Abstract GS3-02: PALLET: A neoadjuvant study to compare the clinical and antiproliferative effects of letrozole with and without palbociclib

Background: CDK4/6 inhibitors, such as palbociclib, are used to treat ER+ metastatic breast cancer in combination with endocrine therapy with trials ongoing in patients with primary disease. No biomarkers exist to identify those who do/do not benefit from added CDK4/6 inhibition. PALLET is an investigator-initiated/led phase II randomized trial collaboration between UK and NSABP investigators evaluating the biological and clinical effects of palbociclib with letrozole combination as neoadjuvant therapy.

Methods: Postmenopausal women with ER+ primary breast cancer and tumors >2.0cm (ultrasound) were randomized to one of 4 treatment groups (3:2:2:2 ratio): Group A: letrozole (2.5mg/d) for 14 weeks; Group B: letrozole for 2 weeks followed by letrozole + palbociclib to 14 weeks; Group C: palbociclib for 2 weeks followed by letrozole + palbociclib to 14 weeks; Group D: letrozole + palbociclib for 14 weeks. Palbociclib was given 125mg/d PO on a 21 days on, 7 days off schedule. Post-14 week treatment was at the discretion of the treating clinician including letrozole until surgery. Core-cut biopsies were taken at baseline, 2 weeks and 14 weeks. Co-primary endpoints for letrozole alone vs palbociclib groups (Group A vs Groups B+C+D) were: (i) change in Ki67 (IHC) between baseline and 14 weeks (log-fold change, Mann-Whitney test); (ii) clinical response (ultrasound) after 14 weeks (4 group, ordinal, Mann-Whitney test). Complete cell-cycle arrest (CCCA) (Ki67≤2.7%) was analyzed using a logistic regression model adjusting for recruitment region. Pre-specified exploratory biomarkers included c-PARP (apoptosis).

Results: 307 patients were recruited between 27 Feb 2015 and 08 Mar 2018; 103 were randomized to letrozole alone and 204 to letrozole + palbociclib. 279 (90.9%) patients were evaluable for 14 week clinical response. Clinical response was not significantly different between letrozole vs letrozole + palbociclib groups [(p=0.20; CR+PR 49.5% (46/93) vs 54.3% (101/186) and PD 5.4% (5/93) vs 3.2% (6/186)] nor was the small proportion of patients with pathological CR (1/87, 1.1% vs 6/180, 3.3%; p=0.43). 190 (61.9%) patients were evaluable for 14 week change in Ki67. The median log-fold change in Ki67 was greater with letrozole + palbociclib vs letrozole alone (-4.1 vs -2.2; p<0.001) corresponding to a geometric mean change of -97.4% vs -88.5%. Similarly, a greater proportion of patients who received letrozole + palbociclib achieved CCCA (90% vs 59%, p<0.001). 146 (47.6%) patients were evaluable for c-PARP and the log-fold change (suppression) was greater with letrozole + palbociclib vs letrozole alone (-0.80 vs -0.42; p=0.003) corresponding to a geometric mean change of -56.8% vs -31.4%. Other biomarkers of response / resistance are being evaluated. A higher proportion of patients had a grade ≥3 toxicity on letrozole + palbociclib than letrozole alone (49.8% vs 17.0%; p<0.001) mainly due to asymptomatic neutropenia.

Conclusion: Adding palbociclib to letrozole markedly enhanced the suppression of malignant cell proliferation as assessed by Ki67 but did not substantially increase the clinical response of primary ER+ breast cancer over a 14-week period. Concurrent reductions in cell death may have reduced the speed of tumor shrinkage.

Citation Format: Dowsett M, Jacobs S, Johnston S, Bliss J, Wheatley D, Holcombe C, Stein R, McIntosh S, Barry P, Dolling D, Snowdon C, Perry S, Batten L, Dodson A, Martins V, Modi A, Cornman C, Puhalla S, Wolmark N, Julian T, Pogue-Geile K, Robidoux A, Provencher L, Boileau JF, Shalaby I, Thirlwell M, Fisher K, Huang Bartlett C, Koehler M, Osborne K, Rimawi M. PALLET: A neoadjuvant study to compare the clinical and antiproliferative effects of letrozole with and without palbociclib [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr GS3-02.

Final efficacy and updated safety results of the randomized phase III BEATRICE trial evaluating adjuvant bevacizumab-containing therapy in triple-negative early breast cancer

Background

The purpose of this analysis was to assess the long-term impact of adding bevacizumab to adjuvant chemotherapy for early triple-negative breast cancer (TNBC).

Methods

Patients eligible for the open-label randomized phase III BEATRICE trial had centrally confirmed triple-negative operable primary invasive breast cancer (pT1a-pT3). Investigators selected anthracycline- and/or taxane-based chemotherapy for each patient. After definitive surgery, patients were randomized 1:1 to receive ≥4 cycles of chemotherapy alone or with 1 year of bevacizumab (5 mg/kg/week equivalent). Stratification factors were nodal status, selected chemotherapy, hormone receptor status, and type of surgery. The primary end point was invasive disease-free survival (IDFS; previously reported). Secondary outcome measures included overall survival (OS) and safety.

Results

After 56 months' median follow-up, 293 of 2591 randomized patients had died. There was no statistically significant difference in OS between treatment arms in either the total population (hazard ratio 0.93, 95% confidence interval [CI] 0.74-1.17; P = 0.52) or pre-specified subgroups. The 5-year OS rate was 88% (95% CI 86-90%) in both treatment arms. Updated IDFS results were consistent with the primary IDFS analysis. Five-year IDFS rates were 77% (95% CI 75-79%) with chemotherapy alone versus 80% (95% CI 77-82%) with bevacizumab. From 18 months after first study dose to study end, new grade ≥3 adverse events occurred in 4.6% and 4.5% of patients in the two arms, respectively.

Conclusion

Final OS results showed no significant benefit from bevacizumab therapy for early TNBC. Late-onset toxicities were rare in both groups. Five-year OS and IDFS rates suggest that the prognosis for patients with TNBC is better than previously thought.

ClinicalTrials.gov

NCT00528567.

Prognostic and predictive value of low estrogen receptor expression in breast cancer

PURPOSE

Anti-hormonal therapy (tamoxifen) is recommended for estrogen receptor (er)-positive breast cancer (bca); however, its effect on low-receptor cancers is unclear. We retrospectively evaluated the effect of adjuvant tamoxifen in patients with weakly er-positive bca.

METHODS

We identified 2221 bca patients who had been er-tested by ligand-based assay (lba) during 1976-1995 and who had been treated and followed until 2008. Cox proportional hazards models adjusted for age, body mass index, tumour size, nodal status, surgery, and chemotherapy were used to assess the effect of er level on bca survival in patients who received tamoxifen.

RESULTS

Overall, 17% (383) of patients were within 0-3 fmol/mg cytosol protein, and 12% (266) were within 4-9 fmol/mg cytosol protein. Patients with er levels of 0-3, 4-9, 10-19, 20-49, and 50 fmol/mg or more cytosol protein had 20-year bca survival rates of 56%, 56%, 63%, 71%, and 60% respectively. Of the 2221 patients studied, 661 (29.8%) received anti-hormonal therapy. Within the latter group, er levels of 0-3, 4-9, 10-19, 20-49, and 50 fmol/mg or more cytosol protein were associated with a hazard ratio for lower bca mortality: respectively, 1.00 (reference), 0.59 (p = 0.09), 0.19 (p < 0.0001), 0.26 (p < 0.0001), and 0.31 (p < 0.0001)-the risk reduction being significant only for er levels of 10 fmol/mg or more cytosol protein.

CONCLUSIONS

Tamoxifen use in bca patients with a weakly positive er status (4-9 fmol/mg cytosol protein), compared with those having higher er levels (≥10 fmol/mg cytosol protein), is not associated with a significantly lower bca-specific mortality. Our results do not support treatment with anti-hormonal therapy for bca patients with a weakly positive er status as identified by lba.

Abstract P4-22-08: A single-arm phase 2 study to assess clinical activity, efficacy and safety of enzalutamide with trastuzumab in HER2+ AR+ metastatic or locally advanced breast cancer

Background:Androgen receptor (AR) expression has been observed in up to 77% of human epidermal growth factor receptor 2–positive (HER2+) breast cancer (BC).References:1 Enzalutamide (ENZA) is a potent AR inhibitor approved for patients (pts) with metastatic castration-resistant prostate cancer. In vitro, ENZA enhances antitumor activity of trastuzumab in HER2+ AR+ cell lines and inhibits proliferation in trastuzumab-resistant HER2+ cell lines.2

Methods:Pts with metastatic or locally advanced BC that was HER2+ AR+ by local or central laboratory assessment were enrolled in a single-arm, Simon 2-stage phase 2 study (NCT02091960). Key eligibility criteria included availability of a tissue sample, presence of measurable or evaluable disease per RECIST v1.1, progression on prior trastuzumab and ≥1 prior line of anti-HER2 therapy as the most recent regimen. Brain metastases and history of seizure were exclusionary. Evaluable pts were those with centrally confirmed nuclear AR expression≥10% by immunohistochemistry who received ≥1 dose of ENZA and had ≥1 postbaseline tumor assessment. Pts received ENZA 160 mg daily and trastuzumab 6 mg/kg every 21 days until disease progression. The primary objective was clinical benefit rate at 24 weeks (CBR24), defined as complete or partial response (CR or PR) or stable disease (SD) for ≥24 weeks in evaluable pts. Additional endpoints included safety and progression-free survival (PFS). CBR24 in ≥3 of 21 evaluable pts was required to continue to stage 2 and enrollment of up to 66 evaluable pts total. This design yields a 1-sided type 1 error of 5% and 90% power when the true response is 25%.

Results:Here we present results from stage 1 (data cutoff: Mar 23, 2016), with 22 evaluable pts enrolled (pts 21 and 22 enrolled simultaneously); 18 had received ≥4 prior lines of therapy. Median duration of ENZA exposure was 144 days (range, 22-495), mean number of complete trastuzumab infusions was 6.5. CBR24 was 27.3% (95% confidence interval [CI], 10.7-50.2); 2 confirmed PR and 4 SD ≥24 weeks. Median PFS was 108 days (95% CI, 56-144). All pts experienced ≥1 adverse event (AE) any grade; 5 pts experienced AEs grade ≥3. ENZA-related AEs were reported in 16 pts (72.7%), the most common (in ≥10% of pts) were fatigue (22.7%), nausea (18.2%), diarrhea (13.6%) and arthralgia (13.6%). Serious AEs were reported in 6 pts (27.3%; 2 each of infection and back pain, 1 each of abdominal pain, nausea, vomiting, pyrexia, urinary retention and pulmonary edema). Two pts discontinued due to drug-related AEs: 1 related to both drugs, 1 related to trastuzumab. One on-study death from pulmonary edema was reported, which was not considered related to either drug.

Conclusion:Stage 1 met its primary objective. No new safety signals were identified, and the safety profile in this study was similar to that in men with prostate cancer and women with other BC subtypes treated with ENZA. These results are encouraging for a heavily pretreated population with advanced HER2+ AR+ BC. Enrollment in stage 2 continues with the combination of ENZA and trastuzumab.

1. Micello D et al. Virchows Arch. 2010;457:467-476.

2. Richer J. Presented at AACR Advances in Breast Cancer, San Diego, CA, 2013.

Citation Format: Krop I, Cortes J, Miller K, Huizing MT, Provencher L, Gianni L, Chan S, Trudeau M, Steinberg J, Sugg J, Liosatos M, Paton VE, Peterson A, Wardley A. A single-arm phase 2 study to assess clinical activity, efficacy and safety of enzalutamide with trastuzumab in HER2+ AR+ metastatic or locally advanced 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 P4-22-08.

Recommendations on breast cancer screening and prevention in the context of implementing risk stratification: impending changes to current policies

In recent years, risk stratification has sparked interest as an innovative approach to disease screening and prevention. The approach effectively personalizes individual risk, opening the way to screening and prevention interventions that are adapted to subpopulations. The international perspective project, which is developing risk stratification for breast cancer, aims to support the integration of its screening approach into clinical practice through comprehensive tool-building. Policies and guidelines for risk stratification-unlike those for population screening programs, which are currently well regulated-are still under development. Indeed, the development of guidelines for risk stratification reflects the translational aspects of perspective. Here, we describe the risk stratification process that was devised in the context of perspective, and we then explain the consensus-based method used to develop recommendations for breast cancer screening and prevention in a risk-stratification approach. Lastly, we discuss how the recommendations might affect current screening policies.

Is clinical breast examination important for breast cancer detection?

BACKGROUND

Screening clinical breast examination (cbe) is controversial; the use of cbe is declining not only as a screening tool, but also as a diagnostic tool. In the present study, we aimed to assess the value of cbe in breast cancer detection in a tertiary care centre for breast diseases.

METHODS

This retrospective study of all breast cancers diagnosed between July 1999 and December 2010 at our centre categorized cases according to the mean of detection (cbe, mammography, or both). A cbe was considered "abnormal" in the presence of a mass, nipple discharge, skin or nipple retraction, edema, erythema, peau d'orange, or ulcers.

RESULTS

During the study period, a complete dataset was available for 6333 treated primary breast cancers. Cancer types were ductal carcinoma in situ (15.3%), invasive ductal carcinoma (75.7%), invasive lobular carcinoma (9.0%), or others (2.2%). Of the 6333 cancers, 36.5% (n = 2312) were detected by mammography alone, 54.8% (n = 3470) by mammography and cbe, and 8.7% (n = 551) by physician-performed cbe alone (or 5.3% if considering ultrasonography). Invasive tumours diagnosed by cbe alone were more often triple-negative, her2-positive, node-positive, and larger than those diagnosed by mammography alone (p < 0.05).

CONCLUSIONS

A significant number of cancers would have been missed if cbe had not been performed. Compared with cancers detected by mammography alone, those detected by cbe had more aggressive features. Clinical breast examination is a very low-cost test that could improve the detection of breast cancer and could prompt breast ultrasonography in the case of a negative mammogram.

Long-term outcomes after adjuvant treatment of sequential versus combination docetaxel with doxorubicin and cyclophosphamide in node-positive breast cancer: BCIRG-005 randomized trial

BACKGROUND

The optimal regimen for adjuvant breast cancer chemotherapy is undefined. We compared sequential to concurrent combination of doxorubicin and cyclophosphamide with docetaxel chemotherapy in women with node-positive non-metastatic breast cancer. We report the final, 10-year analysis of disease-free survival (DFS), overall survival (OS), and long-term safety.

PATIENTS AND METHODS

A total of 3298 women with HER2 nonamplified breast cancer were randomized to doxorubicin and cyclophosphamide every 3 weeks for four cycles followed by docetaxel (AC → T) every 3 weeks for four cycles or docetaxel, doxorubicin, and cyclophosphamide (TAC) every 3 weeks for six cycles. The patients received standard radiotherapy and endocrine therapy and were followed up for 10 years with annual clinical evaluation and mammography.

RESULTS

The 10-year DFS rates were 66.5% in the AC → T arm and 66.3% in the TAC arm (P = 0.749). OS was 79.9% in the AC → T arm and 78.9% in the TAC arm (P = 0.506). TAC was associated with higher rates of febrile neutropenia, although G-CSF primary prophylaxis greatly reduced this risk. AC → T was associated with a higher rate of myalgia, hand-foot syndrome, fluid retention, and sensory neuropathy.

CONCLUSION

This 10-year analysis of the BCIRG-005 trial confirmed that the efficacy of TAC was not superior to AC → T in women with node-positive early breast cancer. The toxicity profiles differ between arms and were consistent with previous reports. The TAC regimen with G-CSF support provides shorter adjuvant treatment duration with less toxicity.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier NCT00312208.

No effect of scalp cooling on survival among women with breast cancer

Scalp cooling can prevent chemotherapy-induced alopecia in some cancer patients. It is not used in all countries. No data are available regarding its impact, if any, on survival. The aim of this study was to compare overall survival according to whether or not scalp cooling was used during neoadjuvant or adjuvant chemotherapy for non-metastatic breast cancer. We conducted a retrospective cohort study of 1,370 women with non-metastatic invasive breast carcinoma who received chemotherapy in the neoadjuvant or adjuvant setting. A total of 553 women who used scalp cooling came from a tertiary breast cancer clinic in Quebec City (diagnosed between 1998 and 2002) and 817 were treated in other hospitals in the province of Quebec (between 1998 and 2003) where scalp cooling was not routinely available. Overall survival of women who used scalp cooling and those who did not was compared using Cox proportional hazards models. Median follow-up for the scalp-cooled and the non-scalp-cooled groups was 6.3 years and 8.0 years, respectively. Overall mortality was no different (adjusted hazard ratio 0.89, 95 % confidence interval: 0.68-1.17, p = 0.40) among scalp-cooled women, compared to those not getting scalp cooling. Among women getting neoadjuvant or adjuvant chemotherapy for non-metastatic breast cancer, scalp cooling used to prevent chemotherapy-induced alopecia had no negative effect on survival. To our knowledge, this is the first study to compare survival of women who used scalp cooling to that of women who did not.

Everolimus plus exemestane for hormone-receptor-positive, human epidermal growth factor receptor-2-negative advanced breast cancer: overall survival results from BOLERO-2†

BACKGROUND

The BOLERO-2 study previously demonstrated that adding everolimus (EVE) to exemestane (EXE) significantly improved progression-free survival (PFS) by more than twofold in patients with hormone-receptor-positive (HR(+)), HER2-negative advanced breast cancer that recurred or progressed during/after treatment with nonsteroidal aromatase inhibitors (NSAIs). The overall survival (OS) analysis is presented here.

PATIENTS AND METHODS

BOLERO-2 is a phase III, double-blind, randomized international trial comparing EVE 10 mg/day plus EXE 25 mg/day versus placebo (PBO) + EXE 25 mg/day in postmenopausal women with HR(+) advanced breast cancer with prior exposure to NSAIs. The primary end point was PFS by local investigator assessment; OS was a key secondary end point.

RESULTS

At the time of data cutoff (3 October 2013), 410 deaths had occurred and 13 patients remained on treatment. Median OS in patients receiving EVE + EXE was 31.0 months [95% confidence interval (CI) 28.0-34.6 months] compared with 26.6 months (95% CI 22.6-33.1 months) in patients receiving PBO + EXE (hazard ratio = 0.89; 95% CI 0.73-1.10; log-rank P = 0.14). Poststudy treatments were received by 84% of patients in the EVE + EXE arm versus 90% of patients in the PBO + EXE arm. Types of poststudy therapies were balanced across arms, except for chemotherapy (53% EVE + EXE versus 63% PBO + EXE). No new safety concerns were identified.

CONCLUSIONS

In BOLERO-2, adding EVE to EXE did not confer a statistically significant improvement in the secondary end point OS despite producing a clinically meaningful and statistically significant improvement in the primary end point, PFS (4.6-months prolongation in median PFS; P < 0.0001). Ongoing translational research should further refine the benefit of mTOR inhibition and related pathways in this treatment setting.

TRIAL REGISTRATION NUMBER

NCT00863655.

Abstract P2-16-17: Characterization of response to everolimus (EVE) in BOLERO-2: A phase 3 trial of EVE plus exemestane (EXE) in postmenopausal women with HR+, HER2- advanced breast cancer

Introduction: The BOLERO-2 trial demonstrated that combining the oral mammalian target of rapamycin (mTOR) inhibitor, EVE, with the steroidal aromatase inhibitor, EXE, more than doubled median progression-free survival (PFS) compared with placebo (PBO) plus EXE in postmenopausal women with hormone-receptor-positive (HR+), human epidermal growth factor receptor-2-negative (HER2−) breast cancer (BC) who relapsed or progressed following a nonsteroidal aromatase inhibitor (NSAI). Patients also achieved responses per Response Evaluation Criteria in Solid Tumors (RECIST) during treatment with EVE+EXE.

Methods: The phase 3, double-blind, BOLERO-2 trial randomized postmenopausal women with HR+ BC progressing or recurring after NSAIs in a 2:1 manner to EVE 10 mg once daily plus EXE 25 mg once daily (EVE+EXE; n = 485) or placebo (PBO) plus EXE (PBO+EXE; n = 239). The primary endpoint was PFS by local assessment. Overall response rate (ORR; complete + partial response per investigator assessment based on RECIST 1.0) and duration of overall response were secondary endpoints. In addition, best percentage change from baseline in sum of longest diameters of target lesions was assessed.

Results: At the time of final PFS analyses at 18 months’ median follow-up, ORR was significantly higher in the EVE+EXE arm compared with the PBO+EXE arm (12.6% vs 1.7%, respectively, by local assessment; P&lt;.0001). Among patients with measurable disease at baseline, 71% in the EVE+EXE arm had a decrease in the sum of longest diameters of target lesions compared with baseline vs 30% in the PBO+EXE arm. Median duration of overall response was 10.5 months (95% confidence interval [CI]: 8.2, 21.9 months) for EVE+EXE and 6.9 months (95% CI: 4.2, 6.9 months) for PBO+EXE. Of note, only 4 patients in the PBO+EXE arm had an objective response to treatment.

Conclusions: In addition to PFS, the combination of EVE plus EXE significantly improved ORR vs PBO+EXE in patients with HR+, HER2− advanced BC progressing during or after NSAI therapy. Furthermore, greater than two-thirds of patients treated with EVE+EXE experienced tumor shrinkage during treatment. These results further support the rationale for combining EVE with EXE to improve clinical outcomes in HR+, HER2− advanced BC progressing after NSAI therapy.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P2-16-17.

Endocrine therapy for postmenopausal women with hormone receptor-positive her2-negative advanced breast cancer after progression or recurrence on nonsteroidal aromatase inhibitor therapy: a Canadian consensus statement

Approximately 22,700 Canadian women were expected to be diagnosed with breast cancer in 2012. Despite improvements in screening and adjuvant treatment options, a substantial number of postmenopausal women with hormone receptor positive (hr+) breast cancer will continue to develop metastatic disease during or after adjuvant endocrine therapy. Guidance on the selection of endocrine therapy for patients with hr+ disease that is negative for the human epidermal growth factor receptor 2 (her2-) and that has relapsed or progressed on earlier nonsteroidal aromatase inhibitor (nsai) therapy is of increasing clinical importance. Exemestane, fulvestrant, and tamoxifen are approved therapeutic options in this context. Four phase iii trials involving 2876 patients-efect, sofea, confirm, and bolero-2-have assessed the efficacy of various treatment options in this clinical setting. Data from those trials suggest that standard-dose fulvestrant (250 mg monthly) and exemestane are of comparable efficacy, that doubling the dose of fulvestrant from 250 mg to 500 mg monthly results in a 15% reduction in the risk of progression, and that adding everolimus to exemestane (compared with exemestane alone) results in a 57% reduction in the risk of progression, albeit with increased toxicity. Multiple treatment options are now available to women with hr+ her2- advanced breast cancer recurring or progressing on earlier nsai therapy, although current clinical trial data suggest more robust clinical efficacy with everolimus plus exemestane. Consideration should be given to the patient's age, functional status, and comorbidities during selection of an endocrine therapy, and use of a proactive everolimus safety management strategy is encouraged.

Extending Neoadjuvant Care through Multi-Disciplinary Collaboration: Proceedings from the Fourth Annual Meeting of the Canadian Consortium for Locally Advanced Breast Cancer

The use of systemic therapy before surgery (“neoadjuvant therapy”) is the standard of care for the treatment of locally advanced and nonoperable breast cancer. The advantages of neoadjuvant therapy include improved rates of breast-conserving surgery, the possibility of early measurement of response, and potentially improved outcomes for certain subgroups of high-risk patients. The use of neoadjuvant therapy in operable breast cancer is increasing, although there are no clear guidelines in Canada to help guide patient selection and management. Multidisciplinary experts in the diagnosis and treatment of locally advanced breast cancer (labc) converged at the fourth annual meeting of the Canadian Consortium for LABC (colab) to further their goals of improved standards for neoadjuvant care and clinical research through education and collaboration. Canadian clinical researchers were joined by Dr. Michael Untch of the Helios Hospital Berlin–Buch—representing the German neoadjuvant treatment groups German Gynecologic Oncology Working Group (Arbeitsgemeinschaft Gynakologische Onkologie) and German Breast Group—to discuss the advancement of research in the neoadjuvant setting and important issues of clinical care and investigator-led research. The group reached a consensus on the importance of multidisciplinary collaboration, the use of clips to mark tumour location, and core biopsy testing for the estrogen and progesterone receptors and the human epidermal growth factor receptor 2 at the time of diagnosis. Other initiatives—including creation of a prospective database, inception of the colab Neoadjuvant Network, and development of a clinical survey to evaluate current practice—continue to further the colab mandate of transforming the neoadjuvant treatment landscape in Canada.

P1-12-12: Evaluation of Ile655Val HER2 Polymorphism Associated with Cardiac Toxicity Following the Administration of Trastuzumab in Women with Non-Metastatic Breast Cancer

Background: Trastuzumab is well tolerated without major side effects except for cardiac toxicity. Although a number of clinical parameters have been associated with trastuzumab-associated cardiac toxicity (TACT), there is some indication that genetic variation of the HER2 gene may be associated with TACT in a population of metastatic breast cancer patients. However, this finding needs confirmation and we looked at a population of non-metastatic breast cancer.

Purpose: This study aimed to evaluate the association between cardiac toxicity and HER2 [Ile655Val] polymorphism in non-metastatic breast cancer patients treated with trastuzumab.

Method: The Ile655Val HER2 polymorphism was assessed in 41 women using TaqMan technology. For this study, the genotyping was performed using DNA extracted from normal breast tissue located at more than 1 cm of any other lesions. Charts review was used to collect information on TACT which was defined as a decrease in the left ventricular ejection fraction (LVEF) of ≥15% or ≥10% with a resulting LVEF &lt; 50% or any follow-up LVEF of &lt; 45%. The Fisher exact test was used to evaluate the association between cardiac toxicity and HER2 polymorphism.

Results: No deviation from the Hardy-Weinberg equilibrium has been observed for the allele and genotype frequencies. The distribution of HER2 polymorphism was 10 Ile/Val (24%) and 31 Ile/Ile (76%). In this population, 22% (9/41) developed a cardiac toxicity. The Val655Ile genotype was associated with cardiac toxicity (0.03). In this preliminary study, 50% (5/10) of Ile/Val carriers compared to 13% (4/31) of Ile/Ile carriers showed TACT.

Conclusion: HER2 Ile655Val polymorphism may be an efficient marker of TACT considering this tendency with this small cohort of patients. Larger sample is needed to strengthen this conclusion, since this result may influence on prescribing decision for adjuvant chemotherapy and anti-HER2 therapy in HER2 positive patients.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P1-12-12.

The role of neoadjuvant (HER)2-targeted therapies in (HER)2-overexpressing breast cancers

Women receiving neoadjuvant systemic therapy for primary operable or inoperable breast cancer can potentially benefit in a number of ways, but the main advantage, which has been consistently demonstrated, is improved tumour resectability. Given the improvement in outcomes with the adjuvant use of trastuzumab in patients with early-stage breast cancer positive for the human epidermal growth factor receptor 2 (her2), questions have been raised about the use of trastuzumab in the neoadjuvant setting. The present paper reviews the currently available data and outlines suggestions from a panel of Canadian oncologists about the use of trastuzumab and other her2-targeted agents in the neoadjuvant setting.

The panel focussed on

the use of trastuzumab and other her2-targeted agents as neoadjuvant therapy in primary operable, locally advanced, and inflammatory breast cancer; and

possible choices of chemotherapeutic regimens with trastuzumab.

The suggestions described here will continue to evolve as data from current and future trials with trastuzumab and other her2-targeted agents emerge.

Emerging trends in the treatment of triple-negative breast cancer in Canada: a survey

Triple-negative breast cancer (TNBC) has a poor prognosis compared to other subtypes and lacks common therapeutic targets, including HER 2 and the estrogen and progesterone receptors. The clinicopathological heterogeneity of the disease and limited treatment options make clinical management particularly challenging. Here we present the results of a survey of Canadian clinical oncologists regarding treatment of TNBC, and review recent and ongoing clinical research in this area. Our survey results show that the majority of respondents use a combination of anthracyclines-taxanes as adjuvant therapy for early TNBC. For the first-line treatment of metastatic TNBC, most clinicians recommend taxanes, while single agent capecitabine and platinum-based therapies are more common for subsequent lines of therapy. Despite the ongoing development of novel targeted therapies, chemotherapy remains the mainstay of treatment for TNBC.

Optimizing the management of HER2-positive early breast cancer: the clinical reality

Breast cancer positive for HER2 (human epidermal growth factor receptor 2) is associated with a poor prognosis for patients with both early-stage and metastatic breast cancer. Trastuzumab has been shown to be effective and is now considered the standard of care for early-stage patients with HER2-positive breast cancer. In that population, trastuzumab has been studied in six randomized clinical trials. Overall, use of this agent leads to a significant reduction in risk of disease recurrence and improvement in overall survival. Despite the strong evidence for the use of trastuzumab in managing HER2-positive early breast cancer (EBC), a number of clinical controversies remain. The authors of this paper undertook a review of the available scientific literature on adjuvant trastuzumab to produce practical considerations from Canadian oncologists. The panel focused their discussion on five key areas: Management of node-negative disease with tumours 1 cm or smaller in size. Management of HER2-positive EBC across the spectrum of the disease (that is, nodal and steroid hormone receptor status, tumour size) Timing of trastuzumab therapy with chemotherapy for early-stage disease: concurrent or sequential. Treatment duration of trastuzumab for EBC. The role of non-anthracycline trastuzumab-based regimens.

The role of HER2-targeted therapies in women with HER2-overexpressing metastatic breast cancer

The role of targeted therapies in the treatment of women with breast cancer has been rapidly evolving. Trastuzumab, a monoclonal antibody against the human epidermal growth factor receptor 2 (HER2), was the first HER2-targeted therapy that clearly demonstrated a significant clinical benefit for women with HER2-overexpressing metastatic breast cancer (mbc). However, in recent years it has become increasingly apparent that, when trastuzumab is used in the first-line setting in combination with chemotherapy, most women eventually develop progressive disease. Determining the treatment options available to women who have progressed while on trastuzumab therapy has been hampered by a paucity of high-quality published data. In addition, with the standard use of trastuzumab in the adjuvant setting (for eligible HER2-positive patients), the role of anti-HER2 agents for patients who experience a breast cancer relapse has become a clinically relevant question. This manuscript reviews current available data and outlines suggestions from a panel of Canadian oncologists about the use of trastuzumab and other HER2-targeted agents in two key mbc indications:Treatment for women with HER2-positive mbc progressing on trastuzumab (that is, treatment beyond progression)Treatment for women with HER2-positive mbc recurring following adjuvant trastuzumab (that is, re-treatment)The suggestions set out here will continue to evolve as data and future trials with trastuzumab and other HER2-targeted agents emerge.

Phase II study of sagopilone (ZK-Epo) in patients with recurrent metastatic breast cancer (MBC)

1083

Background: Sagopilone is a novel, fully synthetic epothilone, which represents a new class of microtubule stabilizing agents. It has shown significant pre-clinical activity in taxane resistant breast cancer cell lines and in tumor models, as well as clinical activity in both taxane naïve and pretreated MBC. Methods: MBC patients who received ≤ 3 prior anthracycline and taxane containing chemotherapies were eligible. Sagopilone was given either at 16 mg/m2 (arm A) or at 22 mg/m2 (arm B, amended additional cohort) IV over 3 hours every 21 days for up to 6 cycles. The primary end point was tumor response by RECIST. The Simon 2-Stage design required 3 responders in the first 24 evaluable patients in stage 1 and 10 responders in 65 evaluable patients to declare success. Results: Between June 2006 and June 2008, 65 patients were enrolled and treated (39 in arm A, 26 in arm B). Majority of metastases were in lymph nodes (62%), liver (55%), bone (49%), lung (37%), and cutaneous sites (19%). Median number of cycles delivered was 2 (1–17). Neither arm met Stage 1 criteria for responders. Nevertheless, 2 patients in arm A and 1 in arm B had confirmed partial response, and lasted 4, 7, and 2 months, respectively. 26% patients in arm A, and 42% in arm B had stable disease. 42 patients discontinued study prior to cycle 6 due to progressive disease/death, 14 due to adverse events, and 1 due to other reasons. All 65 patients are evaluable for safety. Adverse events documented or reported in ≥ 20% patients are: sensory neuropathy 80% (23% grade 3), nausea 57% (no grade 3), fatigue 45% (12% grade 3), vomiting 29% (no grade 3), myalgia 28% (5% grade 3), diarrhea 25% (2% grade 3), insomnia 25% (no grade 3), pain in extremity 25% (2% grade 3), headache 23% (5% grade 3), arthralgia 22% (5% grade 3), constipation 22% (2% grade 3). Conclusions: Sagopilone had limited activity in these heavily pretreated MBC patients. It appeared tolerable at both dose levels.

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Evaluation of the incidence and of risk factors associated with trastuzumab-associated cardiac toxicity in routine clinical practice

589

Background: Data on trastuzumab-associated cardiac toxicity (TACT) in routine clinical practice are scarce. Alcohol is a potential cardiotoxic but it has not been evaluated as a potential risk factor for TACT. Methods: This is a single institution retrospective study, conducted at the Centre des Maladies du Sein Deschênes-Fabia, Quebec City. Charts review was used to collect information on tumor, cardiovascular risk factors (coronary artery disease (CAD), heart failure, high blood pressure (HBP), obesity, diabetes), alcohol (yes/no), smoking (yes/no), type chemotherapy, anthracyclines doses, trastuzumab doses and left ventricular ejection fraction (LVEF). A questionnaire about smoking and use of alcohol (before chemotherapy, during chemotherapy and during trastuzumab alone) was administered to patients. TACT was defined as a decrease in the LVEF of ≥15% or ≥10% with a resulting LVEF < 50% or any follow-up LVEF of < 45%. Results: Data were collected on 117 patients with non-metastatic breast cancer who started adjuvant trastuzumab between 2002 and 2007. Questionnaires on alcohol use/smoking were administered to 61 patients from these 117 patients. Median age was 53 years old and 95.7% received anthracyclines-based chemotherapy. Median follow-up of LVEF was 16.3 months. TACT developed in 25.6% of patients (10.3 % with a decreased in the LVEF of ≥15%, 7.7% with a decreased in the LVEF of ≥10% with a resulting LVEF < 50% and 7.7% with a LVEF < 45%). None of the following risks factors for TACT were significant (using logistic regression): age (p =0.95), CAD (p = 0.29), HBP (p = 0.46), body mass index (p = 0.64), diabetes (p = 0.29), smoking (p = 0.9), anthracycline doses (p = 0.12), baseline LVEF (p = 0.26). Alcohol use was not associated with TACT (p = 0.76). Further data will be collected in next months about alcohol use. Conclusions: In routine clinical practice, TACT was observed in 25.6% of patients, which is higher than what was reported in trastuzumab phase III clinical trials. Results about alcohol use and TACT will be updated in the spring 2009.

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Cardiac management during adjuvant trastuzumab therapy: recommendations of the Canadian Trastuzumab Working Group

Trastuzumab has been shown to be an effective therapy for women with breast cancer that overexpresses the human epidermal growth factor receptor 2 (her2) protein. In the pivotal metastatic breast cancer trials, cardiac dysfunction was observed in women treated with trastuzumab and chemotherapy. The incidence and severity of cardiac dysfunction was greatest among patients who received trastuzumab in combination with anthracycline-based therapy. Those findings influenced the design of subsequent trastuzumab trials to include prospective evaluations of cardiac effects and protocols for cardiac monitoring and management. The risk of cardiotoxicity has also driven efforts to develop non-anthracycline-based regimens for women with her2-positive breast cancers.With the increasing use of trastuzumab, particularly in the curative adjuvant setting, the need for a rational approach to the treatment and cardiac management of the relevant patient population is clear. The mandate of the Canadian Trastuzumab Working Group was to formulate recommendations, based on available data, for the assessment and management of cardiac complications during adjuvant trastuzumab therapy. The panel formulated recommendations in four areas: Risk factors for cardiotoxicity, Effects of various regimens, Monitoring, Management. The recommendations published here are expected to evolve as more data become available and experience with trastuzumab in the adjuvant setting grows.

Pegylated liposomal doxorubicin (PLD) with cyclophosphamide (C) as 1st-line chemotherapy for metastatic breast cancer (MBC) patients previously treated with adjuvant anthracyclines

10627

Background: Anthracyclines (A) are key elements in adjuvant and metastatic chemotherapy regimens for breast cancer. Pre-exposure limits the utilization of A in advanced disease due to cumulative cardiotoxicity. PLD (Caelyx/Doxil) has equivalent activity to conventional doxorubicin in MBC. However PLD has reduced toxicity, including significantly less cardiotoxicity. Combinations of A+C are the backbone of many adjuvant therapies, thus C represents a logical drug to combine with PLD. Methods: MBC patients with measurable disease who completed anthracycline containing adjuvant therapy > 12 months ago were entered in a multi-center single arm phase II trial. They received PLD 35mg/m2 + cyclophosphamide 600 mg/m2 every 3 weeks. This study was powered to demonstrate an objective response rate > 25%. Results: Seventy three patients were enrolled. Prior adjuvant therapy included: AC (37%), CEF/FEC (28%), AC-T (15%), AT (7%), EC (7%). The median cumulative dose of prior A were 240mg/m2 and 580mg/m2 for doxorubicin or epirubicin, respectively. Median time since adjuvant chemotherapy was 4.4 years (1–14). Patients received a median of 6 cycles (2–10) of PLD + C. Major toxicities were; grade 3/4 neutropenia (7.5%), asymptomatic > 10% declines in LVEF (9%) (reversible upon discontinuation of PLD), grade 3/4 hand foot syndrome (6%). Other toxicities were uncommon and usually did not require discontinuation. The objective response rate (ORR) was 38% (4% CR and 34% PR), with an additional 32% having stable disease > 6 months for a clinical benefit of 70% (CB). ORR was similar for patients who had received adjuvant taxanes. Kaplan-Meyer estimated median time to progression was 31.5 weeks (23% progression free). Conclusions: The combination of PLD + C every 3 weeks in patients who have completed adjuvant anthracycline chemotherapy after more than one year prior is well tolerated and has a clinical benefit rate of 70%. This finding is similar to other commonly employed chemotherapeutic regimens for MBC and suggests that re-treatment with a non-cardiotoxic anthracycline following previous anthracycline therapy may be a reasonable therapeutic option for some patients.

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Comparison of the effects of the new orally active antiestrogen EM-800 with ICI 182 780 and toremifene on estrogen-sensitive parameters in the ovariectomized mouse

The nonsteroidal antiestrogen EM-800 is approximately 10-fold more potent than ICI 182 780, the most potent known steroidal antiestrogen, at inhibiting estrone-stimulated uterine weight in ovariectomized mice (half-maximal inhibitory daily s.c. doses of 0.2 and 2.0 microg, respectively). At maximal doses, however, both compounds lead to a similar maximal 90% inhibition of estrone-stimulated uterine weight. A 10-fold higher activity of EM-800 compared with ICI 182 780 was also observed on estrone-stimulated vaginal weight, with maximal inhibitions of 96% and 90%, respectively, achieved by the two compounds. In addition, EM-800 injected s.c. or administered orally led to a marked loss of uterine and vaginal estrogen receptor levels measured by binding assay, whereas ICI 182 780 exerted no inhibitory effect on this parameter under the experimental conditions used. Comparable effects were observed when estrogen receptor protein levels were measured by enzyme immunoassay. After oral administration, EM-800 exerted maximal 83% and 88% inhibitions of uterine and vaginal weight, respectively, whereas maximal inhibitions limited to 51% and 67% were achieved with toremifene. This limited inhibition by toremifene of the stimulatory effect of estrone on uterine and vaginal weight is probably due to the intrinsic estrogenic activity of the compound. The present data also show that the steroidal antiestrogen ICI 182 780 has less than 3% the activity of EM-800 when administered by the oral route. In fact, EM-800 administered orally is 2- to 3-fold more potent than ICI 182 780 injected s.c.

Binding characteristics of novel nonsteroidal antiestrogens to the rat uterine estrogen receptors

Tamoxifen (TAM), the only antiestrogen currently available for the endocrine therapy of breast cancer behaves as a mixed agonist/antagonist of estrogen action, thus limiting its therapeutic potential. We report the binding characteristics of a novel series of nonsteroidal antiestrogens to the rat uterine estrogen receptor. As measured by competition studies, the affinity of EM-652, the active metabolite of the prodrug EM-800, for the estrogen receptor is 7-11 times higher than that of 17beta-estradiol (E2), ICI 182780, and hydroxy-tamoxifen (OH-TAM), the active metabolite of Tamoxifen. EM-652 is 20x more potent than ICI 164384 and Droloxifene while it is 400 times more potent than Toremifene in displacing [3H]E2 from the rat uterine estrogen receptor. On the other hand, the prodrug EM-800 and Tamoxifen have respectively 150-fold and 410-fold less affinity for the estrogen receptor than the pure antiestrogen EM-652. No significant binding of EM-652, EM-800, TAM or OH-TAM was observed to the rat uterine progesterone receptor at concentrations up to 10,000 nM except for TAM that caused a 50% displacement of labeled R5020 at 4000 nM. No significant binding of EM-652 or EM-800 was observed on the rat ventral prostate androgen receptor or the rat uterine progesterone receptor. The present data demonstrate the high affinity and specificity of the new antiestrogen, EM-652, for the rat uterine estrogen receptor. The antiestrogen EM-652 thus becomes the compound having the highest known affinity for the estrogen receptor. Due to its unique potency and its pure antiestrogenic activity already demonstrated in many systems, this antiestrogen could well offer an important advance for the endocrine therapy of breast cancer, uterine cancer, and other estrogen-sensitive diseases in women.

Comparative efficacy and safety of controlled-release morphine suppositories and tablets in cancer pain

Although the oral route is the preferred method of opioid therapy in patients with cancer pain, many patients will require an alternate route of analgesic administration at some point during the trajectory of their illness. This study compared the efficacy and safety of a novel, controlled-release suppository of morphine (MSC-R) and controlled-release morphine tablets (MSC-T) in patients with cancer pain. In a double-blind crossover study, 27 patients with cancer pain were randomized to receive MSC-R or MSC-T every 12 hours for 7 days each, using a 1:1 analgesic equivalence ratio. Pain intensity was assessed using a visual analog scale (VAS) and the Present Pain Intensity Index of the McGill Pain Questionnaire. Nausea and sedation were also assessed with a VAS. Pharmacodynamic assessments were made by the patient at 8:00 AM, 12:00 PM, 4:00 PM, and 8:00 PM and rescue morphine use recorded in a daily diary. There were no significant differences between MSC-R and MSC-T in overall scores for pain intensity VAS, ordinal pain intensity, and sedation. There was a small but significant difference in overall nausea VAS score in favor of MSC-R. Mean daily rescue analgesic use did not differ significantly during between treatment with MSC-R and MSC-T. MSC-R provides pain control comparable to that provided by MSC-T when given every 12 hours at a 1:1 dose ratio, and represents a reliable alternative method of pain control for patients unable to take oral opioid agents.

Evolving cooperation: the role of individual recognition

To evaluate the role of individual recognition in the evolution of cooperation, we formulated and analyzed genetic algorithm model (EvCo) for playing the Iterated Prisoner's Dilemma (IPD) game. Strategies compete against each other during each generation, and successful strategies contribute more of their attributes to the next generation. Each strategy is encoded on a 'chromosome' that plays the IPD, responding to the sequences of most recent responses by the interacting individuals (chromosomes). The analysis reported in this paper considered different memory capabilities (one to five previous interactions), pairing continuities (pairs of individuals remain together for about one, two, five, or 1000 consecutive interactions), and types of individual recognition (recognition capability was maximal, nil, or allowed to evolve between these limits). Analysis of the results focused on the frequency of mutual cooperation in pairwise interactions (a good indicator of overall success in the IPD) and on the extent to which previous responses by the focal individual and its partner were associated with the partner's identity (individual recognition). Results indicated that a fixed, substantial amount of individual recognition could maintain high levels of mutual cooperation even at low pairing continuities, and a significant but limited capability for individual recognition evolved under selection. Recognition generally increased mutual cooperation more when the recent responses of individuals other than the current partner were ignored. Titrating recognition memory under selection using a fitness cost suggested that memory of the partner's previous responses was more valuable than memory of the focal's previous responses. The dynamics produced to date by EvCo are a step toward understanding the evolution of social networks, for which additional benefits associated with group interactions must be incorporated.

Five-membered ring azasugars as potent inhibitors of alpha-L-rhamnosidase (naringinase) from Penicillium decumbens

Five-membered ring azasugars with the L-rhamnose configuration were synthesized as inhibitors of alpha-L-rhamnosidase from Penicillium decumbens. All compounds tested were in the microM or sub-microM range. Substitution at the nitrogen shifted the inhibition mechanism from mixed to competitive.