR) represent therapeutic challenge because of a bi-directional cross-talk between HR and HER2 pathways leading to tumor progression and drug resistance. There is a strong rationale for evaluation of novel targeted drug combinations in this breast cancer subtype.

We designed a phase IB /II clinical trial to test the combination of novel oral HER2 small molecule inhibitor tucatinib with CDK4/6 inhibitor palbociclib and aromatase inhibitor letrozole in patients with HR+/HER2+ metastatic breast cancer (NCT03054363). In addition to the rationale for the synergy of targeting HR, HER2 and CDK4/6 pathways simultaneously in this disease setting and its potential for anti-tumor efficacy, we propose this novel combination of three oral agents, if well tolerated, will be highly patient-centered as an effective non-chemotherapy based regimen for treatment of HR+/HER2+ breast cancer.

This multicenter clinical trial is conducted through the Academic Breast Cancer Consortium (ABRCC), with the University of Colorado Cancer Center as the lead site.

Target enrollment: 40 patients (20 patients in phase IB and 20 patients in phase II part).

Main inclusion criteria:

1. HR+/HER2+ locally advanced unresectable / metastatic breast cancer

2. Measurable or evaluable disease. Bone only disease is allowed.

3. Subjects without brain metastases are eligible; subjects with untreated asymptomatic CNS metastases not needing immediate local therapy, and subjects with stable brain metastases previously treated with radiation therapy or surgery are eligible

4. ECOG 0-1

5. Postmenopausal women, or premenopausal women on ovarian suppression

6. Prior treatments:

- At least two approved HER2-targeted agents (trastuzumab, pertuzumab, or TDM-1) at any time in the course of the disease

- At least 1 line of HER2-targeted therapy in the metastatic setting (with the exception of asymptomatic subjects with oligometastatic or bone / soft tissue only disease who, on investigator opinion, are appropriate for a front line single agent anti-endocrine therapy per NCCN guidelines)

- Up to 2 lines of prior endocrine therapy in the metastatic setting are allowed

7. Adequate organ and marrow function

Main exclusion criteria:

1. Previously treated progressing brain metastases

2. Brain metastases and contraindications to undergo contrast brain MRI

3. Toxicities of prior cancer therapies that have not resolved to grade 1 or less, except peripheral neuropathy, which must have resolved to grade 2 or less, and alopecia

4. Previous treatment with EGFR or HER2 tyrosine kinase inhibitors or CDK4/6 inhibitors

5. Systemic anti-cancer therapy or radiation within 2 weeks of the first dose of study drugs

6. Active bacterial, fungal or viral infections, hepatitis B, C, or HIV

7. Clinically significant cardio-vascular disease

Primary objectives:

- Phase IB: safety and tolerability of combination therapy

- Phase II: efficacy by PFS

Exploratory assessment of biomarkers of resistance and response will be performed in the blood and biopsy samples

Study contact: Elena Shagisultanova, MD, PhD, elena.shagisultanova@ucdenver.edu

Citation Format: Shagisultanova E, Diamond J, Stopeck A, Pusztai L, O'Regan R, Gradishar W, Brown-Glaberman U, Chalasani P, McSpadden T, Borakove M, Shedin T, Kabos P, Borges V. Phase IB/II clinical trial to evaluate safety and efficacy of tucatinib in combination with palbociclib and letrozole in patients with hormone receptor positive and HER2-positive metastatic breast cancer [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr OT1-03-06.

Abstract P4-22-21: NCI9782: A phase 1 study of talazoparib in combination with carboplatin and paclitaxel in patients with advanced solid tumors

Background: Poly(ADP-ribose) polymerase (PARP) enzymes are involved in DNA repair and activated by DNA strand breaks. DNA damage from carboplatin is associated with activation of PARP. Preclinical data indicate that PARP inhibition potentiates the anti-tumor effect of platinum chemotherapy. Talazoparib (T) is an oral, selective PARP inhibitor with a single agent maximum tolerated dose (MTD) of 1mg orally qd. Primary dose-limiting toxicity (DLT) was thrombocytopenia. This phase I study combines T with the commonly used chemotherapy regimen of carboplatin (C) and paclitaxel (P).

Methods: Two dosing schedules are being investigated. In both schedules, C is administered on day 1 and P on days 1, 8, and 15 of a 21-day cycle. T (100-1000mcg) is dosed once daily for days 1-7 (schedule A) or days 1-3 (schedule B) starting on day 1. A 3+3 design is used for dose escalation. Key eligibility criteria include age 318 with a measurable or evaluable solid incurable malignancy. Patients (pts) must have tumor type that is expected to respond to C + P or have BRCA germline or somatic mutation. Stable, treated brain metastases are allowed. No prior C for metastatic disease is allowed. Pts must have platelets&gt;150 and no need for anticoagulation. After 4-6 cycles of combination therapy, pts may continue the combination, change to C and intermittent T without P or change to T alone with continuous daily dosing. Each schedule will have a 6 subject dose expansion at the MTD. The starting dose level for schedule B will be the MTD from schedule A.

Results: Schedule A cohort results are reported: 11 pts (median age 59 [range 39-68]; 8 female; 3 male) have been enrolled. Pts had breast (6), ovarian (2), pancreatic (1), and SCC of oropharynx (1) and concurrent ovarian and pancreatic (1). Five pts are BRCA2+ and 3 pts are BRCA1+. Dose level 3 on schedule A (T 350mcg with C AUC 6 and P 80mg/m2) exceeded the MTD with 2 of 3 pts experiencing hematologic dose limiting toxicities (DLTs) including 1 pt with grade (gr) 3 neutropenic fever and gr 4 thrombocytopenia and another pt with grade 3/4 neutropenia lasting &gt; 7 days. Most common AEs include neutropenia (grade 3-4: 7), anemia (grade 3-4: 3), and thrombocytopenia (grade 3-4: 4). Results from expansion of dose level 2 (T 250mcg with C AUC 6 and T 80mg/m2) will be presented. The 11 pts were on study a median of 9 weeks (range 9-36+). Four pts have discontinued study therapy: 1 due to need for anticoagulation for PE, 1 for prolonged cytopenias, and 2 for disease progression. Of the 8 pts with measurable disease evaluated for response to date, 4 had SD, 1 had a cPR, 1 had radiographic CR, and 2 with PD. A pt with BRCA 1+ triple negative breast cancer has maintained a prolonged PR (36+ weeks) even after dose reductions to T 100mcg with C AUC 3. One pt with ovarian cancer (BRCA WT) has radiographic CR (CA 125 remains mildly elevated) after 15+ weeks of therapy.

Conclusion: PARP inhibition with talazoparib days 1-7 in combination with carboplatin and paclitaxel leads to DLT of myelosuppression. However, clinical responses are seen even with lower dose combinations.

Citation Format: Turk A, Chan N, Leal T, O'Regan R, Tevaarwerk A, Rice L, Campbell T, Barroilhet L, Mehnert J, Eickhoff J, Kolesar J, Liu G, Wisinski K. NCI9782: A phase 1 study of talazoparib in combination with carboplatin and paclitaxel in patients with advanced solid tumors [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 P4-22-21.

Abstract OT2-01-19: A randomized phase II trial of fulvestrant with or without ribociclib after progression on aromatase inhibition plus cyclin-dependent kinase 4/6 inhibition in patients with unresectable or metastatic hormone receptor positive, HER2 negative breast cancer

Background

Cyclin dependent kinase 4 and 6 inhibitors (CDK4/6i), including palbociclib and ribociclib (R), have demonstrated remarkable benefit in progression free survival (PFS) in patients (pts) with hormone receptor positive (HR+), HER2- metastatic breast cancer (MBC) when combined with anti-estrogen therapy. Switching between anti-estrogen therapies at disease progression is standard of care in the treatment of HR+ MBC. We evaluate the strategy of switching anti-estrogen therapy to fulvestrant (F) and maintaining CDK4/6 inhibition with R in pts with HR+, HER2- MBC who have progressed on an aromatase inhibitor (AI) + CDK4/6i.

Trial Design

Phase II, multi-center, randomized, double-blind, placebo-controlled trial to evaluate F +/- R in pts with HR+, HER2- MBC who have previously progressed on any AI + CDK4/6i. Pts can be screened and registered at two different time points:

Scenario 1: Before receiving any CDK4/6i

Scenario 2: At the time of progression of disease (POD) while being treated with an AI + CDK4/6i

In scenario 1, the study will provide pts with letrozole + R, but pts will not be randomized until they demonstrate POD. At randomization, pts will be assigned 1:1 to either a) F + R or b) F + placebo, with treatment given in 4-week cycles. F will be given as a 500 mg dose intramuscularly every 2 weeks for 3 times and then every 4 weeks, as per standard of care. R or placebo will be given orally at 600 mg daily, 3 weeks on/1 week off. CT scans and bone scan are to be performed prior to every third cycle. Serum and whole blood samples and optional tissue biopsies for biomarker assessment will be performed prior to study treatment (scenario 1), prior to randomization to R +/- F, and when the patient goes off study.

Main Eligibility Criteria:

1. Age ≥ 18 years with unresectable or metastatic BC

2. Estrogen and/or progesterone receptor positive, HER2 negative, as per ASCO-CAP

3. Postmenopausal status or receiving ovarian suppression

4. Measurable or unmeasurable disease; stable CNS disease allowed

5. No clinically significant cardiac disease

6. No concomitant CYP3A4/5 inducer or inhibitor

Specific Aims

Primary: Progression free survival (PFS), defined as the time from randomization to POD or death.

Secondary: Objective response rate (ORR), clinical benefit rate (CBR = ORR + stable disease rate), overall survival (OS), and duration of response. Pts in scenario 1 will also be assessed for PFS, OS, CBR, and safety while receiving AI + R (pre-randomization).

Biomarker assessment will include amplification of cyclin D1 and cyclin E, phosphoRb and TK1 expression, Rb1 and p16 loss, and ctDNA for ESR1 and PIK3CA mutations.

Target Accrual

132 pts accrued from 11 academic medical centers in the U.S, with a goal of completing accrual in two years (∼60 to 72 pts in each scenario).

Statistical Methods

Assuming a median PFS of 3.8 months with F alone, we predict that F + R will lead to a median PFS of at least 6.5 months. A one-sided log-rank test with a sample size of N=120 and alpha=0.025, achieves 80% power to detect a difference in PFS of 2.7 months. N=132 pts allows for a 10% drop-out rate.

Citation Format: Mundi PS, Codruta C, Accordino MK, Sparano J, Andreopoulou E, Vadhat LT, Tiersten A, Esteva F, O'Regan R, Jain S, Mayer I, Forero A, Crew KD, Hershman DL, Kalinsky KM. A randomized phase II trial of fulvestrant with or without ribociclib after progression on aromatase inhibition plus cyclin-dependent kinase 4/6 inhibition in patients with unresectable or metastatic hormone receptor positive, HER2 negative breast cancer [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 OT2-01-19.

Abstract P6-16-03: Phase 2 trial of everolimus and/or trastuzumab in hormone refractory, hormone receptor (HR)-positive, HER2-normal metastatic breast cancer (MBC)

Background: Increased signaling through growth factor pathways including PI3K/Akt/mTOR and HER2 have been implicated in hormone resistance. Everolimus (EVE) improves outcomes when added to endocrine therapy for patients with HR-positive MBC. This study evaluated the efficacy of everolimus (EVE) and trastuzumab (TRAS) in hormone refractory HER2-normal metastatic breast cancer.

Methods: Eligible patients had HR-positive, HER2/neu-negative (IHC +1 or +2, HER2-non-amplified) MBC that had progressed within 6 months of the most recent endocrine therapy. Patients continued on the most recent endocrine therapy they received and were randomized to receive EVE 10 mg oral daily or TRAS IV (8 mg/kg loading dose followed by 6 mg/kg every 3 weeks). At progression, the other agent was added (TRAS in the EVE arm and EVE in the TRAS arm). Patients were followed until disease progression or death.

Results: 54 eligible patients were included in the analysis, and were randomized to EVE (n=30) or TRAS (n=24). 33% of patients were on fulvestrant, 31% exemestane, 22% tamoxifen and 7% letrozole, which were continued. The median PFS was 5.7 months for EVE vs. 2 months for TRAS until first progression or death with hazard ratio of 0.45 (95% CI 0.25-0.81, p=0.008). Among 48 patients who had disease progression, EVE was added to 16 patients who were originally treated by TRAS, and TRAS was added to 12 patients who were originally treated by EVE; the median time to the second progression was 6.3 months for the arm where EVE was added vs. 3.1 months in the arm where TRAS was added. Three patients were taken off study due to decrease in ejection fraction.

Conclusions: This trial demonstrates the efficacy of EVE alone or in combination with TRAS in patients with hormone refractory HR-positive, HER2-negative metastatic breast cancer, who remained on the endocrine therapy they had experienced disease progression on. This suggests that mTOR inhibition has the potential of restoring sensitivity to endocrine therapy and potentially allows the re-use of endocrine agents. Updated results and correlative studies will be presented. Clinical trial information: NCT00912340.

Citation Format: Paplomata E, Gogineni K, Meisel J, Santa-Maria C, Yuan L, Kramer J, Bill Li X, Zelnak A, Pakkala S, Kaklamani V, O'Regan R. Phase 2 trial of everolimus and/or trastuzumab in hormone refractory, hormone receptor (HR)-positive, HER2-normal metastatic breast cancer (MBC) [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 P6-16-03.

Abstract P4-13-12: Everolimus plus trastuzumab and vinorelbine for trastuzumab-resistant, taxane-pretreated, HER2+ advanced breast cancer: Overall survival results from BOLERO-3

Background

PI3K/AKT/mTOR pathway activation due to PTEN loss may lead to trastuzumab (TRAS) resistance. mTOR inhibition has been shown to restore TRAS sensitivity in PTEN-deficient tumors. This provided the rationale for the BOLERO-3 trial which evaluated the combination of everolimus (EVE), an mTOR inhibitor, plus TRAS and a taxane in HER2+ advanced breast cancer (ABC). The addition of EVE to TRAS plus vinorelbine (VNB) led to a statistically significant prolongation of 1.2 months in median progression free survival (PFS) vs TRAS plus VNB in patients with TRAS-resistant and taxane-pretreated, HER2+ ABC (7.0 months vs 5.78 months; hazard ratio, 0.78; p=0.0067). The final overall survival (OS) analysis from this study is presented here.

Materials and methods

BOLERO-3 is a randomized, double-blind, placebo-controlled, phase 3 trial. Women with HER2+ ABC progressing on prior TRAS and taxane therapy were randomized (1:1) to receive either daily EVE (5 mg) or PBO plus weekly TRAS (2 mg/kg) and VNB (25 mg/m2), in 3-week cycles, stratified by previous lapatinib use. The primary endpoint was PFS by local investigator assessment. Overall survival was a key secondary endpoint.

Results

Overall, 569 patients were enrolled; 284 patients received EVE and 285 patients received PBO. As of April 1, 2015, after a median follow-up of 44.7 months, 388 deaths had occurred, 191 (67.3%) in the EVE arm and 197 (69.1%) in the PBO arm. The median OS in the EVE arm vs PBO arm was 23.5 months vs 24.1 months (HR = 0.96; 95% CI, 0.79-1.17; p = 0.3392). In the HR+ subgroup, the median OS with EVE was 23.5 months (vs 25.5 months with PBO; HR = 1.03; 95% CI, 0.79-1.35); in the HR subgroup, the median OS with EVE was 22.9 months (vs 23.1 months with PBO; HR = 0.86; 95% CI, 0.64-1.17). AEs leading to treatment discontinuation were reported in 81 (28.9%) vs 46 (16.3%) patients in the EVE vs PBO arms. Serious adverse events (SAEs) were reported in 122 (43.6%) vs 58 (20.6%) patients in the EVE vs PBO arms. Overall, 14 on-treatment deaths were observed, 7 (2.5%) in the EVE arm and 7 (2.5%) in the PBO arm; on-treatment deaths due to AEs were balanced between treatment arms (0.7% in each treatment arm). Types of post-progression therapies were balanced across both treatment arms.

Conclusions

In BOLERO-3, EVE showed a statistically significant prolongation of PFS. OS was similar in both treatment arms. The safety profile of EVE was comparable to that observed previously with EVE in breast cancer. (Funded by Novartis; BOLERO-3 ClinicalTrials.gov number, NCT01007942.)

Citation Format: Isaacs C, O'Regan R, Xu B, Masuda N, Arena F, Yap Y-S, Papai Z, Lang I, Armstrong A, Lerzo G, White M, Shen K, Zhang Y, Jappe A, Pacaud LB, Taran T, Ozguroglu M. Everolimus plus trastuzumab and vinorelbine for trastuzumab-resistant, taxane-pretreated, HER2+ advanced breast cancer: Overall survival results from BOLERO-3. [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 P4-13-12.

Abstract P3-15-03: Safety analysis of BOLERO-3: A phase 3 trial of daily everolimus (EVE) vs placebo (PBO), both with weekly trastuzumab (TRAS) and vinorelbine in trastuzumab-resistant, advanced breast cancer

Background: Activation of the PI3K/mTOR pathway is thought to be involved in resistance to TRAS. BOLERO-3 is a randomized phase 3, double-blind, placebo-controlled, international, clinical trial evaluating the addition of the mTOR inhibitor EVE (5 mg/day) to TRAS plus vinorelbine (25 mg/m2) in patients with HER2+ advanced breast cancer resistant to TRAS and who were previously treated with a taxane. A total of 569 adult women were randomized 1:1 to receive EVE (n = 284) or PBO (n = 285). Study treatment represented the 2nd, 3rd, or 4th line of chemotherapy-containing regimen for 83% of patients in the metastatic setting. The primary endpoint, progression-free survival based on local radiologic assessment, was significantly longer in the EVE arm versus PBO (HR = 0.78; P = .0067) at a median follow-up of 20 months.

Methods: Study drugs were continued until disease progression or unacceptable toxicity. Incidences of adverse events (AEs) were monitored continuously. Dose modifications and discontinuations were recorded.

Results: The median duration of exposure to study treatment was similar across treatment groups: 24.8 weeks for EVE, 25.1 weeks for TRAS, and 24.0 weeks for vinorelbine (EVE arm); and 22.9 weeks for PBO, 24.0 weeks for TRAS, and 23.1 weeks for vinorelbine (PBO arm). The AEs were consistent with known drug-safety profiles. Class-effect AEs with mTOR inhibitors (including stomatitis, rash, noninfectious pneumonitis, and hyperglycemia) were higher in the EVE arm and were mainly grade 1/2. Grade 3 class-effect AEs each occurred in &lt;15% of patients (stomatitis [13%], hyperglycemia [2%], and noninfectious pneumonitis [&lt;1%]). Grade 4 noninfectious pneumonitis (&lt;1%) was uncommon; there were no grade 4 events of stomatitis or hyperglycemia, and no grade 3/4 events of rash. The incidence and grade of hematologic AEs were increased in the EVE arm vs the PBO arm, including all grade neutropenia (81% vs 70%), anemia (49% vs 29%), febrile neutropenia (17% vs 4%) and thrombocytopenia (14% vs 2%); grade 3/4 hematologic AEs included neutropenia (grade 3: 35% vs 32%; grade 4: 38% vs 30%), anemia (grade 3: 17% vs 6%; grade 4: 2% vs &lt;1%), febrile neutropenia (grade 3: 11% vs 3%; grade 4: 5% vs 1%), and thrombocytopenia (grade 3: 3% vs &lt;1%; grade 4: 1% vs 0). The incidences and grades of changes in liver enzymes and hyperlipidemia were similar between arms. Serious AEs were reported in 42% of patients in the EVE arm and 20% of patients in the PBO arm (26% and 6% were attributed to study treatments, respectively). A higher percentage of patients discontinued treatment because of AEs in the EVE arm versus PBO (10% vs 5%). In all, 83% of patients required at least 1 EVE dose interruption and/or reduction; 96% of these were attributed to AEs. There were fewer deaths in the EVE arm (37%) compared with PBO (41%).

Conclusions: The safety of the combination of EVE, TRAS, and vinorelbine was considered manageable in this heavily pretreated patient population. Overall, the results from BOLERO-3 demonstrate that EVE can be combined with TRAS and chemotherapy to improve efficacy in TRAS-resistant HER2+ advanced breast cancer previously treated with a taxane.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P3-15-03.

Abstract P4-12-19: BOLERO-3: Everolimus plus trastuzumab and vinorelbine in Asian patients with HER2-positive metastatic breast cancer

Background: Resistance to trastuzumab may occur through activation of the PI3K/Akt/mTOR signaling pathway, the inhibition of which may restore trastuzumab sensitivity. BOLERO-3, a phase 3, double-blind, international trial involving 569 patients with trastuzumab-resistant, HER2-positive (HER2+), advanced breast cancer pretreated with a taxane, recently reported that adding everolimus (EVE; an mTOR inhibitor) to vinorelbine and trastuzumab significantly improved progression-free survival (PFS) vs placebo (PBO) plus vinorelbine and trastuzumab (hazard ratio [HR] = 0.78; log-rank P = .0067). As EVE pharmacokinetics and, therefore, clinical effects may be different in Asian patients, we analyzed the efficacy and safety data from BOLERO-3 for the Asian population.

Methods: Eligible women with trastuzumab-resistant, HER2+, advanced breast cancer who received prior taxane therapy were randomized (1:1) to EVE (5 mg/day) or matching PBO in combination with weekly vinorelbine (25 mg/m2) and trastuzumab (2 mg/kg after 4-mg/kg loading dose). The primary endpoint was PFS by investigator. Secondary endpoints included safety.

Results: Among 569 patients enrolled in this study, 166 (29%) patients were Asian; 88 and 78 were assigned to EVE or PBO arms, respectively. In this subpopulation, adding EVE to vinorelbine and trastuzumab prolonged median PFS compared with the PBO arm (8.3 vs 6.8 months, respectively; HR = 0.83; 95% confidence interval, 0.59 - 1.18). In general, the incidence of all grade adverse events was similar for Asian versus non-Asian patients in the EVE arm (stomatitis, 71% vs 59%; pneumonitis, 7% vs 5%; and infections, 58% vs 70%) and the PBO arm (stomatitis, 31% vs 26%; pneumonitis, 1% vs 4%; and infections, 48% vs 49%). Serious adverse events had a low incidence and included febrile neutropenia (9.1%), neutropenia (2.3%), stomatitis (2.3%), anemia (2.3%), and cataract (2.3%) as the most common among Asian patients in the EVE arm. The incidence of serious pneumonitis was low: Asian (1.1%) versus non-Asian patients (0%) in the EVE arm and 0% versus 1.5%, respectively, in the PBO arm.

Conclusions: Asian patients in the BOLERO-3 trial treated with EVE plus vinorelbine and trastuzumab showed PFS benefits similar to the overall population and had a comparable manageable safety profile. Thus, EVE in combination with vinorelbine and trastuzumab may be considered as a new therapeutic option for Asian women with trastuzumab-resistant, HER2+, advanced breast cancer progressing after taxane-based therapies.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P4-12-19.

Abstract P4-12-18: BOLERO-3: Quality-of-life maintained in patients with metastatic breast cancer treated with everolimus plus trastuzumab plus vinorelbine

Background: Activation of the PI3K/mTOR pathway is implicated in resistance to trastuzumab. Accordingly, the BOLERO-3 study evaluated the efficacy of adding everolimus (EVE), an mTOR inhibitor, to vinorelbine and trastuzumab. At the final progression-free survival (PFS) analysis, EVE significantly improved PFS vs PBO (hazard ratio [HR] = 0.78; log-rank P = .0067) but EVE-treated patients had higher rate of grade 3/4 toxicity. To further qualify the benefit:risk of adding EVE to trastuzumab-based therapy, per-protocol, patient-reported, health-related quality-of-life (HRQoL) data were analyzed.

Methods: BOLERO-3 is a randomized phase 3, double-blind, placebo-controlled, international multicenter trial. Taxane-pretreated patients (N = 569) with trastuzumab-resistant, HER2+, advanced breast cancer were randomized (1:1) to treatment with EVE or placebo (PBO) plus vinorelbine and trastuzumab. The European Organisation for Research and Treatment of Cancer (EORTC) quality-of-life questionnaire C30 (QLQ-C30) (including the breast cancer-specific BR23 module) was administered at baseline and every 6 weeks thereafter until progression. The QLQ-C30 consists of 30 items combined into 15 subscales, including Global Health Status and functional subscales, where higher scores (range, 0 to 100) indicate better HRQoL. Time to definitive deterioration (TTD) based on a 10% decrease from baseline for GHS and for the physical, emotional, and social function subscales was determined using the Kaplan-Meier method. Treatment arms were compared using a 2-sided log-rank test stratified by prior use of lapatinib.

Results: Overall, there was no significant difference in median TDD of HRQoL between treatment arms. The median TTD in global health status score was 8.3 months for EVE (95% confidence interval [CI], 6.9-11.5) vs 7.3 months for PBO (95% CI, 5.6-10.4; P = .8386). The median TTD in the physical, emotional, and social function subscale scores showed no significant difference between arms. For example, median TTD in the physical function subscale score was 12.0 months (95% CI, 8.3-14.1) for EVE vs 12.5 months (95% CI, 8.3-20.9) for PBO (P = .4251), and median TTD in the emotional function subscale score was 15.2 months (95% CI, 9.2-17.3) for EVE vs 12.5 months (95% CI, 9.7-16.4) for PBO (P = .8140).

Conclusions: These analyses demonstrate that, despite increased frequency of adverse events observed with the addition of EVE to the standard treatment of vinorelbine and trastuzumab, overall and functional HRQoL scores were not negatively impacted in patients with trastuzumab-resistant, HER2+, advanced breast cancer.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P4-12-18.

P1-02-06: Silencing of IGF-1R Has Paradoxical Effects in Triple Negative Breast Cancer Phenotypes

Background: Triple negative (TN) breast cancers are a heterogeneous group of breast cancers with a poor prognosis in part due to a lack of effective targeted agents. Insulin-like growth factor-1 receptor (IGF-1R) has been shown to play a role in breast cancer cell proliferation, adhesion, invasion, and migration and is overexpressed in more than a third of TN breast tumors. We hypothesized that IGF-1R could be a therapeutic target for a subset of TN breast cancers. Methods: We evaluated the effects of IGF-1R silencing on the metastatic properties of TN breast cancer cells by knock down in two morphologically distinct TN breast cancer cell lines using shRNA lentiviral techniques. Reverse-transcription polymerase chain reaction (RT-PCR) and immunoblotting were used to detect mRNA and protein expression levels, respectively, of IGF-1R signaling molecules. Anchorage-dependent growth and Matrigel chamber assays were performed to assess the effects of IGF-1R silencing on colony formation and invasion of TN breast cancer cells, respectively; wound-healing and spheroid migration were also performed to assess the effects of IGF-1R inhibition on TN breast cancer cell motility. Results: Stably transfected mesenchymal MDA-MB-231 TN cells showed effective downregulation of IGF-1R protein expression, which resulted in mesenchymal-to-epithelial transition (MET), confirmed by upregulation of the epithelial marker E-cadherin and downregulation of the mesenchymal marker vimentin. Importantly, this MET resulted in reduced colony formation (p&lt;0.0042) and cell motility and dramatically reduced invasion (p&lt;0.0001). Conversely, silencing of IGF-1R in epithelial MDA-MB-468 TN cells induced epithelial-to-mesenchymal transition (EMT), confirmed by downregulation of E-cadherin and upregulation of vimentin expression, with resultant increased colony formation (p&lt;0.006), cell motility, and invasion (p&lt;0.0001). Conclusion: Collectively, these results demonstrate a paradoxical effect of targeting IGF-1R in TN breast cancers of mesenchymal and epithelial origin. Targeting IGF-1R in TN breast cancers with a mesenchymal phenotype decreases invasion and metastatic potential. In contrast, targeting IGF-1R in TN breast cancers with an epithelial phenotype could have potentially detrimental effects. Our data suggest that IGF-1R inhibition should be explored as a therapeutic modality in TN breast cancers with a mesenchymal phenotype.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P1-02-06.

Time interval as a quality measure: What is our baseline prior to nurse navigator implementation?

208

Background: There are various outcome measures to evaluate the quality of multidisciplinary care for breast cancer patients. The National Consortium of Breast Centers defines quality of breast cancer care as accurate evaluation and appropriate services in a timely manner. In a tertiary academic center a diverse referral pattern possibly influences time to treatment. We choose to examine two outcome measures before the start of a nurse navigator: Time from initial diagnosis to first consultation and if the pretreatment consultation for those receiving neoadjuvant chemotherapy or hormonal therapy included all subspecialists.

Methods: Electronic medical records of female patients with breast cancer seen during January-June 2010 were reviewed. Patients with stage IV breast cancer were excluded.

Results: 150 patients were divided into 4 categories: external pathology consult (B1), internally diagnosed with a primary care physician (PCP) at our institution (B2), evaluated by a surgical oncologist before the biopsy (B3), and internally diagnosed with PCP outside of the institution (B4). For B2, B3 and B4 we examined the time intervals to first surgical oncology appointment after diagnosis as shown in the table. For all patients (n=10) who received neoadjuvant therapy, 1 patient saw a surgical oncologist, medical oncologist and radiation oncologist, 9 patients saw 2 subspecialties prior to initiation of first treatment.

Conclusions: Patients are seen within an average of 2 weeks whether they are diagnosed internally (B2, B3) or externally (B4). The group seen by a surgical oncologist prior to biopsy (B3) were seen sooner. For the patients receiving neoadjuvant therapy, 10% saw all 3 specialties prior to initiation of therapy. In July 2010 a nurse navigator was added to the care team. With this new position, our goal is to decrease the time from biopsy to visit by 33% and have 100% of patients receiving neoadjuvant therapy evaluated by all 3 specialists prior to treatment. Our intent is to quantify the effect of a nurse navigator in a large academic center as a quality metric in improving care.

[Table: see text]

Abstract S6-3: Four vs 6 Cycles of Doxorubicin and Cyclophosphamide (AC) or Paclitaxel (T) as Adjuvant Therapy for Breast Cancer in Women with 0-3 Positive Axillary Nodes: CALGB 40101 — A 2x2 Factorial Phase III Trial: First Results Comparing 4 vs 6 Cycles of Therapy

Background: Four cycles of chemotherapy are frequently used as standard adjuvant chemotherapy for patients with low-risk primary breast cancer, though other regimens such as CAF, CMF, and TAC frequently are given for 6 cycles. Using a phase 3 factorial design we attempted to define whether 6 cycles of one chemotherapy regimen are superior to 4 cycles in patients with low-risk primary breast cancer. We also sought to determine if T would be equally efficacious as compared to AC, with reduced toxicity. Methods: The study enrolled women with operable breast cancer and 0-3 positive nodes. Study stratifiers were ER/PgR, HER2, and menopausal status. When the study was activated in May 2002, AC (60 and 600 mg/m2) was administered every 3 wks for 4 or 6 cycles, and T (80mg/m2) weekly for 12 or 18 wks. In 2003 (after 570 enrolled patients) treatment schedule was changed to every 2 wks for both AC and T (175 mg/m2), each given for 4 or 6 cycles. In 2008 accrual to the 6-cycle regimens was permanently closed due to slow accrual, with 3173 patients enrolled. The primary endpoint for this comparison was the superiority of 6 vs 4 cycles in relapse-free survival (RFS). The study was powered to have 567 RFS events. Data comparing AC with T are not yet available. Results: This report describes the impact of treatment duration and includes the 3173 patients randomized to 6- versus 4-cycles of chemotherapy, 93% of whom had node-negative disease. At a median follow-up of 4.6 years (2.5 - 8 yrs), the number of RFS events is 288 (with 138 on 4 cycles vs 150 on 6 cycles). The 4-yr RFS was 91.6% and 91.8% for 6 and 4 cycles, respectively. The Hazard Ratio of 6 to 4 cycles was 1.10 (95% CI = 0.87-1.39, p=0.42). Four-year OS was 95.3% and 96.4% for 6 and 4 cycles, respectively, with a HR of 6 to 4 cycles of 1.31 (95% CI = 0.95-1.82, p=0.097). Based on the present data the Bayesian predictive probability of concluding superiority of 6 cycles [a primary goal of the study] with 567 RFS events is only 0.001. There was no interaction between the number of cycles and type of chemotherapy, ER/PgR status, or HER2 status. In particular, the effect of number of cycles on RFS and OS was similar for both AC and T.

Conclusions: For women with primary breast cancer and 0-3 positive nodes, we found no evidence that extending chemotherapy from 4 to 6 cycles improves clinical outcome.

Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr S6-3.

Chromosome Instability Associates with Radiation and Doxorubicin Resistance in Triple Negative Breast Cancer Cell Lines

BackgroundTriple negative (TN) breast cancers often have a worse prognosis, despite receiving appropriate chemotherapy and radiation treatment. Thus, one of the most pressing issues in breast cancer research is investigating the molecular basis for the inherent resistance of TN cells to standard of care treatment. Chromosome instability strongly associates with chemo-resistance and poor prognosis in breast cancer. We hypothesized that genetic heterogeneity imparted by chromosome instability provides the basis for chemotherapy and radiotherapy resistance in TN cells.MethodsFour TN cell lines (HS578, HCC1806, MB231, MB468) and a benign breast tissue line (MCF10) were treated with radiation or doxorubicin. The effects of the treatments were evaluated by the colony forming unit (CFU), MTT survival, Ki-67 immuno-histochemistry (IHC), caspase-3 IHC, micronuclei, and γ-H2AX assays.ResultsRadiation and Chemotherapy Dose Responses: Table I reveals the data from the CFU and MTT assays after treatment with radiation at 0, 1, 2, 4, 6, 8 Gy or doxorubicin at 0.5, 1, 2 μg/ml, respectively. The analyses revealed a range of sensitivities to radiation and doxorubicin, where HS578 was more sensitive to both treatments.Table I. Relative radio- and chemo-resistance of TN cell linesCell TypeTD 50 (Gy)IC50 (μg/ml)HS5781.60.31HCC18061.80.86MB4681.90.95MB2311.91.05MCF101.80.32 Apoptosis and Proliferation: Because the basis for chemo-and radio-resistance of TN cells may be uncontrolled proliferation frequencies and/or decreased apoptosis, proliferation assays (assessed by Ki-67 IHC), as well as apoptotic indexes (i.e. cleaved caspase 3) were performed. The Ki-67 assay showed that 2 Gy reduced proliferation by 13% in the HS578 line, but by only 2% with the MB231cells.After receiving 2 Gy, there was a wide range of apoptotic activity among the TN cell lines. The largest percentage of apoptosis occurred with the MB468 cells at 19% vs the lowest apoptotic activity seen with the HCC1806 line, 7%. Importantly, apoptotic activity was ≤ 7% when these cell lines were treated with 1 μg/ml of doxorubicin.Chromosome instability: The micronuclei and the γ-H2AX assays showed that 3 of the 4 TN cell lines harbored active genomic instability in the absence of doxorubicin or irradiation. The unstable TN cell lines had 15-30% γ-H2AX activity and 20-40% micronuclei formation, whereas the MCF10 and HCC1806 cells had approximately 11% γ-H2AX activity and 10% micronuclei present. To assess the molecular markers contributing to chromosome instability, we performed a real time PCR screen, as well as Western blot analyses of the cyclins, cyclin-dependent inhibitors and other signaling molecules that may contribute to chromosome instability. All cell lines that had high frequencies of chromosome instability had increased levels of cyclin D1, whereas a subset also de-regulated cyclin A.ConclusionOur results show that radio- and chemo- resistance in TN breast cancer cells closely associates with a de-regulated cell cycle and active chromosome instability. We conclude that the molecular basis for chromosome instability, chemotherapy and radiation resistance may be secondary to the unregulated expression of cyclins D1 and A.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 1143.

The Triple Threat of Recurrence after Breast Conserving Therapy: Race, Receptor Status and Age

PurposeThe purpose of this study is to evaluate the impact of race, receptor status, and age on recurrence in patients undergoing breast conserving therapy (BCT).MethodsThe study population consisted of 510 primary invasive female breast cancer patients (excluding Stage IV), who resided in Fulton-Dekalb counties, in Atlanta, GA. These patients were diagnosed in 2003-2004 and treated within the Emory University Affiliated Hospitals. Data was obtained from the SEER cancer registry and augmented with medical record abstraction. Median follow-up was 3.5 and 4.4 years for recurrence and survival, respectively. Breast tumors were categorized as either triple negative (TN), which were estrogen, progesterone, and Her2-neu receptor negative tumors, versus (vs) non-TN, all other possible iterations. Women were evaluated for recurrence and death by TN status, race (African American (AA) vs Caucasian (C)), age, grade, tumor size, nodal status, socioeconomic status (SES), and receipt of chemotherapy. Both recurrence and survival were evaluated using chi-square, fisher exact, and cox regression analyses, p ≤ 0.05 significance.ResultsOf the 510 women, 193 received BCT. Of the 193, 92% completed radiation therapy and 45% received chemotherapy. Of the 184 women with known recurrence status, 11 recurred locally, 11 distantly, and none regionally. Compared to patients with non-TN tumors, TN patients had significantly higher local (13% vs 5%) and distant (16% vs 4%) recurrence rates. AA women had non-significant higher local recurrence than C women (7% vs 4%) and a higher distant recurrence rate (8% vs 3%). Finally, compared to women ≥50 years old, women age &lt;50 had a significantly higher local and distant recurrence rates, (13% vs 4%) and (9% vs 5%) respectively.Unadjusted hazard ratios (HR) and 95% confidence intervals (CI) for any recurrence were calculated: TN status (HR=2.8, 95%CI 1.2-6.5), AA race (HR=2.3, 95% CI 0.9-5.8), age &lt;50 years (HR= 2.3, 95%CI 1.0-5.1), grade 2/3 vs 1 (HR=2.3, 95%CI 1.0-5.1), and chemotherapy receipt (HR=3.0, 95%CI 1.2-7.4). Factors that were highly non-statistically significant included stage, tumor size, nodal status, and SES.In a multivariate model including receptor status, race, and age results were similar (HR = 2.5, 2.1, and 2.1 respectively). When tumor size, nodal status, grade, SES, and chemotherapy status were included in the previous model, only AA race independently predicted recurrence (HR=3.4, 95%CI 1.1-11.1), while TN status demonstrated a trend (HR=1.9, 95%CI 0.8-5.7).In survival analyses, neither TN status, AA race, nor age &lt;50 years predicted outcome in any of the models described above. However, TN status did show a trend for significance (HR=2.6, 95%CI 0.8-9.0).ConclusionWe observed that there was a significant increase in local and distant metastatic recurrence rates after BCT among patients diagnosed with TN breast cancers, AA women, and women &lt;50 years old. In contrast, we did not observe differences in survival, with the exception of TN breast cancers. This study suggests that among women who receive BCT, current standard radiation and systemic therapies may not be adequate in preventing recurrence among women with TN breast cancers, of AA race, or younger age.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 6045.

eIF4E Expression Predicts Apoptosis in Response to Epidermal Growth Factor Receptor Inhibition and Mammalian Target of Rapamycin Inhibition in Triple Negative Breast Cancers

Background: Triple negative (TN) breast cancers account for 15% of all breast cancers, are two-fold higher in African American women, have high histological grade, a poor prognosis and until recently no viable therapeutic targets. Epidermal growth factor receptor (EGFR) is over-expressed in more than 50% of triple negative breast cancers, but the use of agents blocking EGFR has produced disappointing results in metastatic breast cancer. Inhibitors of Mammalian Target of Rapamycin (mTOR) have demonstrated moderate activity as single agents in metastatic breast cancer. mTOR inhibitors have been demonstrated to activate the Akt pathway by a possible feedback mechanism, which could potentially sensitize TN breast cancer cells to upstream inhibitors. We have previously demonstrated synergistic antitumor effects with combined mTOR and EGFR inhibition in TN breast cancers. Eukaryotic translation initiation factor (eIF4E) is a protein downstream of mTOR and a target of PI3K/Akt and Erk signaling, and is important in mRNA translation, cell proliferation and apoptotic resistance. We evaluated the effects of EGFR and mTOR inhibition on apoptotic markers, and correlated these effects with eIF4E protein expression.Methods: Apoptotic assay and colony formation analysis were performed following mTOR inhibition with rapamycin and EGFR inhibition with lapatinib or erlotinib in TN breast cancer cells (MDA-MB-231, MDA-MB-468, HCC1806). Effects of EGFR and mTOR inhibition on downstream proteins in TN breast cancer in vitro and in vivo were examined through western blotting analysis with p-EGFR, pAkt, p-Erk, p-S6, and p-eIF4E.Results: We observed differential apoptotic effects of EGFR and mTOR inhibition in TN breast cancers cells. The combination resulted in a significant increase in apoptosis in MDA-MB-468 cells in vitro, but no increase in apoptosis was seen in MDA-MB-231 or HCC1806 cells. As expected, correlating with the apoptotic effects, expression of p-eIF4E was decreased in MDA-MB-468 cells treated with the combination of mTOR and EGFR inhibition in vitro. In contrast, both MDA-MB-231 and HCC1806 cells had high baseline levels of eIF4E, which increased in response to treatment with EGFR and mTOR inhibitors. Using a colony forming assay, we demonstrated that the combination of EGFR and mTOR inhibition resulted in cytostatic effects in HCC1806 cells. The combination of EGFR and mTOR inhibition did not result in apoptosis in MDA-MB-231 cancers in vivo, and these xenograft tumors had high level of eIF4E at baseline.We are currently evaluating the effects of lapatinib and rapamycin on apoptotic pathways in MDA-MB-468 cancers in vivo.Conclusion: Based on our previous findings, we are developing a clinical trial in which patients with metastatic TN breast cancers are treated with lapatinib and everolimus. These results suggest that this combination may be more effective in TN breast cancers with low levels of eIF4E, and this will be explored using metastatic research biopsies.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 5078.

The Effect of Radiotherapy on Local Regional Recurrence among Patients with Pathologic Complete Response to Neoadjuvant Chemotherapy in Locally Advanced Breast Cancer

Background: Radiotherapy has been shown to reduce local recurrence rates of breast cancer after treatment with surgery and adjuvant chemotherapy. Indications for postmastectomy radiation have historically been based on pathology, but indications for radiation in the setting of pathologic complete response (pCR) to neoadjuvant chemotherapy are not well defined. The aim of this study was to evaluate the rates of local regional recurrence (LRR) among patients with pCR to neoadjuvant chemotherapy followed by surgery with or without radiation (XRT).Patients and Methods: The case histories of 337 patients with locally advanced breast cancer treated with neoadjuvant chemotherapy, surgery with or without radiation from October 1997 to December 2006 were analyzed. Median age at diagnosis was 50.6 years (range: 25-84). The clinical stage at diagnosis was I in 3 (1%), IIA in 105 (31%), IIB in 94 (28%), and III in 135 (40%) patients. All patients received preoperative systemic therapy with a doxorubicin-based regimen (92%) or a single-agent taxane regimen (7%) or CMF (1%). A total of 272 patients received radiation following surgery and 65 did not receive any radiation. Median follow-up time was 40 months among all patients. The Kaplan-Meier method and log rank test were used to evaluate LRR rates and overall survival among both groups.Results: Patients treated with neoadjuvant chemotherapy followed by surgery and XRT had a lower incidence of LRR at 3 years with 24 cases of local recurrence among 272 patients who received XRT compared with 12 cases of local recurrence among the 65 patients who did not receive XRT (8.9% v 18.5%, P=0.02). Radiation also reduced local regional recurrence at 3 years among a subset of patients with clinical stage T2N1 disease (4.9% v 28.6%, P=0.03). There was no difference in overall survival or disease free survival among patients who received XRT compared to patients who did not receive XRT. There were 62 (18%) patients who achieved a pCR to neoadjuvant chemotherapy. Among patients with a pathologic complete response, radiation appeared to reduce the risk of LRR compared to patients who did not receive XRT (7.4% v 25%, P=0.17).Conclusion: Radiotherapy significantly reduced local regional recurrence rate among patients with locally advanced breast cancer treated with neoadjuvant chemotherapy and surgery. Of particular interest, patients who achieve a pathologic complete response to neoadjuvant chemotherapy still had high LRR rates and may benefit from radiotherapy by lowering the risk of local regional recurrence. Further studies on the significance of LRR and overall survival among these patients are needed.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 4114.

Triple negative breast cancer confers higher recurrence rates after breast conserving therapy

Abstract #5127

Purpose&#x2028; There has been a recent surge of information regarding the treatment outcomes for women with estrogen receptor (ER) negative, progesterone receptor (PR) negative, and human epidermal growth factor receptor 2 (HER2) negative breast cancer; known as the triple negative (TN) subtype. The purpose of this study is to evaluate the impact of these receptor expressions on local, regional and distant recurrences, and overall survival (OS) in patients undergoing breast conserving therapy (BCT).&#x2028; Patients and Methods&#x2028; The study population included 475 primary invasive female breast cancer patients (excluding Stage IV); who were residents of Fulton-Dekalb counties in Atlanta when diagnosed in 2003-2004 and treated within the Emory University affiliated hospitals. Data was obtained from the SEER cancer registry and augmented with medical record abstraction. Median follow-up was 3.4 years. The endpoints of the study were local, regional and distant recurrences, and OS. Tumors were subgrouped as: ER-/PR-/HER2- (TN), ER+/PR+/HER2-, ER+/PR+/HER2+, ER+/PR+/HER2-. Chi-square and Fisher exact tests were employed.&#x2028; Results&#x2028; For the entire population, median age was 58 years. TN tumors accounted for 17% of the cases. Of the TN patients, 78% were African-American (p&lt;0.01) and 40% had BCT. The majority of TN tumors were high grade (71%), p&lt; 0.01. Total recurrence was 33% among the TN patients vs. 14% in the combined non-TN patient group, p&lt; 0.01. Death occurred among 29% of TN vs. 14% of non-TN, p&lt; 0.01.&#x2028; For the patients that were treated with BCT, 94% of TN patients completed their adjuvant radiation therapy and 73% received chemotherapy. Of those receiving BCT, recurrence was 28% for TN patients and 6% for non-TN patients (p&lt;0.01). Local recurrence was 9% and 4% for TN and non-TN patients, respectively and distant metastatic rate was 16% versus 2% respectively (p&lt; 0.01). There were no regional recurrences in the BCT group. Time to recurrence, OS, time to death, and breast cancer specific death did not differ between the two groups.&#x2028; Conclusion&#x2028; A significant increase in local recurrence and distant metastatic rates were observed after BCT among patients diagnosed with TN breast cancers; however there was not a significant short-term survival difference between the TN and non-TN receptor groups. The complexity of this patient population within the conventional treatment algorithm warrants further investigation to reduce local and distant recurrences.

Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 5127.

Increased HER2 expression in women with recurrent ER positive breast cancer

10516

Introduction: Tamoxifen (TAM) remains widely used in the treatment of all stages of breast cancer. Although the majority of hormone receptor (HR) positive tumors respond to TAM, many of these breast cancers will develop resistance resulting in disease recurrence or progression. Over-expression of HER2 appears to play a role in de novo tamoxifen-resistance. We have demonstrated previously that HR-positive breast cancers exposed to selective estrogen receptor modulators (SERMs), such as tamoxifen, in vivo continue to express HR but have an increase in the expression of HER2 (O'Regan Clin Cancer Res 2006). However the above finding has not been confirmed in patient samples. Materials and Methods: We evaluated 30 paired tissue samples from patients with HR positive tumors whose cancers recurred. The first tissue sample is from diagnosis and the paired sample comes from metachronous metastatic disease. Results: The median age of diagnosis was 56 (29–96). Seven patients presented with stage I disease, 11 with stage II and nine with stage III3, and three patients had missing staging information. The median time to recurrence was three years. The expression of ER decreased from diagnosis to recurrence from 79% to 59% (p=0.035). PR also decreased between diagnosis and recurrence from 34% to 22% (p=0.13). HER2 score was 2 or 3 in 27% of samples at diagnosis and in 53% at time of recurrence (p=0.01). These cancers did not have HER2 gene amplification. Conclusions: These results confirm our in vivo findings that over-expression of HER2 plays a significant role in acquired TAM- resistance. We have previously demonstrated that trastuzumab inhibits growth of SERM-resistant breast cancers in vivo despite the fact that these cancers did not have HER2 gene amplification. Taken together, our findings suggest that trastuzumab should be examined clinically in patients with TAM-resistant metastatic breast cancer, as they may be particularly sensitive to inhibition of HER2-driven pathways.

No significant financial relationships to disclose.

Antiestrogen stimulated human endometrial cancer growth: laboratory and clinical considerations

The new antiestrogen toremifene (TOR) is currently on the market for the treatment of advanced breast cancer in postmenopausal women. TOR is known to exhibit a similar efficacy profile as tamoxifen (TAM) in the treatment of advanced breast cancer and there are studies to suggest that the beneficial side effects of TAM on bone and blood lipids are also achieved with TOR. However, the data concerning the action of TOR on the endometrium is sorely lacking. In light of the estrogenic effect of TAM on the uterus and the 2-3-fold increased incidence in endometrial carcinoma detected in patients receiving TAM therapy, it is imperative to investigate the effect of TOR on endometrial carcinoma. We compared the actions of TAM and TOR on the EnCa101 human endometrial tumor model and find that both antiestrogens have similar growth stimulatory effects. To investigate a potential mechanism of antiestrogen-stimulated endometrial tumor growth, we have examined known activators of the AP-1 signal transduction pathway, the protein kinase C (PKC) family of isozymes, in the EnCa101 human endometrial tumor model. We find that increased PKC isozyme expression correlates with hormone-independent breast cancer as well as antiestrogen-stimulated endometrial cancer.

Upper airway obstruction during sleep in normal subjects after selective topical oropharyngeal anesthesia

Previous animal studies support the presence of an upper airway reflex mechanism that when blocked by topical anesthesia of the upper airway results in upper airway occlusion. We sought a similar reflex mechanism in humans. Nine normal male volunteers 20 to 28 yr of age underwent 3 successive overnight sleep studies: a control study (C); a study in which selective topical oropharyngeal anesthesia (OPA) was achieved prior to sleep using a 10% lidocaine spray and 0.25% bupivocaine solution; a study in which selective nasal anesthesia (NA) was achieved prior to sleep using a mixture of 2% lidocaine and 0.25% bupivocaine solutions instilled into the nose while the nasal airway was positioned as the most dependent part of the upper airway. Total sleep times were similar during the 3 study nights as were the amounts of slow-wave and rapid-eye-movement (REM) sleep. Obstructive apneas and hypopneas (OAH) differed significantly between the 3 study nights [13(3.8), mean (SEM), during OPA as compared to 3(1.8) during C and 7(2.5) during NA; p less than 0.01 by ANOVA] and were most frequent during REM sleep. Total apneas and hypopneas also differed significantly between the 3 study nights [19(3.9) during OPA as compared to 8(2.1) during C and 14(3.9) during NA; p less than 0.01 by ANOVA]. Movement arousals terminating periods of abnormal respiration also differed significantly [21(6.1) during OPA as compared to 12(3.6) during C and 14(4.6) during NA; p less than 0.05 by ANOVA]. No subject, however, developed clinically significant sleep apnea or significant oxygen desaturation during sleep.(ABSTRACT TRUNCATED AT 250 WORDS)