Comparison of Circulating Tumor DNA Assays for Molecular Residual Disease Detection in Early-Stage Triple-Negative Breast Cancer

PURPOSE

Detection of circulating tumor DNA (ctDNA) in patients who have completed treatment for early-stage breast cancer is associated with a high risk of relapse, yet the optimal assay for ctDNA detection is unknown.

EXPERIMENTAL DESIGN

The cTRAK-TN clinical trial prospectively used tumor-informed digital PCR (dPCR) assays for ctDNA molecular residual disease (MRD) detection in early-stage triple-negative breast cancer. We compared tumor-informed dPCR assays with tumor-informed personalized multimutation sequencing assays in 141 patients from cTRAK-TN.

RESULTS

MRD was first detected by personalized sequencing in 47.9% of patients, 0% first detected by dPCR, and 52.1% with both assays simultaneously (P < 0.001; Fisher exact test). The median lead time from ctDNA detection to relapse was 6.1 months with personalized sequencing and 3.9 months with dPCR (P = 0.004, mixed-effects Cox model). Detection of MRD at the first time point was associated with a shorter time to relapse compared with detection at subsequent time points (median lead time 4.2 vs. 7.1 months; P = 0.02).

CONCLUSIONS

Personalized multimutation sequencing assays have potential clinically important improvements in clinical outcome in the early detection of MRD.

A real-world study of the first use of palbociclib for the treatment of advanced breast cancer within the UK National Health Service as part of the novel Ibrance® Patient Program

BACKGROUND

The Ibrance® Patient Program was established to provide access to palbociclib for UK National Health Service (NHS) patients with metastatic breast cancer (MBC), pending a funding decision.

METHODS

Non-interventional cohort study involving a retrospective medical record review of patients commenced on palbociclib between April and December 2017 at eight UK centres. Primary outcomes included clinicopathological characteristics, treatment patterns, clinical outcomes and selected adverse events.

RESULTS

Overall, 191 patients were identified, median age of 57.0 years (range 24.3-90.9); 30% were diagnosed with de novo MBC; 72% received first-line and 10% as ≥ second-line treatment. Median progression-free survival (95% CI) was 22.8 months (16.5-not reached [NR]) in first-line; NR in patients with de novo MBC; 7.8 months (6.8-NR) in ≥ second-line (median follow-up: 24 months). Median overall survival (OS) was NR in the overall cohort; OS rate (95% CI) at 24 months was 74.2% (67.1-81.9%) in first-line; 82.1% (72.6-92.8%) in patients with de novo MBC; 55.0% (37.0-81.8%) in ≥ second-line. Forty-seven per cent of patients developed grade 3-4 neutropenia; 3% febrile neutropenia.

CONCLUSION

This study supports the effectiveness of palbociclib and demonstrates the benefit to patients of early access schemes that bridge the gap between regulatory approval and NHS funding for new medicines.

CLINICAL TRIAL REGISTRATION

Clinical trial: ClinicalTrial.gov:NCT03921866.

A population-scale temporal case-control evaluation of COVID-19 disease phenotype and related outcome rates in patients with cancer in England (UKCCP)

Patients with cancer are at increased risk of hospitalisation and mortality following severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. However, the SARS-CoV-2 phenotype evolution in patients with cancer since 2020 has not previously been described. We therefore evaluated SARS-CoV-2 on a UK populationscale from 01/11/2020-31/08/2022, assessing case-outcome rates of hospital assessment(s), intensive care admission and mortality. We observed that the SARS-CoV-2 disease phenotype has become less severe in patients with cancer and the non-cancer population. Case-hospitalisation rates for patients with cancer dropped from 30.58% in early 2021 to 7.45% in 2022 while case-mortality rates decreased from 20.53% to 3.25%. However, the risk of hospitalisation and mortality remains 2.10x and 2.54x higher in patients with cancer, respectively. Overall, the SARS-CoV-2 disease phenotype is less severe in 2022 compared to 2020 but patients with cancer remain at higher risk than the non-cancer population. Patients with cancer must therefore be empowered to live more normal lives, to see loved ones and families, while also being safeguarded with expanded measures to reduce the risk of transmission.

Abstract PD5-03: PD5-03 Comparison of a personalized sequencing assay and digital PCR for circulating tumor DNA based Molecular Residual Disease detection in early-stage triple negative breast cancer in the cTRAK-TN trial

Background: Detection of circulating tumour DNA (ctDNA) in patients (pts) who have completed treatment for early-stage breast cancer is associated with a high risk of future relapse. Identifying those at high risk of subsequent relapse may allow tailoring of further therapy to delay or prevent recurrence. Previous analysis of this cohort showed that tools capable of detecting ctDNA at lower concentrations are needed to increase sensitivity and lengthen the lead time between ctDNA detection and relapse. We compared ctDNA detection via a personalised sequencing assay to dPCR in patients from the cTRAK TN clinical trial. Methods: The cTRAK-TN trial recruited 161 pts into prospective ctDNA surveillance with dPCR, with ctDNA positive pts randomised to 1) CT staging plus pembrolizumab therapy for patients without relapse or 2) observation. Pts had serial post-treatment surveillance plasma samples collected every 3 months for up to 2 years. Whole exome sequencing (WES) was performed on tumor DNA from FFPE samples to design personalised Residual Disease and Recurrence (RaDaR®) multiplex PCR based NGS assays. Retrospectively, plasma DNA extracted from a minimum of 2mls banked plasma, was sequenced with personalised RaDaR assays, and ctDNA detection identified with a proprietary algorithm. dPCR assays tracked 1-2 mutations, as previously described. Primary endpoint was rate of positive ctDNA detection by 12 months from start of surveillance in both assays. Secondary endpoints were agreement in ctDNA detection between RaDaR and dPCR assays and lead-time between ctDNA detection and disease recurrence. Results: Overall, 147 pts and 241 tissue samples were subject to WES, and RaDaR assays were developed for 142 pts with sufficient plasma for testing. RaDaR assays tracked a median of 47 variants (range 33-56) per patient, and a total of 907 timepoints were analysed (median 6 timepoints per pt, range 1-11). With RaDaR, 39.4% (56/142) patients tested ctDNA positive during follow-up, with a median ctDNA detected level of 0.081% estimated variant allele fraction (eVAF). With dPCR, 35.2% (50/142) pts tested ctDNA positive. The ctDNA detection rate by 12 months from the start of ctDNA surveillance was 36.2% (95% CI; 27.6% – 43.7%) with RaDaR and 29.9% (95%CI; 21.6% – 37.3%) with dPCR. The overall test agreement between RaDaR and dPCR assays was 92.7% (95%CI; 90.7% – 94.4%). From a patient perspective, 58.7% pts were ctDNA negative for both assays, 32.9% ctDNA were positive for both assays and 8.6% presented discrepancies. ctDNA was detected by RaDaR but not by dPCR in 9 pts and it was detected by dPCR but not by RaDaR in 3 pts. Among ctDNA positive pts, 55.2% were first detected positive by RaDaR, 5.2% by dPCR, and 39.6% were detected at the same time-point (test of proportions, p&lt; 0.001). The median lead time from ctDNA detection to relapse was 7.1 months (95% CI 5.9 – 15.9%) with RaDaR and 5.7 months (95% CI 3.2% – 7.4%) with dPCR. Conclusion: The RaDaR personalised multi-mutation sequencing assay detected MRD with a longer median lead time prior to relapse, and with higher sensitivity, than dPCR mutation tracking assays. These findings have implications for the choice of ctDNA assay in clinical trials designed to treat patients at the point of MRD detection.

Citation Format: Maria Coakley, Prithika Sritharan, Guillermo Villacampa, Claire Swift, Kathryn Dunne, Lucy Kilburn, Katie Goddard, Patricia Rojas, Andy Joad, Warren Emmett, Charlene Knape, Karen Howarth, Peter S. Hall, Catherine Harper-Wynne, Tamas Hickish, Iain Macpherson, Alicia F. Okines, Andrew M. Wardley, Duncan Wheatley, Simon Waters, Rosalind Cutts, Isaac Garcia-Murillas, Judith Bliss, Nicholas Turner. PD5-03 Comparison of a personalized sequencing assay and digital PCR for circulating tumor DNA based Molecular Residual Disease detection in early-stage triple negative breast cancer in the cTRAK-TN trial [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr PD5-03.

Abstract OT2-03-01: heredERA Breast Cancer: Phase III study of first-line, fixed-dose combination of pertuzumab and trastuzumab for subcutaneous injection ± giredestrant (GDC-9545) for estrogen receptor+, HER2+ advanced breast cancer

BACKGROUND Giredestrant is a highly potent, nonsteroidal, oral selective estrogen receptor antagonist and degrader (SERD) that was found to be well tolerated and active as a monotherapy and in combination therapy in Phase I/II studies in early BC and pretreated locally advanced/metastatic BC (LA/mBC). Dual HER2 blockade with pertuzumab + trastuzumab (PH) + a taxane (induction therapy) followed by maintenance PH is the first-line standard of care for most patients (pts) with HER2+ LA/mBC. Despite HER2–ER blockade synergy, paucity of Phase III data evaluating maintenance PH + endocrine therapy (ET) vs. PH in pts with ER+/HER2+ LA/mBC leads to variable use of ET in this setting. Adding giredestrant to the maintenance phase could improve outcomes. TRIAL DESIGN This is a Phase III, randomized, two-arm, open-label, multicenter study evaluating the efficacy and safety of giredestrant + the fixed-dose combination of PH for subcutaneous injection (PH FDC SC) vs. PH FDC SC after induction therapy with PH FDC SC + a taxane in pts with ER+/HER2+ LA/mBC. In the induction phase, pts will receive 4–6 PH FDC SC cycles (1200 mg P/600 mg H in the first cycle, followed by 600/600 mg every 3 weeks) + a taxane (investigator choice of docetaxel/paclitaxel). Pts deriving clinical benefit may receive two additional cycles per investigator’s discretion. Pts completing ≥4 induction therapy cycles, achieving at least stable disease, and with a left ventricular ejection fraction (LVEF) ≥50% will be randomly assigned 1:1 to maintenance giredestrant 30 mg/day + PH FDC SC every 3 weeks or PH FDC SC only, until disease progression (PD). ET (aromatase inhibitor/tamoxifen) will be allowed in the PH FDC SC-only arm. Study treatment will continue until PD, limiting toxicity, death, or consent withdrawal. ELIGIBILITY Enrolled pts must have ER+/HER2+ LA/mBC, disease-free interval from completion of (neo)adjuvant non-ET ≥6 months, Eastern Cooperative Oncology Group performance status 0/1, LVEF ≥50%, and adequate organ function. Pts with prior SERD treatment or presence of symptomatic central nervous system metastases will be excluded. All men and pre-/perimenopausal women must be eligible for a luteinizing hormone-releasing hormone agonist. AIMS The primary endpoint is investigator-assessed, maintenance progression-free survival. Secondary endpoints include overall survival (OS), objective response rate, duration of response, clinical benefit rate, pt-reported outcomes, and safety. STATISTICAL METHODS The primary endpoint analysis will use a stratified log-rank test at an overall 0.05 significance level (two-sided). An interim OS analysis is planned, and an independent data monitoring committee will be in place. ACCRUAL The study is open for enrollment. Approximately 812 pts will be enrolled in the induction phase, to allow for approximately 730 pts to be randomized in the maintenance phase. CONTACT INFORMATION For more information or to refer a patient, email global.rochegenentechtrials@roche.com or call 1-888-662-6728 (USA only). Clinicaltrials.gov number: NCT05296798.

Citation Format: Sherko Küemmel, Catherine Harper-Wynne, Yeon H. Park, Fábio Franke, Michelino De Laurentiis, Eva Schumacher-Wulf, Daniel Eiger, Sarah Heeson, Mahesh Shivhare, Eleonora Restuccia, Joyce O’Shaughnessy. heredERA Breast Cancer: Phase III study of first-line, fixed-dose combination of pertuzumab and trastuzumab for subcutaneous injection ± giredestrant (GDC-9545) for estrogen receptor+, HER2+ advanced breast cancer [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr OT2-03-01.

Results of the c-TRAK TN trial: a clinical trial utilising ctDNA mutation tracking to detect molecular residual disease and trigger intervention in patients with moderate- and high-risk early-stage triple-negative breast cancer

BACKGROUND

Post-treatment detection of circulating tumour DNA (ctDNA) in early-stage triple-negative breast cancer (TNBC) patients predicts high risk of relapse. c-TRAK TN assessed the utility of prospective ctDNA surveillance in TNBC and the activity of pembrolizumab in patients with ctDNA detected [ctDNA positive (ctDNA+)].

PATIENTS AND METHODS

c-TRAK TN, a multicentre phase II trial, with integrated prospective ctDNA surveillance by digital PCR, enrolled patients with early-stage TNBC and residual disease following neoadjuvant chemotherapy, or stage II/III with adjuvant chemotherapy. ctDNA surveillance comprised three-monthly blood sampling to 12 months (18 months if samples were missed due to coronavirus disease), and ctDNA+ patients were randomised 2 : 1 to intervention : observation. ctDNA results were blinded unless patients were allocated to intervention, when staging scans were done and those free of recurrence were offered pembrolizumab. A protocol amendment (16 September 2020) closed the observation group; all subsequent ctDNA+ patients were allocated to intervention. Co-primary endpoints were (i) ctDNA detection rate and (ii) sustained ctDNA clearance rate on pembrolizumab (NCT03145961).

RESULTS

Two hundred and eight patients registered between 30 January 2018 and 06 December 2019, 185 had tumour sequenced, 171 (92.4%) had trackable mutations, and 161 entered ctDNA surveillance. Rate of ctDNA detection by 12 months was 27.3% (44/161, 95% confidence interval 20.6% to 34.9%). Seven patients relapsed without prior ctDNA detection. Forty-five patients entered the therapeutic component (intervention n = 31; observation n = 14; one observation patient was re-allocated to intervention following protocol amendment). Of patients allocated to intervention, 72% (23/32) had metastases on staging at the time of ctDNA+, and 4 patients declined pembrolizumab. Of the five patients who commenced pembrolizumab, none achieved sustained ctDNA clearance.

CONCLUSIONS

c-TRAK TN is the first prospective study to assess whether ctDNA assays have clinical utility in guiding therapy in TNBC. Patients had a high rate of metastatic disease on ctDNA detection. Findings have implications for future trial design, emphasising the importance of commencing ctDNA testing early, with more sensitive and/or frequent ctDNA testing regimes.

Association of SARS-CoV-2 Spike Protein Antibody Vaccine Response With Infection Severity in Patients With Cancer: A National COVID Cancer Cross-sectional Evaluation

Importance

Accurate identification of patient groups with the lowest level of protection following COVID-19 vaccination is important to better target resources and interventions for the most vulnerable populations. It is not known whether SARS-CoV-2 antibody testing has clinical utility for high-risk groups, such as people with cancer.

Objective

To evaluate whether spike protein antibody vaccine response (COV-S) following COVID-19 vaccination is associated with the risk of SARS-CoV-2 breakthrough infection or hospitalization among patients with cancer.

Design, Setting, and Participants

This was a population-based cross-sectional study of patients with cancer from the UK as part of the National COVID Cancer Antibody Survey. Adults with a known or reported cancer diagnosis who had completed their primary SARS-CoV-2 vaccination schedule were included. This analysis ran from September 1, 2021, to March 4, 2022, a period covering the expansion of the UK's third-dose vaccination booster program.

Interventions

Anti-SARS-CoV-2 COV-S antibody test (Elecsys; Roche).

Main Outcomes and Measures

Odds of SARS-CoV-2 breakthrough infection and COVID-19 hospitalization.

Results

The evaluation comprised 4249 antibody test results from 3555 patients with cancer and 294 230 test results from 225 272 individuals in the noncancer population. The overall cohort of 228 827 individuals (patients with cancer and the noncancer population) comprised 298 479 antibody tests. The median age of the cohort was in the age band of 40 and 49 years and included 182 741 test results (61.22%) from women and 115 737 (38.78%) from men. There were 279 721 tests (93.72%) taken by individuals identifying as White or White British. Patients with cancer were more likely to have undetectable anti-S antibody responses than the general population (199 of 4249 test results [4.68%] vs 376 of 294 230 [0.13%]; P < .001). Patients with leukemia or lymphoma had the lowest antibody titers. In the cancer cohort, following multivariable correction, patients who had an undetectable antibody response were at much greater risk for SARS-CoV-2 breakthrough infection (odds ratio [OR], 3.05; 95% CI, 1.96-4.72; P < .001) and SARS-CoV-2-related hospitalization (OR, 6.48; 95% CI, 3.31-12.67; P < .001) than individuals who had a positive antibody response.

Conclusions and Relevance

The findings of this cross-sectional study suggest that COV-S antibody testing allows the identification of patients with cancer who have the lowest level of antibody-derived protection from COVID-19. This study supports larger evaluations of SARS-CoV-2 antibody testing. Prevention of SARS-CoV-2 transmission to patients with cancer should be prioritized to minimize impact on cancer treatments and maximize quality of life for individuals with cancer during the ongoing pandemic.

COVID-19: Third dose booster vaccine effectiveness against breakthrough coronavirus infection, hospitalisations and death in patients with cancer: A population-based study

PURPOSE

People living with cancer and haematological malignancies are at an increased risk of hospitalisation and death following infection with acute respiratory syndrome coronavirus 2. Coronavirus third dose vaccine boosters are proposed to boost waning immune responses in immunocompromised individuals and increase coronavirus protection; however, their effectiveness has not yet been systematically evaluated.

METHODS

This study is a population-scale real-world evaluation of the United Kingdom's third dose vaccine booster programme for cancer patients from 8th December 2020 to 7th December 2021. The cancer cohort comprises individuals from Public Health England's national cancer dataset, excluding individuals less than 18 years. A test-negative case-control design was used to assess the third dose booster vaccine effectiveness. Multivariable logistic regression models were fitted to compare risk in the cancer cohort relative to the general population.

RESULTS

The cancer cohort comprised of 2,258,553 tests from 361,098 individuals. Third dose boosters were evaluated by reference to 87,039,743 polymerase chain reaction coronavirus tests. Vaccine effectiveness against breakthrough infections, symptomatic infections, coronavirus hospitalisation and death in cancer patients were 59.1%, 62.8%, 80.5% and 94.5%, respectively. Lower vaccine effectiveness was associated with a cancer diagnosis within 12 months, lymphoma, recent systemic anti-cancer therapy (SACT) or radiotherapy. Patients with lymphoma had low levels of protection from symptomatic disease. In spite of third dose boosters, following multivariable adjustment, individuals with cancer remain at an increased risk of coronavirus hospitalisation and death compared to the population control (OR 3.38, 3.01, respectively. p < 0.001 for both).

CONCLUSIONS

Third dose boosters are effective for most individuals with cancer, increasing protection from coronavirus. However, their effectiveness is heterogenous and lower than the general population. Many patients with cancer will remain at the increased risk of coronavirus infections even after 3 doses. In the case of patients with lymphoma, there is a particularly strong disparity of vaccine effectiveness against breakthrough infection and severe disease. Breakthrough infections will disrupt cancer care and treatment with potentially adverse consequences on survival outcomes. The data support the role of vaccine boosters in preventing severe disease, and further pharmacological intervention to prevent transmission and aid viral clearance to limit the disruption of cancer care as the delivery of care continues to evolve during the coronavirus pandemic.

Vaccine effectiveness against COVID-19 breakthrough infections in patients with cancer (UKCCEP): a population-based test-negative case-control study

BACKGROUND

People with cancer are at increased risk of hospitalisation and death following infection with SARS-CoV-2. Therefore, we aimed to conduct one of the first evaluations of vaccine effectiveness against breakthrough SARS-CoV-2 infections in patients with cancer at a population level.

METHODS

In this population-based test-negative case-control study of the UK Coronavirus Cancer Evaluation Project (UKCCEP), we extracted data from the UKCCEP registry on all SARS-CoV-2 PCR test results (from the Second Generation Surveillance System), vaccination records (from the National Immunisation Management Service), patient demographics, and cancer records from England, UK, from Dec 8, 2020, to Oct 15, 2021. Adults (aged ≥18 years) with cancer in the UKCCEP registry were identified via Public Health England's Rapid Cancer Registration Dataset between Jan 1, 2018, and April 30, 2021, and comprised the cancer cohort. We constructed a control population cohort from adults with PCR tests in the UKCCEP registry who were not contained within the Rapid Cancer Registration Dataset. The coprimary endpoints were overall vaccine effectiveness against breakthrough infections after the second dose (positive PCR COVID-19 test) and vaccine effectiveness against breakthrough infections at 3-6 months after the second dose in the cancer cohort and control population.

FINDINGS

The cancer cohort comprised 377 194 individuals, of whom 42 882 had breakthrough SARS-CoV-2 infections. The control population consisted of 28 010 955 individuals, of whom 5 748 708 had SARS-CoV-2 breakthrough infections. Overall vaccine effectiveness was 69·8% (95% CI 69·8-69·9) in the control population and 65·5% (65·1-65·9) in the cancer cohort. Vaccine effectiveness at 3-6 months was lower in the cancer cohort (47·0%, 46·3-47·6) than in the control population (61·4%, 61·4-61·5).

INTERPRETATION

COVID-19 vaccination is effective for individuals with cancer, conferring varying levels of protection against breakthrough infections. However, vaccine effectiveness is lower in patients with cancer than in the general population. COVID-19 vaccination for patients with cancer should be used in conjunction with non-pharmacological strategies and community-based antiviral treatment programmes to reduce the risk that COVID-19 poses to patients with cancer.

FUNDING

University of Oxford, University of Southampton, University of Birmingham, Department of Health and Social Care, and Blood Cancer UK.

Adoption of adjuvant bisphosphonates for early breast cancer into standard clinical practice: Challenges and lessons learnt from comparison of the UK and Australian experience

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Adoption of adjuvant bisphosphonates for early breast cancer into standard clinical practice.

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UK and Australian experience of adjuvant bisphosphonates in early breast cancer.

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Pathway taken for adjuvant bisphosphonates implementation in the UK.

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Steps to increase update of adjuvant bisphosphonates in early breast cancer.

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Improve the care of women with early breast cancer.

International guidelines recommend adjuvant bisphosphonates (BPs) for post-menopausal women with early breast cancer to reduce recurrence and mortality. However, globally, wide variation exists in their adoption. In the UK, adjuvant BPs were a recommendation in the breast cancer Clinical Reference Group service specification and were included as a priority for implementation by the national oncologists group UK Breast Cancer Group in November 2015, promoting national uptake, guidance and funding arrangements. In 2018, adjuvant BPs were recommended by the UKs National Institute for Health and Care Excellence. In Australia, adjuvant BPs are still ‘off-label’ and do not receive national reimbursement or endorsement. To date there has been no research into the prescribing habits of these agents in Australia. With the aim to gather data on adjuvant BPs prescribing practices, online surveys were developed and disseminated to breast oncologists in both countries between December 2018 and June 2019. Almost all of the UK oncologists prescribed adjuvant BPs, demonstrating that education, endorsement from professional bodies, presence of national guidelines and funding decisions have been critical to implementation. In contrast, only 48% of the Australian responders prescribed adjuvant BPs, while 83% reported that they would prescribe them if funding was available. Lack of local protocol guidance was also seen as a major barrier. This study was intended to assess the pathway taken for adjuvant BP implementation in the UK and how it might inform changes in Australian practice and also guide other countries with similar issues with the ultimate aim of improving the care of women with early breast cancer globally.

Palbociclib in combination with aromatase inhibitors in patients ≥ 75 years with oestrogen receptor-positive, human epidermal growth factor receptor 2 negative advanced breast cancer: A real-world multicentre UK study

BACKGROUND

Breast cancer incidence increases with age and real-world data is essential to guide prescribing practices in the older population. The aim of this study was to collect large scale real-world data on tolerability and efficacy of palbociclib + AI in the first line treatment of ER+/HER2-advanced breast cancer in those aged ≥75 years.

METHODS

14 cancer centres participated in this national UK retrospective study. Patients aged ≥75 years treated with palbociclib + AI in the first line setting were identified. Data included baseline demographics, disease characteristics, toxicities, dose reductions and delays, treatment response and survival data. Multivariable Cox regression was used to assess independent predictors of PFS, OS and toxicities.

RESULTS

276 patients met the eligibility criteria. The incidence of febrile neutropenia was low (2.2%). The clinical benefit rate was 87%. 50.7% of patients had dose reductions and 59.3% had dose delays. The 12- and 24- month PFS rates were 75.9% and 64.9%, respectively. The 12- and 24- month OS rates were 85.1% and 74.0%, respectively. Multivariable analysis identified PS, Age-adjusted Charlson Comorbidity Index (ACCI) and number of metastatic sites to be independent predictors of PFS. Dose reductions and delays were not associated with adverse survival outcomes. Baseline ACCI was an independent predictor of development and severity of neutropenia.

CONCLUSION

Palbociclib is an effective therapy in the real-world older population and is well-tolerated with low levels of clinically significant toxicities. The use of geriatric and frailty assessments can help guide decision making in these patients.

Abstract PS10-25: Tolerability and efficacy of palbociclib in combination with an aromatase inhibitor (AI) in older women (≥75 years) with ER +ve, HER2-ve metastatic breast cancer. A large ‘real world’ UK multi-centre study

IntroductionThe management of metastatic oestrogen receptor (ER) positive and human epidermal growth factor receptor 2 (HER2) negative advanced breast cancer has evolved with the introduction of CDK4/6 inhibitors improving disease outcomes when added to an AI in the first line setting. The FDA evaluated toxicity of all CDK4/6 inhibitors in women ≥75 years (n=198), and found increased toxicity and dose modifications [1], however, toxicity profiles differ between the CDK4/6 inhibitors. Palbociclib has been shown to be well tolerated in patients ≥75 years (n=83) [2] and ≥ 70 years (n=92) [3], however, more real-world data is essential to inform prescribing practices in larger datasets.MethodsWe undertook a national multi-centre retrospective study with 15 cancer centres participating. All patients aged ≥75 years with ER+/HER2- advanced breast cancer who had received at least 1 cycle of Palbociclib + AI as part of a patient access scheme or NICE approved by 1st December 2019 were included. Data collected included baseline characteristics, comorbidities, disease characteristics, toxicities with palbociclib, dose modifications, dose delays, discontinuation and response to treatment.ResultsData from 123 patients aged ≥75 years are included in this analysis from 3 UK cancer centres. Median age was 79 years (range 75 - 90). 98% had an ECOG performance status of 0-2. Co-morbidities were scored using Charlston comorbidity index (CCI - higher score signifies more co-morbidities). 102 patients had a CCI of ≤10 and 18 had a CCI &gt;10. The starting dose of palbociclib was 125mg in 115 patients, but 8 (6.5%) patients started at a lower dose, a third of whom had a CCI of &gt;10. The average number of concurrent medications was 4 (range 0-12). Visceral metastases were present in 52% of patients, and 33 patients (26.8%) had bone only metastases. The median number of cycles received was 10 (range 1 -36). 60 (48.8%) patients required one dose reduction, 18 patients required a 2nd dose reduction and 2 patients required a 3rd dose reduction. The most common cause for dose reductions was neutropenia G3-4 (n=31) and fatigue G1-3 (n=12). 75 patients (61%) required a dose delay and 9% of patients discontinued treatment due to toxicity. The rate of all grade neutropenia was 88.6% with only 1 patient (0.8%) developing febrile neutropenia. Other all grade common toxicities were fatigue (62.6%), anaemia (61.8%) and thrombocytopaenia (57.7%). 12 (9.7%) patients required hospital admission due to side effects of treatment. At the time of data analysis, 111 patients had had a radiological response assessment and the best response was stable disease in 57.7%, partial response in 32.4% and complete response in 0.9% (1 patient) with a clinical benefit rate (CR+PR+SD ≥24 weeks) of 83.8%. 10 patients (9%) had disease progression. The median progression free survival is immature, but at the time of this analysis was 13 months (range 1-36 months).ConclusionOur real world data contributes to the existing smaller published datasets in the over 75s to reassure clinicians that palbociclib is an effective and manageable treatment choice in older women. Compared to published data in older patients [2, 3], febrile neutropenia rates from palbociclib were lower. Despite a higher dose reduction and delay rate than published data [3], the clinical benefit rate was not adversely affected and the early PFS signal is reassuring.

Citation Format: Salma El Badri, Daniel Hills, Alicja Synowiec, Catherine Harper-Wynne, Maung Moe, Caroline Wilson. Tolerability and efficacy of palbociclib in combination with an aromatase inhibitor (AI) in older women (≥75 years) with ER +ve, HER2-ve metastatic breast cancer. A large ‘real world’ UK multi-centre study [abstract]. In: Proceedings of the 2020 San Antonio Breast Cancer Virtual Symposium; 2020 Dec 8-11; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2021;81(4 Suppl):Abstract nr PS10-25.

Abstract PS14-06: Changes in management of breast cancer patients during first wave of COVID19, throughout the area of Kent, United Kingdom. An audit of ESMO guideline implementation

Background: The global COVID-19 pandemic has placed unprecedented burden on individual oncology patients, oncology departments, hospitals and national health systems. In order to protect individual patients from the risk of COVID-19 infection as well as improve capacity for COVID-19 patient management, a series of national and internationally agreed measures were proposed. During the first wave of infections the virulence and effect on cancer patients was not known. It is vitally important that the measures implemented to combat these risks are assessed and evaluated in order to learn best how to manage potential future waves of known and unknown viral infections.Methods: The international ESMO COVID-19 guidelines and national (NICE) guidelines were implemented across Kent, UK. All changes to treatment regimens were audited to assess what were the most frequent changes and in which patient groups could these be implemented. Data was subdivided for both early and advanced breast cancer as well as ER+, HER2+ or triple negative disease.Results: We collected full treatment history from 1,718 breast cancer patients currently receiving active oncology treatments. We were able to change treatment regimens due to COVID19 for 32.8% of patients. Of these 27.1% were early breast cancer patients compared with 43.7% were those with advanced metastatic disease. The most common changes for neoadjuvant changes were proceeding to surgery before completion of planned chemotherapy (10.2%), switch to 3 weekly Paclitaxel (10%) and chemotherapy break (8%). For adjuvant patients the most common changes included postponement of bisphosphonates (70.8%), chemotherapy break (13.5%), and curtailment to 6 months of adjuvant Trastuzumab (10.4%). For our palliative patients the most common changes included delay CDK4/6 inhibitor treatment (79.2%), postponement of bisphosphonates (24.8%), break in HER2 antibody (9.6%) and break in chemotherapy (8%).Conclusions: A large proportion of breast cancer oncology patients were deemed suitable to have a change in original planned treatment. We are fortunate to have comparatively large number of treatment options that can be customised on a patient basis to individual reduce risk of COVID-19. Further analysis is needed over time to compare the oncological outcomes of those in whom treatment was changes from the current gold standards of care.

Citation Format: Simon N Rodney, Charlotte Abson, Russell Burcombe, Rema Jyothirmayi, Catherine Harper-Wynne. Changes in management of breast cancer patients during first wave of COVID19, throughout the area of Kent, United Kingdom. An audit of ESMO guideline implementation [abstract]. In: Proceedings of the 2020 San Antonio Breast Cancer Virtual Symposium; 2020 Dec 8-11; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2021;81(4 Suppl):Abstract nr PS14-06.

The impact of Oncotype DX breast cancer assay results on clinical practice: a UK experience

BACKGROUND

Genomic tests are increasingly being used by clinicians when considering adjuvant chemotherapy for patients with oestrogen receptor-positive (ER+), human epidermal growth factor 2-negative (HER2-) breast cancer. The Oncotype DX breast recurrence score assay was the first test available in the UK National Health Service. This study looked at how UK clinicians were interpreting Recurrence Scores (RS) in everyday practice.

METHODS

RS, patient and tumour characteristics and adjuvant therapy details were retrospectively collected for 713 patients from 14 UK cancer centres. Risk by RS-pathology-clinical (RSPC) was calculated and compared to the low/intermediate/risk categories, both as originally defined (RS < 18, 18-30 and > 30) and also using redefined boundaries (RS < 11, 11-25 and > 25).

RESULTS

49.8%, 36.2% and 14% of patients were at low (RS < 18), intermediate (RS 18-30) and high (RS > 30) risk of recurrence, respectively. Overall 26.7% received adjuvant chemotherapy. 49.2% of those were RS > 30; 93.3% of patients were RS > 25. Concordance between RS and RSPC improved when intermediate risk was defined as RS 11-25.

CONCLUSIONS

This real-world data demonstrate the value of genomic tests in reducing the use of adjuvant chemotherapy in breast cancer. Incorporating clinical characteristics or RSPC scores gives additional prognostic information which may also aid clinicians' decision making.

Abstract P2-18-08: Inclusion of adjuvant bone-modifying agents for early breast cancer into standard clinical practice: Challenges and lessons learnt from an international collaboration

Background: International guidelines recommend adjuvant bone-modifying agents (BMAs) for post-menopausal women with early breast cancer (EBC) to reduce recurrence and mortality. Despite this, wide variation exists internationally in the adoption of these recommendations. BMAs are off-patent with generic formulations being manufactured. Therefore, pharmaceutical lobbying for BMAs to gain regulatory approval for this indication are lacking. This may have negative impact on promotion and education of prescribing physicians, resulting in EBC patients not receiving this intervention. In the UK, BMAs were included as a recommendation in the breast cancer CRG (Clinical Reference Group) service specification and were endorsed as a priority for implementation by the UK Breast Cancer Group (UKBCG) in November 2015, promoting national uptake, local guidance and sharing of funding arrangements through local commissioning agreements. Following these, UKBCG and Breast Cancer Now, conducted 2 surveys in March and October 2016, showing that 24% and 44% respectively, of oncologists prescribe BMAs. In November 2017, a subsequent survey was performed at the annual UKBCG meeting, showed that 77% of the attendees prescribe BMAs. From 2018, BMAs are also part of the UKs NICE (National Institute for Health and Care Excellence) recommendations for EBC treatment, with the current survey to come after the full endorsement of BMAs into UK EBC guidelines. In Australia, BMAs are still ‘off-label’ and do not receive national reimbursement or endorsement. To date there has been no formal inquiry into the prescribing habits in Australia. The aim of this international collaboration was to further evaluate this and translate the methodology for adjuvant BMA implementation in the UK to Australian practice and potentially pave a pathway for other nations struggling with similar barriers to ultimately improve outcomes for women with EBC globally.

Methods: Brief, anonymous, online surveys were developed at each of our institutions using a similar template. The surveys consisted of a series of questions aimed to gather data on their respective local oncologists including demographics, knowledge of current guidelines, current prescribing habits and perceived barriers to prescribing BMAs to women with EBC. The results of the UK survey and experience were used in a collaborative manner to understand the health economics and promote the deliverability of BMAs to women with EBC in Australia.

Results: Between March 2019 and June 2019, the national UK survey received 67 responses from 35 centres around the UK. 98.5% of UK respondents currently prescribe adjuvant BMAs for prevention of disease recurrence. 84.6% report they follow the UKBCG guidelines on the topic and 67.7% report it is discussed in their MDTs.

Between December 2018 and April 2019, 60 responses to the Australian survey were received. 48% of Australian respondents currently prescribe adjuvant BMAs for prevention of disease recurrence. However, 83% reported that they would prescribe adjuvant BMAs if funding was available. Most respondents were aware of the international guidelines on the topic but lack of local protocol guidance was seen as a significant barrier. Only 18.3% report it is discussed in their MDTs.

Conclusions: From 2016 to 2019, the number of UK oncologists who prescribe BMAs has significantly increased, demonstrating that education, pressure from national bodies, national guidelines and funding decisions have been critical to implementation. Acquiring national data on this topic for Australian medical oncologists will help to address the vital need for the development of a national consensus and to clarify the financial and educational barriers that currently limit the prescription of adjuvant BMAs to women with EBC.

Citation Format: Sally Baron-Hay, Elisavet Theodoulou, Isobel Porter, Caroline Wilson, Ingunn Holen, Catherine Harper-Wynne, Janet Brown. Inclusion of adjuvant bone-modifying agents for early breast cancer into standard clinical practice: Challenges and lessons learnt from an international collaboration [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr P2-18-08.

Fulvestrant Plus Vistusertib vs Fulvestrant Plus Everolimus vs Fulvestrant Alone for Women With Hormone Receptor-Positive Metastatic Breast Cancer: The MANTA Phase 2 Randomized Clinical Trial

Question

Does the addition of vistusertib increase progression-free survival and other measures of antitumor activity of fulvestrant in postmenopausal women with estrogen receptor–positive advanced or metastatic breast cancer that progressed after prior therapy with aromatase inhibitors?

Findings

This randomized clinical trial in 333 patients failed to demonstrate a benefit of vistusertib plus fulvestrant vs fulvestrant alone. In addition, the outcomes in both vistusertib groups were inferior to those in the group treated with fulvestrant plus everolimus.

Meaning

The results suggest that dual mammalian target of rapamycin inhibition with vistusertib at the maximal tolerated doses is inferior to mammalian target of rapamycin complex 1 inhibition with the rapamycin analogue everolimus.

Importance

Randomized clinical trials have demonstrated a substantial benefit of adding everolimus to endocrine therapy. Everolimus inhibits the mammalian target of rapamycin complex 1 (mTORC1) complex but not mTORC2, which can set off an activating feedback loop via mTORC2. Vistusertib, a dual inhibitor of mTORC1 and mTORC2, has demonstrated broad activity in preclinical breast cancer models, showing superior activity to everolimus.

Objective

To evaluate the safety and efficacy of vistusertib in combination with fulvestrant compared with fulvestrant alone or fulvestrant plus everolimus in postmenopausal women with estrogen receptor–positive advanced or metastatic breast cancer.

Design, Setting, and Participants

The MANTA trial is an open-label, phase 2 randomized clinical trial in which 333 patients with estrogen receptor–positive breast cancer progressing after prior aromatase inhibitor treatment underwent randomization (2:3:3:2) between April 1, 2014, and October 24, 2016, at 88 sites in 9 countries: 67 patients were assigned to receive fulvestrant, 103 fulvestrant plus vistusertib daily, 98 fulvestrant plus vistusertib intermittently, and 65 fulvestrant plus everolimus. Treatment was continued until disease progression, development of unacceptable toxic effects, or withdrawal of consent. Analysis was performed on an intention-to-treat basis.

Interventions

Fulvestrant alone or in combination with vistusertib (continuous or intermittent dosing schedules) or everolimus.

Main Outcomes and Measures

The primary end point was progression-free survival (PFS).

Results

Among the 333 women in the study (median age, 63 years [range, 56-70 years]), median PFS was 5.4 months (95% CI, 3.5-9.2 months) with fulvestrant, 7.6 months (95% CI, 5.9-9.4 months) with fulvestrant plus daily vistusertib, 8.0 months (95% CI, 5.6-9.9 months) with fulvestrant plus intermittent vistusertib, and 12.3 months (95% CI, 7.7-15.7 months) with fulvestrant plus everolimus. There was no significant difference in PFS between those receiving fulvestrant plus daily or intermittent vistusertib and fulvestrant alone (hazard ratio, 0.88 [95% CI, 0.63-1.24]; P = .46; and hazard ratio, 0.79 [95% CI, 0.55-1.12]; P = .16).

Conclusions and Relevance

The combination of fulvestrant plus everolimus demonstrated significantly longer PFS compared with fulvestrant plus vistusertib or fulvestrant alone. The trial failed to demonstrate a benefit of adding the dual mTORC1 and mTORC2 inhibitor vistusertib to fulvestrant.

Trial Registration

ClinicalTrials.gov identifier: NCT02216786 and EudraCT number: 2013-002403-34

Bronchoalveolar carcinoma as an unsuspected cause for worsening shortness of breath in a patient with metastatic breast cancer

A 70-year-old woman with lung metastases from a breast cancer presented with worsening cough and dyspnoea. She recently had a pleurodesis for a malignant pleural effusion. Chest CT scans demonstrated various radiological changes leading to diagnostic challenges. Differential diagnoses included empyema, pleural disease progression, pulmonary oedema, pneumonitis, lymphangitis and atypical infections. She deteriorated despite a multimodality treatment strategy. Postmortem examination confirmed that lung changes were consistent with a bronchoalveolar carcinoma unrelated to the known metastatic breast cancer. The eventual knowledge of this diagnosis was reassuring to the treating medical team and a comfort to the relatives who witnessed the lack of response to standard treatment.

Patient/oncologist decisions about adjuvant chemotherapy in ER+ve, HER2-ve early breast cancer following endopredict testing

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Background: Endopredict is a multigene test including tumor size and nodal status; it predicts low or high risk of distant recurrence in patients (pts) with ER+ve, HER2–ve breast cancer treated with adjuvant endocrine therapy alone. We compared adj chemotherapy decisions pre and post Endopredict test results, pts’ anxiety, decisional conflict and oncologists’ (oncs) confidence about decisions made. Methods: 14 oncs in 8 UK hospitals saw 149 pts judged by clinical teams to have equivocal indications for chemotherapy. Pts and oncs discussed provisional treatment decisions based on conventional prognostic factors. Initial decisions were reconsidered when Endopredict results were available. Pre and post-test pts completed Spielberger’s State/Trait Anxiety inventory (STAI) and a decision conflict scale (DCS). Oncs answered questionnaires probing:- basic demographic,/clinical details, agreement with, and confidence about treatment decisions (endocrine (E) therapy +/- chemotherapy(C)) Results: 66.7% pts with an initial E alone decision and a high risk result upgraded to E+C. 9.4% pts with initial E+C decisions and high risk results down-graded to E. None of 46 pts initially favouring E alone who were low risk changed decisions. 82.8% who initially wanted E+C and had low risk scores downgraded to E alone. Endopredict results increased oncs’ confidence (8% ‘strongly agreed’ pre-test, 50% post-test). Oncs neither agreeing nor disagreeing with decisions fell (24% to 5%). Anxiety was stable in pts with unchanged decisions. Pts whose therapy was downgraded had significantly lower anxiety scores (p<0.01); those whose treatment was upgraded had increased scores (p<0.001). Likewise overall uncertainty on DCS fell post-test (p<0.023) Conclusions: Endopredict results increased oncs’ and pts’ decision-making confidence, improved matching of risk with therapy decisions and thus a potential for improved outcomes. Clinical trial information: ISRCTN69220108. [Table: see text]

Antiproliferative Effect of Lapatinib in HER2-Positive and HER2-Negative/HER3-High Breast Cancer: Results of the Presurgical Randomized MAPLE Trial (CRUK E/06/039)

PURPOSE

Not all breast cancers respond to lapatinib. A change in Ki67 after short-term exposure may elucidate a biomarker profile for responsive versus nonresponsive tumors.

EXPERIMENTAL DESIGN

Women with primary breast cancer were randomized (3:1) to 10 to 14 days of preoperative lapatinib or placebo in a multicenter phase II trial (ISRCTN68509377). Biopsies pre-/posttreatment were analyzed for Ki67, apoptosis, HER2, EGFR, ER, PgR, pAKT, pERK, and stathmin by IHC. Further markers were measured by RT-PCR. Primary endpoint was change in Ki67. HER2(+) was defined as 2+/3+ by IHC and FISH(+).

RESULTS

One hundred twenty-one patients (lapatinib, 94; placebo, 27) were randomized; of these, 21% were HER2(+), 78% were HER2(-) nonamplified, 26% were EGFR(+). Paired samples containing tumor were obtained for 98% (118 of 121). Ki67 fell significantly with lapatinib (-31%; P < 0.001), but not with placebo (-3%). Whereas Ki67 reduction with lapatinib was greatest in HER2(+) breast cancer (-46%; P = 0.003), there was a significant Ki67 decrease in HER2(-) breast cancer (-27%; P = 0.017) with 14% of HER2(-) breast cancer demonstrating ≥50% Ki67 reduction with lapatinib. Among HER2(+) patients, the only biomarker predictive of Ki67 response was the EGFR/HER4 ligand epiregulin (EREG) (rho = -0.7; P = 0.002). Among HER2(-) tumors, only HER3 mRNA levels were significantly associated with Ki67 response on multivariate analysis (P = 0.01). In HER2(-) breast cancer, HER2 and HER3 mRNA levels were highly correlated (rho = 0.67, P < 0.001), with all Ki67 responders having elevated HER3 and HER2 expression.

CONCLUSIONS

Lapatinib has antiproliferative effects in a subgroup of HER2(-) nonamplified tumors characterized by high HER3 expression. The possible role of high HER2:HER3 heterodimers in predicting response to lapatinib merits investigation in HER2(-) tumors.

Abstract PD07-07: Prediction of antiproliferative response to lapatinib by HER3 in an exploratory analysis of HER2-non-amplified (HER2−) breast cancer in the MAPLE presurgical study (CRUK E/06/039)

Aim: To identify pretreatment biomarker predictors of Ki67 response to lapatinib in women with HER2− primary breast cancer.

Background: Lapatinib is an EGFR/HER2 inhibitor. Its clinical use is restricted to HER2 overexpressing disease. The MAPLE (Molecular Antiproliferative Predictors of Lapatinib's Effects) presurgical window of opportunity study of lapatinib vs placebo was conducted in women with HER2-amplified (HER2+) or HER2− primary disease. Ki67 (primary end-point) was reduced by a geomean 46% (95%CI 23–63%, p = 0.002) and 27% (95%CI 8–42%, p = 0.008) in HER2+ and HER2− disease, respectively (Leary et al, AACR 2012). We have now assessed whether predictive biomarkers of the antiproliferative response in HER2− disease could be identified.

Methods: 121 primary breast cancer patients were randomized (3:1) to 14 days of 1500mg/d lapatinib or placebo before surgery. Biopsies were taken before treatment and at surgery. Ki67 responders were defined as having a &gt;/=50% reduction in Ki67 compared to baseline (Ellis, P et al, Breast Cancer Res Treat 1998, 48, 107). ER, PgR, HER2, EGFR, pAKT, pERK1/2 (nuclear and cytoplasmic), stathmin and apoptosis (TUNEL) were assessed by IHC (+FISH for HER2[all cases]) and scored visually by continuous methods. HER2, HER3, epiregulin (epir), amphiregulin (amphir) and neuregulin (neur) were assessed by qrtPCR.

Results: Three of the 121 patients were excluded because of inadequate biopsy material. Ninety-one of the remaining 118 patients received lapatinib: 7/19 (37%) HER2+ cases and 10/72 (14%) HER2− cases were Ki67 responders. Thus while the proportion of Ki67 responders was higher for HER2+ disease there was a similar or higher absolute number of responders with HER2− disease. All of the following relates to patients with HER2− disease. None of the pretreatment levels of ER, PgR, pAKT, pERK1/2, EGFR, epir, amphir or neur were associated with Ki67 response (p &gt; 0.20). However, HER3 (p = 0.01) and HER2 (p = 0.06) mRNA levels were associated with greater Ki67 response. There was a tendency for Ki67 response to be greater with lower baseline Ki67 (p = 0.07). Multivariate analysis showed only HER3 mRNA levels to be independently significant. HER2 and HER3 mRNA levels were highly correlated (rho = 0.67, p &lt; 0.001), a relationship confirmed in 2 other datasets (Wang et al, Breast Cancer Res, 2011, 13, R92; Dunbier et al, submitted). All Ki67 responders were above the median for both HER3 and HER2 expression.

Conclusions: Lapatinib is antiproliferative in a subgroup of HER2− tumours. This exploratory analysis indicates that they are characterized by high HER3 expression. The possible importance of high HER2:HER3 heterodimers in predicting this response is supported by the relationship between HER2 and HER3 expression. Further exploration of lapatinib is merited in HER2− cases with high HER3 expression.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr PD07-07.

Abstract LB-222: Lapatinib has antiproliferative effects in both HER2 positive (+) and HER2 negative (-) breast cancer (BC): results from the MAPLE short-term pre-surgical trial (CRUK E/06/039)

Not all patients (pts) with HER2 positive (+) breast cancer (BC) benefit from treatment (tx) with EGFR/HER2 tyrosine kinase inhibitor lapatinib (L) & it is not known whether HER2 over-expression or amplification are obligate requirements for L response. Assessment of in vivo biomarkers of drug activity, e.g. change in Ki67, after short-term pre-surgical tx may elucidate the differential molecular profile of sensitive vs. resistant tumors. Aims: i) Determine whether L induces anti-proliferative effects in HER2+ & HER2 negative (-) BC & ii) identify biomarkers of sensitivity/resistance to anti-proliferative effects of L. Methods: Women with newly diagnosed BC were randomized (3:1) to receive 10-14 days of pre-operative L (1500mg/day) or placebo (P) in a multicentre phase II trial (ISRCTN68509377). Paired core biopsies before & after tx were analyzed for Ki67, TUNEL, HER2, EGFR, ER, PgR, pAkt, pErk, & stathmin (candidate marker of PI3K/Akt activation) by IHC +/− FISH. HER2, HER3 & ligands EREG, AREG & NRG1 mRNA was measured by RT-PCR. The primary endpoint was change in Ki67. HER2+ was defined as 3+ or 2+ by IHC and FISH+. Differences in geometric means were assessed by Mann-Whitney & correlations by Spearman rank. Results: 121 pts (L=94, P=27) were randomized between 12/2007-04/2011, 70% were ER+/PgR+, 13% ER+/PgR- & 17% ER-; 22% were HER2+ (including one 2+/FISH+) & 26% were EGFR+. L pts reported significantly more frequent G1-2 (64%) or G3 (6%) rash, & G1 diarrhea (56%); the only other G3 toxicity was infection in 1 pt. There were no delays in surgery. Paired samples containing tumor were obtained for 98% (118/121) of randomized pts. Ki67 fell significantly in the L group (relative reduction in post- vs. pre-tx samples = -31%, 95%CI: -44 to -16; p&lt;0.001), but not in the P group (-3%, 95%CI: -16 to 13). There was no increase in apoptosis (-21%, 95%CI: -39 to 2.2). While Ki67 reduction in the L group was greatest in HER2+ BC (- 46%, 95%CI: -63 to -23; p&lt;0.01), there was also a significant Ki67 fall in HER2- BC (-27%, 95%CI: -42 to -8; p&lt;0.05) with 13% (9/72) of HER2- BC demonstrating ≥50% Ki67 reduction with L. Both pERK & stathmin were also significantly downregulated by L. Among HER2+ pts, there was a trend for high nuclear pAkt to predict for Ki67 response (R=−0.4; p=0.1). Among HER2- pts, neither moderate HER2 nor EGFR expression nor any other biomarker correlated with Ki67 fall. The only biomarker change associated with Ki67 fall among HER2- L-treated pts was stathmin (R=0.4; p=0.001); stathmin did not correlate with pAkt at baseline or with tx. RT-PCR analyses of HER2, HER3 & ligands are ongoing. Conclusion A short-term pre-surgical study for an agent such as L where the main endpoint is molecular rather than clinical, is feasible & safe. Whilst L is currently used exclusively in HER2+ disease, MAPLE has shown it also has antiproliferative effects in a subset of HER2- BC.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr LB-222. doi:1538-7445.AM2012-LB-222

What is the evidence for rechallenging with anthracyclines or taxanes in metastatic breast cancer? A review of the data

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Background: Anthracyclines and taxanes are widely used in the adjuvant setting for high risk, early stage breast cancer. This raises the issue of what is the optimal therapy for those patients who relapse, and what the potential role, if any, there is for rechallenge with these agents. The current evidence base for rechallenging with anthracyclines/anthracediones and taxanes in metastatic breast cancer (MBC) is examined in this study. Methods: Medline/Pubmed database searches were performed upto October 2008 to identify studies in which patients (pts) were rechallenged with anthracyclines/anthracediones or taxanes in MBC. Results: The efficacy data, as well as the safety data relating to neurotoxicity and cardiotoxicity from these studies, are summarized in the Table. Twenty-seven studies were identified (20=anthracycline/anthracedione, 7= taxane) of which only two were prospective studies. Both were small (n= 74 & 51) and related to anthracycline rechallenging. Conclusions: Evidence exists to support rechallenging with anthracyclines and taxanes. However, there are few prospective data on reexposure to taxanes and no data comparing anthracyclines versus taxanes following adjuvant exposure to both agents, supporting the need for clinical trials in this area. Such trials should ideally incorporate a cross-over design at treatment failure, which would shed light on the optimal sequence in which these agents should be administered.

[Table: see text]

No significant financial relationships to disclose.

Report of two protocol planned interim analyses in a randomised multicentre phase III study comparing capecitabine with fluorouracil and oxaliplatin with cisplatin in patients with advanced oesophagogastric cancer receiving ECF

The purpose of the study was to establish the optimal dose of capecitabine (X) to be used within a multicentre, randomised study evaluating the potential roles of oxaliplatin (O) and X in chemonaive patients (pts) with advanced oesophagogastric cancer. Two by two design was used, and pts were randomised to one of four regimens and stratified for extent of disease, performance status (PS) and centre. The treatment regimens are epirubicin, cisplatin, 5-fluorouracil (ECF), EOF, ECX or EOX. Doses: E 50 mg m⁻², C 60 mg m⁻² and O 130 mg m⁻² i.v. 3 weekly; F 200 mg m⁻² day⁻¹ i.v. and X 500 mg m⁻² b.i.d.⁻¹ (escalated to 625 mg m⁻² b.i.d.⁻¹ after results of first interim analysis) p.o., continuously. First interim analysis was performed when 80 pts had been randomised. Dose-limiting fluoropyrimidine toxicities were stomatitis, palmar plantar erythema (PPE) and diarrhoea; 5.1% of X-treated pts experienced grade 3/4 toxicity. Protocol planned dose escalation of X to 625 mg m⁻² b.i.d.⁻¹ was instituted and a second interim analysis has been performed; results are presented in this paper. A total of 204 pts were randomised at the time of the protocol planned 2nd interim analysis. Grade 3/4 fluoropyrimidine-related toxicity was seen in 13.7% pts receiving F, 8.4% pts receiving X 500 mg m⁻² b.i.d.⁻¹ and 14.7% pts receiving X 625 mg m⁻² b.i.d.⁻¹. Combined complete and partial response rates were ECF 31% (95% CI 18.7–46.3), EOF 39% (95% CI 25.9–53.1), ECX 35% (95% CI 21.4–50.3), EOX 48% (95% CI 33.3–62.8). Grade 3/4 fluoropyrimidine toxicity affected 14.7% of pts treated with X 625 mg m⁻² b.i.d.⁻¹, which is similar to that observed with F, confirming this to be the optimal dose. The replacement of C by O and F by X does not appear to impair efficacy. The trial continues to total accrual of 1000 pts.

Oxaliplatin and capecitabine chemotherapy for advanced colorectal cancer: a single institution's experience

AIMS

To determine the efficacy of the combination of oxaliplatin and capecitabine in patients with advanced colorectal cancer.

MATERIALS AND METHODS

A retrospective review of all patients with advanced colorectal cancer treated with oxaliplatin 130 mg/m2 on day 1 and capecitabine 2 g/m2 daily in two divided doses days 1-14 every 3 weeks, outside of a clinical trial at the Royal Marsden Hospital. Patients could have received any number of lines of previous treatment.

RESULTS

Between September 2000 and March 2002, 47 patients were treated with the combination. Fifteen patients had not received previous chemotherapy for advanced disease, 10 had received one line of treatment and 21 had received two or more lines of previous treatment. The overall response rate was 27.6%, with a complete response rate of 2.1%. Overall response rates according to line of treatment were 33% for non pre-treated patients, 36% for second line and 19% for third and more lines. The median overall survival was 13.4 months and the median failure-free survival was 6.5 months. There were no treatment-related deaths and no grade 4 haematological toxicity.

CONCLUSIONS

The combination of oxaliplatin and capecitabine is active in advanced colorectal cancer. It can result in down-staging of tumours to enable hepatic resection. In addition, it is a well-tolerated regimen.

Effects of the aromatase inhibitor letrozole on normal breast epithelial cell proliferation and metabolic indices in postmenopausal women: a pilot study for breast cancer prevention

The aromatase enzyme converts androgens to estrogens and is the therapeutic target for aromatase inhibitors in postmenopausal patients with estrogen receptor-positive metastatic breast cancer. Third-generation inhibitors such as letrozole are being considered as potential prophylactic agents for breast cancer. The rationale for their preventive application would be aided by knowledge of their effects on the normal breast and on other estrogen-dependent processes such as bone and lipid metabolism. Thirty-two women without active breast disease were recruited to 3-month treatment with letrozole (2.5 mg/day). Core-cut biopsies from the breast and blood samples were collected before and at the end of treatment. Plasma estradiol levels were markedly suppressed in all but two patients, who were excluded from the efficacy assessment. There was no significant change in the proliferation marker Ki67 (mean change, -23%; 95% confidence interval, -50% to +23%) or estrogen receptor in breast epithelial cells with treatment. Similarly, there were no significant changes in plasma levels of insulin-like growth factor I or lipid profiles. However, there was a significant increase (25%) in the levels of the bone resorption marker C-telopeptide crosslinks (CTx). We conclude that any prophylactic effect of letrozole is not likely to be dependent on antiproliferative effects on normal breast. Studies in healthy patients will need to recognize the potential for enhanced bone resorption.

HER-2 amplification impedes the antiproliferative effects of hormone therapy in estrogen receptor-positive primary breast cancer

In experimental models, human epidermal growth factor receptor-2 (HER-2) amplification leads to estrogen independence and tamoxifen resistance in estrogen receptor (ER)-positive human breast cancer cells. Some but not all reports suggest an association between HER-2 positivity and hormone independence in breast cancer patients. This study aimed to evaluate the antiproliferative effects of endocrine therapy in HER-2-positive/ER-positive primary human breast cancer. The effect on proliferation (Ki67) of hormone therapy was assessed at 2 weeks and/or 12 weeks in biopsies from 115 primary breast cancers with ER-positive tumors. The patients took part in one of 3 neoadjuvant trials of hormonal therapy with a SERM (tamoxifen or idoxifene) or an aromatase inhibitor (anastrozole or vorozole). HER-2 status was assessed by immunocytochemistry and fluorescence in situ hybridization (FISH). Fifteen patients were defined as HER-2 positive by both immunohistochemistry and FISH, with the remaining 100 patients HER-2 negative. Geometric mean Ki67 levels were substantially higher in HER-2-positive than HER-2-negative tumors (27.7% versus 11.5%, respectively; P = 0.003). In HER-2-negative patients, Ki67 was reduced by 62 and 71% at 2 and 12 weeks, respectively (P < 0.0001 for both), but HER-2-positive patients showed no significant fall. The proportional change in Ki67 was significantly different between HER-2-positive and -negative patients (P = 0.014 at 2 weeks; P = 0.047 at 12 weeks). Mean ER levels were lower in the HER-2-positive patients (P = 0.06) but the change in Ki67 was impeded even in those with high ER. Apoptotic index was reduced by 30% at 2 weeks in the HER-2-negative group. However, there were no statistically significant differences in apoptotic index between the groups. It is concluded that ER-positive/HER-2-positive primary breast carcinomas show an impeded antiproliferative response to endocrine therapy that nonetheless may vary between individual treatments. This together with high baseline proliferation is likely to translate to poor clinical response.

Multisite phosphotyping of the ErbB-2 oncoprotein in human breast cancer

BACKGROUND

Overexpression of the ErbB-2 (HER2/neu) receptor tyrosine kinase is one of the most common molecular changes in human cancer, but the functional significance of this phenotype remains uncertain.

METHODS AND RESULTS

Using phosphorylation-specific antibodies recognizing different ErbB-2 functional states, we assessed the phosphorylation status of ErbB-2 in 102 human breast cancer specimens. Quantitative ErbB-2 immunoblotting intensity correlated directly with that of immunohistochemistry (r = 0.84). Widely varying phosphorylation profiles were evident in 65 ErbB-2-positive carcinomas, suggesting different ErbB-2 functions in different tumors. In a subset of patients for whom clinical data were obtainable, mortality trends were strongly associated with the quantitative signal intensities of ErbB-2 phosphoantibodies (P < or =.02), but not with those of conventional antibodies to ErbB-2 (P = .147), epidermal growth factor receptor (P = .44), or phosphotyrosine (P = .94).

CONCLUSION

Although requiring corroboration in larger prospective clinical studies, these findings suggest that immunophenotyping using phosphorylation-specific antibodies may enable more accurate prediction of cancer behavior than is currently obtainable using conventional reagents.

Recent advances in the clinical application of aromatase inhibitors

Aromatase inhibitors have evolved over a period of 20 years to well tolerated agents that can effectively obliterate aromatase activity in postmenopausal women. Breast cancer is the predominant clinical application and here the newer agents have established themselves as the preferred second-line agent after tamoxifen in the treatment of advanced disease. Recent data indicate that they be more efficacious than tamoxifen and, therefore, may replace it as the first-line agent of choice in the near future. On-going clinical trials in the adjuvant setting and prospective prevention studies will elucidate whether these drugs have a yet greater role in breast cancer.

Randomized trial to compare the efficacy and toxicity of cyclophosphamide, methotrexate and 5-fluorouracil (CMF) with methotrexate mitoxantrone (MM) in advanced carcinoma of the breast

One hundred and sixteen patients with locally advanced or metastatic breast cancer were randomized to receive CMF (cyclophosphamide 600 mg m(-2) day 1 and 8 i.v., 5-fluorouracil 600 mg m(-2) day 1 and 8 i.v., methotrexate 40 mg m(-2) day 1 and 8 i.v., monthly for 6 cycles) or MM (methotrexate 30 mg m(-2), mitoxantrone 6.5 mg m(-2), both i.v. day 1 3-weekly for 8 cycles) as first line treatment with chemotherapy. Objective responses occurred in 17 patients out of 58 (29%) who received CMF and nine out of 58 (15%) who received MM; 95% confidence interval for difference in response rates (-1%-29%), P = 0.07. No statistically significant differences were seen in overall survival or time to progression between the two regimes although a tendency towards a shorter progression time on the MM regime must be acknowledged. There was, however, significantly reduced haematological toxicity (P < 0.001) and alopecia (P < 0.001) and fewer dose reductions and delays in patients randomized to MM. No statistically significant differences were seen between the two regimes in terms of quality of life (QOL). However, some association between QOL and toxicity was apparent overall with pooled QOL estimates tending to indicate a worsening in psychological state with increasing maximum toxicity over treatment. Despite the fact that results surrounding response rates and time to progression did not reach statistical significance, their possible compatibility with an improved outcome on CMF treatment must be borne in mind. However, MM is a well-tolerated regimen with fewer side-effects than CMF, which with careful patient management and follow-up, therefore, may merit consideration as a first-line treatment to palliate patients with metastatic breast cancer who are infirm or elderly.

Aromatase inhibitors and their use in the sequential setting

Over the past decade several novel aromatase inhibitors have been introduced into clinical practice. The discovery of these drugs followed on from the observation that the main mechanism of action of aminogluthemide was via inhibition of the enzyme aromatase thereby reducing peripheral levels of oestradiol in postmenopausal patients. The second-generation drug, 4-hydroxyandrostenedione (formestane), was introduced in 1990 and although its use was limited by its need to be given parenterally it was found to be a well-tolerated form of endocrine therapy. Third-generation inhibitors include vorozole, letrozole, anastrozole and exemestane, the former three being non-steroidal inhibitors, the latter being a steroidal inhibitor. All are capable of inhibiting aromatase action by >95% compared with 80% in the case of 4-hydroxyandrostenedione. The sequential use of different generations of aromatase inhibitors in the same patients is discussed. Studies suggest that an optimal sequence of these compounds may well result in longer remission in patients with hormone receptor positive tumours.

Anastrozole shows evidence of activity in postmenopausal patients who have responded or stabilised on formestane therapy

Formestane (Lentaron) and anastrozole (Arimidex) are in clinical use as second-line treatments for advanced breast cancer. Current practice is often to use an aromatase inhibitor only once before switching to third-line agents such as progestins. There are few clinical data on the sequential use of aromatase inhibitors. We therefore decided to study the clinical effects of anastrozole in postmenopausal patients with advanced breast cancer who had already received formestane. 21 patients were recruited. When receiving formestane 2/21 (10%) achieved a partial response (UICC criteria) and 10/21 (48%) stable disease. Of these 12 patients, 9 achieved further stable disease on anastrozole (78%; 7/9 oestrogen receptor positive). 4 of 9 patients who progressed on formestane also stabilised on anastrozole, of whom 3 had oestrogen receptor positive breast carcinomas. The explanation of this second stabilisation may relate to a further fall in oestradiol levels. We feel these results are of interest and warrant further clinical investigation.