Abstract P6-13-05: Association between the UGT2B17 gene deletion, exemestane metabolites and vasomotor QOL in women participating on the MAP3 prevention trial

Background: The aromatase inhibitor Exemestane (EXE) reduces the risk of breast cancer in postmenopausal women. However, participants have varied responses to EXE treatment in terms of efficacy and toxicity, possibly due to differences in EXE metabolism. One of the main elimination pathways for EXE is through glucuronidation by UGT2B17. Aims: This project examined the relationship between the UGT2B17 gene deletion, EXE metabolites and menopause-related quality of life (QOL) in postmenopausal women. Hypothesis: Glucuronidation of the main EXE metabolite, 17-dihydroexemestane (17-DHE), is reduced in women with the UGT2B17 double gene deletion, leading to increased circulating 17-DHE and potential toxicity. Methods: This study included 3576 women nested within the CCTG MAP.3 trial, who were allocated to EXE or placebo treatment groups. Genotyping analysis was conducted with baseline blood cell DNA using real-time PCR and allelic discrimination. Women who were homozygous null were considered “exposed”. In addition to EXE, EXE metabolites including 17-DHE and glucuronidated 17-DHE (17 DHE-Gluc) were analyzed from serum by UPLC/MS. Ratios of the main metabolites (17-DHE/EXE) and glucuronidated metabolites (17-DHE-Gluc/17-DHE) were standardized, using an autoscaling method. Metabolite levels that were below the detection limit were replaced by “half the detection limit for that metabolite”. Women had the outcome if they experienced a clinically meaningful (>10%) worsening in vasomotor QOL from baseline within the first year. Modified Poisson regression models were used to calculate the relative risks for both the (1) UGT2B17 gene deletion and (2) metabolite ratios and vasomotor QOL. Results: Ten percent of participants exhibited the homozygous UGT2B17 deletion genotype. There was no significant relationship between the UGT2B17 deletion polymorphism and worsened vasomotor QOL (RR= 1.04, 95% CI: 0.93, 1.17), adjusted for age, race and treatment. Among women with no vasomotor symptoms at baseline but extremely bothersome symptoms at follow-up (incident vasomotor symptoms), there was a suggestive but non-significant protective effect of the UGT2B17 deletion (RR=0.61, 95% CI: 0.32-1.19). This effect was more extreme in the placebo arm (RR=0.20) than in the EXE arm (RR=0.78; p-interaction=0.17). Among women on EXE, levels of EXE and 17-DHE were not different between UGT2B17 genotypes, but levels of 17-DHE-Gluc were significantly lower for the UGT2B17 deletion genotype (p=<0.0001). An increasing ratio of 17-DHE-Gluc/17-DHE [per standard deviation (SD) increase] had a borderline protective effect against worsened vasomotor QOL (RR=0.94, p=0.049), adjusted for age and race. In contrast, an increasing ratio of 17-DHE /EXE (per SD increase) was associated with a small but significant increased risk of worsened vasomotor QOL (RR=1.02, p=0.01). The effect observed for the 17-DHE/EXE ratio was stronger for very bothersome incident vasomotor symptoms at follow-up, but this did not reach statistical significance [17-DHE/EXE (per SD increase): RR=1.36, p=0.12]. Conclusion: EXE metabolite levels could potentially be used as a biomarker for extreme vasomotor QOL changes in breast cancer chemoprevention settings using EXE.

Citation Format: Richardson H, Knight B, Chen G, Luo S, Massey T, Goss PE, Lazarus P. Association between the UGT2B17 gene deletion, exemestane metabolites and vasomotor QOL in women participating on the MAP3 prevention trial [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P6-13-05.

Abstract P1-11-17: Effects of depression, anxiety, and sexual functioning on quality of life among young breast cancer patients in Mexico

Background: Despite the disproportionately high-rates of breast cancer (BC) in young women in Mexico, cancer-control efforts have been predominantly aimed at improving oncological treatment, bypassing survivorship issues and supportive care for this group. The “Joven & Fuerte” cohort, the first supportive care and research program for young BC patients in Latin America, aims to describe and assess the burden of BC in young Mexican women. In this study, we focused on evaluating the association between quality of life (QoL) and anxiety, depression, and sexual functioning in young women with BC (≤ 40 years).

Methods: This study included non-metastatic and non-recurrent patients belonging to the cohort's pilot phase. QoL was assessed with the EORTC QLQ-C30 global score. Patients were classified in the domains of anxiety and depression with the Hospital Anxiety and Depression Scale (HADS) as either probable case, doubtful case, or not a case. Sexual functioning was assessed with the Female Sexual Function Index (FSFI) and the sexual functioning and enjoyment domains of the EORTC QLQ-BR23. Assessments were performed at baseline, 6 months, 1 year, and 2 years. Pearson chi-square and analysis of variance (ANOVA) were used for analysis. Nominal unadjusted significance is reported with p<0.05.

Results: 73 out of 96 (76%) pilot phase patients met the inclusion criteria and had complete assessments up to 2 years follow-up. Global QoL was significantly worse for cases with anxiety and depression at baseline (means for non-cases, doubtful cases and cases, respectively: for anxiety, 81.09, 69.54, and 61.54, p<.001; and for depression, 75.63, 64.17, and 55.00, p=0.01) and depression at 6 months (76.55, 66.67, and 35.42, respectively, p<.001). Classification of case level anxiety was associated with FSFI morbidity during the first year (baseline, p=0.03; 6 months, p=0.09; 1 year, p=0.04). There was no significant association between case level depression and FSFI morbidity in the first 2 years. Neither anxiety nor depression was generally associated with significantly different BR23 sexual functioning or sexual enjoyment; however, a sporadic association was observed between anxiety and BR23 sexual functioning at 6 months (p=0.04).

Conclusion: This study confirmed an association between anxiety and/or depression and worse QoL at diagnosis of BC and after 6 months. Additionally, worse sexual function was significantly associated with the classification of case level anxiety. These findings support the current recommendation that physicians should regularly assess patients' psychosocial health and sexual functioning and provide prompt referral to corresponding supportive care services. Additional efforts must be conducted in low-resource settings, where sexual health and psychosocial care are not considered routine cancer treatment. Dedicated programs that promote multidisciplinary and supportive care services, such as “Joven & Fuerte”, should be incorporated into institutional health-care protocols to systematically address patients' emerging needs and improve QoL.

Citation Format: Villarreal-Garza C, Platas A, Miaja M, Lopez-Martinez EA, Muñoz-Lozano JF, Fonseca A, Pineda C, Barragan-Carrillo R, Martinez-Cannon BA, Chapman J-AW, Goss PE, Bargallo-Rocha JE, Mohar A, Castro-Sanchez A. Effects of depression, anxiety, and sexual functioning on quality of life among young breast cancer patients in Mexico [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P1-11-17.

Abstract P5-13-18: Barriers to adjuvant radiotherapy treatment for breast cancer in a teaching hospital in Brazil

BACKGROUND: Adjuvant treatment of non-metastatic breast cancer (BC) represents an important paradigm of multimodality approach in oncology practice, with an established role for radiotherapy (RT). A delay of adjuvant radiotherapy can lead to poorer results. When chemotherapy (CT) is not indicated, RT should be initiated within 8 weeks after surgery. If CT is administered first, RT should be started within 7 months from surgery, since there is a continuous relation between time to radiotherapy and local recurrence. Brazil's public healthcare system, SUS, faces many challenges caring for cancer patients: inadequate funding, inequitable distribution of resources and services, among others. According to research done by Lins et al, around 458 linear accelerators would be necessary to supply the Brazilian public health demand and end the waiting line for radiation therapy. Currently, our healthcare system has 283 machines, which are responsible for more than 70% of our population. Furthermore, patients lack understanding of treatment windows, which is an additional hurdle.

METHODS: We randomly selected 122 charts of female BC patients submitted to treatment with curative intent from 2003-2017 in Hospital das Clínicas da UFMG, the biggest teaching hospital of the 3rd largest city in Brazil. Primary endpoint was to determine median time from surgery to adjuvant radiotherapy, and second point was to determine median radiotherapy time.

RESULTS: Twenty eight patients were not included in the analysis, 26 due to lack of information in the charts and two for not having received the proposed radiotherapy. Ninety four patients were included: median age was 49 years old (21-90), 21.5% were stage I, 41.9% stage II and 34.4% stage III at diagnosis. Patients received chemotherapy (neo or adjuvant), hormonotherapy, or both, according to oncologists discretion. All patients were submitted to surgery and radiotherapy. Long median times from referral to RT initiation and to radiotherapy completion were identified: 54 days and 97 days, respectively, as well as 7 months from surgery to beginning of RT (1-16) and 9 months from diagnosis to its completion (2-29).Biopsies were performed in 27 different sites and RT in 12.

IntervalMedian Time (days)Biopsy to results13 (1-77)Referral to RT initiation54 (1-238)Referral to RT completion97 (43-238)RT initiation to RT completion42 (20-80)

IntervalMedian Time (months)Surgery to RT initiation7 (1-16)Diagnosis to RT completion9 (2-29)

CONCLUSIONS: This study shows that intervals for completion of adjuvant radiotherapy are well above recommended, mostly due to long delays in initiating radiotherapy. Although in our study all patients were conducted by the same oncology team, the system is fragmented, making it even more difficult for patients to receive multidisciplinary care and improve prognosis. There is undeniable need for more radiotherapy machines, but since their acquisition depends on costly governmental actions, we need to think about strategies that may allow us to better use the resources already available. We believe that Patient Navigation plays an important role here and were are establishing this program in our institution with Global Cancer Institute support.

Citation Format: Vieira CM, Nogueira-Rodrigues A, Sousa CF, Krush L, Goss PE. Barriers to adjuvant radiotherapy treatment for breast cancer in a teaching hospital in Brazil [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P5-13-18.

Abstract P5-13-12: Breast cancer in Colombia: A growing challenge for the health care system

INTRODUCTION

Colombia has a population of roughly 49 million people of predominantly Mestizo ethnicity. Cancer has become a growing public health problem in Colombia with nearly 71,000 newly diagnosed malignant tumors per year. It is expected that by 2035, 150,000 new cases of cancer will be diagnosed, making Colombia an intermediate country with regards to global cancer incidence according to IARC.

METHODS

Epidemiological data on breast cancer is scarce and varied due to multiple sources of information. These numbers are obtained thru population-based cancer registries that represent 4 distinct regions of the country. Other data originate from non-governmental institutions and healthcare providers within Colombia. The Colombian National Cancer Institute publishes a Cancer Mortality Atlas annually.

RESULTS

Local cancer registries have shown increases in breast cancer incidence in Colombia. In 2007, age-standardized incidence rate was 27.8 per 100,000 persons increasing to 49.7 cases per 100,000 persons in 2012. Approximately, 2200 women die every year in Colombia due to breast cancer with rates increasing historically, but now are stabilizing. Advanced breast cancers are most frequently found among women without health insurance, while early breast cancers are usually found among working women and those covered by private health insurance. Early breast cancer screening was made mandatory as public policy in the year 2000. However, only 30% of health care coverage was reported, translating to very low coverage by opportunistic screening programs with only 33% of women having had a mammography. In 2012, a National Cancer Control Plan was planned and implemented. It aims to increase early stage cancer diagnosis, increase biannual screening coverage, and guarantee timely access to diagnosis and treatment. A national health survey in 2015 showed only 48% of women had an annual mammographic screening. Multiple disparities have been found with regards to screening and early diagnosis such as economic strata, health insurance coverage, origin, and accessibility. Specifically, data shows that 23% needed to travel in order to obtain access to mammography. Often it is necessary for some patients to sue healthcare insurance systems to obtain specific health care, causing an increase in time to diagnosis and treatment. In 2016, on average a 90-day period was reported from time of onset of symptoms to suspected diagnosis of breast cancer, while the time to the initiation of treatment was 100 days for chemotherapy and close to 120 days for surgery.

DISCUSSION

These data serve to impact the landscape of breast cancer and improve patient outcomes in Colombia. While the National Cancer Plan has led to major changes, a big challenge remains related to the delays between suspicion of breast cancer and diagnosis and treatment. Quality of care provided by private and public insurance administrators is also of concern. General practitioners should receive more detailed training in breast cancer detection and management. The healthcare system should provide quality cancer care with urgent improvement in mammography, especially in more rural areas. Widely, more timely and appropriate follow-up is needed.

Citation Format: Duarte C, Salazar A, Strasser-Weippl K, de Vries E, Wiesner C, Krush L, Goss PE. Breast cancer in Colombia: A growing challenge for the health care system [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P5-13-12.

Abstract P5-16-03: Global Cancer Institute online breast tumor boards: A tool to facilitate multidisciplinary discussions in resource-limited settings

Background: Multidisciplinary tumor boards (MTBs) are commonly practiced among specialists in high-income countries (HICs) to ensure evidence-based, concordant decisions for patient treatment. MTBs have also been shown to improve patient outcomes and quality of life. Cancer specialists in low-and middle-income countries (LMICs) have limited time and few opportunities to discuss breast cancer patient care with colleagues. The Global Cancer Institute (GCI) established online MTBs in 2012 to facilitate live telemedicine discussions of breast cancer case scenarios between specialists in LMICs and expert specialists in HICs. GCI MTBs aim to improve clinical knowledge and patterns of practice among specialists in LMICs with a low-cost, interactive, and educational tool.

Methods: In each monthly, hour-long MTB, three de-identified breast patient case scenarios are presented in English by specialists in LMICs for live discussion with a multidisciplinary expert panel of breast specialists based in the US. Discussions are held for each case scenario and provide an overview of evidence-based treatment, international and resource-stratified clinical guidelines, clinical trials, and best clinical practices for limited resource settings. After each MTB, links to clinical practice guidelines, clinical trials, and other resources are shared with MTB attendees. For educational purposes, each MTB is privately live-streamed online and uploaded to a private YouTube channel for viewing by cancer specialists and trainees worldwide.

Results: The GCI MTB program has interacted with over 500 participants from 44 hospitals in 25 LMIC countries across Latin America (LA), Eastern Europe, Africa, and Asia. 17 expert breast cancer specialists from 10 US cancer centers provide multidisciplinary guidance for each case.

To date, 142 breast cancer case scenarios have been presented. For breast MTBs, 83% of case scenarios were invasive ductal carcinomas. Common subtypes presented were ER/PR+ (62%), HER2+ (31%), and triple negative disease (29%). 60 cases (43%) involved management of advanced disease in resource-limited settings.

Conclusions: GCI MTBs are a low-cost educational tool for specialists in LMICs to improve patterns of clinical practice and engage in multidisciplinary discussions with colleagues. GCI continues to expand its MTB among cancer facilities in LMICs worldwide. GCI will pilot the implementation of a LA-based online MTB conducted in Spanish for wider participation of community and rural/remote breast cancer specialists in the region.

Citation Format: St. Louis J, Espalter MC, Moreno J, Hambardzumyan V, Goss PE. Global Cancer Institute online breast tumor boards: A tool to facilitate multidisciplinary discussions in resource-limited settings [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P5-16-03.

Impact of baseline BMI and weight change in CCTG adjuvant breast cancer trials

Background

We hypothesized that increased baseline BMI and BMI change would negatively impact clinical outcomes with adjuvant breast cancer systemic therapy.

Methods

Data from chemotherapy trials MA.5 and MA.21; endocrine therapy MA.12, MA.14 and MA.27; and trastuzumab HERA/MA.24 were analyzed. The primary objective was to examine the effect of BMI change on breast cancer-free interval (BCFI) landmarked at 5 years; secondary objectives included BMI changes at 1 and 3 years; BMI changes on disease-specific survival (DSS) and overall survival (OS); and effects of baseline BMI. Stratified analyses included trial therapy and composite trial stratification factors.

Results

In pre-/peri-/early post-menopausal chemotherapy trials (N = 2793), baseline BMI did not impact any endpoint and increased BMI from baseline did not significantly affect BCFI (P = 0.85) after 5 years although it was associated with worse BCFI (P = 0.03) and DSS (P = 0.07) after 1 year. BMI increase by 3 and 5 years was associated with better DSS (P = 0.01; 0.01) and OS (P = 0.003; 0.05). In pre-menopausal endocrine therapy trial MA.12 (N = 672), patients with higher baseline BMI had worse BCFI (P = 0.02) after 1 year, worse DSS (P = 0.05; 0.004) after 1 and 5 years and worse OS (P = 0.01) after 5 years. Increased BMI did not impact BCFI (P = 0.90) after 5 years, although it was associated with worse BCFI (P = 0.01) after 1 year. In post-menopausal endocrine therapy trials MA.14 and MA.27 (N = 8236), baseline BMI did not significantly impact outcome for any endpoint. BMI change did not impact BCFI or DSS after 1 or 3 years, although a mean increased BMI of 0.3 was associated with better OS (P = 0.02) after 1 year. With the administration of trastuzumab (N = 1395) baseline BMI and BMI change did not significantly impact outcomes.

Conclusions

Higher baseline BMI and BMI increases negatively affected outcomes only in pre-/peri-/early post-menopausal trial patients. Otherwise, BMI increases similar to those expected in healthy women either did not impact outcome or were associated with better outcomes.

Clinical Trials numbers

CAN-NCIC-MA5; National Cancer Institute (NCI)-V90-0027; MA.12-NCT00002542; MA.14-NCT00002864; MA.21-NCT00014222; HERA, NCT00045032;CAN-NCIC-MA24; MA-27-NCT00066573.

Outcomes in women with invasive ductal or invasive lobular early stage breast cancer treated with anastrozole or exemestane in CCTG (NCIC CTG) MA.27

BACKGROUND

Histological subtype, (invasive ductal breast cancer (IDBC)/invasive lobular breast cancer (ILBC)), might be a marker for differential response to endocrine therapy in breast cancer.

METHODS

Clinical trial MA.27 compared 5 years of adjuvant anastrozole or exemestane in postmenopausal patients with hormone receptor positive early breast cancer. We evaluated IDBC versus ILBC (based on original pathology reports) as predictor for event-free survival (EFS) and overall survival (OS).

RESULTS

A total of 5709 patients (5021 with IDBC and 688 with ILBC) were included (1876 were excluded because of missing or other histological subtype). Median follow-up was 4.1 years. Overall, histological subtype did not influence OS or EFS (HR (hazard ratio) 1.14, 95% confidence interval (CI) [0.79-1.63], P = 0.49 and HR 1.04, 95% CI [0.77-1.41], P = 0.81, respectively). There was no significant difference in OS between treatment with exemestane versus treatment with anastrozole in the IDBC group (HR = 0.92, 95% CI [0.73-1.16], P = 0.46). In the ILBC group, a marginally significant difference in favour of treatment with anastrozole was seen (HR = 1.79, 95% CI [0.98-3.27], P = 0.055). In multivariable analysis a prognostic effect of the interaction between treatment and histological subtype on OS (but not on EFS) was noted, suggesting a better outcome for patients with ILBC on anastrozole (HR 2.1, 95% CI [0.99-4.29], P = 0.05). After stepwise selection in the multivariable model, a marginally significant prognostic effect for the interaction variable (treatment with histological subtype) on OS (but not on EFS) was noted (Ratio of HR 2.1, 95% CI [1.00-4.31], P = 0.05).

CONCLUSION

Our data suggest an interaction effect between treatment and histology (P = 0.05) on OS. Here, patients with ILBC cancers had a better OS when treated with anastrozole versus exemestane, whereas no difference was noted for patients with IDBC.

CLINICAL TRIAL INFORMATION

NCT00066573.

Abstract P4-17-03: Global Cancer Institute online tumor boards to improve global patterns of clinical practice for breast cancer

Background: The Global Cancer Institute (GCI) breast cancer multi-disciplinary tumor boards (MTBs) are live, online telemedicine discussions of breast cancer patient case scenarios between breast cancer specialists in low- and middle-income countries (LMICs) and expert breast cancer specialists in the United States (US). In the US MTBs are routinely held in most cancer centers and have been shown to improve patient outcomes and patient and family quality of life. GCI launched breast cancer MTBs in 2012 with the goals to improve breast cancer patient care in underserved populations globally, to establish an online platform to allow live communication and collaboration among oncologists, and to serve as an educational tool for oncologists.

Methods: During our MTBs case scenarios are presented by global oncologists for discussion and input by a panel of both community/tertiary care expert breast oncologists from our global network. During each MTB, three cancer centers present challenging breast cancer patient scenarios. Patient scenarios are presented in English, according to a standard PowerPoint template. After presentation guideline - or clinical trial-based discussions are held for each case. As the patient cases originate from oncologists in LMICs, optimal and best locally available clinical care in rural and remote settings are discussed. For educational purposes the MTBs and the associated YouTube panel discussions are archived online and can subsequently be viewed by practicing oncologists and trainees globally. Links to relevant international guidelines, published and ongoing clinical trials, and other educational resources are also provided to all MTB attendees.

Results: Since its initiation in 2012, the GCI MTBs have engaged a network of 370 oncologists in LMICs and 20 expert panelists from nine cancer centers in the United States. Together the oncologists in LMICs represent 28 tertiary cancer centers and 116 community oncologists in 19 countries across Latin America, Eastern Europe, Asia, and Africa.

Conclusions: GCI breast cancer MTBs are a powerful educational and networking tool for oncologists in LMICs to improve their patterns of clinical practice, conduct multi-disciplinary discussions and access research collaborations. GCI invites oncologists throughout Latin America, Europe, Asia, and Africa to join our tumor boards and further expansion of its MTB network. GCI currently surveys oncologists in our network before and after attendance of MTBs to measure modifications in oncologists' practice and adherence to international clinical practice guidelines.

Citation Format: St. Louis J, Bukowski A, Paulino E, Ferreyra ME, Nunes J, Mejia G, Duarte C, Ruiz R, Touya D, Polo S, Chavarri-Guerra Y, Moreno J, Georgieva N, Tsolko T, Obayedullah Baki M, Luna HC, Goss PE. Global Cancer Institute online tumor boards to improve global patterns of clinical practice for 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 P4-17-03.

New onset vasomotor symptoms but not musculoskeletal symptoms associate with clinical outcomes on extended adjuvant letrozole - Analyses from NCIC CTG MA.17

PURPOSE

New onset symptoms on adjuvant aromatase inhibitors for hormone receptor positive early breast cancer may associate with clinical outcomes. We performed this exploratory analysis of the association of new onset musculoskeletal (MSK) and vasomotor (VM) symptoms with clinical outcomes in the NCIC CTG MA.17 trial 5 years of extended adjuvant endocrine therapy with letrozole after tamoxifen.

METHODS

Symptoms were collected at baseline, 1, 6, and every 12 months on study. Multivariate Cox Models adjusting for age, nodal status, duration of tamoxifen and prior chemotherapy were used to compare disease-free survival (DFS), distant disease-free survival (DDFS), and overall survival (OS) based on data collected before, and after, the unblinding between women with VM or MSK symptoms and those without.

RESULTS

Data post-unblinding showed new VM symptoms on extended letrozole significantly improved DFS and DDFS when occurring 1 month (DFS HR 0.52, 95% CI, 0.28-0.96; p = 0.04; DDFS HR 0.49, 95% CI, 0.24-0.99; p = 0.046) and 6 months (DFS HR 0.43, 95% CI, 0.24-0.78; p = 0.006; DDFS HR 0.44, 95% CI, 0.22-0.85; p = 0.02) after treatment initiation. Those with new VM symptoms at 12 months also had a significantly better DFS (HR 0.47, 95% CI 0.26, 0.84; P = 0.01) and a trend in improved DDFS. Only a trend to improved OS was found for those with VM symptoms 6 month after treatment. No significant improvement was found for those with new MSK symptoms at any time point or for any endpoint.

CONCLUSIONS

New onset VM symptoms with extended letrozole may be useful in predicting treatment benefit.

Impact of premenopausal status at breast cancer diagnosis in women entered on the placebo-controlled NCIC CTG MA17 trial of extended adjuvant letrozole

BACKGROUND

MA17 showed improved outcomes in postmenopausal women given extended letrozole (LET) after completing 5 years of adjuvant tamoxifen.

PATIENTS AND METHODS

Exploratory subgroup analyses of disease-free survival (DFS), distant DFS (DDFS), overall survival (OS), toxic effects and quality of life (QOL) in MA17 were performed based on menopausal status at breast cancer diagnosis.

RESULTS

At diagnosis, 877 women were premenopausal and 4289 were postmenopausal. Extended LET was significantly better than placebo (PLAC) in DFS for premenopausal [hazard ratio (HR) = 0.26, 95% confidence interval (CI) 0.13-0.55; P = 0.0003] and postmenopausal women (HR = 0.67; 95% CI 0.51-0.89; P = 0.006), with greater DFS benefit in those premenopausal (interaction P = 0.03). In adjusted post-unblinding analysis, those who switched from PLAC to LET improved DDFS in premenopausal (HR = 0.15; 95% CI 0.03-0.79; P = 0.02) and postmenopausal women (HR = 0.45; 95% CI 0.22-0.94; P = 0.03).

CONCLUSIONS

Extended LET after 5 years of tamoxifen was effective in pre- and postmenopausal women at diagnosis, and significantly better in those premenopausal. Women premenopausal at diagnosis should be considered for extended adjuvant therapy with LET if menopausal after completing tamoxifen.

Abstract P2-10-15: Evaluation of Prognostic and Predictive Performance of Breast Cancer Index and Its Components in Hormonal Receptor-Positive Breast Cancer Patients: A TransATAC Study

Background: The Arimidex, Tamoxifen, Alone or in Combination (ATAC) trial compared the efficacy and safety of 5 years of anastrozole with tamoxifen as adjuvant treatment for postmenopausal women with localized HR+ breast cancer. At a median follow-up of 10 years, a statistically significant improvement with anastrozole vs. tamoxifen for disease-free survival, time to recurrence and time to distant recurrence was observed. The HOXB13:IL17BR gene expression ratio (H/I) quantifies recurrence risk in ER positive (ER+) breast cancer patients and is predictive of benefit from endocrine therapy. Molecular Grade Index (MGI) is a five-gene index that provides quantitative and objective molecular assessment of tumor grade and proliferative status. Breast Cancer Index (BCI) combines H/I and MGI into a continuous risk model that provides a likelihood of distant recurrence in patients treated with endocrine therapy, and efficacy from neoadjuvant chemotherapy. In the current analysis, evaluation of the prognostic and predictive performance of BCI, H/I and MGI in the ATAC study cohort was conducted.

Methods: Under the TransATAC protocol, formalin-fixed, paraffin-embedded (FFPE) blocks of primary tumor were collected from HR+ patients from each monotherapy arm. The current study examined samples collected from the United Kingdom, which constituted 79% of the collection. RNA extracted from 1102 samples from the TransATAC study was amplified, converted to cDNA and subjected to RT-PCR with primers and probes to HOXB13, IL17BR, BUB1A, CENPA, NEK2, RACGAP1 and RRM2. H/I, MGI and BCI were calculated and risk groups were determined using pre-specified cutpoints.

Results: Of 1102 tumor specimens assayed, 29 failed QC criteria, leaving 1073 samples for analysis. Detailed results on the prognostic and predictive performance of BCI, H/I and MGI will be presented. Data on whether BCI and its components provided independent prognostic information in the presence of classical variables, their prognostic value for risk of late recurrence, interaction by treatment arms, and comparative performance vs other models will also be discussed.

Discussion: The ATAC trial has established the long-term efficacy and safety of anastrozole over tamoxifen as initial adjuvant treatment for post-menopausal early stage breast cancer patients. Continued efforts are needed to improve on quantification of residual risk in patients who were treated with endocrine therapy to guide decision-making in selecting additional adjuvant chemotherapy and/or administering extended endocrine treatment. This study will help to establish the strategy to more effectively select patients for adjuvant therapies.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P2-10-15.

Abstract P1-07-13: Prognostic relevance of statistically standardized estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor 2 (HER2) in tamoxifen(TAM)-treated NCIC CTG MA.14 patients

Background: Poor inter-laboratory comparability of common clinically used breast cancer biomarkers led to a proposal of statistical standardization (SS) of laboratory results, similar to bone mineral density (BMD) z-scores. This analysis is the first utilization of SS in a trial where all women received TAM.

Methods: MA.14 allocated 667 postmenopausal women to TAM +/− Octreotide LAR (OCT) based on locally determined ER/PR, without HER2 status. At 9.8 yrs median follow-up, the secondary endpoint of relapse-free survival (RFS) had a non-significant hazard ratio (HR) for TAM-OCT to TAM of 0.87 (95% CI 0.63–1.21; p = 0.40). 299 patients who were representative of MA.14 patients by treatment and stratification factors (exact Fisher p-values=0.19–0.90) had their tumors centrally assessed for ER, PR, and HER2 by RT-PCR. Continuous values were used for SS of each biomarker. Univariate (uni) assessment used similar categorizations as those for BMD, assigning ER/PR/HER2 values by number of standard deviations (SD) about the mean (Group 1, z-score ≥1.0 SD below mean; Group 2, z-score <1.0 SD below mean; Group 3, z-score ≤1.0 SD above mean; Group 4, z-score >1.0 SD above mean). A log-rank statistic was used to test for differences between SS biomarker groups with K-M plots for graphical description. Multivariate (multi) effects of SS biomarkers and baseline patient characteristics on RFS were examined with exploratory (un)stratified Cox step-wise forward regression, adding a factor if likelihood ratio criterion was p ≤ 0.05. Sensitivity analyses used a prior external HER2+ cut-point of ≥1.32 SD.

Results: 292 patient samples passing internal analytical quality control were included in this analysis. Uni analyses indicated SS ER was not associated with RFS (p = 0.31). SS PR had a significant uni effect on RFS [p = 0.03; Group 4 compared to Group 1, HR of 0.33 (95% CI 0.12–0.90); Group 3 compared to Group 1, HR of 0.42 (95% CI 0.21–0.83); and Group 2 compared to Group 1 HR of 0.70 (95%CI 0.36–1.37)]. SS HER2 also had a significant uni effect on RFS [p = 0.004; Group 4 compared to Group 1, HR of 0.90 (95% CI 0.37–2.16)]; Group 3 compared to Group 1, HR of 0.39 (95% CI 0.18–0.84); and, Group 2 compared to Group 1, HR of 0.34 (95% CI 0.16–0.70)]. Multi stratified/unstratified Cox models indicated T1 tumours (p = 0.02/p = 0.0002) and higher SS PR (p = 0.02/0.01) were associated with significantly longer RFS; other unstratified results showed that N-ve patients had better RFS (p < .0001), while local ER/PR status did not impact RFS (p > 0.05). The HER2+ cut-point of ≥1.32 SD indicated directionally worse RFS (uni p-value=0.05; multi p-value=0.06).

Discussion: In MA.14, all women received TAM. Local ER/PR status using categorical or semi-quantitative values did not impact RFS. A statistically standardized approach using continuous centralized ER, PR, HER2 by RT-PCR demonstrated that increasing PR values were associated with better RFS. Evaluation in other trials may provide support for this methodology.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P1-07-13.

Abstract PD10-05: HLA-DQA1*02:01/DRB1*07:01 as a biomarker for lapatinib-induced hepatotoxicity: prospective confirmation in a large randomised clinical trial (TEACH, EGF105485)

Hepatotoxicity is associated with small molecule tyrosine kinase inhibitors (TKI) in use for the treatment of a variety of cancers. Retrospective studies have identified and confirmed that specific Class II Human Leukocyte Antigen (HLA) alleles are strongly associated with ALT elevation in women treated with the TKI lapatinib for breast cancer. This study aimed to further evaluate and validate the role of the specified HLA alleles as predictors of elevated ALT in a pre-defined analysis of a large, randomized, double-blind, placebo-controlled study of lapatinib monotherapy in early stage HER2 positive breast cancer, the TEACH study (Tykerb Evaluation After Chemotherapy, EGF105485).

This prospectively defined pharmacogenetic study compared the frequency of hepatobiliary adverse events between pre-specified Major Histocompatibility Complex (MHC) genetic variants, including the HLA alleles DQA1*02:01 and DRB1*07:01. The primary focus was on elevated ALT, as well as rare cases of concurrent ALT (>3x ULN) and bilirubin (>2x ULN) elevation, which represent possible Hy's Law cases and a high risk of acute liver failure, among 1194 patients randomized to lapatinib treatment from whom pharmacogenetic data was available.

This study prospectively validated prior reports of the association of the specified MHC variants with elevated ALT among women treated with lapatinib. The strongest effects were observed for carriers of the HLA alleles DQA1*02:01 and DRB1*07:01, with odds ratios of 20 (95% CI: 8–40) between cases (n = 34) and controls (n = 807–808). These two HLA alleles are highly correlated, inherited together in most individuals and are consistent with a single genetic association. The overall risk of patients having an ALT (>3xULN) elevation was 3.0% and 0.7% during treatment with lapatinib and placebo respectively. Carriers of either HLA allele had a 12% chance (positive predictive value) of having an elevated ALT (>3xULN), in contrast to a 0.9% risk (negative predictive value, 99.1%) for non-carriers of the specified HLA alleles. These associations were maintained for higher ALT elevation thresholds and for cases of concurrent ALT and TBL elevation, consistent with possible Hy's Law cases. These results strongly support the role of Class II HLA-modulated immune mechanisms in lapatinib-induced hepatotoxicity.

Our results validate the large strength of association of the HLA alleles DRB1*07:01 and DQA1*02:01 with hepatotoxicity and provide the possibility of managing the risk of hepatotoxicity in women receiving lapatinib for early or late stage HER2 positive breast cancer. This association with immune mechanisms may have implications for toxicities with other TKIs in current use in cancer patients.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr PD10-05.

P4-11-13: Influence of Two Years of Exemestane on Bone Mineral Density in Postmenopausal Women at Increased Risk of Developing Breast Cancer; a Companion Study to the NCIC CTG MAP.3 Trial

Background

Exemestane significantly reduced invasive and preinvasive breast cancers in postmenopausal women at increased risk for breast cancer in the NCIC CTG MAP3 trial with no serious toxicities, including excess fractures or osteoporosis.

Purpose: To provide additional information on the effect of exemestane on bone loss in women at high risk for breast cancer, within a subset of women participating on the NCIC CTG MAP.3B study. The primary hypothesis is that exemestane does not induce clinically significant bone loss in postmenopausal women at increased risk of developing breast cancer at 2 years. The primary objective of this companion study is to examine the effect of exemestane on lumbar spine and total hip BMD by DEXA at 2 years in women participating in the MAP3 trial.

Methods: The MAP.3B bone sub-study registered women from the main MAP. 3 trial from May 2008 to March 2010. Eligible women had to have an acceptable quality BMD scan by DEXA taken within 12 months prior to randomization to MAP.3. A BMD T-score >-2.0 SD (i.e. better than 2 standard deviations below the average peak BMD of a young adult woman) was established as the study population cutoff. A questionnaire including information on height, falls, fractures, lifestyle information including physical activity, tobacco and alcohol use was completed at baseline, 12 months, 24 months and at last visit. Fasting serum for bone biomarkers was collected at 12 months and total hip and L1-L4 (postero-anterior) spine BMD were measured 2 years after randomization on the same Lunar or Hologic scanner. The primary objective was to determine differences in hip and spine BMD at 2 years. Secondary outcomes include number of skeletal fractures and development of osteoporosis 2 years after randomization and changes in bone biomarkers at 1 year after randomization. For the analysis of the primary endpoints, the upper limit of a one sided 95% confidence interval for the difference in mean percentage changes between placebo and exemestane will be calculated for the BMD by DEXA at each site. We will conclude that exemestane does not induce significant bone loss in postmenopausal women at increased risk of developing breast cancer at 2 years when the upper limit is less than 3% for both sites. Similar confidence interval approach will be used to analyze the secondary endpoints.

Results: Between May 2008 and March 2010, 238 postmenopausal women were recruited. Median age was 61.8 years, and the majority of women were Caucasian (91%), with approximately 20% of the participants reporting a recent fall (within past 12 months) and another 13% reporting a recent fracture prior to randomization. We will report results from the primary as well as the secondary endpoints at the SABCS meeting.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P4-11-13.

P5-14-01: Differences in Efficacy by Assessment Method: NCIC CTG Adjuvant Breast Cancer Trials MA.5, MA.12, MA.14, MA.21, MA.27 Meta-Analysis

Background: Based on recent breast cancer literature, we hypothesized that there could be substantive differences in apparent efficacy estimates using a log-normal (LN) survival model rather than with standard Kaplan-Meier (K-M) or Cox model methods. While both Cox and LN survival analyses offer greater specification by individual patient characteristics, the LN model may more robustly estimate survival under model misspecification. Methods: We recently pooled data for 5 NCIC CTG primary breast cancer trials: MA.5, MA.12, MA.14, MA.21, and MA.27. The total patient count for patients who received at least 1 dose of trial therapy is 11,253. Compilation included definition of STEEP endpoints (C Hudis, JCO, 2008) and standardized factor categorizations. The primary endpoint is Breast Cancer Free Interval (BCFI) defined as the time from randomization until recurrence: first local invasive or DCIS; regional, or distant; contralateral invasive or DCIS; or death from breast cancer. We found substantive evidence of non-proportionality for 7 factors compiled for the meta-analyses. In this work, we fit multivariate Cox and LN models with these 7 factors, lymph node status and pathologic T status. We then compare BCFI efficacy estimates for patient and tumour characteristics at 1-, 3-, and 5-years obtained with K-M, Cox, and LN models. Results: There was evidence that the Cox assumption of proportional hazards was violated for 7 factors: age, menopausal status, hormone receptor status, anthracycline use, chemotherapy use, race, and ECOG performance status. Differences between models were intrinsically affected by timing and extent of non-proportionality; there was no consistent pattern. In particular, investigations to date indicate efficacy estimates with absolute differences between K-M, Cox and LN estimates which varied by time of assessment: at 1-year 0.0 to 6.7%, at 3-years 0.4 to 18.6%, and at 5-years 0.2 to 17.0%. BCFI estimates with the K-M were inconsistently closer to those with the LN or Cox model: for K-M to Cox at 1-year 0.4 to 5.2%, at 3-years 0.4 to 15%, at 5-years 0.4 to 14.3%; for K-M to LN at 1-year 0.0 to 6.7%, at 3-years 0.5 to 18.6%, at 5-years 0.2 to 17.0%; for Cox to LN at 1-year 0.8 to 1.8%, at 3-years 1.9 to 6.0%, at 5-years 0.6 to 5.7%. K-M and Cox models have step-wise adjustments at events for K-M and Cox, rather than smooth modeling with the LN. Discussion: Even with reasonably large population subgroups, there were substantive differences in apparent survival (0.0 to 18.6%) between K-M, Cox and LN model types. The magnitude of differences in survival estimates was large enough to be clinically relevant and warrant further consideration as we evaluate new therapies and prognostic/predictive factors. We will be statistically investigating framework robustness under differing levels of model misspecification.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P5-14-01.

P1-08-17: Pregnancy-Associated Breast Cancer Does Not Have a Worse Outcome in the 4912 Women with Breast Cancer of the AMAZONA Project

Introduction: Pregnancy traditionally is considered a protective factor for breast cancer. Recent data suggests that pregnancy-associated breast cancer (PABC), a distinct biologic variant possibly related to breast involution, can occur up to 10 years post-partum and may carry a worse prognosis than that of age matched sporadic or nulliparous breast cancer. The Amazona project is a retrospective cohort of 4,912 Brazilian women with breast cancer that has previously reported on worse outcomes of patients according to type of institution where treatment was received (San Antonio 2009 abstr. 3082). We have assessed the outcomes of PABC in the Amazona cohort.

Objectives: 1- To identify whether women who were diagnosed with breast cancer up to 10 years after their first pregnancy had worse disease free survival (DFS) and overall survival (OS) than nulliparous women (NW); 2- to assess if age at first pregnancy is related to age of breast cancer diagnosis and worse DFS or OS; 3- to assess whether number of pregnancies is associated with worse DFS or OS; 4- to assess whether time from first pregnancy to diagnosis or age of first pregnancy are associated with histological grade, clinical stage or tumor expression of ER, PR, and HER2.

Methods: We analyzed 4836 women for whom parous history was available, in respect to DFS, OS, tumor clinical stage, histological grade, expression of ER, PR and HER2, according to age of first pregnancy, diagnosis up to 5 and 10 years after first pregnancy, and number of pregnancies, using NW as controls. Analysis of DFS and OS was done by Cox regression modeling adjusted for institution type, stage, ER, PR, HER2 and grade.

Results: Our cohort had 1996 nulliparous women and 2840 parous women. The median follow up was 28 months and there were 318 deaths and 735 recurrences. We did not find any correlation between PABC with DFS (5 year interval HR 1.15, 95%CI 0.43−3.07; 10 year interval HR 1.01, 95%CI 0.57−1.81) or OS (5 year interval HR 1.88, 95%CI 0.6−5.94; 10 year interval HR 0.5, 95%CI 0.73−3.09), nor was there a correlation between age at first pregnancy with age of breast cancer diagnosis. We also did not see any difference between age of first pregnancy and DFS or OS.

Women with 3 or more pregnancies had worse OS (HR 0.71, 95%CI 0.54−0.93) but not worse DFS (HR 0.93, 95%CI 0.76−1.13).Tumors diagnosed within 5 or 10 years from first pregnancy did not differ by grade, ER, PR, HER2, and clinical stage from those of NW. Women who had their first pregnancy after age 20 tended to have more ER positive (OR 1.99, 95%CI 1.49−2.65), PR positive (OR 1.40, 95%CI 1.06−1.87), and HER2 positive (OR 1.85, 95%CI 1.22−2.79) tumors than NW.

Conclusions: In this large cohort of breast cancer patients from the diverse geographic and socioeconomic spectrum of Brazil we did not find any association between PABC or age of first pregnancy to DFS or OS. The association with worse OS but not DFS for women with 3 or more pregnancies might be due to confounding factors. PABC was not associated with worse clinical prognostic factors. Women who had their first pregnancy after age 20 were more likely to have ER+, PR+ and HER2 + tumors than nulliparous patients.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P1-08-17.

S6-1: Menopause-Specific and Health-Related Qualities of Life among Post-Menopausal Women Taking Exemestane for Prevention of Breast Cancer: Results from the NCIC CTG MAP.3 Placebo-Controlled Randomized Controlled Trial

Background: Exemestane, a steroidal aromatase inhibitor, reduced the incidence of invasive breast cancers by 65% among 4560 post-menopausal randomized to exemestane or placebo for 5 years on MAP.3. Differences in quality of life (QOL) were judged to be minimal, but only summary information was reported.

Purpose: To provide more detailed information about effects of exemestane on menopause-specific and health-related qualities of life.

Method: Participation in quality of life assessment was an eligibility criterion. Menopause-specific and health-related qualities of life were assessed using the MENQOL (4 scales; physical, vasomotor, psychosocial, sexual) and SF-36 (8 scales; physical health, role function — physical, bodily pain, general health, vitality, social function, role function — emotional, mental health, and 2 summary scales) instruments, respectively at baseline, 6 months and then yearly after randomization. Compliance with QOL questionnaire completion at each follow-up visit ranged from 93–98%, and did not differ by group. Change scores for each MENQOL and SF-36 scale, calculated for each assessment time relative to baseline, were compared using the Wilcoxon Rank-Sum test. Summary scores were used to summarize the QOL scores observed at each time point for each SF-36 dimension and overall mental (MCS) and physical component summaries (PCS) and MENQOL domains. Clinically important worsening of MENQOL change scores was defined as an increase of ≥0.5/8 points. SF-36 change scores were considered worsened if scores decreased by ≥ 5 points from baseline.

Results: Both groups were balanced on scores for MENQOL and SF-36 at baseline. Median follow-up was 35 months and the proportion of women who stopped study medication early for toxicity reasons was 15% in the exemestane arm and 11% in the placebo arm. There was a statistically significant difference in change scores for vasomotor symptoms among women on exemestane during the first 4 years (p-values <0.01), compared to placebo. However, no between-group differences in vasomotor change met the criterion for clinical importance. Women on exemestane had statistically poorer sexual functioning (mean change = −0.02, SD=1.37) compared to placebo (mean change = −0.12, SD=1.32) during the first 6 months on study (p-value = 0.03) but the differences were not statistically significant thereafter or clinically important at any time. Among the 8 SF-36 scales, only bodily pain was statistically different between exemestane and placebo for the first 24 months on study medication (p-value <0.01), but no between-group difference in change scores exceeded 5 points. Overall SF-36 PCS and MCS assessing changes in overall physical and mental health-related QOL did not differ significantly by group at any assessment.

Conclusion: Our assessment that early differences in vasomotor symptoms and pain were probably not clinically important is supported by the observation of no between-group differences when overall physical and mental health-related QOL changes were compared. Exemestane does not appear to have a major negative impact on the quality of life among these women.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr S6-1.

OT1-01-03: A Phase 3 Randomized, Double-Blind, Placebo-Controlled Multicenter Study Comparing Denosumab with Placebo as Adjuvant Treatment for Women with Early-Stage Breast Cancer Who Are at High Risk of Disease Recurrence (D-CARE)

Background

Bone is a common site of distant recurrence in women with early-stage breast cancer. Cancer cells are thought to stimulate osteoclast-mediated bone resorption, which releases growth factors and cytokines that promote tumor growth. RANK Ligand (RANKL) is the key mediator of osteoclast-induced bone destruction. In preclinical studies, RANKL inhibition reduced the incidence of bone and lung metastases, suppressed tumor progression, and prolonged survival of tumor-bearing mice. Effects were additive with hormonal, chemotherapy, or targeted therapies. Denosumab is a fully human monoclonal antibody against RANKL, approved in the U.S. for the prevention of skeletal-related events in patients with bone metastases from solid tumors. In patients with castrate-resistant prostate cancer, denosumab significantly improved bone metastasis-free survival (BMFS) compared to placebo. The D-CARE trial evaluates BMFS effects of denosumab in women with stage II or III breast cancer.

Methods: Women with node-positive or locally advanced (T3 or T4) disease, and known hormone and HER-2 receptor status are eligible. Standard-of-care adjuvant or neoadjuvant chemo-, endocrine, or HER-2 targeted therapy, alone or in combination must be planned with curative intent. Women with a prior history of breast cancer (other than ductal carcinoma in situ [DCIS] or lobular carcinoma in situ [LCIS]) or distant metastasis, oral bisphosphonate (BP) use within 1 year or any intravenous BP use are excluded. Patients are randomized 1:1 to receive denosumab 120 mg or placebo subcutaneously monthly for 6 mos, then every 3 mos, for a total of 5 yrs treatment. All patients receive vitamin D (≥ 400 IU) and calcium (≥ 500 mg) supplements. Primary endpoint of this event-driven trial is BMFS. Secondary endpoints include disease-free (DFS) and overall survival. The study is powered for both, BMFS and DFS. Safety, quality of life assessments and biomarkers are additional endpoints. The trial, sponsored by Amgen Inc. and registered with the ClinicalTrials.gov identifier NCT01077154 began enrolling patients in June 2010. PG and DF are supported in part by the Avon Foundation, NY.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr OT1-01-03.

P1-11-12: Patterns of Care of Newly Diagnosed Patients with Breast Cancer in Mexico

Background: Breast cancer is the most common form of cancer and the leading cause of cancer death in women worldwide. More than 55% of breast cancer deaths occur in low and middle income countries. Although incidence rates for breast cancer are lower in developing countries, mortality rates are higher. This phenomenon has been attributed to limited access to care for breast cancer patients, including screening and early diagnosis as well as primary surgical, radiation and systemic therapies. Similar to trends in other poor and middle income countries, breast cancer mortality in Mexico is rising. The goal of this survey of physicians caring for patients with breast cancer in Mexico is to obtain information about current treatment patterns of newly diagnosed patients and to describe their clinical characteristics. Methods: A web-based closed survey has been sent to 854 physicians providing care to newly diagnosed breast cancer patients across Mexico, including medical oncologists and breast cancer surgeons. The survey instrument contains 35 questions assessing demographic data, access to diagnosis and treatment in a variety of clinical patient scenarios. The responses will be anonymous and entered automatically into a secure database for analysis. Fisher exact test will be used for the frequency analysis. Chi-squared statistics and Kendall correlation will be used for nominal and ordinal variables respectively. Results: The results will be presented at the 2011 San Antonio Breast Cancer Symposium.

Conclusions: The results of this survey will highlight potential disparities in care received by breast cancer patients across the full geographic and socioeconomic spectrum of Mexico in order to highlight the need for uniform, quality based approaches for the diagnosis and treatment of breast cancer patients in Mexico, and will serve as an example of how one middle income country faces challenges and unmet medical needs regarding access to care of women with breast cancer.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P1-11-12.

Prediction of late recurrences by breast cancer index in the NCIC CTG MA.17 cohort

2

Background: The MA.17 trial demonstrated that extended adjuvant endocrine therapy with letrozole after 5-y of tamoxifen markedly reduced the risk of recurrence in women with ER+ early stage breast cancer. This trial provides an opportunity to assess the ability of biomarkers to predict late recurrences in ER+ breast cancer. The Breast Cancer Index (BCI), a continuous risk index based on the combination of HOXB13:IL17BR (H:I) and the molecular grade index (MGI), estimates the individual risk of recurrence in ER+ breast cancer patients. In this study, the prognostic utility of BCI to predict late recurrences was examined.

Methods: FFPE tumor blocks were collected from patients who experienced a breast cancer recurrence up to unblinding of MA.17. Controls were matched 2:1 for age, tumor size, nodal status and prior chemotherapy, and were disease free for longer than cases. All cases were reviewed for standard histopathology and evaluated using the real-time RT-PCR BCI assay.

Results: Patient characteristics for the case-control study were similar to that from the overall study. Characteristics for cases (N=83) and controls (N=166) were not significantly different except for treatment. A higher percentage of controls compared to cases tended to be categorized as low risk by BCI (58% vs 43%), while a lower percentage of controls than cases tended to be categorized as high risk by BCI (34% vs 24%). In univariate analysis, treatment, BCI, H:I and HOXB13, but not tumor grade or MGI, were significant predictors of late recurrence. After adjusting for standard variables (age, tumor grade and treatment), BCI (OR 2.37; P=0.03), H:I (OR 2.55; P=0.04) and HOXB13 (OR 1.35; P=0.02) remained significant predictors of recurrence. HOXB13 expression at diagnosis predicted patient benefit from extended endocrine therapy with letrozole.

Conclusions: In this case-controlled study, the data demonstrate that BCI is a significant predictor of late recurrences in ER+ patients following 5-y of tamoxifen. The prognostic performance of BCI to predict late recurrences was largely dependent on HOXB13 expression. The integration of H:I and MGI within BCI provides prognostic utility for both early and late recurrences.

Exemestane for primary prevention of breast cancer in postmenopausal women: NCIC CTG MAP.3—A randomized, placebo-controlled clinical trial

LBA504

Background: Limited efficacy and serious toxicities have limited uptake of tamoxifen or raloxifene as preventatives of breast cancer. Aromatase inhibitors (AIs) prevent contralateral breast cancers more than tamoxifen in adjuvant trials and have fewer serious side effects. This is the first report of an AI used in primary prevention. Methods: NCIC CTG MAP.3 is a randomized trial designed to detect a 65% reduction in annual incidence of invasive breast cancer (IBC) on exemestane (E) versus placebo (P). Eligible postmenopausal women had ≥ one of the following risk factors: Gail score >1.66%, prior ADH, ALH, LCIS or DCIS with mastectomy, age over 60. Health-related and menopause-specific quality of life (QOL) were assessed by SF-36 and MENQOL questionnaires. Results: From 2004-2010, 4,560 women were randomized: age 62.5 yrs (37-90); Gail Score 2.3 % (0.6-21); BMI 28.0 kg/m2 (15.9-65.4). Risk factors included: age >60 yrs (49%); Gail score >1.66 (40%); and prior ADH, ALH, LCIS or DCIS with mastectomy (11%). At median follow-up of 35 months there were 11 IBCs on E and 32 on P (annual incidence 0.19% vs 0.55%; HR= 0.35, 95% CI 0.18-0.70, p = 0.002); ductal (10E/27P), lobular (1E/5P). Most tumors were ER positive (7E/27P); Her2/neu negative (10E/26P); TNM stage T1 (8E/28P), N0 (7E/22P), M0 (11E/30P). E was superior in all subgroups: by Gail score, age, BMI, prior LCIS and DCIS. The annual incidence rate of IBC or DCIS was 0.35% E and 0.77% P (HR=0.47;95% CI 0.27-0.79; p = 0.004) based on 64 IBCs or DCISs (20E/44P). Clinical bone fractures, osteoporosis, hypercholesterolemia or cardiovascular events were equal in both arms. No clinically meaningful differences in QOL were detected. Conclusions: Exemestane significantly reduced invasive and pre-invasive breast cancers in postmenopausal women at increased risk for breast cancer with no serious toxicities. Exemestane should be considered a new option for primary prevention of breast cancer. Supported by the Canadian Cancer Society; Pfizer Inc. PEG supported in part by Avon Foundation.

A randomized, placebo-controlled trial (NCIC CTG MAP.2) examining the effects of exemestane on mammographic breast density, bone density, markers of bone metabolism and serum lipid levels in postmenopausal women

We hypothesized that exemestane (EXE) would reduce mammographic breast density and have unique effects on biomarkers of bone and lipid metabolism. Healthy postmenopausal women were randomized to EXE (25 mg daily) or placebo (PLAC) for 12 months and followed for a total of 24 months. The primary endpoint was change in percent breast density (PD) between the baseline and 12-month mammograms and secondary endpoints were changes in serum lipid levels, bone biomarkers, and bone mineral density (BMD). Ninety-eight women were randomized (49 to EXE; 49 to PLAC) and 65 had PD data at baseline and 12 months. Among women treated with EXE, PD was not significantly changed from baseline at 6, 12, or 24 months and was not different from PLAC. EXE was associated with significant percentage increase from baseline in N-telopeptide at 12 months compared with PLAC. No differences in percent change from baseline in BMD (lumbar spine and femoral neck) were observed between EXE and PLAC at either 12 or 24 months. Patients on EXE had a significantly larger percent decrease in total cholesterol than in the PLAC arm at 6 months and in HDL cholesterol at 3, 6, and 12 months. No significant differences in percent change in LDL or triglycerides were noted at any time point between the two treatment arms. EXE administered for 1 year to healthy postmenopausal women did not result in significant changes in mammographic density. A reversible increase in the bone resorption marker N-telopeptide without significant change in bone specific alkaline phosphatase or BMD during the 12 months treatment period and 1 year later was noted. Changes in lipid parameters on this trial were modest and reversible.

Abstract P3-10-26: Quantitative Protein and Gene Expression Biomarkers of Tamoxifen and Letrozole Recurrence in the NCIC CTG MA.17 Cohort

Background: The MA.17 study showed that extended adjuvant endocrine therapy with letrozole (LET) after completing 5 years of tamoxifen (TAM) markedly reduced the risk of recurrence in women with ER+ early stage breast cancer and improved overall survival in women presenting with node +ve disease. The HOXB 13:IL17BR gene expression ratio (signature) has been shown to predict outcome in breast cancer patients treated with adjuvant tamoxifen monotherapy and provides additional information beyond that from known positive (ER and PR) and negative (Her-1 and Her-2) predictors of responsiveness to tamoxifen in node-ve women. We report a case control evaluation of the Breast Cancer Index (BCI; bioTheranostics, Inc.), which combines the HOXB13 and IL17BR twogene and the molecular grade index (MGI) gene expression signatures, with respect to distinguishing which patients are at risk of late recurrences and who would respond to extended endocrine therapy with LET. The prognostic and predictive utility of quantitative immunofluorescence of ER, PR, Her-2, tumor aromatase, COX-2, GATA3 and Nat1 in the TAM-PLACEBO and the TAM-LET cohorts will also be evaluated and compared to results derived by standard immunohistochemistry. Methods: FFPE tumor blocks were collected from patients who experienced a breast cancer recurrence up to unblinding of MA.17. Controls were matched 2:1 for age, tumor size, lymph node status, and prior chemotherapy, and were all disease free for longer than cases. All cases were reviewed for standard histopathology by two independent pathologists. RNA was extracted, amplified, converted to cDNA and subjected to RT-PCR with primers and probes to HOXB13, IL17BR, BUB1A, CENPA, NEK2, RACGAP1 and RRM2. ER, PR HER1, HER2, COX2, Aromatase, GATA3 and NAT1 will be analyzed by routine IHC techniques and by immunoflourescent Automated Quantitative Analysis (AQuA).

Results: 105 cases and 210 matched controls are available for evaluation. All sections are under review and tissue microarrays have been performed on all cases and controls. Detailed results on the BCI and ER, PR, Her-2 will be available at the SABCS.

Discussion: MA.17 has shown that extended adjuvant endocrine therapy after tamoxifen is effective at preventing disease recurrence given for an additional 5 years. Numerous clinical trials are exploring whether extending AIs will show this benefit, and there is an increasing need to improve the therapeutic index by distinguishing those at risk from those who are not. It is also important to determine which patients will benefit from the therapy and which will recur without benefit. The latter patients could be triaged to clinical trials of novel therapies to overcome endocrine resistance. This study will help to define these issues and pave the way for more effective selection of specific patients for adjuvant endocrine strategies.

Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P3-10-26.

Abstract P2-09-03: Mammographic Density Response to Aromatase Inhibitor Therapy

Background: Mammographic density, the variation in fat, epithelial and stromal tissues seen on screening mammography, is a strong risk factor for breast cancer and can be modified by hormonal agents. Changes in density from tamoxifen or postmenopausal hormone (PMH) use are associated with risk, suggesting that density may be a surrogate marker of therapeutic efficacy. Aromatase inhibitors (AIs) are given as adjuvant therapy in hormone receptor positive postmenopausal breast cancer and are known to decrease levels of estrone and estradiol in both serum and breast tissue. Our goal here was to examine the influence of AIs on mammographic density in women with early breast cancer.

Methods: We conducted a case-control study of postmenopausal breast cancer patients initiating adjuvant AI therapy (anastrozole or exemestane) on protocols NCIC CTG MA27, NCCTG N063I and MC (Mayo Clinic) 0532. Eligibility included; an intact contralateral breast with no prior surgery; a screening mammogram within twelve months before AI initiation and at 9-15 months on therapy; no prior endocrine therapy and informed consent. Controls were sampled from the Mayo Mammography Health Study, a cohort of 19,924 receiving screening mammography at the Mayo Clinic, and matched to cases on age, prior PMH use, baseline body mass index (BMI) and interval between mammograms. Pre-treatment and on-study mammograms for cases (corresponding mammograms for controls) were digitized. Change in percent density was estimated on the craniocaudal view of the non-cancerous breast using two methods: a subjective assessment of change by an expert radiologist (within 5%; 5-10% increase, 10-25% increase, 25%+ increase, 5-10% decrease, 10-25% decrease and 25%+ decrease) and a quantitative assessment of absolute change using a computer-assisted thresholding program (Cumulus). Analyses compared magnitude of change in density by both the subjective and quantitative methods between cases and matched controls. Results: 574 pairs were eligible for analyses (MA27-505 cases; N063I-12 cases; MC0532-57 cases). Characteristics of the two groups are shown in the table below. Using either density estimation method, there was a greater decrease in density among women on AI therapy vs. matched controls. In 33% (95% CI: 29-37%) of pairs, there was at least a one greater category decrease for the case relative to her control by subjective estimation. In 14% (95% CI: 11-18%) of the pairs, there was at least a 5% greater decrease for the case relative to her control by quantitative estimation. Data will be available according to AI class (non-steroidal versus steroidal) in November.

Conclusions: In the largest report to date to examine the influence of AI therapy on mammographic density, we provide evidence that AI is associated with decreases in density in a small subgroup of women. We are currently examining factors that influence these AI-associated decreases in density and whether these differences are unique to one class of AI. (Supported in part by NIH grants P50CA116201, U01GM61388, U10CA77202, U10CA25224)

Abstract PD03-04: Effects of Diabetes (DM), Hypertension (HTN) and Coronary Artery Disease (CAD) on Prognosis after 5 Years of Adjuvant Tamoxifen (TAM) and on Treatment Outcomes with the Use of Extended Letrozole (LET): NCIC CTG MA.17

Background: Women with early stage breast cancer and DM have poorer survival compared to non-DM women (Lipscombe 2008). Mechanisms include insulin dysregulation and/or DM related comorbidities such as HTN and CAD. MA.17 showed that adjuvant LET after five yrs of TAM reduced the risk of recurrence in women with ER+ early stage breast cancer and improved survival in node +ve disease. We evaluated the impact of DM, HTN, or CAD on prognosis after 5 yrs of TAM and the efficacy of LET in MA.17.

Methods: All 5170 women randomized to MA.17 were included. Four year disease free survival (DFS), distant disease free survival (DDFS) and overall survival (OS) were compared using Cox regression model adjusting for other prognostic factors: a) in women treated with placebo (PLAC) based on the presence or absence of baseline DM (n=462), HTN (n=1627), CAD (n=604) or any one of these comorbidities (n=2049), and b) between LET and PLAC groups in each comorbidity. Analyses based on nodal status were also performed. Test for interaction assessed for differential treatment effects in comorbidity groups. Results: Women with DM on PLAC had non-significant lower DFS (89.7 vs. 89.9%, p=0.68), DDFS (92.1 vs 93.9%, p=0.85), and OS (92.1 vs 95.2, p=0.37) than those without DM on PLAC. Treatment effect outcomes were similar between those with and without DM. Women with HTN on PLAC trended toward lower DDFS (92.2 vs 94.4%, HR=1.50, 95%CI: 0.98-2.3, p=0.06) and OS (93.7 vs. 95.5%, HR=1.61, 95%CI: 0.95-2.72, p=0.08) than non-HTN women on PLAC. The interaction between treatment and HTN status was significant for DDFS (p=0.004) with HTN women having significantly better outcome on LET vs PLAC (HR=0.27, 95%CI: 0.13 to 0.54; p=0.0002) compared to non-HTN women on LET vs PLAC (HR=0.82, 95%CI: 0.56-1.20; p=0.31). Women with CAD on PLAC did not have worse outcome, nor did CAD status have a treatment related effect. Women with at least one co-morbidity on PLAC had significantly lower OS (93.6 vs. 95.8%, HR=2.10, 95%CI:1.26-3.51, p=0.004) than those free of comorbidity. For node +ve women, the difference between LET and PLAC in DDFS was greater among women with at least one co-morbidity (HR=0.30, 95%CI:0.15-0.60, p=0.001) compared to those without any co-morbidity (HR=0.72, 95%CI:0.45-1.16, p=0.17) with interaction p=0.04.

Conclusions: Having at least one comorbidity was a negative prognostic indicator for OS after 5 yrs of TAM and led to improved DDFS for node +ve women taking LET. DM was not prognostic nor did it predict treatment outcomes. Explanations include not controlling for DM medications; as well, MA.17 enrolled women 5 yrs after TAM with evidence suggesting hyperinsulinemia being a risk for early rather than late recurrence. HTN was a potential risk factor with a trend for worse DDFS and OS. HTN also predicted for treatment benefit: HTN women on LET had improved DDFS compared to non-HTN women on LET. Hypothesis include antihypertensive agents slowing the metabolism of LET; alternatively there may be variations in VEGF levels between groups. HTN predictive effects will be further explored in MA.27 with potential to correlate with VEGF levels.

Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr PD03-04.

Hepatobiliary abnormalities in patients with metastatic cancer treated with lapatinib

1043

Background: Lapatinib (LAP), a dual tyrosine kinase inhibitor (TKI), is effective in the treatment of HER-2-positive metastatic breast cancer. Liver toxicity has been reported as a side effect of several TKIs. We analyzed the liver safety of LAP using available data from 16 metastatic cancer trials. Methods: LAP (as monotherapy or in combination) was administered to 2,968 patients (pts) in metastatic cancer trials. Liver function tests were prospectively evaluated. We defined liver toxicity events as either NCI CTCAE grade (Gr) 3 or 4 alanine and aspartate aminotransaminases (ALT/AST) or meeting Hy's Law criteria (liver injury with jaundice). Results: Overall Gr 3 and 4 ALT/AST events were seen in 45/2,968 (1.5%) and 2/2,968 (0.07%) pts, respectively. Of LAP monotherapy pts, Gr 3 and 4 ALT/AST was seen in 13/1,470 (0.9%) and 1/1,470 (0.07%), respectively. Of LAP + monoclonal antibody (mAb) pts (trastuzumab or bevacizumab), Gr 3 and 4 ALT/AST was seen in 2/199 (1.0%) and 1/199 (0.5%), respectively. Ten of 645 pts (1.6%) treated with LAP + chemotherapy (capecitabine or paclitaxel) had Gr 3 ALT/AST. Twenty of 654 pts (3%) treated with LAP + letrozole had Gr 3 ALT/AST. Among 2,968 pts, Hy's law toxicity occurred in 8 (0.3%) pts: 2/1,470 (0.14%) pts treated with LAP alone, 1/199 (0.5%) pts treated with LAP + mAb, 4/645 (0.6%) pts treated with LAP + chemotherapy, and 1/654 (0.2%) pts treated with LAP + letrozole. Alternative causes of liver toxicity such as metastatic liver disease, infectious hepatitis, and heart failure will be reported at the meeting. Conclusions: Review of data from 16 clinical trials in metastatic cancer revealed low levels of liver toxicity for LAP. Oncologists should be vigilant for this rare side effect of LAP. A proposed monitoring algorithm of symptom assessment and frequency of hepatobiliary laboratory monitoring will be shown.

[Table: see text]

NCIC CTG MA.17: hormone receptor expression of in-breast recurrences and contralateral primary breast cancers arising on aromatase inhibitors

Abstract #1134

Background: The selective estrogen receptor modulators (SERMs) tamoxifen and raloxifene reduce the risk of ER+ (but not ER-) invasive breast cancers in healthy women at high risk for developing breast cancer. Aromatase inhibitors (AIs) given as adjuvant therapy to treatment-naïve or post-tamoxifen patients significantly reduce the risk of in-breast recurrences (IBRs) and contralateral breast cancers (CBCs) and are currently in clinical trials for breast cancer prevention (NCIC CTG MAP.3 and IBIS-II). It is hypothesized that SERMS inhibit promotion of ER+ breast cancer whereas AIs may reduce both ER+ and ER- breast cancer by inhibiting both tumor initiation and promotion. Little is known about the characteristics of IBRs and CBCs that arise on AI therapy. We present the ER/PR expression and clinicopathologic features of IBRs and CBCs that occurred on MA.17.
 Methods: We examined ER/PR status of IBRs and CBCs that arose on letrozole vs. placebo among women enrolled in MA.17, a placebo-controlled (PLAC) trial of letrozole (LET) following 5 years of tamoxifen in postmenopausal women with early stage breast cancer.
 Results: Seventy-one patients (pts) developed an IBR and 87 developed a CBC on trial. Consistent with results previously reported, fewer IBRs (LET 20 vs PLAC 51) and CBCs (LET 35 vs PLAC 52) were observed in the LET group. ER and PR status is currently available on 35 women with an IBR and 39 with a CBC. The majority of IBRs were ER+ in both the LET and PLAC groups (10/11 [91%] vs 18/24 [75%], respectively; p=NS) but numbers of both ER+ and – IBRs were less in LET group, suggesting that letrozole may decrease both ER+ and ER- IBRs. CBCs that arose on PLAC were more likely to be ER+ than on LET (16/22 [73%] vs 6/19 pts [32%], respectively; p=0.01), suggesting that letrozole predominantly prevents ER+ CBCs. Discordance in ER expression between primary breast cancer and IBRs among women randomized to LET vs. PLAC was observed in 1/11 [9%] and 6/24 [26%] women respectively (p=NS) and between primary breast cancer and CBCs in 12/18 pts [67%] vs. 6/21 [29%] women respectively (p=0.01). Other clinicopathologic characteristics such as grade, tumor size, PR, HER-2/neu, and nodal status of IBRs and CBCs will be presented at the meeting.
 Conclusion: Extended adjuvant endocrine therapy with letrozole results in fewer IBRs and CBCs compared with placebo as previously reported. Our data suggests that letrozole may decrease both ER+ and ER- IBRs. Letrozole appears to prevent ER+ CBCs but has little or no apparent effect on the development of ER- CBCs. These results need confirmation in the primary prevention trials of AIs.
 


Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 1134.

Safety of the anti-IGF-1R antibody CP-751,871 in combination with exemestane in patients with advanced breast cancer

Abstract #2136

Background: Aromatase inhibitors (AIs) are established first-line treatment for postmenopausal estrogen receptor (ER)+ metastatic breast cancer. However, not all patients benefit from AIs and those whose tumors initially respond eventually relapse. One hypothesized mechanism for tumor insensitivity to hormonal agents seems to be cross-talk between the ER pathway and other growth factor signaling pathways, in particular the insulin-like growth factor receptor type 1 (IGF-1R). In xenograft breast cancer models, CP-751,871 administration increased tumor growth inhibition induced by tamoxifen. Thus our trial addresses the effect of combining AI with an IGF-1R antagonist.
 Methods: A phase II, multicenter, randomized, two-arm, comparative, two-stage trial to determine PFS of CP-751,871, a fully human IgG2 monoclonal antibody targeting IGF-1R, in combination with exemestane versus exemestane alone as first-line treatment in patients with hormone receptor positive, advanced breast cancer. Secondary endpoints include clinical benefit (CR, PR, or SD ≥6 months), safety/tolerability and PK. Patients included in the study are post menopausal, ≥18 years with locally advanced/metastatic breast cancer (stage IIIB or IV), ECOG PS 0–2, and adequate hematological, biochemical, and cardiac functions. CP-751,871 is given by intravenous infusion at a dose of 20 mg/kg every 21 days while 25 mg exemestane was given p.o. daily.
 Results: To date 37 patients have been dosed with CP-751,871 plus exemestane. Median age is 60.5 years (range 34–84). Patients received a median of 9.5 treatment cycles (range 1–22). One GR 4 CP-751,871-related AE (hoarse voice) was reported, which resolved after 3 days without intervention. GR 3 CP-751,871-related toxicities included 8.1% hyperglycemia (n=3), 8.1% GGT elevation (n=3), 5.4% allergic reaction (n=2), 5.4% hearing loss (n=2), 5.4% weight loss (n=2), and 2.7% anorexia (n=1). GR 2 CP-751,871-related AEs >10% were headaches, muscle cramps, and nail changes. Both hyperglycemia and hypersensitivity reactions were manageable (with oral hypoglycemic drug/insulin and antihistamine), while GGT elevation seems to be reversible.
 Conclusions: CP-751,871 in combination with exemestane is well tolerated. The most frequent GR 3 side effects are either well managed with medications or appear to be reversible. Therefore, CP-751,871, due to its safety profile, is a good targeted agent to combine with standard hormonal therapy. The stage I portion of the study to determine efficacy and toxicity is ongoing.

Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 2136.

Effects of novel retinoic acid metabolism blocking agent (VN/14-1) on N-methyl-N-nitrosourea (MNU)-induced mammary carcinoma and uterus in the rat model

Abstract #2133

Background: All-trans-retinoic acid (ATRA) and other retinoids play key roles in prevention and therapy of many proliferative diseases including cancers. VN/14-1 [4-(±)-(1H-Imidazol-1-yl)-(E)-retinoic acid], which is a new generation novel retinoic acid metabolism blocking agent (RAMBA), works by inhibiting the breakdown of ATRA. The inhibitory effects of VN/14-1 on the growth of human breast cancer cells and human breast tumors in the nude mouse model have been previously demonstrated. The purpose of this study was to evaluate the effects of VN/14-1 on the N-methyl-N-nitrosourea (MNU)-induced rat mammary carcinoma model, as well as on the uterus in immature ovariectomized (OVX) rats.
 Methods: (1) VN/14-1 (5, 10, and 20 mg/kg/d) was given by oral gavage to grouped female Sprague Dawley (SD) rats bearing MNU-induced mammary carcinoma for 8 weeks, after which tumor weight and volume, as well as histology were measured. (2) VN/14-1 (10 and 20 mg/kg/d) and b-estradiol (10 mg/kg/d) were given alone or in combination, by oral gavage (VN/14-1) and subcutaneous injection (b-estradiol), to immature OVX SD rats for 3 days, after which uterine weight and histology were measured.
 Results: (1) At the end of the treatment period, the administration of 5, 10 and 20 mg/kg/d VN/14-1 caused significant reductions of 19.1, 34.4 and 44.3%, respectively, in mean tumor weight compared with the control animals (all p < 0.05). The cumulative tumor growth was also significantly slower in groups receiving 5, 10 and 20 mg/kg/d compared to the control group in a dose-dependent manner. (2) Immature OVX rats given VN/14-1 at doses of 10 and 20 mg/kg, had reduction in uterine wet weight of up to 56% compared to OVX controls (P < 0.001). OVX rats given VN/14-1 of 10 and 20 mg/kg in combination with β-estradiol had reduction in uterine wet weight of up to 58% compared to the OVX rats given β-estradiol alone (P < 0.001). The adverse toxic effects such as fatigue and anorexia were occurred in the groups at high dose of 20 mg/kg.
 Conclusions: RAMBA VN/14-1 was able to inhibit the growth of tumors in the MNU-induced ER positive rat mammary tumor model and antagonized the stimulatory effect of β-estradiol on the uterus. The studies suggest VN/14-1 might be an effective novel therapy for ER positive breast cancer.

Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 2133.

Intent-to-treat analysis of the placebo-controlled trial of letrozole for extended adjuvant therapy in early breast cancer: NCIC CTG MA.17

BACKGROUND

MA.17 evaluated letrozole or placebo after 5 years of tamoxifen and showed significant improvement in disease-free survival (DFS) for letrozole [hazard ratio (HR) 0.57, P = 0.00008]. The trial was unblinded and placebo patients were offered letrozole.

PATIENTS AND METHODS

An intent-to-treat analysis of all outcomes, before and after unblinding, on the basis of the original randomization was carried out.

RESULTS

In all, 5187 patients were randomly allocated to the study at baseline and, at unblinding, 1579 (66%) of 2383 placebo patients accepted letrozole. At median follow-up of 64 months (range 16-95), 399 recurrences or contralateral breast cancers (CLBCs) (164 letrozole and 235 placebo) occurred. Four-year DFS was 94.3% (letrozole) and 91.4% (placebo) [HR 0.68, 95% confidence interval (CI) 0.55-0.83, P = 0.0001] and showed superiority for letrozole in both node-positive and -negative patients. Corresponding 4-year distant DFS was 96.3% and 94.9% (HR 0.80, 95% CI 0.62-1.03, P = 0.082). Four-year overall survival was 95.1% for both groups. The annual rate of CLBC was 0.28% for letrozole and 0.46% for placebo patients (HR 0.61, 95% CI 0.39-0.97, P = 0.033).

CONCLUSIONS

Patients originally randomly assigned to receive letrozole within 3 months of stopping tamoxifen did better than placebo patients in DFS and CLBC, despite 66% of placebo patients taking letrozole after unblinding.

Screening mammography for young women treated with supradiaphragmatic radiation for Hodgkin’s lymphoma

BACKGROUND

Female survivors of Hodgkin's lymphoma (HL) treated with supradiaphragmatic radiation therapy (SRT) are at increased risk of breast cancer (BC), but there is little data on the optimal screening strategy.

PATIENT AND METHODS

We report a prospective surveillance study of women treated for HL with SRT before age 30 participating in a high-risk screening clinic. Starting 8 years after treatment, women received annual mammography and clinical follow-up from 1997 to 2006. Method of detection and characteristics of BCs were identified.

RESULTS

In all, 115 female HL survivors attended at least one clinic; 100 participated in annual surveillance. The majority had mammography alone; adjunctive magnetic resonance imaging (MRI) was used more frequently in women with high breast density (P = 0.025). Median age at first mammogram was 36 years and decreased with more recent year of diagnosis. Twelve of the 100 participating women (12%) were diagnosed with BC after a median of 5 years of surveillance (range, 1-9). Seven BCs presented as palpable masses [six invasive, one ductal carcinoma in situ (DCIS)], five were detected by mammography (one invasive, four DCIS).

CONCLUSIONS

Despite earlier initiation of mammographic screening, most BCs were detected clinically and had unfavorable pathologic characteristics. Evaluation of more intensive screening and the contribution of MRI for earlier detection is warranted.

Participant characteristics on an international NCIC CTG breast cancer prevention trial

1531

Background: Antagonizing estrogen with tamoxifen has set the precedent for preventing breast cancer. Aromatase inhibitors reduce contralateral breast cancer in the adjuvant setting more than tamoxifen. The goal of MAP.3 is to determine whether exemestane reduces invasive breast cancers in post-menopausal women at risk for the disease. Methods: NCIC CTG MAP.3 is a randomized placebo controlled double blind trial of exemestane versus placebo. Recruitment began in September 2004 in North America and Spain. Criteria for entry on MAP.3 include: a Gail score of 1.66%; previous benign breast disease including LCIS; age over 60. The target sample size for the trial is 4560. Baseline characteristics of women enrolled thus far on MAP.3 were reviewed to determine whether their projected risk of breast cancer is consistent with the assumptions made in designing the trial. Results: Baseline characteristics are available on the 1784 women enrolled to MAP.3 to date. Over 70% of participants are over 60 years old (mean 64; SD=8.2 years) and the majority of the women are Caucasian (85%). The average 5-year risk of breast cancer is 2.7% (median, 2.2%). However, a greater proportion of women over 60 (30%) have a substantially lower Gail score (<1.66) compared to women less than 60 years of age (8%). Few women in the MAP.3 cohort have been enrolled on a basis of a history of prior breast atypical hyperplasia or LCIS (8%), or DCIS treated with mastectomy (2%). Nearly half the MAP.3 participants (45%) have at least one first degree relative with malignant breast cancer, and 7.5% of these women have 2 or more first degree relatives with the disease. Conclusions: The risk profile of the women on MAP.3 will determine the event rate and therefore the time to trial unblinding and analysis. This initial description of the MAP.3 population enrolled thus far indicates a slightly lower baseline breast cancer risk in comparison to the risk profile of those enrolled in previous breast cancer prevention trials with tamoxifen or raloxifene (NSABP P1, IBIS-1 and STAR). Reasons for this difference are being explored.

[Table: see text]

p63/p73 expression mediates cisplatin sensitivity in a subset of triple-negative primary breast cancer: Implications for a new clinical trial

10522

Background: Triple-negative breast cancer (ER-, PgR- and HER2-negative) has a poor prognosis relative to other subtypes, even with the best available chemotherapy. We recently reported that in squamous cell cancers, p63 promotes survival by direct interaction with and inhibition of p73-dependent apoptosis. We now report on the role of p63/p73 in triple-negative breast cancer. Methods: We performed quantitative RT-PCR on primary breast cancer specimens to determine the expression of specific p63 and p73 isoforms. Cell culture experiments used MCF7, HCC-1937, MDA-MB-468, T47D, and MCF10A cell lines. Lentiviral p63 and p73 shRNA were used for knockdown experiments. Chemotherapy dose-response curves were generated using MTT assay. Results: In primary tumors, ΔNp63 and TAp73 isoforms are expressed exclusively within a subset of triple-negative tumors in which p53 mutations are commonly found. Knockdown of p63 in triple-negative cell lines, but not the ER-positive MCF7 line, induced apoptosis which was specifically dependent on p73 expression. Breast cancer cell lines expressing p63/p73 exhibited p73-dependent sensitivity to cisplatin. Knockdown of p73 resulted in a 10–100 fold increase in the IC50 of cisplatin, but no change in doxorubicin or paclitaxel sensitivity. Exogenous p73 expression in MCF10A cells, which have high levels of p63 but no p73, confers increased sensitivity to cisplatin. Conclusion: These results show that p63/p73expression promotes survival in a subset of breast cancers, and they provide a mechanism for cisplatin sensitivity. These findings suggest that p63/p73 expression may serve as a biomarker to predict cisplatin sensitivity in triple-negative breast cancer. Based on these results, we are conducting a phase II study of 39 patients evaluating cisplatin as first line therapy for metastatic triple-negative breast cancer. The primary endpoints are overall objective response rate and response rate in low versus high p63/p73 expressing subgroups.

No significant financial relationships to disclose.

Competing causes of death in NCIC CTG MA.17, a placebo-controlled trial of letrozole as extended adjuvant therapy for breast cancer patients

540

Background: Risk of death from other malignancies (OM) and other causes (OC) than breast cancer (BC) increases with age. Effects of baseline factors on type of death were assessed with competing risks analyses. Methods: In NCIC CTG MA.17, 5,187 women free of recurrent breast cancer after 5 years of tamoxifen were randomized to letrozole (L, 2,593 women) or placebo (P, 2,594 women). The primary endpoint was disease free survival (DFS), and secondary, overall survival (OS). Follow-up was to October 9, 2005: median 3.9 years, range <0.1 to 7.0 years. Effects of competing risks were examined for endpoints of BC, OM, and OC for 11 baseline trial factors: treatment, age, menopausal status, duration of prior tamoxifen, adjuvant radiotherapy, bone fracture, osteoporosis, cardiovascular disease, hormone receptor status, nodal status, adjuvant chemotherapy. Lagakos’ hierarchical method (Lagakos, Appl. Statist. 1978; 27:235–241) was used to test for differential effects of baseline factors on type of death (BC, OM, OC). Results: Rate of censoring was 97.8%, with 256 deaths (BC, 102; OM, 50; OC, 100; unknown, 4). Non-breast cancer deaths accounted for 60% of known deaths; 72%, for those ≥70 years; and 48%, for those <70 years. Two baseline factors differentially affected type of death. Women with cardiovascular disease were more likely to die from OC (p=0.02), while those with osteoporosis were more likely to die of OM (p=0.03). Age and nodal status had directionally similar effects. Older women had shorter survival from all 3 causes of death (p=0.01). Lymph node positivity was associated with worse survival (p=0.003). Conclusions: Extended L provides similar proportional benefit in improving DFS for all ages of women (Muss ref abstract SABCS 2006). However, the magnitude of competing non-breast cancer, and non-treatment related, causes of death needs to be considered more frequently, since with early detection and improved therapies, breast cancer patients may increasingly be expected to survive their disease to die from another cause. The novel association between baseline osteoporosis and other malignancies is being explored quantitatively.

No significant financial relationships to disclose.

Pilot study of the impact of letrozole vs. placebo on breast density in women completing 5 years of tamoxifen

Breast density, a strong risk factor for breast cancer, is reduced by the anti-estrogen, tamoxifen (TAM). We examined whether aromatase inhibitor (AI) therapy results in further reductions in breast density among women completing 5 years of TAM. Among a sample of women with early-onset breast cancer who were randomized to letrozole (LET)(n=56) or placebo (PLAC)(n=48) after 5 years of TAM, we examine the change in percent density at 9-15 months as well as a per-year change in PD by treatment group. There was no difference in the adjusted mean change (-1.0%, LET; -0.3%, PLAC (P=0.58)) or the percentage change (-2.7%, LET; -3.0%, PLAC (P=0.96)) in PD between treatment groups at 9-15 months. Results were similar for longitudinal change (-0.68% per year, LET; -0.12% per year, PLAC (P=0.23)). Breast density does not appear to be a clinically relevant biomarker in women who already have low PD following 5 years of TAM.

Clinical outcomes of ethnic minority women in MA.17: a trial of letrozole after 5 years of tamoxifen in postmenopausal women with early stage breast cancer

BACKGROUND

Aromatase inhibitors are widely employed in the adjuvant treatment of early stage breast cancer. The impact of aromatase inhibitors has not been established in ethnic minority women.

PATIENTS AND METHODS

The purpose of this study was to evaluate the impact of letrozole on minority women in MA.17, a placebo-controlled trial of letrozole following 5 years of tamoxifen in postmenopausal women with early stage breast cancer. Retrospective comparison of disease-free survival (DFS), side effects, and mean changes in quality of life (QOL) scores from baseline between Caucasian and minority women was performed.

RESULTS

Minority (n = 352) and Caucasian (n = 4708) women were analyzed. There was no difference between these groups in DFS (91.6% versus 92.4% respectively for 4 year DFS). Letrozole, compared with placebo, significantly improved DFS for Caucasians (HR = 0.55; P < 0.0001) but not for minorities (HR = 1.39; P = 0.53). Among women who received letrozole, minorities had a significantly lower incidence of hot flashes (49% versus 58%; P = 0.02), fatigue (29% versus 39%; P = 0.005), and arthritis (2% versus 7%; P = 0.006) compared with Caucasians. Mean change in QOL scores for minority women who received letrozole demonstrated improved mental health at the 6-month assessment (P = 0.02) and less bodily pain at the 12-month assessment (P = 0.046).

CONCLUSION

Letrozole improved DFS in Caucasians but a definite benefit in minority women has not yet been demonstrated. Minority women tolerated letrozole better than Caucasians in terms of toxicity. These results need confirmation in other trials of aromatase inhibitors.

Updated analysis of NCIC CTG MA.17 (letrozole vs. placebo to letrozole vs placebo) post unblinding

550

Background: 5187 postmenopausal women were originally randomized to NCIC CTG MA.17 to receive letrozole (LET) or placebo (PLAC) after 5 years of tamoxifen. The hazard ratio (HR) for disease-free survival (DFS) was 0.58 (0.450.76, p=0.00004) after a median follow-up of 30 months (mo). The trial was unblinded in October 2003 after the first interim analysis. Women randomized to PLAC were offered LET at the time of unblinding. The goal of this analysis was to determine whether women switching from PLAC to LET benefit in terms of disease outcome and to evaluate treatment related toxicities. Methods: LET and PLAC-LET have been compared to PLAC, based on the hazard ratio and adjusting for baseline patient and disease variables including, among others, tumor size, nodal status and prior adjuvant chemotherapy. Results: Information about their follow-up treatment after unblinding was available on 2268 women originally assigned to PLAC and who were free of recurrence and alive at the time of unblinding. Among them, 1655 crossed over from PLAC to LET while 613 elected no treatment. With 54 mo f/up the HR for DFS was 0.31 (0.18, 0.55: p<0.0001) favoring patients who crossed over to LET compared to those who stayed on no treatment. The treatment switch was well tolerated with no significant difference in bone fractures or cardiovascular events. An updated analysis of DFS, DDFS and OS by nodal and tumor receptor status, prior chemotherapy, menopausal status at the start of tamoxifen, and duration of prior tamoxifen therapy will be presented at the meeting. Conclusion: Women with hormone dependent breast cancer prescribed LET after a prolonged delay from completing tamoxifen experienced a significant improvement in outcome (DFS, DDFS, OS) and should be considered for this therapy.

[Table: see text]

Phase 3 study of atamestane + toremifene vs. letrozole in advanced breast cancer

LBA525

Background: This study addresses the principle of “complete estrogen blockade” by combining atamestane, an investigational steroidal aromatase inhibitor (AI) with toremifene, an approved first line therapy. The primary objective was to assess whether atamestane + toremifene could improve on the time to disease progression achieved with letrozole alone. Methods: This was a multinational randomized, double blind, double dummy phase 3 clinical trial. Eligible women were postmenopausal with advanced breast cancer (ABC), estrogen and/or progesterone receptor positive. Prior adjuvant hormonal therapy was permitted only if completed >12 months prior to enrollment. Subjects received either atamestane 500 mg per day with toremifene 60 mg per day (A+T), or letrozole 2.5 mg per day (L). The primary endpoint was time to progression (TTP), log-rank test comparison on all randomized patients. Secondary objectives included objective response (OR), overall survival, and time to treatment failure (TTF). The study had 80% power to detect a 25% increase in TTP assuming a TTP of 9.4 months in the L population. Results: 865 patients with locally advanced (9%) or metastatic disease (91%) were randomized: 434 to A+T and 431 to L. Baseline characteristics were: mean age 64 years (S.D. = 9); ECOG Status 0 = 30%, 1 = 60%, 2 = 10%; prior adjuvant hormonal therapy 13%; prior adjuvant chemotherapy 20%. Sites of metastases and number of sites were well balanced between arms. The median TTP was identical in the two arms: 11.2 months (p < .92, log-rank chi square). The hazard ratio (L/A+T) for TTP was 1.00 (0.92–1.08, Cox proportional hazards 95% CI); for TTF was 0.99 (0.92–1.06) and for overall survival was 0.98 (0.87–1.11). OR occurred in 30% of patients on A+T and 36% of patients on L (p < 0.1, likelihood ratio chi square). Most frequent AEs (A+T vs L) were asthenia (11% vs 12%), increased weight (12% vs 10%), and hot flushes (10% vs 11%). Serious AEs were 10% vs 11%. Conclusions: While our study did not demonstrate increased TTP for A+T compared with L, this is the first endocrine therapy to be equally effective as letrozole as first line therapy in ABC. Both treatments were equally well tolerated. Unlike the ATAC trial, addition of an anti-estrogen did not decrease the efficacy of the AI. Further study of combination AI + SERM is warranted.

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