Event-free survival by residual cancer burden with pembrolizumab in early-stage TNBC: exploratory analysis from KEYNOTE-522

BACKGROUND

KEYNOTE-522 demonstrated statistically significant improvements in pathological complete response (pCR) with neoadjuvant pembrolizumab plus chemotherapy and event-free survival (EFS) with neoadjuvant pembrolizumab plus chemotherapy followed by adjuvant pembrolizumab in patients with high-risk, early-stage triple-negative breast cancer (TNBC). Prior studies have shown the prognostic value of the residual cancer burden (RCB) index to quantify the extent of residual disease after neoadjuvant chemotherapy. In this preplanned exploratory analysis, we assessed RCB distribution and EFS within RCB categories by treatment group.

PATIENTS AND METHODS

A total of 1174 patients with stage T1c/N1-2 or T2-4/N0-2 TNBC were randomized 2 : 1 to pembrolizumab 200 mg or placebo every 3 weeks given with four cycles of paclitaxel + carboplatin, followed by four cycles of doxorubicin or epirubicin + cyclophosphamide. After surgery, patients received pembrolizumab or placebo for nine cycles or until recurrence or unacceptable toxicity. Primary endpoints are pCR and EFS. RCB is a prespecified exploratory endpoint. The association between EFS and RCB was assessed using a Cox regression model.

RESULTS

Pembrolizumab shifted patients into lower RCB categories across the entire spectrum compared with placebo. There were more patients in the pembrolizumab group with RCB-0 (pCR), and fewer patients in the pembrolizumab group with RCB-1, RCB-2, and RCB-3. The corresponding hazard ratios (95% confidence intervals) for EFS were 0.70 (0.38-1.31), 0.92 (0.39-2.20), 0.52 (0.32-0.82), and 1.24 (0.69-2.23). The most common first EFS events were distant recurrences, with fewer in the pembrolizumab group across all RCB categories. Among patients with RCB-0/1, more than half [21/38 (55.3%)] of all events were central nervous system recurrences, with 13/22 (59.1%) in the pembrolizumab group and 8/16 (50.0%) in the placebo group.

CONCLUSIONS

Addition of pembrolizumab to chemotherapy resulted in fewer EFS events in the RCB-0, RCB-1, and RCB-2 categories, with the greatest benefit in RCB-2. These findings demonstrate that pembrolizumab not only increased pCR rates, but also improved EFS among most patients who do not have a pCR.

Overall survival in the OlympiA phase III trial of adjuvant olaparib in patients with germline pathogenic variants in BRCA1/2 and high risk, early breast cancer

BACKGROUND

The randomized, double-blind OlympiA trial compared 1 year of the oral poly(adenosine diphosphate-ribose) polymerase inhibitor, olaparib, to matching placebo as adjuvant therapy for patients with pathogenic or likely pathogenic variants in germline BRCA1 or BRCA2 (gBRCA1/2pv) and high-risk, human epidermal growth factor receptor 2-negative, early breast cancer (EBC). The first pre-specified interim analysis (IA) previously demonstrated statistically significant improvement in invasive disease-free survival (IDFS) and distant disease-free survival (DDFS). The olaparib group had fewer deaths than the placebo group, but the difference did not reach statistical significance for overall survival (OS). We now report the pre-specified second IA of OS with updates of IDFS, DDFS, and safety.

PATIENTS AND METHODS

One thousand eight hundred and thirty-six patients were randomly assigned to olaparib or placebo following (neo)adjuvant chemotherapy, surgery, and radiation therapy if indicated. Endocrine therapy was given concurrently with study medication for hormone receptor-positive cancers. Statistical significance for OS at this IA required P < 0.015.

RESULTS

With a median follow-up of 3.5 years, the second IA of OS demonstrated significant improvement in the olaparib group relative to the placebo group [hazard ratio 0.68; 98.5% confidence interval (CI) 0.47-0.97; P = 0.009]. Four-year OS was 89.8% in the olaparib group and 86.4% in the placebo group (Δ 3.4%, 95% CI -0.1% to 6.8%). Four-year IDFS for the olaparib group versus placebo group was 82.7% versus 75.4% (Δ 7.3%, 95% CI 3.0% to 11.5%) and 4-year DDFS was 86.5% versus 79.1% (Δ 7.4%, 95% CI 3.6% to 11.3%), respectively. Subset analyses for OS, IDFS, and DDFS demonstrated benefit across major subgroups. No new safety signals were identified including no new cases of acute myeloid leukemia or myelodysplastic syndrome.

CONCLUSION

With 3.5 years of median follow-up, OlympiA demonstrates statistically significant improvement in OS with adjuvant olaparib compared with placebo for gBRCA1/2pv-associated EBC and maintained improvements in the previously reported, statistically significant endpoints of IDFS and DDFS with no new safety signals.

Prognostic role of serum thymidine kinase 1 kinetics during neoadjuvant chemotherapy for early breast cancer

Background

Emerging data support the use of thymidine kinase 1 (TK1) activity as a prognostic marker and for monitoring of response in breast cancer (BC). The long-term prognostic value of TK1 kinetics during neoadjuvant chemotherapy is unclear, which this study aimed to elucidate.

Methods

Material from patients enrolled to the single-arm prospective PROMIX trial of neoadjuvant epirubicin, docetaxel and bevacizumab for early BC was used. Ki67 in baseline biopsies was assessed both centrally and by automated digital imaging analysis. TK1 activity was measured from blood samples obtained at baseline and following two cycles of chemotherapy. The associations of TK1 and its kinetics as well as Ki67 with event-free survival and overall survival (OS) were evaluated using multivariable Cox regression models.

Results

Central Ki67 counting had excellent correlation with the results of digital image analysis (r = 0.814), but not with the diagnostic samples (r = 0.234), while it was independently prognostic for worse OS [adjusted hazard ratio (HR_adj) = 2.72, 95% confidence interval (CI) 1.19-6.21, P = 0.02]. Greater increase in TK1 activity after two cycles of chemotherapy resulted in improved event-free survival (HR_adj = 0.50, 95% CI 0.26-0.97, P = 0.04) and OS (HR_adj = 0.46, 95% CI 0.95, P = 0.04). There was significant interaction between the prognostic value of TK1 kinetics and Ki67 (p_interaction 0.04).

Conclusion

Serial measurement of serum TK1 activity during neoadjuvant chemotherapy provides long-term prognostic information in BC patients. The ease of obtaining serial samples for TK1 assessment motivates further evaluation in larger studies.

•

This is a correlative analysis of a prospective phase II study on neoadjuvant chemotherapy for breast cancer.

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Serial measurement of serum TK1 activity during treatment provides independent long-term prognostic information.

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We demonstrate the validity and clinical utility of both central and automated image analysis-based Ki67 assessment.

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Finally, we explore the biologic correlations between TK1 and Ki67.

The EMA review of trastuzumab emtansine (T-DM1) for the adjuvant treatment of adult patients with HER2-positive early breast cancer

Trastuzumab emtansine (T-DM1) is an antibody-drug conjugate of trastuzumab [a monoclonal antibody against human epidermal growth factor receptor 2 (HER2)] and DM1 (an inhibitor of tubulin polymerisation). It was initially approved in the European Union for the treatment of adult patients with HER2-positive unresectable locally advanced or metastatic breast cancer (BC) who had previously received trastuzumab and taxanes. On 18 December 2019, a variation of the marketing authorisation was approved extending this use to the adjuvant therapy of adult patients with HER2-positive early BC who have residual invasive disease in the breast and/or lymph nodes after neoadjuvant taxane-based and HER2-targeted therapy. A phase III randomised, multicentre, open-label trial compared T-DM1 with trastuzumab as adjuvant therapy in patients with HER2-positive early BC who had received preoperative chemotherapy and HER2-targeted therapy followed by surgery, with a finding of invasive residual disease in the breast and/or axillary lymph nodes. The study met its primary endpoint by showing an increased 3-year invasive disease-free survival rate in the T-DM1 arm (88.3%) compared with the trastuzumab arm (77.0%), with an unstratified hazard ratio of 0.50 (95% confidence interval: 0.39-0.64). There was a higher incidence of hepatotoxicity (37.3% versus 10.6%), thrombocytopenia (28.5% versus 2.4%), peripheral neuropathy (32.3% versus 16.9%), haemorrhage (29.2% versus 9.6%) and pulmonary toxicity (2.8% versus 0.8%) in the T-DM1 arm compared with the control arm. The aim of this manuscript was to summarise the scientific review of the application leading to regulatory approval of this additional indication in the European Union.

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T-DM1 was approved for the adjuvant therapy of HER2+ early BC not in pathological complete response after taxanes + anti-HER2 neoadjuvant therapy.

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A phase III randomised trial revealed an increased 3-year invasive disease-free survival rate in patients receiving T-DM1 compared with trastuzumab.

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Patients receiving T-DM1 experienced more hepatotoxicity, thrombocytopenia, neuropathy, bleeding and lung toxicity.

Approaches to management of cardiovascular morbidity in adult cancer patients - cross-sectional survey among cardio-oncology experts

Background

In cardio-oncology, a range of clinical dilemmas can be identified where high-quality evidence for management is still lacking. The aim of this project was to study clinical practices and expert approaches to several clinical cardio-oncological dilemmas regarding prediction, prevention and treatment of cardiovascular disease in adult cancer patients.

Methods

A cross-sectional online survey was sent out to internationally renowned experts in the field of cardio-oncology. Participants were selected based on being first or last authors of papers in the field of cardio-oncology, or principal investigators to trials in this field.

Results

Topics discussed include, among others, the use of biomarkers for subclinical cardiovascular toxicity, approaches towards primary prevention and follow-up with medication and life-style recommendations, and management of fluoropyrimidine-vasospasm, QTc-prolongation and asymptomatic declines in left ventricular ejection fraction.

Conclusion

The answers provided in this survey have shed light on expert-based practices in cardio-oncologic dilemmas. Attitudes towards, as well as discrepancies in those dilemmas are presented. Existing discrepancies clearly indicate the need for generation of high-quality data that allows for more evidence-based recommendations in the future.

Dose tailoring of adjuvant chemotherapy for breast cancer based on hematologic toxicities: further results from the prospective PANTHER study with focus on obese patients

Background

Adjuvant chemotherapy (ACT) for breast cancer improves relapse-free survival (BCRFS) and overall survival. Differences in terms of efficacy and toxicity could partly be explained by the significant interpatient variability in pharmacokinetics which cannot be captured by dosing according to body surface area. Consequently, tailored dosing was prospectively evaluated in the PANTHER trial.

Patients and methods

PANTHER is a multicenter, open-label, randomized phase III trial which compared tailored, dose-dense (DD) epirubicin/cyclophosphamide (E/C) and tailored docetaxel (D) (tDD) with standard interval 5-fluorouracil/E/C and D. The primary end point was BCRFS and the primary efficacy analysis has been previously published. In this secondary analysis, we aimed to retrospectively explore the concept of dose tailoring. Our two hypotheses were that BCRFS would not vary depending on the cumulative administered epirubicin dose; and that dose tailoring would lead to appropriate dosing and improved outcomes for obese patients, who are known to have worse prognosis and increased toxicity after DD ACT.

Results

Patients treated with tDD had similar BCRFS regardless of the cumulative epirubicin dose (P = 0.495), while obese patients in this group [body mass index (BMI) ≥30] had improved BCRFS compared with nonobese ones (BMI <30) [hazard ratio (HR) = 0.51, 95% confidence interval (CI) 0.30-0.89, P = 0.02]. Moreover, tDD was associated with improved BCRFS compared with standard treatment only in obese patients (HR = 0.49, 95% CI 0.26-0.90, P = 0.022) but not in nonobese ones (HR = 0.79, 95% CI 0.60-1.04, P = 0.089). The differences were not formally statistically significant (P for interaction 0.175). There were no differences in terms of toxicity across the epirubicin dose levels or the BMI groups.

Conclusions

Dose tailoring is a feasible strategy that can potentially improve outcomes in obese patients without increasing toxicity and should be pursued in further clinical studies.

ClinicalTrials.gov identifier

NCT00798070.

Avoiding over- and undertreatment in patients with resected node-positive breast cancer with the use of gene expression signatures: are we there yet?

Prediction of benefit from adjuvant chemotherapy following resection of early breast cancer and, as a result, proper selection of candidates remains an elusive goal since the relative magnitude of benefit is the same regardless of the presence of clinicopathologic factors. Multiple studies, including randomized trials, establish the role of certain gene expression signatures in node-negative disease since they predict the risk of breast cancer relapse being so low that adjuvant chemotherapy can be omitted. In contrast, more limited data are available in higher risk, node-positive breast cancer patients, making the exclusion of adjuvant chemotherapy potentially hazardous. 'Prospective-retrospective' studies and limited prospective data show that several signatures, namely Oncotype Dx, MammaPrint, Prosigna, EndoPredict and Breast Cancer Index, select with different levels of success node-positive patients at very low risk for distant recurrence despite not receiving chemotherapy, although the long-term follow-up is still awaited. Pending, however the publication of the results from ongoing randomized studies which enroll patients with node-positive disease, major caution is warranted. Improper use and misinterpretation of these transcriptomic profiles can lead to undertreatment and exposure of patients to unnecessary risks resulting in increased breast cancer mortality for patients with axillary node-positive disease. With this review we critically discuss the available data on gene expression signatures that are used in clinical practice and offer practical recommendations regarding the management of patients with ER-positive, human epidermal growth factor receptor 2 (HER2)-negative, node-positive breast cancer.

Abstract P2-07-05: A clinical calculator to predict disease outcomes in women with hormone receptor-positive advanced stage breast cancer treated with first-line endocrine therapy

Purpose: Endocrine based therapy is an effective strategy to manage hormone receptor-positive, human epidermal growth factor receptor 2-negative (HR+/HER2-) advanced breast cancer (ABC). However, nearly all patients exhibit/develop either de novo or acquired resistance. While prognostic biomarkers of endocrine responsiveness are well established for the adjuvant treatment in ER+ breast cancer, less is known regarding prognostic and predictive biomarkers of response in the first line ABC setting. We sought to develop a clinical calculator based on clinical criteria for predicting progression-free survival (PFS) and overall survival (OS) of women with HR+/HER2- ABC who will be receiving endocrine monotherapy as first-line treatment for ABC.

Methods: The development of the clinical calculator will be based on data from modern clinical trials in women with HR+/HER2- ABC. The studies to be included in the final analyses are given in Table 1. The control arm data from trials1-6 will form the training dataset (N = 1,223) and be used to construct the clinical prediction models. Variables considered include age, race, ECOG status, disease measurability, body mass index, disease-free interval, number of metastatic sites, locations of metastatic sites, prior endocrine therapy, and prior chemotherapy. Missing values will be imputed using single imputation with all variables included in the imputation model. For continuous variables, restricted cubic splines will be used to determine if non-linear effects may be more appropriate. The Lasso regression will be used as a variable selection technique to reduce the dimensionality of covariates; initially all pairwise interactions will be included in the model. Following Lasso regression, the multivariable Cox proportional hazards models will be constructed for PFS and OS including only variables retained in Lasso. The final model will be internally validated for discrimination and calibration using 10-fold cross-validation. External validation will be performed using control arm data from EGF 30008 (N = 536).

Results: To date, control arm data from four trials (trials 1-4) have been received. The preliminary results presented here are based on pooled data from C40503 and LEA, for which data elements have been harmonized. Models for predicting PFS and OS have good calibration and are associated with bias-corrected C-indices of 0.61 and 0.65, respectively. These models will be updated using pooled data from trials 1-6.

Conclusions: Our preliminary data demonstrate that clinical calculators based on baseline clinical factors can provide accurate prediction of PFS and OS in patients with HR+/HER2- ABC treated with first-line ET. If validated, these tools may be used for risk stratification in future clinical trials and to identify patients who may require more or less aggressive therapy.

Table 1:Studies to be includedTrial NumberTrial NameTrial PISample Size in Control Arm1C40503Maura Dickler152 (letrozole)2LEAMiguel Martin179 (letrozole)3FACTJonas Bergh188 (anastrozole)4FALCONJohn Robertson194 (anastrozole)5S0226Rita Mehta345 (anastrozole)6MONARCH 3Matthew Goetz165 (nonsteroidal AI)7EGF 30008Stephen Johnston536 (letrozole)

Citation Format: Polley M-YC, Dickler MN, Johnston S, Goetz MP, de la Haba J, Loibl S, Mehta RS, Bergh J, Roberston J, Barlow W, Liu H, Tenner K, Martin M. A clinical calculator to predict disease outcomes in women with hormone receptor-positive advanced stage breast cancer treated with first-line endocrine therapy [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 P2-07-05.

Abstract P2-08-25: PD-L1 expression at the protein and RNA levels as prognostic factor in early breast cancer

Introduction:PD-L1 expression as assessed by immunohistochemistry (IHC) is a clinically relevant biomarker in certain malignancies such as lung cancer, since it selects appropriate candidates for PD-1 blockade. Since these agents are under evaluation for breast cancer, discovering and validating predictive biomarkers is of outmost importance. However, the clinical utility of PD-L1 expression in breast cancer is questionable, in light of prior inconclusive reports which have used various IHC antibodies, scoring methods and cut-offs. Moreover, there are only few previous studies on comparing IHC and RNA data at the same cohort, not limited to a single subtype.Methods: Our cohort is derived from a nested case-control study consisting of 619 patients diagnosed with primary breast cancer between 1997-2005 in Stockholm health care region.Tissue microarrays from epithelial tumor areas have been constructed using duplicate cores from primary tumors and tissue sections were used for IHC with PD-L1 (Ventana; clone SP263) antibody. Positivity was defined as the presence of any single cell with membranous expression of PD-L1. Gene expression profiling was performed using DNA microarrays (GSE48091). Data on clinical and pathological tumor characteristics, survival, loco-regional and systemic treatments, and follow-up have been collected. Correlations between transcript and protein expression levels were estimated using Mann-Whitney test, while survival analyses were conducted using the Kaplan-Meier method. Furthermore, we associated an immune gene module score (IMS) –whose predictive power in neoadjuvant and metastatic settings has been previously demonstrated- with PD-L1 transcript levels by using Spearman's rank correlation coefficient.Results: IHC data were available for 87.4% (541/619) of the patients. PD-L1 was expressed on tumor cells in 9.6% (52/541) of the patients while it was also expressed by immune cells in 23.1% (125/541) of the patients. Any PD-L1 expression (tumor and/or immune cells) was noted in 24.2% (131/541) of the patients. PD-L1 transcript levels and protein expression on tumor, immune and/or both cell types were statistically significantly associated (p&lt; 2.2e-16). In the whole cohort, patients with higher PD-L1 transcript levels were associated with better breast cancer-specific survival(BCSS) (p=0.0061). In addition, within intrinsic subtypes, high PD-L1 transcript expression was significantly associated with better BCSS only in basal-like (p=0.019) disease. There was no significant correlation between improved BCCS and PD-L1 protein expression by tumor (p=0.13), immune (p=0.12) or both types of cells (p=0.2). PD-L1 transcript levels were also positively associated with the IMS (Spearman's rho = 0.85). Conclusions:The prognostic value of PD-L IHC expression in breast cancer remains inconclusive. However, RNA expression of PD-L1 may be more informative as a prognostic factor, especially in basal-like disease and merits further validation.

Citation Format: Zerdes I, Sifakis E, Matikas A, Tobin NP, Charlotte R, Rassidakis GZ, Bergh J, Foukakis T. PD-L1 expression at the protein and RNA levels as prognostic factor in early breast cancer [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 P2-08-25.

Abstract P2-08-05: Withdrawn

This abstract was withdrawn by the authors.

Citation Format: Jaraj D, Ahlgren J, Arnesson L-G, Einbeigi Z, Höijer J, Klintman M, Malmström P, Vikhe Patil E, Sund M, Fredriksson I, Bergh J, Pettersson A. Withdrawn [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 P2-08-05.

Abstract P6-21-01: Xentuzumab (BI 836845), an insulin-like growth factor (IGF)-neutralizing antibody (Ab), combined with exemestane and everolimus in hormone receptor-positive (HR+) locally advanced/metastatic breast cancer (LA/mBC): Randomized phase 2 results

Background:

Xentuzumab (Xen), an IGF-1/-2-neutralizing Ab, binds IGF-1 and IGF-2, inhibits their growth-promoting signaling, and suppresses AKT activation by everolimus (Ev). This Phase 1b/2 trial evaluates Xen in combination with Ev and exemestane (Ex) in HR+/HER2− LA/mBC.

Methods:

The two-arm, open-label, randomized Phase 2 part enrolled female patients (pts) with HR+/HER2− LA/mBC not amenable to curative therapy and refractory to nonsteroidal aromatase inhibitors. Pts were randomized (1:1) to: oral Ev (10 mg/d) + Ex (25 mg/d); or Xen (1000 mg/wk iv) + Ev (10 mg/d) + Ex (25 mg/d). Randomization was stratified by visceral metastases (VM; Y vs N). Treatment continued in 28-day cycles until progression, intolerable adverse events (AEs) or other reasons for discontinuation. Primary endpoint was progression-free survival (PFS), with an interim futility analysis incorporated in the study design.

Results:

Following the results of the interim analysis, the Data Monitoring Committee (DMC) advised early termination of the trial and discontinuation of Xen treatment. Thus, Xen treatment exposure time and time-to-event data for the Xen+Ev+Ex arm are limited. Of the 139 women treated (Xen+Ev+Ex 70; Ev+Ex 69), 77% had VM. Median PFS was not significantly different between arms (Xen+Ev+Ex vs Ev+Ex, 7.3 vs 5.6 months; HR [95% CI] 0.97 [0.57–1.65]; p=0.91). In a pre-specified subgroup of pts without VM, Xen+Ev+Ex showed favorable PFS vs Ev+Ex (HR 0.21 [0.05–0.98]; Pint=0.0141). Pint values &lt;0.05 were also observed for ad hoc subgroups: measurable disease at baseline; bone-only metastases. Rates of total AEs/grade ≥3 AEs/drug-related AEs were similar between arms (Xen+Ev+Ex, 100/60/96%; Ev+Ex, 99/58/96%). The most common AEs overall were diarrhea (44 vs 33%), mucosal inflammation (39 vs 32%), rash (34 vs 33%) and stomatitis (34 vs 38%); most were grade 1/2. 6% of pts in the Xen+Ev+Ex arm discontinued Xen due to AEs. Ev/Ex discontinuations (Xen+Ev+Ex vs Ev+Ex) occurred in 13/6% vs 23/6%; 1 pt each in the Xen+Ev+Ex arm died from pneumonitis and liver injury and 1 pt each in the Ev+Ex arm died from Burkitt's lymphoma, acute kidney injury and metastases to the peritoneum.

Conclusion:

In the overall population, PFS did not improve with the addition of Xen to Ev+Ex and the trial was therefore discontinued early. Nevertheless, a favorable signal was observed in the pre-specified subgroup of pts without VM when treated with Xen+Ev+Ex, which warrants additional investigation. The safety profile was comparable between arms.

Citation Format: Crown J, Sablin M-P, Cortés J, Bergh J, Im S-A, Lu Y-S, Martínez N, Neven P, Lee KS, Morales S, Pérez-Fidalgo JA, Adamson D, Goncalves A, Prat A, Jerusalem G, Schlieker L, Espadero R-M, Bogenrieder T, Chin-Lun Huang D, Schmid P. Xentuzumab (BI 836845), an insulin-like growth factor (IGF)-neutralizing antibody (Ab), combined with exemestane and everolimus in hormone receptor-positive (HR+) locally advanced/metastatic breast cancer (LA/mBC): Randomized phase 2 results [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 P6-21-01.

Abstract P1-13-03: Grade of leukopenia predicts treatment effect in early breast cancer in patients treated with tailored epirubicin/cyclophosphamide chemotherapy

Background: Body surface based dosing of chemotherapy is unreliable due to marked inter-individual variations in pharmacokinetics/-dynamics. Multiple retrospective studies have demonstrated that hematological toxicity could be a surrogate marker for efficacy of chemotherapy. The SBG 2000-1 trial was the first adjuvant randomized trial designed to compare the same drugs and number of courses of individually dosed chemotherapy based on grade of toxicity vs. standard dosed chemotherapy in early breast cancer. The aim was to study the relations between dose of chemotherapy, leukopenia nadir grade and prognosis.

Methods: Women (n=1452) in Sweden and Denmark with early breast cancer aged 18-60 years, received the first cycle at a standard dose of FEC (fluorouracil 600 mg/m2, epirubicin 60 mg/m2, cyclophosphamide 600 mg/m2). Patients (n=1052) with nadir leukopenia grade 0-2 after first cycle were randomized between either 6 tailored FEC with increased doses of epirubicin and cyclophosphamide aimed at achieving grade 3 leukopenia or treatment with 6 standard FEC. Patients with nadir leukopenia grade 3-4 represented a second control group (registered group) treated with 6 standard FEC. Dose escalation did not significantly improve 10 year distant disease-free survival (HR 0.87, p=0.32, Eur J Cancer 13:79-86, 2018). In this report grade of leukopenia at course 3 (after final escalation) was assessed as a prognostic marker in a Cox regression model adjusted for chemotherapy doses.

Results: Eight-year distant disease-free survival (DDFS) was 73%, 77%, 78% and 83% for patients with leucocyte nadir grade 0, 1, 2 and 3-4 and overall survival (OS) 77%, 81%, 81% and 86% respectively. Cox regression analysis of leucocyte grade and DDFS showed a statistically significant hazard ratio (HR) of 0.84 (CI 0.74-0.96, p=0.008) per grade of leukopenia, with non-significant trend for OS (HR 0.88, CI 0.76-1.02, p=0.066). The correlations with DDFS and cumulative dose of epirubicin and cyclophosphamide were not significant with hazard ratios of 0.96 (0.91-1.014 p=0.15) and 1.002 (1.00-1.005 p=0.21) per mg cumulative dose per meter squared. Patients with grade 3 tumors had a significantly stronger impact of leukopenia on DDFS (HR 0.76, 95% CI 0.65-0.90 p&lt;0.001) and a test of interaction between the prognostic effect of grade and leukopenia was significant (p=0.026).

Conclusions: The grade of leukopenia predicts the individual treatment effect better than chemotherapy doses. The results of this prospective trial are in agreement with previous retrospective studies indicating that chemotherapy induced leukopenia is predictive for outcome in early breast cancer. Dose dependent toxicity should be monitored for optimal adjustment of the dosage of chemotherapy.

Citation Format: Lindman H, Poikonen-Saksela P, Ahlgren J, Andersson M, Bergh J, Blomqvist C. Grade of leukopenia predicts treatment effect in early breast cancer in patients treated with tailored epirubicin/cyclophosphamide chemotherapy [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 P1-13-03.

Abstract P2-03-07: Digital image analysis of Ki67 in hot spots is superior to alternative proliferation associated markers in breast cancer

INTRODUCTION

Proliferative activity is one of the most important prognostic parameters in cancer. During the pathological examination of breast tumors, it is routinely evaluated by a count of the number of mitoses. Adding immunohistochemical stains of the nuclear protein Ki67 provides extra prognostic and predictive information. However, the currently used methods for both of these evaluations battle imperfections, primarily in reproducibility. In this study, we make an equally broad and detailed evaluation of mitoses, Ki67 and the more recently described Phosphohistone H3 (PHH3) in primary breast cancer using digital image analysis (DIA). Furthermore, we aim to investigate the prognostic and predictive value of proliferation-associated biomarkers in breast cancer stromal cells in relation to patient outcome.

MATERIALS AND METHODS

Two cohorts of primary breast cancer specimens (total n=297) with clinicopathological data including &gt;10 years survival data, were sectioned and stained for Ki67, PHH3 and pancytokeratin (CKMNF116) and all glass slides were digitally scanned at x20. The DIA software used was the Visiopharm Integrator System (VIS) by Visiopharm A/S, Hoersholm, Denmark. VIS operates by a 'digital fusion' method that automatically excludes non-epithelial tissue restricting the analysis of the biomarkers (Ki67 and PHH3) to CKMNF116 positive cells. Both manual and DIA scores were compared for sensitivity and specificity for the gene expression based Luminal B versus A subtype, for high versus low transcriptomic grade as well as for their prognostic value in terms of Cox regression hazard ratios and breast cancer specific and overall survival. Further, we investigated whether the expression of Ki67 in the tumors' hot spots, invasive edges or as an average across all regions should be assessed for maximum power in relation to these outcomes. In addition, by inverting the DIA algorithm run by the VIS on the same cohorts, the expression of Ki67 and PHH3 was evaluated in the tumor stromal compartment.

RESULTS

Regardless of tumor region, DIA of Ki67 outperformed the other markers in sensitivity and specificity for gene expression subtypes and transcriptomic grade. In contrast to mitotic counts, tumors with high expression of Ki67 as defined by DIA, had significantly increased hazard ratio for all-cause mortality within 10 years from diagnosis. DIA of Ki67 was superior to manual Ki67 and PHH3 evaluations as well as to mitotic counts in terms of separation of patients with poor versus relatively good survival. Finally, we replaced the manual mitotic counts with DIA of Ki67 in hot spots as the marker for proliferation when determining histological grade. This increased the differences in estimated mean overall survival between the highest and lowest grades and added significantly more prognostic information to the classic Nottingham histological grade.

CONCLUSIONS

We conclude that digital image analysis of Ki67 in hot spots should be suggested as the marker of choice for proliferative activity in breast cancer.

Citation Format: Robertson S, Stålhammar G, Wedlund L, Gholizadeh S, Lippert M, Rantaleinen M, Bergh J, Hartman J. Digital image analysis of Ki67 in hot spots is superior to alternative proliferation associated markers in breast cancer [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 P2-03-07.

Abstract P4-09-08: A targeted breast cancer radiosensitivity gene expression panel

Background: A majority of patients with early breast cancer is operated with breast conserving surgery (BCS) and adjuvant radiotherapy (RT) is administered to prevent ipsilateral breast tumor recurrence (IBTR), including a new ipsilateral cancer. The EBCTCG meta-analysis showed a majority of patients treated with surgery only to be recurrence free at 10 years, and more than 10% to suffer an IBTR despite RT, thus implying considerable over- and under treatment. A wide range of prognosticators, including multigene tests, are well established, but we lack predictive factors for RT, which is the aim in the present study.

Patients and methods: Fresh frozen tissue from 340 patients operated with BCS with or without RT and with or without IBTR was collected (without IBTR N=196, with IBTR n=144). Patients were stratified according to estrogen receptor (ER) status and RT, and divided into a training cohort (N=172) and a validation cohort (N=168). The training cohort was analyzed with whole transcriptome analysis (Illumina HT12 v4) and top discriminating genes for IBTR (N=155) were selected based on a random forest machine learning algorithm with recursive feature elimination and cross-validation. Further, genes described in the literature as associated with radioresistance were included in the panel to a total of 248 genes. A custom nCounter (Nanostring Technologies) gene expression panel was designed and both the training and validation cohorts were analyzed with the custom panel. Single-sample classifiers using a k-top scoring pairs algorithm were trained in the training cohort and validated in the validation cohort. Area under the curve (AUC) with a receiver operator characteristics (ROC) analysis were calculated and p-values were calculated with a log-rank test. All calculations were done using the R statistical environment.

Results: Our classifiers were prognostic for IBTR in the validation cohort among ER+ patients given RT (AUC 0.67, p=0.005), ER+ patients not given RT (AUC=0.89, p=0.015) and ER- patients given RT (AUC=0.78, p&lt;0.001), while the number of ER- patients not given RT was too small for subgroup analysis (N=4). We also created a sequential algorithm were a first classifier was applied to test the risk of IBTR without RT. If low, the tumor was classified as “surgery only”. If classified as high, a second classifier was applied to test the risk of recurrence when given RT. If the risk was predicted low after RT, the tumor was classified as “radiosensitive”. If high, the tumor was classified as “radioresistant”. Among ER+ patients in the validation cohort, the “radiosensitive” tumors had an excellent effect of RT (p&lt;0.001), the “radioresistant” had no effect of RT (p=0.4) and a very high risk of recurrence (55% at 10 years). The tumors predicted as “surgery only” had no effect of RT (p=0.4), and a lower risk of recurrence than the “radioresistant” patients (25% at 10 years).

Conclusions: Our targeted radiosensitivity gene expression panel could identify patients of high or low risk of LR, with or without RT. The most promising was however that it seems as the panel could be used as a predictive marker, i.e., finding patients that do, or do not, respond to RT. Further refinement and testing of the panel and models is ongoing.

Citation Format: Sjöström M, Staaf J, Edén P, Wärnberg F, Bergh J, Malmström P, Fernö M, Niméus E, Fredriksson I. A targeted breast cancer radiosensitivity gene expression panel [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 P4-09-08.

Research needs in breast cancer

New research questions emerge as medical needs continue to evolve and as we improve our understanding of cancer biology and treatment of malignancies. Although significant advances have been made in some areas of breast cancer research resulting in improvements in therapies and outcomes over the last few decades, other areas have not benefited to the same degree and we continue to have many gaps in our knowledge. This article summarizes the 12 short and medium-term clinical research needs in breast cancer deemed as priorities in 2016 by a panel of experts, in an attempt to focus and accelerate future research in the most needed areas: (i) de-escalate breast cancer therapies in early breast cancer without sacrificing outcomes; (ii) explore optimal adjuvant treatment durations; (iii) develop better tools and strategies to identify patients with genetic predisposition; (iv) improve care in young patients with breast cancer; (v) develop tools to speed up drug development in biomarker-defined populations; (vi) identify and validate targets that mediate resistance to chemotherapy, endocrine therapy and anti-HER2 therapies; (vii) evaluate the efficacy of local-regional treatments for metastatic disease; (viii) better define the optimal sequence of treatments in the metastatic setting; (ix) evaluate the clinical impact of intra-patient heterogeneity (intra-tumor, inter-tumor and inter-lesion heterogeneity); (x) better understand the biology and identify new targets in triple-negative breast cancer; (xi) better understand immune surveillance in breast cancer and further develop immunotherapies; and (xii) increase survivorship research efforts including supportive care and quality of life.

Phosphorus and nitrogen co-limitation of forest ground vegetation under elevated anthropogenic nitrogen deposition

Plant growth in northern forest ecosystems is considered to be primarily nitrogen limited. Nitrogen deposition is predicted to change this towards co-limitation/limitation by other nutrients (e.g., phosphorus), although evidence of such stoichiometric effects is scarce. We utilized two forest fertilization experiments in southern Sweden to analyze single and combined effects of nitrogen and phosphorus on the productivity, composition, and diversity of the ground vegetation. Our results indicate that the productivity of forest ground vegetation in southern Sweden is co-limited by nitrogen and phosphorus. Additionally, the combined effect of nitrogen and phosphorus on the productivity was larger than when applied solely. No effects on species richness of any of these two nutrients were observed when applied separately, while applied in combination, they increased species richness and changed species composition, mainly by promoting more mesotrophic species. All these effects, however, occurred only for the vascular plants and not for bryophytes. The tree layer in a forest has a profound impact on the productivity and diversity of the ground vegetation by competing for both light and nutrients. This was confirmed in our study where a combination of nitrogen and high tree basal area reduced cover of the ground vegetation compared to all the other treatments where basal area was lower after stand thinning. During the past decades, nitrogen deposition may have further increased this competition from the trees for phosphorus and gradually reduced ground vegetation diversity. Phosphorus limitation induced by nitrogen deposition may, thus, contribute to ongoing changes in forest ground vegetation.

De-escalating and escalating treatments for early-stage breast cancer: the St. Gallen International Expert Consensus Conference on the Primary Therapy of Early Breast Cancer 2017

The 15th St. Gallen International Breast Cancer Conference 2017 in Vienna, Austria reviewed substantial new evidence on loco-regional and systemic therapies for early breast cancer. Treatments were assessed in light of their intensity, duration and side-effects, seeking where appropriate to escalate or de-escalate therapies based on likely benefits as predicted by tumor stage and tumor biology. The Panel favored several interventions that may reduce surgical morbidity, including acceptance of 2 mm margins for DCIS, the resection of residual cancer (but not baseline extent of cancer) in women undergoing neoadjuvant therapy, acceptance of sentinel node biopsy following neoadjuvant treatment of many patients, and the preference for neoadjuvant therapy in HER2 positive and triple-negative, stage II and III breast cancer. The Panel favored escalating radiation therapy with regional nodal irradiation in high-risk patients, while encouraging omission of boost in low-risk patients. The Panel endorsed gene expression signatures that permit avoidance of chemotherapy in many patients with ER positive breast cancer. For women with higher risk tumors, the Panel escalated recommendations for adjuvant endocrine treatment to include ovarian suppression in premenopausal women, and extended therapy for postmenopausal women. However, low-risk patients can avoid these treatments. Finally, the Panel recommended bisphosphonate use in postmenopausal women to prevent breast cancer recurrence. The Panel recognized that recommendations are not intended for all patients, but rather to address the clinical needs of the majority of common presentations. Individualization of adjuvant therapy means adjusting to the tumor characteristics, patient comorbidities and preferences, and managing constraints of treatment cost and access that may affect care in both the developed and developing world.

Abstract P6-01-04: Evolutionary analyses of matched primary and metastatic breast cancer reveal both linear and parallel progression with lack of axillary lymph node involvement

This abstract was withdrawn by the authors.

Abstract P1-07-16: Multi-level gene expression signatures provide significant prognostic information in metastatic breast cancer patients

Background: We have previously demonstrated how transcriptional pathway activity and the molecular subtypes of breast cancer metastases significantly influence patient post-relapse survival. Here we extend our analysis to determine whether the prognostic information provided by gene expression signatures in primary breast tumours is also relevant in the metastatic setting. Specifically, we test the research versions of the Genomic Grade Index (GGI), Mammaprint, Recurrence score (RS) and PAM50 gene signatures along with our own cell-cycle based classifier (CCS).

Methods: 287 patients with morphologically confirmed loco-regional or distant breast cancer relapse were enrolled in the Swedish multicenter TEX trial from December 2002 until June 2007. Of these, sufficient tumour RNA for gene expression profiling was obtained from metastatic tissue by fine needle aspiration from 111 patients (totalling 120 relapse biopsies). Gene signatures were applied as described in the original research articles and their relationship to short (1.5 year) and long-term (5 year) post-relapse survival was assessed using likelihood ratio, Kaplan-Meier and Cox regression analysis.

Results: As anticipated from an aggressive metastatic cohort, the majority of samples (&gt; 70%) were classified into intermediate or high risk groups by all signatures. In both short and long-term survival analysis only PAM50 provided statistically significant prognostic information (short: LRχ2 = 14.7, p = 0.005 and long: LRχ2 = 13.2, p = 0.010), with the cell cycle score signature displaying a prognostic trend in long-term survival only (LRχ2 = 5.2, p = 0.074). Kaplan-Meier curves and Cox regression analysis suggest that the strength of both signatures resides in their ability to select a group of low-risk patients with better long-term survival.

Conclusions: Our findings demonstrate the prognostic utility of the multi-level PAM50 and to a lesser extent, cell cycle score signatures in predicting survival of patients with metastatic breast cancer. Simpler binary gene expression signatures (GGI and Mammaprint) do not appear to capture the same prognostic information and as such may have limited utility in a metastatic setting.

Short and long term survival Likehood Ratios for five gene expression signatures in metastatic breast cancer Short term survival (1.5 year)Long term survival (5 year)Gene SignatureLRχ2P-valueLRχ2P-valueGGI1.30.2510.50.500Mammaprint1.70.1900.60.427RS3.90.1434.40.110CCS2.80.2425.20.074PAM5014.70.00513.20.010GGI: Genomic grade index; RS: Recurrence score; CCS: Cell cycle score

Citation Format: Tobin NP, Lundberg A, Lindström LS, Harrell JC, Egyhazi Brage S, Frostvik Stolt M, Einbeigi Z, Loman N, Malmberg M, Perou CM, Bergh J, Hatschek T. Multi-level gene expression signatures provide significant prognostic information in metastatic breast cancer patients [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 P1-07-16.

Abstract P2-03-03: Molecular differences between screen-detected and interval breast cancers are largely explained by PAM50 subtypes

Purpose:Interval breast cancer is of clinical interest as it exhibits an aggressive phenotype and evades detection by screening mammography. A comprehensive picture of somatic changes that drive tumors to become symptomatic in the screening interval can improve understanding of the biology underlying these aggressive tumors.

Experimental design:Initiated in April 2013, Clinical Sequencing of Cancer in Sweden (Clinseq) is a scientific and clinical platform for the genomic profiling of cancer. The breast cancer pilot study consisted of women diagnosed with breast cancer between 2001-2012 in the Stockholm/Gotland regions. A subset of 318 breast tumors were sequenced, of which 113 were screen-detected and were 60 interval cancers.We applied targeted deep-sequencing of cancer-related genes, low-pass whole-genome sequencing and RNA-sequencing technology to characterize somatic differences in the genomic and transcriptomic architecture by interval cancer status. Mammographic density and PAM50 molecular subtypes were considered.

Results:In the crude analyses, TP53, PPP1R3A, and KMT2B were significantly more frequently mutated in interval cancers than in screen-detected cancers. Acquired somatic copy number aberrations with a frequency difference of at least 15% between the two groups included gains in 17q23-q25.3 and losses in 16q24.2. Gene expression analysis identified 447 significantly differentially expressed genes, of which 120 were replicated in an independent microarray dataset. After adjusting for PAM50, most differences were no longer significant.

Conclusions: Molecular differences by interval cancer status were observed, but they were largely explained by PAM50 subtypes. This work offer new insights into the biological differences between the two tumor groups.

Translational relevance: Although screen-detected cancers are biologically distinct from interval cancers in terms of somatic mutations, copy number aberrations and gene expression, most of the differences are no longer significant after adjusting for breast cancer intrinsic subtypes (PAM50). We also show that the molecular differences appear to form a spectrum from less aggressive (screen-detected) to more aggressive (interval) manifestations of the disease, which can be characterized by PAM50 subtypes, namely, luminal A, luminal B, HER2-enriched and basal-like, in that order. This work clarifies the picture on what type of breast cancer we are likely to identify through population-based screening, and what type of cancer we are likely to miss. Current knowledge of PAM50 subtype-specific risk factors need to be expanded as our findings might influence how we screen women with a higher risk of basal-like breast cancer for example, beyond known risk groups BRCA1 mutation carriers and women of African-American descent.

Citation Format: Czene K, Ivansson E, Klevebring D, Tobin NP, Lindström LS, Holm J, Prochazka G, Hilliges C, Palmgren J, Törnberg S, Humphreys K, Hartman J, Frisell J, Rantalainen M, Lindberg J, Hall P, Bergh J, Grönberg H, Li J. Molecular differences between screen-detected and interval breast cancers are largely explained by PAM50 subtypes [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 P2-03-03.

Abstract P2-09-03: Long-term comparison of anastrozole versus tamoxifen: Results from LATTE/ATAC

Background: Previous reports from the Anastrozole Tamoxifen Alone or in Combination (ATAC) trial have shown significantly prolonged disease-free survival, lower rates of recurrence and distant recurrence, and reduced contralateral breast cancer in patients treated with anastrozole compared to tamoxifen (Cuzick et al., Lancet, 2010). Here, we compare the long-term effects of anastrozole versus tamoxifen in patients randomised to either monotherapy arm in the ATAC trial.

Methods: Postmenopausal women with hormone receptor positive breast cancer randomised to anastrozole or tamoxifen in the main ATAC trial were eligible for the LATTE observational study. The primary objective was to compare the long-term effects of tamoxifen and anastrozole on time to recurrence and death beyond 10 years after randomisation. Secondary objectives included time to distant recurrence, cancer-specific survival, new breast primaries, other cancers, fractures, and cardiac/cerebrovascular events. Cox proportional hazard methods were used to compute hazard ratios (95% CI) for recurrence from the time of last publication (10 years median follow-up).

Results: 2452 women from 11 countries were entered into the LATTE study. 40 women withdrew consent and 759 women died or had a recurrence within 10 years, which left 1653 women for analysis (838 anastrozole vs. 815 tamoxifen). A total of 118 breast events (69 anastrozole (8.2%) vs. 49 tamoxifen (6.0%)) were reported. No significant difference between the two treatment arms were observed (HR=1.36 (0.94-1.97), P=0.098). 57 women had a distant recurrence (33 (3.9%) vs. 24 (2.9%)), 41 reported a loco-regional recurrence (23 (2.7%) vs. 18 (2.2%)), and 26 contra-lateral breast cancer were recorded (17 (2.0%) vs. 9 (1.1%)). None of the treatment comparisons were statistically significant. 305 deaths were recorded (147 (17.5%) vs. 158 (19.4%)), of which 31 were due to breast cancer. Significantly fewer gynaecological cancers were recorded with anastrozole (7 vs. 16; OR=0.42 (0.15-1.09), P=0.05), but overall the effect on other cancers was not significant (54 (6.4%) vs. 64 (7.9%). Fractures, cardiovascular, and cerebrovascular events were evenly distributed between the treatment arms.

Conclusions: Although anastrozole was associated with significant fewer recurrences compared to tamoxifen in the first 10 years of follow-up, in this analysis, with limited number of patients, we could not find a significant difference between the two treatment arms.

Citation Format: Cuzick J, Sestak I, Bianco A, Strobbe L, Bergh J, Hanusch C, Neven P, Dowsett M, Forbes JF, Buzdar A, Smith R, Howell A. Long-term comparison of anastrozole versus tamoxifen: Results from LATTE/ATAC [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 P2-09-03.

Abstract P1-07-07: Gene expression signatures and immunohistochemical subtypes add prognostic value to each other

Background: We have previously demonstrated that gene expression signatures and Ki67 stratify the same breast tumour into opposing good/poor prognosis groups in approximately 20% of cases. Given this, we hypothesized that the combination of a clinically relevant gene signature and IHC markers may provide more prognostic information than either classifier alone. We tested this hypothesis in a large independent cohort of Swedish breast cancer patients with long-term follow-up data.

Methods: We assessed Ki67, ER, PR, HER2 and the research versions of the Genomic Grade Index (GGI), Mammaprint, cell-cycle score (CCS), Recurrence Score (RS) and PAM50 gene expression classifiers on matching TMA and microarray data in a Swedish breast cancer cohort of 623 patients. Change in likelihood-ratio (Δ LR-χ2) was used to first determine the additional prognostic information provided by gene expression signatures beyond that provided by 1) Ki67 alone and 2) Ki67 plus ER, PR and HER2, grouped to form the IHC molecular subtypes. Secondly and conversely, we then determined the additional prognostic information provided by Ki67/IHC subtypes beyond gene expression signatures.

Results: Representative images from Ki67/gene signature contrast groups show tumours with high levels of Ki67 expression that are classified as good prognosis by gene signatures and conversely, tumours with low Ki67 that are classified into poor prognosis groups by gene signatures. In all patients (n=623), the majority of signatures provided statistically significant information beyond that of Ki67 alone, however only RS and PAM50 remained significant in the presence of the IHC subtypes (Δ LR-χ2 RS= 11.7 and PAM50 = 15.4; P = 0.002 and 0.004, respectively). Conversely, IHC subtypes added prognostic information beyond gene signatures whilst Ki67 alone did not, a notable exception to this was PAM50.

Conclusions: In general, a combination of the IHC subtypes with gene signatures provides more prognostic information than either classifier alone when considering all breast cancer patients. Subsequent analyses will focus on patient subgroups including ER positive, node positive and ER positive, node negative groups, along with validation of our work in a second dataset of 253 patients.

Change in likelhood ratio with the addition of gene expression signatures to Ki67/IHC subgroups and vice-versa All Patients All PatientsSig. added to Ki67:Sig. Δ LRχ2P-valueSig. added to IHC subtypesSig. Δ LRχ2P-valueGGI6.00.014GGI2.50.108Mammaprint6.30.011Mammaprint1.10.279RS20.8&lt; 0.001RS11.70.002CCS1.70.409CCS2.00.360PAM5025.0&lt; 0.001PAM5015.40.004      Ki67 added to sig.:Ki67 Δ LRχ2P-valueIHC added to sig.:IHC Δ LRχ2P-valueGGI1.60.205GGI14.90.001Mammaprint1.60.199Mammaprint15.30.001RS0.50.477RS12.60.005CCS4.10.041CCS16.10.001PAM502.30.13PAM506.10.107Sig.: Gene expression signature; GGI: Genomic grade index; RS: Recurrence score; CCS: Cell cycle score.

Citation Format: Lundberg A, Lindström LS, Falato C, Carlson JW, Foukakis T, Czene K, Bergh J, Tobin NP. Gene expression signatures and immunohistochemical subtypes add prognostic value to each other [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 P1-07-07.

Early assessment of neoadjuvant chemotherapy by FEC-courses of locally advanced breast cancer using 99mTc-MIBI

Purpose: Response assessment at neoadjuvant (preoperative) chemotherapy of locally advanced breast cancer using clinical examination and mammography is insensitive. Mammoscintigraphy with 99mTc-MIBI was studied for the prediction of response at such therapy before finishing the chemotherapy cycles.

Material and Methods: Chemotherapy was given as repeated courses of 5-fluorouracil, epirubicin and cyclophosphamide (FEC). In 1 patient group ( n = 23), the tumor uptake relative to surrounding breast tissue and lung tissue at SPECT examination after finishing neoadjuvant chemotherapy was compared with the examination made before chemotherapy. In another group ( n = 30), a similar comparison after the first therapy cycle (mean 19 days) with a baseline examination was made. Histologic examination of the resected tumors was made.

Results: After finishing chemotherapy, there was a strong reduction of the relative tumor activity, while there was no correlation with therapy effect as assessed by histology. After one therapy course, there was no significant reduction of the relative tumor uptake.

Conclusion: Scintigraphy with 99mTc-MIBI demonstrated the response after finished neoadjuvant chemotherapy of breast cancer using FEC-courses. It cannot be used to predict a therapy response after one therapy course.

Effect of granulocyte colony-stimulating factor (G-CSF)-supported chemotherapy on MR imaging of normal red bone marrow in breast cancer patients with focal bone metastases

Purpose: To investigate the effect of granulocyte colony-stimulating factor (G-CSF)-supported chemotherapy on normal red bone marrow MR imaging in breast cancer patients with focal bone metastases.

Material and Methods: Fifteen breast cancer patients who were examined before and after chemotherapy with T1-weighted-SE and long echo-time inversion-recovery turbo-spin-echo (long TE IR-TSE) sequences in the thoracolumbar spine and pelvis were retrospectively studied. Nine of them received G-CSF therapy after the administration of each chemotherapy course. Of these 9 patients, the MR follow-ups were performed during G-CSF in 4 patients and after G-CSF therapy in 5 patients. Six patients did not receive G-CSF. Signal intensity (SI) changes in normal bone marrow were evaluated visually in all patients and quantitatively in 13 patients.

Results: In all 4 patients investigated during G-CSF therapy a diffuse, homogeneous SI increase on long TE IR-TSE was observed visually and quantitatively in initially normal bone marrow. This change obscured some focal lesions in 2 patients. No such SI change was visible after G-CSF therapy ( p = 0.008) or in patients not receiving G-CSF. On T1-weighted images an SI decrease was found both during and after G-CSF therapy, but an increase occurred in patients not receiving G-CSF.

Conclusion: G-CSF-supported chemotherapy can induce diffuse SI changes in normal red bone marrow on MR imaging. On long TE IR-TSE, the changes are visible during G-CSF treatment and can lead to misinterpretations in the response evaluation of bone metastases to therapy.