Abstract PD3-10: Higher serum PD-L1 predicts for increased overall survival to lapatinib vs trastuzumab in the phase 3 CCTG MA.31 trial

Background: In the CCTG (Canadian Clinical Trials Group) MA.31 randomized phase 3 trial, the trastuzumab-taxane combination led to longer PFS than lapatinib-taxane in HER2-positive metastatic breast cancer (MBC). We previously reported the prognostic utility of pretreatment serum PD-L1 in the trastuzumab arm of MA.31 (ASCO 2018, #1031), and here we evaluate serum PD-L1 in the lapatinib arm, and in the whole trial. Higher serum PD-L1 has been reported to be associated with reduced response to treatment with the immune checkpoint inhibitors in melanoma and lung cancer.

Methods: MA.31 accrued 652 centrally and/or locally-identified HER2-positivepatients; 186 in the trastuzumab arm, and 202 in the lapatinib armhad pretreatment serum available. TheELLA immunoassay platform (ProteinSimple, San Jose, CA) was used to quantitate serum PD-L1. Step-wise forward Cox multivariate analysis was used for PFS and OS, and testing for treatment-biomarker interaction was based on the local partial-likelihood method (Liu Y, Jiang W, and Chen BE, Statistics in Medicine 34, 3516-3530, 2015).

Results: In the total study population, pretreatment serum PD-L1 concentration had a median of 86.2 pg/ml, and 25% and 75% interquartiles of 64.1 and 134.3 pg/ml, respectively. In univariate analysis in the whole trial, and within both treatment arms, serum PD-L1 was not a significant biomarker for PFS. For OS, higher serum PD-L1 (as a continuous variable) was significant for shorter OS within the trastuzumab arm (HR=3.84, p=0.04), but was not associated with OS in the lapatinib arm (p=0.37). In the whole trial, in multivariate analysis for OS [15 covariates included: age, race, ECOG status, anthracyclines, other chemo, endocrine, radio, other prior adjuvant therapy, disease status, ER status, PR status, Ki67 (log transformed), CK5, EGFR, treatment arm, and serum PD-L1 (with median cut point)], serum PD-L1 remained a significant independent covariate (HR= 2.27, p= 0.001 (Table).There was significant interaction between treatment arm and continuous serum PD-L1 (Bootstrap method, p=0.0025); above 214.2 pg/ml serum PD-L1 (89% percentile), higher pretreatment serum PD-L1 was associated with a shorter OS to trastuzumab treatment, but longer OS to lapatinib treatment.

Conclusions: In the CCTG MA.31 trial, serum PD-L1 was a significant predictive factor: higher pretreatment serum PD-L1 was associated with a shorter OS to trastuzumab treatment, but longer OS to lapatinib treatment. Immune evasion may decrease the effectiveness of trastuzumab therapy. Further evaluation of elevated serum PD-L1 in the advanced breast cancer setting is warranted to identify HER2-positive MBC patients who may benefit from novel immune-targeted therapies in addition to trastuzumab.

Multivariate Analysis (whole trial): Significant Independent CovariatesCovariateP-ValueHRLower 95% CIHigher 95% CISerum PD-L1 (pretreatment) (>median vs <median)0.0012.271.403.68EGFR Status (continuous IHC score)0.0031.0121.0041.019Other Chemotherapy (yes vs no)0.0081.911.193.07Treatment Arm (trastuzumab vs. lapatinib)0.0100.530.330.86ECOG Performance Status (0 vs 1 or 2)0.0250.590.370.94Ki67 (log)0.0461.451.0062.081

Citation Format: Moku PR, Shepherd LE, Ali SM, Leitzel K, Parulekar WE, Zhu L, Virk S, Nomikos D, Aparicio S, Gelmon KA, Drabick JJ, Cream L, Halstead SE, Umstead T, Mckeone D, Maddukuri A, Polimera HV, Ali A, Poulose J, Pancholy N, Spiegel H, Nagabhairu V, Chen BE, Lipton A. Higher serum PD-L1 predicts for increased overall survival to lapatinib vs trastuzumab in the phase 3 CCTG MA.31 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 PD3-10.

Abstract P5-07-01: LncRNA MIR2052HG regulates ERα level and endocrine resistance through LMTK3 by recruiting early growth response protein 1

BACKGROUND: A GWAS for the MA.27 aromatase inhibitors (AIs) adjuvant trial (4,406 controls and 252 cases) identified variant (V) SNPs in a long noncoding (lnc) RNA, MIR2052HG, that were associated with longer breast cancer free interval (HR= 0.37, P= 2.15E-07). V SNPs (MAF= 0.32 to 0.42) were associated with lower MIR2052HG and ERα expression in the presence of AIs. MIR2052HG maintained ERα both by promoting AKT/FOXO3-mediated ESR1 transcription and by limiting ubiquitin-mediated ERα degradation. (Cancer Res 76:7012-23, 2016). Our goal was to further elucidate MIR2052HG's mechanism of action.

METHODS: RNA-Binding Protein Immunoprecipitation (RBPI) assays were performed to demonstrate that the transcription factor, early growth response protein 1 (EGR1), worked together with MIR2052HG to regulate lemur tyrosine kinase-3 (LMTK3) transcription in MCF7/AC1 and CAMA-1 cells. The location of EGR1 on the LMTK3 gene locus was mapped using chromatin immunoprecipitation (ChIP) assays. The co-localization of MIR2052HG RNA and the LMTK3 gene locus was determined using RNA-DNA dual fluorescent in situ hybridization (FISH). SNP effects were evaluated using a panel of human lymphoblastoid cell lines.

RESULTS: TCGA analysis revealed LMTK3 and MIR2052HG expression were highly correlated in ERα-positive breast cancer patients. We found that the MIR2052HG transcript was located in the LMTK3 gene locus by RNA-DNA FISH. Among all of the 12 potential LMTK3 transcription factors identified in the Encode database that were examined by RBPI, only EGR1 showed an interaction with MIR2052HG. CHIP assays confirmed EGR1 binding to the two putative EGR1 binding sites in LMTK3 gene.Depletion of MIR2052HG reduced the binding of EGR1 to the LMTK3 promoter and decreased LMTK3 expression, suggesting that it might function as a scaffold. Mechanistically, decreased LMTK3 levels further increased protein kinase C (PKC) activity and downstream AKT activity, leading to reduced ESR1 mRNA levels via increased pFOXO3. At the protein level, in MIR2052HG depleted cells, increased PKC activity increased the phosphorylation of MEK, ERK, and RSK1, leading to increased ERα phosphorylation at Ser167 and increased ERα degradation. Conversely, overexpression of LMTK3 in MIR2052HG depleted cells reversed these phenotypes. MIR2052HG regulated LMTK3 and ERα expression in a SNP- dependent fashion: the MIR2052HG V SNP, relative to wild-type (WT) genotype, increased LMTK3/ERα expression in response to androstenedione due to increased binding between EGR1 and the LMTK3 promoter in LCLs. However, AI treatment reduced this binding in MIR2052HG variant cells but increased binding in WT cells, resulting in decreased LMTK3/ERα in V cells and increased expression in WT cells.

CONCLUSIONS: Our findings support a model in which the protective MIR2052HG variant genotype regulates LMTK3 via MIR2052HG/EGR1, and LMTK3 regulates ERα stability via the PKC/MEK/ERK/RSK1 axis. This regulation may explain the effect of the MIR2052HG variant genotype on cell proliferation and response to AIs in MA.27. These findings provide new insight into the mechanism of action of MIR2052HG and suggest that LMTK3 may be a new therapeutic target in ERα-positive breast cancer patients treated with AIs.

Citation Format: Cairns J, Ingle JN, Shepherd LE, Kubo M, Goetz MP, Weinshilboum RM, Kalari KR, Wang L. LncRNA MIR2052HG regulates ERα level and endocrine resistance through LMTK3 by recruiting early growth response protein 1 [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 P5-07-01.

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.

Treatment outcomes for older patients with relapsed/refractory aggressive lymphoma receiving salvage chemotherapy and autologous stem cell transplantation are similar to younger patients: a subgroup analysis from the phase III CCTG LY.12 trial

Background

High-dose therapy and autologous stem cell transplantation (ASCT) is often considered for older patients (age >60 years) with relapsed/refractory aggressive lymphomas. Although registry data support the safety and potential efficacy of this approach, there are no prospective trials evaluating outcomes of ASCT in older patients. We evaluated the result of second-line chemotherapy and ASCT in older versus younger patients in the CCTG randomized LY.12 trial.

Patients and methods

From August 2003 to November 2011, 619 patients with relapsed/refractory aggressive lymphoma were randomized to gemcitabine, dexamethasone, cisplatin (GDP) or dexamethasone, cytarabine, cisplatin (DHAP); 177 patients (28.6%) enrolled were >60.0 years of age (range, 60-74) and 442 were ≤60.0 years of age. After two to three cycles, responding patients proceeded to ASCT. Intention-to-treat analysis was used to compare response rate, transplantation rate, event-free survival (EFS) and overall survival (OS) between patients aged ≤60.0 and >60.0 years.

Results

Patient characteristics were comparable between the two cohorts, except a larger proportion of older patients had high International Prognostic Index risk scores. Response to salvage therapy was 48.6% for patients aged  >60.0 versus 43.0% for those aged  ≤60.0 (P = 0.21). Transplantation rates were also similar: 50.3% versus 49.8% (P = 0.87) for older versus younger patients. Rates of febrile neutropenia and adverse events requiring hospitalization were comparable for older and younger patients (30.5% versus 22.9% and 37.9% versus 32.1%, respectively). With a median follow-up of 53 months, there was no difference in 4-year OS (36% and 40% for patients aged >60.0 and ≤60.0 years, P = 0.42), or 4-year EFS (20% versus 28%, P = 0.43). Mortality from salvage therapy was 8/174 (4.60%) and 5/436 (1.15%), and 100-day mortality post-ASCT was 7/88 (8.06%) and 4/219 (1.85%).

Conclusion

This subgroup analysis suggests that older patients derive similar benefit from salvage therapy and ASCT to younger patients, with acceptable toxicity.

ClinicalTrials.gov Identifier

NCT00078949.

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.

An individual patient-data comparison of combined modality therapy and ABVD alone for patients with limited-stage Hodgkin lymphoma

BACKGROUND

Treatment options for patients with nonbulky stage IA-IIA Hodgkin lymphoma include combined modality therapy (CMT) using doxorubicin, bleomycin, vinblastine and dacarbazine (ABVD) plus involved-field radiation therapy (IFRT), and chemotherapy with ABVD alone. There are no mature randomized data comparing ABVD with CMT using modern radiation techniques.

PATIENTS AND METHODS

Using German Hodgkin Study Group HD10/HD11 and NCIC Clinical Trials Group HD.6 databases, we identified 588 patients who met mutually inclusive eligibility criteria from the preferred arms of HD10 or 11 (n = 406) and HD.6 (n = 182). We evaluated time to progression (TTP), progression-free (PFS) and overall survival, including in three predefined exploratory subset analyses.

RESULTS

With median follow-up of 91 (HD10/11) and 134 (HD.6) months, respective 8-year outcomes were for TTP, 93% versus 87% [hazard ratio (HR) 0.44, 95% confidence interval (CI) 0.24-0.78]; for PFS, 89% versus 86% (HR 0.71, 95% CI 0.42-1.18) and for overall survival, 95% versus 95% (HR 1.09, 95% CI 0.49-2.40). In the exploratory subset analysis including HD10 eligible patients who achieved complete response (CR) or unconfirmed complete response (CRu) after two cycles of ABVD, 8-year PFS was 87% (HD10) versus 95% (HD.6) (HR 2.8; 95% CI 0.64-12.5) and overall survival 96% versus 100%. In contrast, among those without CR/CRu after two cycles of ABVD, 8-year PFS was 88% versus 74% (HR 0.35; 95% CI 0.16-0.79) and overall survival 95% versus 91%, respectively (HR 0.42; 95% CI 0.12-1.44).

CONCLUSIONS

In patients with nonbulky stage IA-IIA Hodgkin lymphoma, CMT provides better disease control than ABVD alone, especially among those not achieving complete response after two cycles of ABVD. Within the follow-up duration evaluated, overall survivals were similar. Longer follow-up is required to understand the implications of radiation and chemotherapy-related late effects.

CLINICAL TRIALS

The trials included in this analysis were registered at ClinicalTrials.gov: HD10 - NCT00265018, HD11 - NCT00264953, HD.6 - NCT00002561.

Do alternative methods of measuring tumor size, including consideration of multicentric/multifocal disease, enhance prognostic information beyond TNM staging in women with early stage breast cancer: an analysis of the NCIC CTG MA.5 and MA.12 clinical trials

The AJCC staging criteria consider tumor size to be the largest dimension of largest tumor. Some case series suggest using summation of all tumor dimensions in patients with multicentric/multifocal (MC/MF) disease. We used data from NCIC CTG MA.5 and MA.12 clinical trials to examine alternative methods of assessing tumor size on breast-cancer-free-interval (BCFI). The 710 MA.5 pre-/peri-menopausal node positive and 672 MA.12 pre-menopausal node-negative/-positive patients have 10-year median follow-up. All patients received adjuvant chemotherapy. Tumors were centrally reviewed for grade, hormone receptor, and HER2 status. Continuous pathologic tumor size was: (1) largest dimension of largest tumor (cm); (2) tumor area (cm(2)); (3) volume of tumor (cm(3)); (4) with MC/MF disease, summation of (1)-(3) for up to 3 foci. We examined univariate and multivariate effects of tumor size on BCFI utilizing (un)stratified Cox regression and the Wald test statistic. In univariate analysis, larger tumor dimension was significantly associated with worse BFCI in node positive patients: p < 0.0001 for MA.5; p = 0.01 for MA.12. In MA.5 multivariate analysis, larger summation of largest tumor dimensions was associated with worse BCFI (p = 0.0003), while larger single dimension was associated with worse BCFI (p = 0.02) for MA.12. Presence of MC/MF and other tumor size measurements were not associated (p > 0.05) with BFCI. While physicians could consider the largest diameter of the largest focus of disease or the sum of the largest diameters of all foci in their T-stage determination, it appears that the current method of T-staging offers equivalent determinations of prognosis.

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 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 &lt;1.0 SD below mean; Group 3, z-score ≤1.0 SD above mean; Group 4, z-score &gt;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 &lt; .0001), while local ER/PR status did not impact RFS (p &gt; 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.

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.

P1-06-07: TIMP-1 in Combination with HER2 and TOP2A for Prediction of Benefit from Adjuvant Anthracyclines in High Risk Breast Cancer Patients

Purpose: HER2 amplification, TOP2A aberrations and absence of TIMP-1 (Tissue Inhibitor of Metalloproteinase-1) expression in breast carcinomas have been associated with incremental benefit from anthracycline-containing adjuvant chemotherapy in several reports. In the DBCG 89D trial, we demonstrated that the predictive value of these markers improved when they were combined in a profile and the present study was undertaken to validate these findings in NCIC CTG MA.5, a similar but independent clinical trial.

Design: TIMP-1 was examined by immunohistochemistry in archival tumor tissue from 403 of 716 premenopausal high-risk patients with known HER2 and TOP2A status who were randomized to CEF or CMF in the MA.5 trial. Patients were classified according to 2 predefined marker profiles — the HT profile (HER2, TIMP-1) and the 2T profile (TOP2A, TIMP-1) and the statistical analyses were performed as closely as possible to the analytical approach used previously in the MA.5 trial and when analysing the biomarker profiles in the DBCG 89D trial.

Results: 98 (24%) patients had no TIMP-1 staining of tumor cells, 27% were HER2 amplified, and 18% were TOP2A aberrant. 44% of patients were classified as HT responsive (HER2-positive and/or TIMP-1 negative) and 37% as 2T responsive (TOP2A aberrant and/or TIMP-1 negative). There was no heterogeneity in treatment effect of CEF versus CMF according to TIMP-1. In HT responsive patients, CEF was superior to CMF with improved RFS (adjusted HR, 0.64; 95% CI, 0.42 to 0.98) and a borderline-significant improvement in OS (adjusted HR, 0.66; 95% CI, 0.42 to 1.04). A significant HT profile versus treatment interaction was detected for OS (P=0.03). In 2T responsive patients, CEF was superior to CMF with borderline significant improvement in RFS (adjusted HR, 0.67; 95% CI, 0.43 to 1.03), and with improvement in OS (adjusted HR, 0.58; 95% CI, 0.36 to 0.93). A significant 2T profile versus treatment interaction was detected for OS (P=0.01).

Conclusion: In the MA.5 trial, we have validated the HT and 2T profiles as predictors of incremental benefit from anthracycline-containing chemotherapy. The proportion of patients categorized as anthracycline responsive increases from 18–27% using individual markers to 37–44% when combining TIMP-1 with either HER2 or TOP2A. Patients with responsive profiles had a 34–42% relative reduction in mortality when treated with CEF. In contrast, patients with non-responsive profiles (56-63% of patients) had no incremental benefit from CEF compared with CMF. All 3 biomarkers are easily applied in the pathology lab and as such could be used in daily clinical practice to select patients for anthracycline or non-anthracycline containing adjuvant chemotherapy.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P1-06-07.

P1-06-08: Effect of Treatment Emergent Symptoms on Relapse Free Survival: NCIC CTG MA.12 a Randomized Placebo-Controlled Trial of Tamoxifen after Adjuvant Chemotherapy in Pre-Menopausal Women in Early Breast Cancer

Background: Evidence from the ATAC trial that vasomotor or joint symptomatology by 3 months is associated with reduced recurrence after 3 months led to an interest in examining this phenomenon in other aromatase inhibitor trials. We examined here whether there is such an association in the context of a placebo-controlled tamoxifen therapy trial.

Methods: NCIC CTG MA.12 is a randomized placebo-controlled trial of tamoxifen (TAM) after adjuvant chemotherapy for pre-menopausal women with early breast cancer. Eligible patients were included if they received some protocol therapy, were alive and disease-free at 3 months: 1.) without prior grade 3/4 vasomotor or joint symptoms (N=293; only 3 patients had prior grade 1/2 vasomotor or joint symptoms); separately, 2.) all patients with/without prior vasomotor or joint symptoms (N=631). Vasomotor symptom at 3 months was adverse reporting of any grade of hot flashes and/or sweating, while joint symptom was any adverse event reporting of pain -joint, pain -muscle, pain -bone, arthritis, joint -function, or musculoskeletal —other. Exact Fisher tests were used to examine associations between baseline patient and tumour characteristics, treatment arm, and the development of symptomatology. Univariate testing of effect of symptomatology on relapse-free survival (RFS) was with a stratified Cox model, and multivariate was with stratified step-wise forward Cox modeling.

Results: MA.12 accrued 672 patients, and the median follow-up for this investigation was 9.7 years. Excluding patients with prior vasomotor or joint symptoms, 27.3% of 293 patients reported vasomotor or joint symptoms by three months, all of which was vasomotor. Meanwhile, 20.8% of all 631 patients had symptomatology by 3 months: 19.2% reported vasomotor alone, 1.1% joint alone, and 0.5% both. With no prior symptoms, 23.4% on placebo (P) and 31.7% on TAM developed symptomatology; age was the only baseline factor with significant differences at 3 months (p=0.01), with under 40 years 18% of women on TAM and 8% on P, and 50 or older, 21% on TAM and 14% on P being symptomatic. For all patients, 20.1% on P and 21.4% on TAM reported symptomatology by 3 months, and there was weak evidence that those &gt;50 on TAM had more symptoms (p=0.06). Vasomotor and joint symptoms did not exhibit significant univariate or multivariate effects on RFS (without prior symptoms, respectively, p=0.98 and p=0.90; for all patients, p=0.99 and p=0.93).

Discussion: We did not observe any association of vasomotor or joint symptoms by 3 months and relapse-free survival after 3 months in the MA.12 placebo-controlled trial of tamoxifen therapy in premenopausal women. This mirrors the results we observed in our MA.27 trial of exemestane versus anastrozole in postmenopausal women, and points to the simple metric of early symptomatology not being a universal predictor of reduced relapse.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P1-06-08.

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.

Abstract P4-09-09: Serum SDF-1: Biomarker of Bone Relapse in the NCIC MA.14 Adjuvant Breast Cancer Trial

Background: Massague et al have shown that breast cancer cell line subpopulations with elevated bone metastatic activity overexpress chemokine receptor 4 (CXCR4), interleukin 11 (IL11), osteopontin (OPN) and connective tissue growth factor (CTGF) (Cancer Cell 3:537, 2003). CXCR4 overexpression results in bone-homing and extravasation of tumor cells in bone. In MA.14, we found that serum β-CTx was associated with bone-only relapse while Basik et.al showed that higher serum stromal cell-derived factor 1 (SDF-1) (ligand for CXCR-4) levels were associated with worse overall event-free survival (EFS) (ASCO 2010). In this study, we examined concurrently the association of both β-CTx and serum SDF-1 with bone relapse.

Methods: Serum β-CTx (Serum CrossLaps, Nordic Biosciences, Copenhagen, DN) was determined in pretreatment sera from 621 of 667 NCIC CTG MA.14 patients. SDF-1 (CXCL12) (R&D Systems, Minneapolis, MN) levels were successfully determined in the 4 month post-treatment serum (SDF-1) for 508 (76%) of the patients. Trial stratification was by administration of adjuvant chemotherapy, axillary lymph node status, and ER and/or PR status. Recurrence-free survival (RFS) was defined as the time from randomization to the time of recurrence of the primary disease. Adjusted and unadjusted Cox step-wise forward multivariate analyses were used to assess the effects of β-CTx, SDF-1, trial therapy and baseline patient characteristics on non-bone, all bone and bone-only RFS; a factor was added if p&lt;=0.05.

Results: Joint assessment of β-CTx and SDF-1 was possible for 493 (74%) of the 667 patients. Imbalances in who was, or was not, included in this subset led to the trial arm of Tamoxifen + Octreotide LAR having a significant longer unadjusted ITT non-bone RFS (p=0.03-0.06). There was shorter time to bone metastasis of any type with higher lymph node involvement (p=0.001), larger T (p=0.02), and higher log SDF-1 (p=0.03). Meanwhile, high categorical and continuous β-CTx was associated multivariately with shorter bone-only RFS (p=0.04 and 0.01, respectively); higher log SDF-1 was only associated with shorter bone-only RFS (p=0.02) when the number of strata were reduced to 2 categories per factor.

Conclusions: Higher serum SDF-1 level may be associated with bone metastasis, although there is less evidence of its relevance in bone-only relapse than there is for the biomarker β-CTx. Serum SDF-1 deserves further study as a promising predictive factor of bone relapse in breast cancer.

Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P4-09-09.

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)

Anthracyclines in basal breast cancer: The NCIC-CTG trial MA5 comparing adjuvant CMF to CEF

519

Background: MA5 randomized premenopausal women with node-positive early breast cancers to cyclophosphamide- methotrexate-fluorouracil (CMF) or cyclophosphamide-epirubicin-fluorouracil (CEF) adjuvant chemotherapy. This and other trials have shown that adjuvant regimens containing anthracyclines confer significant survival benefit to breast cancer patients. Meta-analyses have revealed most benefit in women with HER2(+) or TOPO2 (+) tumors. Population-based data suggest that patients with a core basal phenotype (negative for hormone receptors and HER2, positive for CK5/6 or EGFR) conversely have worse survival on anthracycline containing vs. CMF regimens. Here we test the hypothesis specified a priori that for basal breast cancers anthracyclines may be inferior, using data from MA5. Methods: From 710 patients in MA5, blocks suitable for tissue microarray construction were recovered for 549. Immunohistochemistry for ER, PR, HER2, Ki67, CK5/6 and EGFR was obtained, allowing stratification of 511 cases into intrinsic biological subtypes by published methods (Cheang MC et al. Clin Cancer Res 2008;14:1368–76). Prespecified analyses were conducted independently by the NCIC- CTG statistical centre. Results: In the CEF arm, patients with core basal tumors had a hazard ratio of 1.8 (log rank p=0.02) for overall survival (OS) relative to the other biological subtypes. In the CMF arm, there was no significant difference (HR 0.9, p = 0.7). The interaction between core basal status and treatment was borderline significant (p=0.06). Relapse free survival differences did not reach significance. Conclusions: Data from this randomized trial supports the hypothesis that anthracycline containing adjuvant chemotherapy regimens are inferior to adjuvant CMF in women with basal breast cancer.

[Table: see text]

No significant financial relationships to disclose.

Topoisomerase II alpha and responsiveness of breast cancer to adjuvant chemotherapy

BACKGROUND

Amplification or deletion of the topoisomerase II alpha (TOP2A) gene in breast cancers has been postulated to be more closely associated with responsiveness to anthracycline-containing chemotherapy than amplification of the human epidermal growth factor receptor type 2 (HER2) gene.

METHODS

We studied 438 tumors from 710 premenopausal women with node-positive breast cancer who received cyclophosphamide, epirubicin, and 5-fluorouracil (CEF) or cyclophosphamide, methotrexate, and 5-fluorouracil (CMF) as adjuvant chemotherapy in the randomized National Cancer Institute of Canada Clinical Trials Group Mammary 5 (MA.5) trial. TOP2A alterations and HER2 amplification were quantified by fluorescence in situ hybridization. The association of TOP2A and HER2 status with recurrence-free survival (RFS) and overall survival (OS) in the two treatment groups was analyzed using Kaplan-Meier curves, the log-rank test, and Cox proportional hazard models. All statistical tests were two-sided.

RESULTS

In patients whose tumors showed TOP2A alterations (either amplifications or deletions), treatment with CEF was statistically significantly superior to treatment with CMF in terms of RFS (adjusted hazard ratio [HR] = 0.35, 95% confidence interval [CI] = 0.17 to 0.73, P = .005) and OS (adjusted HR = 0.33, 95% CI = 0.15 to 0.75, P = .008). In patients without TOP2A amplification or deletion, the corresponding adjusted hazard ratios for RFS and OS were 0.90 (95% CI = 0.66 to 1.23, P = .49) and 1.09 (95% CI = 0.77 to 1.56, P = .62). Adjusted tests of interaction between treatment and TOP2A status were P = .09 for RFS and P = .02 for OS. Adjusted tests of interaction between treatment and HER2 status were P = .008 for RFS and P = .02 for OS.

CONCLUSION

TOP2A gene alterations (amplifications or deletions) are associated with an increase in responsiveness to anthracycline-containing chemotherapy regimens relative to non-anthracycline regimens that is similar to that seen in patients with HER2 amplification.

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.&#x2028; 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.&#x2028; 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.&#x2028; 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.&#x2028; &#x2028;

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

Reductions in tumor RNA integrity associated with clinical response to epirubicin/docetaxel chemotherapy in breast cancer patients

Abstract #6068

Background: Optimal doses and dosing intervals for neoadjuvant anthracycline/taxane chemotherapy are poorly studied. Moreover, biomarkers for measuring response to such combination regimens are unknown. This study investigated these issues in sequential phase I/II cohorts of women with locally advanced or inflammatory breast cancer treated with epirubicin and docetaxel with pegfilgrastim support at 3- or 2-weekly intervals in association with the NCIC-CTG MA.22 clinical trial.&#x2028; Methods: Accrual has been completed for the 3-weekly regimen (maximum tolerated dose: epirubicin 105 mg/m2, taxotere 75 mg/m2), and continues for the phase II portion of the 2-weekly regimen. Six core biopsies were obtained from 50 patients pre-, mid-, and post-treatment. Immunohistochemical staining was performed to determine baseline levels of ER, PR, HER2 and Topo II expressed as % positive stain. Tumour RNA integrity (RIN) and tumor extent were measured pre-, mid- and post-treatment by capillary electrophoresis and light microscopy after haematoxylin/eosin staining, respectively. Associations between maximum and average RIN at the three time points and tumour extent, clinical response, pathologic complete response, or baseline levels of ER, PR, HER2 and Topo II were assessed using Spearman correlation coefficients after data transformation to improve symmetry and stabilize variances. The association between both RIN and tumour extent, and baseline drug dose was assessed using a 1-way ANOVA.&#x2028; Results: Low mid-treatment maximum RIN was associated with high drug dose level (p=0.05) and eventual pathologic complete response (p=0.01). Post-treatment, low maximum and average RIN were found to be associated with low tumor extent (p=0.004 and p=0.01, respectively). As well, low average RIN was significantly associated with clinical complete response post-treatment (p=0.01). As expected, post-treatment low tumor extent was significantly associated with pathologic complete response (p=0.01). High pre-treatment Topo II levels were also significantly associated with high RIN (p = 0.03). No association was observed between RIN and HER2, ER or PR.&#x2028; Discussion: The association of RIN with tumour extent, pathologic complete response, clinical response, a known risk factor (Topo II), and drug dose suggests that the RIN may represent an important new biomarker for measuring response to anthracycline/taxane combinations (and possible other chemotherapy regimens) in breast cancer patients.

Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 6068.

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.

Patterns of disease progression and outcomes in a randomized trial testing ABVD alone for patients with limited-stage Hodgkin lymphoma

BACKGROUND

In the National Cancer Institute of Canada Clinical Trials Group/Eastern Cooperative Oncology Group HD.6 trial, progression-free survival was better in patients randomized to therapy that included radiation, compared to doxorubicin (Adriamycin), bleomycin, vinblastine and dacarbazine (ABVD) alone. We now evaluate patterns of progression and subsequent outcomes of patients with progression.

PATIENTS AND METHODS

After a median of 4.2 years, 33 patients have progressed. Two radiation oncologists determined whether sites of progression were confined within radiation fields. Freedom from second progression (FF2P) and freedom from second progression or death (FF2P/D) were compared.

RESULTS

Reviewers agreed for the extended (kappa = 0.87) and involved field (kappa = 1.0) analyses. Progression after ABVD alone was more frequently confined within both the extended (20/23 vs. 3/10; P = 0.002) and involved fields (16/23 vs. 2/10; P = 0.02). There was no difference in FF2P between groups [5-year estimate 99% (radiation) versus 96% (ABVD alone)] [hazard ratio (HR) = 3.14, 95% confidence interval (CI) 0.63-15.6; P = 0.14]; the 5-year estimates of FF2P/D were 94% in each group (HR = 1.04, 95% CI 0.41-2.63; P = 0.93).

CONCLUSION

Treatment that includes radiation reduces the risk of progressive Hodgkin lymphoma in sites that receive this therapy, but we are unable to detect differences in FF2P or FF2P/D.

Addition of lenalidomide to melphalan in the treatment of newly diagnosed multiple myeloma: the National Cancer Institute of Canada Clinical Trials Group MY.11 trial

Oral melphalan and prednisone remain an effective and tolerable treatment for patients with multiple myeloma. For approximately 40 years, this combination has been the standard of care for patients not proceeding to stem cell transplant. Within the last 10 years, new agents have been found to be efficacious in the relapsed/refractory setting. Within the last year, two trials of added thalidomide in the newly diagnosed setting have demonstrated outcomes superior to those achieved with melphalan and prednisone alone. This improved outcome comes at the cost of increased toxicity.The National Cancer Institute of Canada Clinical Trials Group (NCIC CTG) has recently developed a randomized phase ii trial (MY.11) that uses a combination of lenalidomide with melphalan for patients with newly diagnosed multiple myeloma. Lenalidomide is a thalidomide analogue and, like thalidomide, is thought to work through immunomodulatory effects. It was shown to have activity in patients with relapsed or refractory disease and, in combination with dexamethasone, is superior to dexamethasone alone. Lenalidomide holds promise as a more effective and potentially less toxic derivative of thalidomide. Experience with lenalidomide in combination with chemotherapy is very limited, and the purpose of MY.11 is to establish tolerability and to gain knowledge about efficacy. The information gained from MY.11 is expected to help inform dosing levels and schedules for a large phase iii trial being developed by the Eastern Cooperative Oncology Group that will include participation by the NCIC CTG.

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.

Prognostic and predictive value of topoisomerase II alpha in a randomized trial comparing CMF to CEF in premenopausal women with node positive breast cancer (NCIC CTG MA.5)

533

Background: It has been suggested that Topoisomerase II alpha (TOP2A) status rather than Her-2/neu status may predict response to anthracycline chemotherapy in breast cancer. Methods: In MA.5, 710 premenopausal women with node positive breast cancer were randomized to receive adjuvant CEF (epirubicin 60 mg/m2 & 5-FU 500 mg/m2 both IV, days 1 & 8, and cyclophosphamide 75 mg/m2 p.o. days 1 through 14); vs CMF (methotrexate 40 mg/m2 & 5-FU 600 mg/m2 both IV days 1 & 8 and cyclophosphamide 100 mg/m2 p.o. days 1 through 14), all for six 28-day cycles. Tissue microarrays (TMAs) were constructed from paraffin embedded specimens from 447 (63%) of these patients. TOP2A was measured by fluorescence-in-situ hybridization (FISH), classifying tumors into 3 groups by TOP2A/CEP 17 ratios: amplified (Amp) if ratio ≥2; deleted (Del) if ratio < 0.8; normal (N) if ratio 0.8 to 2. Cox models assessed interaction between treatment and TOP2A, adjusting for age, nodal status, ER, HER-2/neu status, grade, surgery and tumor size. Results: Thirty-one patients (6.9%) had tumours with Del TOP2A; 53 (11.9%) with Amp TOP2A; and 353 (81.2%) with N TOP2A. 5-year disease-free survival (DFS) was 48%, 51%, and 61% for patients with Del, Amp and N TOP2A respectively (p=0.22 adjusted global test). 5-year overall survival (OS) was 55%, 61% & 75% for patients with Del, Amp, and N TOP2A (p=0.67 adjusted global test). HRs for DFS and OS by treatment and TOP2A are presented in the table . Conclusions: TOP2A status was a significant predictive factor for benefit from CEF treatment for OS. Although there was a trend for TOP2A status predicting improved DFS with CEF, the test for interaction was not significant. In adjusted analysis TOP2A did not reach significance as a prognostic factor for DFS or OS. (This study was supported by the Canadian Breast Cancer Research Alliance (CBCRA), the National Cancer Institute of Canada (NCIC) and the Canadian Cancer Society.)

[Table: see text]

[Table: see text]

NCIC CTG MA.17: Tolerability of letrozole among ethnic minority women

6018

Background: Disease free survival was significantly improved in women receiving letrozole after standard adjuvant tamoxifen in the MA.17 trial. Based on the results of MA.17 and of other trials of aromatase inhibitors in early stage breast cancer, chronic aromatase inhibitor therapy, in postmenopausal women free of breast cancer recurrence, is now being widely employed. We analyzed the toxicity of letrozole according to ethnic status among women enrolled in MA.17. Methods: The chi-square test was used for comparison of rates of side effects between the two groups, Caucasian vs. ethnic minority (defined as all non-Caucasians). In a subset of women, quality of life (QOL) was assessed by the SF-36 Health Survey. Mean change scores in QOL from baseline were compared between groups for summary measures and domains using the Wilcoxon test. Results: 352 minority women and 4,708 Caucasians were enrolled in MA.17, of which 183 minority women and 2,339 Caucasians were randomized to receive letrozole. Caucasians were older than minority women and had a slightly longer duration of treatment with prior tamoxifen. Tumor size and nodal status were not significantly different between the two groups. In women who received letrozole, minority women had significantly lower incidence of hot flashes (49% vs. 58%; p = 0.02), fatigue (29% vs. 39%; p = 0.005), and arthritis (2% vs. 7%; p = 0.006) compared with Caucasians. Mean QOL change scores of SF-36 domains for women who received letrozole were not different but minority women had better mental health at 6 month assessment (p = 0.02) and worse bodily pain at 12 month assessment (p = 0.046). Conclusions: Minority women tolerated letrozole considerably better than Caucasians in the MA.17 trial. These preliminary findings suggest that minority women respond differently to letrozole in terms of toxicity. Recent demonstration of genotypic variations in the aromatase gene in different ethnic groups plus likely pharmacogenomic differences suggests that further research is needed to clarify the clinical outcomes of aromatase inhibition in women of diverse ethnicities. Future research strategies should focus on examining in vivo genotype-phenotype correlations to determine the effects of genetic variation on response to anticancer therapy and on toxicities and end-organ effects.

[Table: see text]

Left ventricular function following adjuvant chemotherapy for breast cancer: The NCIC CTG MA5 experience

522

Background: Cardiac toxicity associated with anthracylines and more recently herceptin used in adjuvant breast cancer treatment is well recognized. Little is known about long term cardiac function as measured by left ventricular ejection fraction (LVEF) in patients post therapy. We analyzed the database of a randomized Phase 3 NCIC CTG study to assess changes over time in LVEF. Methods: Between 1989–1993, 710 pre/perimenopausal patients with node positive breast cancer were allocated to receive CEF (cyclophosphamide (C) 75 mg/m2 po d 1–14, epirubicin (E) 60 mg/m2 IV and fluorouracil (F) 500mg/m2 IV d1,d8) or CMF (C 100mg/m2 po d1–14, methotrexate (M) 40mg/m2 and F 600mg/m2 IV d1,8) given every 28 days for 6 cycles. The 10 year relapse-free survival was 52% (CEF) vs 45% (CMF), HR 1.31; stratified log rank, P=.007 (JCO, 2005,23;5166). LVEF was measured on both arms at baseline, months 6, 12, 36, and 60. Results: Compliance was good with measurements available on 100% of women at baseline, and 39% and 40% of patients at 60 months on the CEF and CMF arms respectively. Changes in LVEF from baseline are shown in the table . Conclusion: Changes in cardiac function as measured by a decrease in LVEF are not infrequent in patients after adjuvant therapy, even in the absence of anthracyclines. At 60 months, decreases of >10% were seen in up to 25% of patients receiving epirubicin administered at a cumulative dose of 720mg/m2 and in up to 10% of patients receiving CMF on whom measurements were available. The clinical significance of these findings needs to be assessed. Acknowledgements: This study was supported by funding from the Canadian Cancer Society through the National Cancer Institute of Canada and Pfizer Inc.

[Table: see text]

[Table: see text]

A pooled analysis of adjuvant chemotherapy for resected colon cancer in elderly patients

BACKGROUND

Adjuvant chemotherapy is standard treatment for patients with resected colon cancer who are at high risk for recurrence, but the efficacy and toxicity of such treatment in patients more than 70 years of age are controversial.

METHODS

We performed a pooled analysis, based on the intention to treat, of individual patient data from seven phase 3 randomized trials (involving 3351 patients) in which the effects of postoperative fluorouracil plus leucovorin (five trials) or fluorouracil plus levamisole (two trials) were compared with the effects of surgery alone in patients with stage II or III colon cancer. The patients were grouped into four age categories of equal size, and analyses were repeated with 10-year age ranges (< or =50, 51 to 60, 61 to 70, and >70 years), with the same conclusions. The toxic effects measured in all trials were nausea or vomiting, diarrhea, stomatitis, and leukopenia. Patients in the fluorouracil-plus-leucovorin and fluorouracil-plus-levamisole groups were combined for the efficacy analysis but kept separate for toxicity analyses.

RESULTS

Adjuvant treatment had a significant positive effect on both overall survival and time to tumor recurrence (P<0.001 for each, with hazard ratios of death and recurrence of 0.76 [95 percent confidence interval, 0.68 to 0.85] and 0.68 [95 percent confidence interval, 0.60 to 0.76], respectively). The five-year overall survival was 71 percent for those who received adjuvant therapy, as compared with 64 percent for those untreated. No significant interaction was observed between age and the efficacy of treatment. The incidence of toxic effects was not increased among the elderly (age >70 years), except for leukopenia in one study.

CONCLUSIONS

Selected elderly patients with colon cancer can receive the same benefit from fluorouracil-based adjuvant therapy as their younger counterparts, without a significant increase in toxic effects.

Bioabsorbable versus stainless steel screw fixation of the syndesmosis in pronation-lateral rotation ankle fractures: a prospective randomized trial

Thirty-two patients who had pronation-lateral rotation (PLR) fractures occurring four centimeters or more proximal to the ankle joint or lower if the talus was displaced greater than one centimeter laterally were enrolled in this study. Seventeen patients were randomized to fibular plate fixation with a 4.5 ml polylactic acid (PLA) bioabsorbable syndesmotic screw, and fifteen patients randomized to fibular plate fixation with a 4.5 mm stainless steel syndesmotic screw. All thirty-two patients had uncomplicated healing of their fibular fracture without loss of reduction. There was neither evidence of osteolysis nor sterile effusion in the patients who were treated with the PLA screw. There were no wound complications in either group. No difference in range of motion or subjective complaints was noted in either group. Use of the PLA syndesmotic screw at short-term follow-up was well tolerated and avoided the need for subsequent screw removal.

The role of ankle arthroscopy on the surgical management of ankle fractures

Nineteen patients were prospectively randomized for operative treatment of their ankle fracture to be supplemented with or without ankle arthroscopy. All patients had an SER or PER fracture with an intact medial malleolus requiring operative treatment without evidence of intra-articular debris preoperatively. All patients underwent plate fixation of their fibula fracture and had a similar postoperative protocol. Ten patients were randomized to the control group with plate fixation only and nine patients randomized to the plate fixation plus operative arthroscopy. The average follow-up was 21 months. The arthroscopic examination of the study group revealed eight of the nine patients to have articular damage to the dome of the talus. Minimal arthroscopic treatment of these joints was required. All patients healed their fractures. No difference was noted between SF-36 scores or lower extremity scores between the two groups. At short-term follow-up, it does not appear that the arthroscopic procedure will impact upon the patient's eventual outcome in this small group of patients.

Prospective randomized study of reamed versus unreamed femoral intramedullary nailing: an assessment of procedures

OBJECTIVE

To determine whether the procedure of unreamed femoral nailing is simpler, faster, and safer than reamed femoral intramedullary nailing.

DESIGN

Prospective randomized.

SETTING/PARTICIPANTS

One hundred femoral shaft fractures without significant concomitant injuries admitted to an academic Level 1 urban trauma center.

INTERVENTION

Stabilization of the femoral shaft fracture using a reamed or unreamed technique.

OUTCOME MEASUREMENTS

The surgical time, estimated blood loss, fluoroscopy time, and perioperative complications were prospectively recorded.

RESULTS

One hundred patients with 100 femoral shaft fractures were correctly prospectively randomized to the study. Thirty-seven patients received reamed and sixty-three patients received unreamed nails. All nails were interlocked proximally and distally. The average surgical time for the reamed nail group was 138 minutes and for unreamed nail group was 108 minutes (p = 0.012). The estimated blood loss for the reamed nail group was 278 milliliters and for the unreamed nail group 186 milliliters (p = 0.034). Reamed intramedullary nailing required an average of 4.72 minutes, whereas unreamed nailing required 4.29 minutes of fluoroscopy time. Seven perioperative complications occurred in the reamed nail group and eighteen in the unreamed nail group. Two patients in the unreamed group required an early secondary procedure. Iatrogenic comminution of the fracture site occurred during three reamed and six unreamed intramedullary nailings. Reaming of the canal was required before the successful placement of three nails in the unreamed group because of canal/nail diameter mismatch.

CONCLUSIONS

Unreamed femoral intramedullary nailing involves fewer steps and is significantly faster with less intraoperative blood loss than reamed intramedullary nailing. The unreamed technique, however, was associated with a higher incidence of perioperative complications, although the difference was not statistically significant (p = 0.5).

Sepsis and osteomyelitis about the ankle joint

Sepsis and osteomyelitis about the ankle joint present a challenging clinical problem. Osteomyelitis usually follows open fracture of the distal tibia, often with a pilon fracture component. This article outlines the prevention of osteomyelitis in these difficult fractures. Treatment of subsequent osteomyelitis and sepsis, including the authors' experiences, is discussed. Septic ankle arthritis can occur hematogenously. In some patients, the optimal treatment for concomitant osteomyelitis and sepsis is a below knee amputation.

Mucormycosis of the tibia: a case report and review of the literature

Mucormycosis is an uncommon but highly aggressive fungal infection most commonly occurring in hosts who are immunologically predisposed to infection. Only seven previously documented cases of tibial osteomyelitis attributable to Mucorales infection exist in the literature. An unusual case is reported of mucormycosis osteomyelitis developing in a patient who was immunocompromised after routine tibial Steinmann pin placement for the application of traction. Surgical debridement and amphotericin B were not sufficient to control the infection, and the patient subsequently underwent above-knee amputation. To the authors' knowledge this is the first description of mucormycosis causing osteomyelitis as a result of Steinmann pin tract infection.