Gelmon, Karen A.

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.

Abstract Background: ASP is hypothesized to decrease the risk of breast cancer (BRCA) and BRCA recurrences. Thus we performed an exploratory analysis of ASP and CC use within the NCIC CTG MA.27 adjuvant trial comparing exemestane (E;N=3789) to anastrozole (A; N=3787) with a factorial second randomization to CC or placebo (P). Neither A or E was superior in breast cancer outcomes. Baseline low-dose ASP use is an accepted surrogate of cardiovascular risk factors and was used as a stratification factor across all 4 arms. Randomization to CC-P was discontinued after 18 months (n = 1622) due to concerns of cardiac toxicity. Methods: Patients taking >81mg of ASP daily at baseline were ineligible for randomization and use of >81mg of ASP daily was not allowed. Women enrolled during CC randomization were included in the comparison of E and A, stratified by whether they had been randomized to CC [yes, no;N=1622] and concomitant low-dose ASP [≤81 mg/day (yes, no); N=2209]. Other stratification factors included: lymph-nodes (negative, positive, or unknown); prior adjuvant chemotherapy (yes, no). The primary endpoint, event-free-survival (EFS), was defined as time from randomization to time of locoregional or distant disease recurrence, new primary breast cancer, or death from any cause. Secondary endpoints included overall survival (OS) defined as time from randomization to time of death from any cause and distant disease-free-survival (DDFS), defined as time from randomization to time of distant disease recurrence. Univariate (uni) assessment of CC and ASP use was assessed with stratified log-rank test, adjusting for lymph-node status and adjuvant chemotherapy and applied by intention-to-treat. Exploratory multivariate (multi) analyses (N = 1622) had forced inclusion of treatment and used step-wise forward stratified Cox modeling to examine the effects of CC, ASP use and baseline patient characteristics on outcomes; a factor was added with Wald test statistic p ≤ 0.05. Results: At median follow-up of 4.1 years, 186/1622 (11%) patients had an EFS event; 125 (8%) had died from any cause, and 80 (5%) had distant BRCA relapse. CC did not have significant uni association with outcomes: EFS p-value=0.92; OS p-value p = 0.56; DDFS p-value=0.55. ASP use was associated with worse EFS [p = 0.006, HR 1.48 (95% CI 1.12–1.96)], worse OS [p = 0.0002, HR 1.87 (95% CI (1.35–2.61)], and non-significant difference in DDFS (p = 0.72). CC had no multi association with EFS, OS or DDFS. ASP use had no multi association with EFS and DDFS (p > 0.05). However, ASP use had multi prognostic association with worse OS [p = 0.01; HR 1.67 (95% CI 1.13–2.49)]. Conclusions: Users of either CC or low dose ASP had similar DDFS to non-users in MA.27. As expected, low-dose ASP users (with presumptive cardiovascular risk factors) had worse OS than non-users. Inadequate numbers of patients randomized to CC and lack of randomization to aspirin leaves inadequate evidence from MA.27 to determine whether anti-inflammatories influence breast cancer outcomes. Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P2-13-02.

Abstract Background: In 2000, cyclophosphamide(C), epirubicin(E) and fluorouracil (F) (CEF) and doxorubicin (A) and C followed by paclitaxel (T) (AC/T) given every three weeks were commonly used regimens in Canada and the USA to treat women with node positive or high risk node negative operable breast cancer. In a previous trial in women with locally advanced breast cancer, 3 months of dose-dense EC was equivalent to six months of CEF. We hypothesized that the addition of 3 months of a taxane following dose-dense EC would be superior to CEF alone or AC/T. In a randomized trial in women with early breast cancer we compared CEF, dose dense EC/T and AC/T. An interim analysis (JCO, 2010) conducted when 50% of the events for the relapse-free-survival (RFS) analysis were observed, demonstrated that AC/T administered every 3 weeks was significantly inferior to CEF or EC/T. The results of the final RFS including CEF versus EC/T will be presented. Methods: Women, 60 years or younger, with operable axillary node positive or high risk node negative breast cancer were randomized to adjuvant CEF, EC/T or AC/T. CEF was given for 6 cycles and consisted of: C 75 mg/m2 orally on Days 1–14, and E 60 mg/m2 and F 500 mg/m2, IV on Days 1 and 8. CEF patients received concurrent antibiotic prophylaxis. EC/T consisted of 6 cycles of EC every 14 days; E 120 mg/m2 and C 830 mg/m2, both IV on Day 1 with filgrastim 5 [ug]/kg/day subcutaneous from Days 2–13 and epoetin alpha 40,000 units subcutaneous once weekly. After completion of EC, 4 cycles of T 175 mg/m2 every 21 days with filgrastim and epoetin alpha were given. The AC/T regimen consisted of A 60 mg/m2 and C 600 mg/m2 IV every 21 days for 4 cycles. This was followed by T 175 mg/m2 every 21 days for 4 cycles. The final analysis for RFS was planned when 453 events were observed permitting the detection of a hazard ratio (HR) of 1.43 between CEF and AC/T and a HR of 1.43 between EC/T and the best of the other two arms. Quality of Life data using the EORTC C-30 and the Breast Cancer Chemotherapy questionnaires were collected throughout the study. The results will be available at the time of the presentation. Results: A total of 2104 women were enrolled between December 2000 and April 2005. The required 453 events for the RFS analysis were observed by the clinical cut-off date of March 30, 2012. At this point 369 deaths had been observed. The median follow-up is 87.5 months. Outstanding data and queries are currently being collected and reviewed with an expected database lock and final analysis mid August, 2012. Febrile neutropenia remains higher on the CEF and EC/T arms while more neuropathy was seen in the taxane containing regimens. Conclusions: Although the two regimens considered a standard of care at the time the study was initiated are no longer widely used, the trial results will enhance our understanding of the magnitude of benefit of taxane following an anthracycline, the significance of cumulative anthracycline dose, and the role of dose density/ intensity as backbone of conventional chemo regimens. Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P1-13-01.

Purpose In patients with hormone-dependent postmenopausal breast cancer, standard adjuvant therapy involves 5 years of the nonsteroidal aromatase inhibitors anastrozole and letrozole. The steroidal inhibitor exemestane is partially non–cross-resistant with nonsteroidal aromatase inhibitors and is a mild androgen and could prove superior to anastrozole regarding efficacy and toxicity, specifically with less bone loss. Patients and Methods We designed an open-label, randomized, phase III trial of 5 years of exemestane versus anastrozole with a two-sided test of superiority to detect a 2.4% improvement with exemestane in 5-year event-free survival (EFS). Secondary objectives included assessment of overall survival, distant disease–free survival, incidence of contralateral new primary breast cancer, and safety. Results In the study, 7,576 women (median age, 64.1 years) were enrolled. At median follow-up of 4.1 years, 4-year EFS was 91% for exemestane and 91.2% for anastrozole (stratified hazard ratio, 1.02; 95% CI, 0.87 to 1.18; P = .85). Overall, distant disease–free survival and disease-specific survival were also similar. In all, 31.6% of patients discontinued treatment as a result of adverse effects, concomitant disease, or study refusal. Osteoporosis/osteopenia, hypertriglyceridemia, vaginal bleeding, and hypercholesterolemia were less frequent on exemestane, whereas mild liver function abnormalities and rare episodes of atrial fibrillation were less frequent on anastrozole. Vasomotor and musculoskeletal symptoms were similar between arms. Conclusion This first comparison of steroidal and nonsteroidal classes of aromatase inhibitors showed neither to be superior in terms of breast cancer outcomes as 5-year initial adjuvant therapy for postmenopausal breast cancer by two-way test. Less toxicity on bone is compatible with one hypothesis behind MA.27 but requires confirmation. Exemestane should be considered another option as up-front adjuvant therapy for postmenopausal hormone receptor–positive breast cancer.

Abstract Background: The non-steroidal reversible aromatase inhibitor (AI), anastrozole (A) is approved as adjuvant monotherapy in hormone receptor (HR) positive early breast cancer (EBC). The steroidal irreversible AI exemestane (E) is approved in sequence after an initial 2-3 years of tamoxifen. MA27 tested the hypothesis that exemestane would have greater efficacy and better end-organ safety than anastrozole for several reasons: E is an irreversible and more potent AI than A; unlike A, E does not induce intra-tumoral aromatase and; through its mild androgenic activity E may exert a second anti-tumor effect and a more favorable bone and lipid metabolism profile than A. Initially the study also tested the role of a cyclooxygenase-2 inhibitor, celecoxib, used in combination with an AI. However, celecoxib was discontinued early in MA27 following identification of cardiovascular toxicity with COX-2 inhibitors. Methods: Postmenopausal women with hormone receptor positive primary breast cancer were randomized after adequate local treatment to 5 years of adjuvant A (1mg/day) or E (25mg/day) with or without celecoxib/placebo (400mg/plac twice daily for 3 years). The primary objective is the comparison of event free survival (EFS) between women treated with A or E. Secondary objectives include overall survival (OS), distant recurrence (DDFS), incidence of contralateral breast cancer (CBC) and safety. Quality of Life in a subset of women has been evaluated, and a very extensive tissue bank created. Stratification included: prior chemotherapy; lymph node status, celecoxib (during use), aspirin use (during randomization to celecoxib), and trastuzumab use (since November 2005). The primary endpoint (EFS) will look for an improvement from 87.5% to 89.9%; HR 0.80, 2-sided 5% level and 80% power, with 644 events required. Results: 7576 women were randomized between June 2003 and July 2008. Celecoxib/placebo, was discontinued 2 years into the trial in December 2004 after 1635 patients had received celecoxib. The number of events required for final analysis was reached April 2010. Patient characteristics were balanced for age (median 64.1yrs); race; ECOG PS; mastectomy; TNM staging and; prior adjuvant chemotherapy. EFS, OS, DDFS, and CBC as well as clinical fractures, cardiovascular events and adverse events will be presented by arm in the final analysis. Conclusions: NCIC CTG MA.27 is the first definitive EBC trial comparing a non-steroidal and steroidal AI as initial adjuvant therapy. Exemestane is not currently approved as initial adjuvant treatment and superiority or equivalence will lead to its inclusion as a first-line option for EBC in postmenopausal HR positive breast cancer. Efficacy, clinical fractures, cardiovascular events and AI related symptoms will help to define the cost-benefit ratios of these two AIs. Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr S1-1.

Purpose To assess cardiac safety and potential cardiac risk factors associated with trastuzumab in the NCCTG N9831 Intergroup adjuvant breast cancer trial. Patients and Methods Patients with HER2-positive operable breast cancer were randomly assigned to doxorubicin plus cyclophosphamide (AC) followed by either weekly paclitaxel (arm A); paclitaxel then trastuzumab (arm B); or paclitaxel plus trastuzumab then trastuzumab alone (arm C). Left ventricular ejection fraction (LVEF) was evaluated at registration and 3, 6, 9, and 18 to 21 months. Results Of 2,992 patients completing AC, 5.0% had LVEF decreases disallowing trastuzumab (decrease below normal: 2.4%, decrease > 15%: 2.6%). There were 1,944 patients with satisfactory or no LVEF evaluation who proceeded to post-AC therapy. Cardiac events (congestive heart failure [CHF] or cardiac death [CD]): arm A, n = 3 (2 CHF, 1 CD); arm B, n = 19 (18 CHF, 1 CD); arm C, n = 19 (all CHF); 3-year cumulative incidence: 0.3%, 2.8%, and 3.3%, respectively. Cardiac function improved in most CHF cases following trastuzumab discontinuation and cardiac medication. Factors associated with increased risk of a cardiac event in arms B and C: older age (P < .003), prior/current antihypertensive agents (P = .005), and lower registration LVEF (P = .033). Incidence of asymptomatic LVEF decreases requiring holding trastuzumab was 8% to 10%; LVEF recovered and trastuzumab was restarted in approximately 50%. Conclusion The cumulative incidence of post-AC cardiac events at 3 years was higher in the trastuzumab-containing arms versus the control arm, but by less than 4%. Older age, lower registration LVEF, and antihypertensive medications are associated with increased risk of cardiac dysfunction in patients receiving trastuzumab following AC.