A randomised phase II study investigating durvalumab in addition to an anthracycline taxane-based neoadjuvant therapy in early triple-negative breast cancer: clinical results and biomarker analysis of GeparNuevo study

BACKGROUND

Combining immune-checkpoint inhibitors with chemotherapy yielded an increased response rates in patients with metastatic triple-negative breast cancer (TNBC). Therefore, we evaluated the addition of durvalumab to standard neoadjuvant chemotherapy (NACT) in primary TNBC.

PATIENTS AND METHODS

GeparNuevo is a randomised phase II double-blind placebo-controlled study randomising patients with TNBC to durvalumab or placebo given every 4 weeks in addition to nab-paclitaxel followed by standard EC. In the window-phase durvalumab/placebo alone was given 2 weeks before start of nab-paclitaxel. Randomisation was stratified by stromal tumour-infiltrating lymphocyte (sTILs). Patients with primary cT1b-cT4a-d disease, centrally confirmed TNBC and sTILs were included. Primary objective was pathological complete response (pCR) (ypT0 ypN0).

RESULTS

A total of 174 patients were randomised, 117 participated in the window-phase. Median age was 49.5 years (range 23-76); 47 patients (27%) were younger than 40 years; 113 (65%) had stage ≥IIA disease, 25 (14%) high sTILs, 138 of 158 (87%) were PD-L1-positive. pCR rate with durvalumab was 53.4% (95% CI 42.5% to 61.4%) versus placebo 44.2% (95% CI 33.5% to 55.3%; unadjusted continuity corrected χ2P = 0.287), corresponding to OR = 1.45 (95% CI 0.80-2.63, unadjusted Wald P = 0.224). Durvalumab effect was seen only in the window cohort (pCR 61.0% versus 41.4%, OR = 2.22, 95% CI 1.06-4.64, P = 0.035; interaction P = 0.048). In both arms, significantly increased pCR (P < 0.01) were observed with higher sTILs. There was a trend for increased pCR rates in PD-L1-positive tumours, which was significant for PD-L1-tumour cell in durvalumab (P = 0.045) and for PD-L1-immune cell in placebo arm (P = 0.040). The most common immune-related adverse events were thyroid dysfunction any grade in 47%.

CONCLUSIONS

Our results suggest that the addition of durvalumab to anthracycline-/taxane-based NACT increases pCR rate particularly in patients treated with durvalumab alone before start of chemotherapy.

TRIAL REGISTRATION

ClinicalTrials.gov number: NCT02685059.

Requirements for Chromium Reactors for Use in the Determination of H Isotopes in Compound-Specific Stable Isotope Analysis of Chlorinated Compounds

There is a strong need for careful quality control in hydrogen compound-specific stable isotope analysis (CSIA) of halogenated compounds. This arises in part due to the lack of universal design of the chromium (Cr) reactors. In this study, factors that optimize the critical performance parameter, linearity, for the Cr reduction method for hydrogen isotope analysis were identified and evaluated. These include the effects of short and long vertically mounted reactors and temperature profiles on trapping of Cl to ensure accurate and precise hydrogen isotope measurements. This paper demonstrates the critical parameters that need consideration to optimize any Cr reactor applications to ensure the accuracy of δ²H analysis for organic compounds and to enhance intercomparability for both international standards and reference materials run by continuous flow versus an elemental analyzer.

Survival analysis of carboplatin added to an anthracycline/taxane-based neoadjuvant chemotherapy and HRD score as predictor of response-final results from GeparSixto

Background

In the neoadjuvant GeparSixto study, adding carboplatin to taxane- and anthracycline-based chemotherapy improved pathological complete response (pCR) rates in patients with triple-negative breast cancer (TNBC). Here, we present survival data and the potential prognostic and predictive role of homologous recombination deficiency (HRD).

Patients and methods

Patients were randomized to paclitaxel plus nonpegylated liposomal doxorubicin (Myocet®) (PM) or PM plus carboplatin (PMCb). The secondary study end points disease-free survival (DFS) and overall survival (OS) were analyzed. Median follow-up was 47.3 months. HRD was among the exploratory analyses in GeparSixto and was successfully measured in formalin-fixed, paraffin-embedded tumor samples of 193/315 (61.3%) participants with TNBC. Homologous recombination (HR) deficiency was defined as HRD score ≥42 and/or presence of tumor BRCA mutations (tmBRCA).

Results

A significantly better DFS (hazard ratio 0.56, 95% CI 0.34-0.93; P = 0.022) was observed in patients with TNBC when treated with PMCb. The improvement of OS with PMCb was not statistically significant. Additional carboplatin did not improve DFS or OS in patients with HER2-positive tumors. HR deficiency was detected in 136 (70.5%) of 193 triple-negative tumors, of which 82 (60.3%) showed high HRD score without tmBRCA. HR deficiency independently predicted pCR (ypT0 ypN0) [odds ratio (OR) 2.60, 95% CI 1.26-5.37, P = 0.008]. Adding carboplatin to PM significantly increased the pCR rate from 33.9% to 63.5% in HR deficient tumors (P = 0.001), but only marginally in HR nondeficient tumors (from 20.0% to 29.6%, P = 0.540; test for interaction P = 0.327). pCR rates with carboplatin were also higher (63.2%) than without carboplatin (31.7%; OR 3.69, 1.46-9.37, P = 0.005) in patients with high HRD score but no tmBRCA. DFS rates were improved with addition of carboplatin, both in HR nondeficient (hazard ratio 0.44, 0.17-1.17, P = 0.086) and HR deficient tumors (hazard ratio 0.49, 0.23-1.04, P = 0.059).

Conclusions

The addition of carboplatin to neoadjuvant PM improved DFS significantly in TNBC. Long-term survival analyses support the neoadjuvant use of carboplatin in TNBC. HR deficiency in TNBC and HRD score in non-tmBRCA TNBC are predictors of response. HRD does not predict for carboplatin benefit.

H2 Kinetic Isotope Fractionation Superimposed by Equilibrium Isotope Fractionation During Hydrogenase Activity of D. vulgaris Strain Miyazaki

We determined ²H stable isotope fractionation at natural abundances associated with hydrogenase activity by whole cells of Desulfovibrio vulgaris strain Miyazaki F expressing a NiFe(Se) hydrogenase. Inhibition of sulfate reduction by molybdate inhibited the overall oxidation of hydrogen but still facilitated an equilibrium isotope exchange reaction with water. The theoretical equilibrium isotope exchange δ²H-values of the chemical exchange reaction were identical to the hydrogenase reaction, as confirmed using three isotopically different waters with δ²H-values of – 62, +461, and + 1533‰. Expected kinetic isotope fractionation of hydrogen oxidation by non-inhibited cells was also superimposed by an equilibrium isotope exchange. The isotope effects were solely catalyzed biotically as hydrogen isotope signatures did not change in control experiments without cells of D. vulgaris Miyazaki.

Influence of patient and tumor characteristics on early therapy persistence with letrozole in postmenopausal women with early breast cancer: results of the prospective Evaluate-TM study with 3941 patients

Background

Patients' compliance and persistence with endocrine treatment has a significant effect on the prognosis in early breast cancer (EBC). The purpose of this analysis was to identify possible reasons for non-persistence, defined as premature cessation of therapy, on the basis of patient and tumor characteristics in individuals receiving adjuvant treatment with letrozole.

Patients and methods

The EvAluate-TM study is a prospective, multicenter, noninterventional study in which treatment with the aromatase inhibitor letrozole was evaluated in postmenopausal women with hormone receptor-positive EBC in the early therapy phase. Treatment persistence was evaluated at two pre-specified study visits after 6 and 12 months. As a measure of early therapy persistence the time from the start to the end of treatment (TTEOT) was analyzed. Cox regression analyses were carried out to identify patient characteristics and tumor characteristics predicting TTEOT.

Results

Out of the total population of 3941 patients with EBC, 540 (13.7%) events involving treatment cessation unrelated to disease progression were observed. This was due to drug-related toxicity in the majority of cases (73.5%). Persistence rates were 92.2%, 86.9%, and 86.3% after 6, 12, and 15 months, respectively. The main factors influencing premature treatment discontinuation were older age [hazard ratio (HR) 1.02/year], comorbidities (HR 1.06 per comorbidity), low body mass index, and lower tumor grade (HR 0.85 per grade unit).

Conclusion

These results support the view that older, multimorbid patients with low tumor grade and low body mass index are at the greatest risk for treatment discontinuation and might benefit from compliance and support programs.

Individual stages of bacterial dichloromethane degradation mapped by carbon and chlorine stable isotope analysis

The fractionation of carbon and chlorine stable isotopes of dichloromethane (CH₂Cl₂, DCM) upon dechlorination by cells of the aerobic methylotroph Methylobacterium extorquens DM4 and by purified DCM dehalogenases of the glutathione S-transferase family was analyzed. Isotope effects for individual steps of the multi-stage DCM degradation process, including transfer across the cell wall from the aqueous medium to the cell cytoplasm, dehalogenase binding, and catalytic reaction, were considered. The observed carbon and chlorine isotope fractionation accompanying DCM consumption by cell supensions and enzymes was mainly determined by the breaking of CCl bonds, and not by inflow of DCM into cells. Chlorine isotope effects of DCM dehalogenation were initially masked in high density cultures, presumably due to inverse isotope effects of non-specific DCM oxidation under conditions of oxygen excess. Glutathione cofactor supply remarkably affected the correlation of variations of DCM carbon and chlorine stable isotopes (Δδ¹³C/Δδ³⁷Cl), increasing corresponding ratio from 7.2-8.6 to 9.6-10.5 under conditions of glutathione deficiency. This suggests that enzymatic reaction of DCM with glutathione thiolate may involve stepwise breaking and making of bonds with the carbon atom of DCM, unlike the uncatalyzed reaction, which is a one-stage process, as shown by quantum-chemical modeling.

Abstract P1-13-01: Final results of the ASG1-3 study, a randomized phase III study comparing a standard dose chemotherapy with epirubicin/cyclophosphamide and paclitaxel with a dose dense regimen with epirubicin and paclitaxel

Background

Dose dense chemotherapy (DDT) has shown improvements of disease-free survival (DFS) and overall survival for primary breast cancer patients with a high risk of relapse. There are much less data about the effect of DDT in patients with intermediate risk of recurrence (1-3 positive axillary lymph nodes). Aim of this prospectively randomized trial was to investigate the superiority of a DDT schedule over a standard chemotherapy (ST) in primary breast cancer patients with 1-3 positive axillary lymph nodes.

Methods

The ASG1-3 study is a prospectively randomized, open label phase III study of the Adjuvant Study Group of the NOGGO association. Patients were eligible for the trial, if they had a primary invasive breast cancer (pT1-3) with 1-3 positive axillary lymph nodes and no evidence of distant metastases. Patients were randomized to an adjuvant therapy with either 4 cycles epirubicin (90mg/m2 body surface area, BSA) and cyclophosphamide (600mg/m2 BSA) q3w, followed by 4 cycles of paclitaxel (175mg/m2 BSA) referred to as ST or to a therapy with 4 cycles of epicubicin (120 mg/m2 BSA) q2w and primary G-CSF support followed by 4 cycles of paclitaxel (175mg/m2 BSA) q2w and primary G-CSF support referred to as DDT. Trastuzumab was not given in this study. The study was designed to show an increase of 70% DFS (ST) to 80% DFS (DDT) 5 years after randomization. Comparisons were conducted using Kaplan Meier estimates, log rank tests and Cox regression analyses. In an exploratory way, subgroup analyses were performed for HER2, hormone receptor status and grading using Cox regression models with interaction terms.

Results

A total of 936 patients were eligible for survival analysis, of which 465 were randomized to ST and 471 to DDT from 2001 to 2004. Patient characteristics were mainly well balanced, with patients being 52.5/52.1 years old, 71.9/78.1% being hormone receptor positive, 24.4/24.6% being HER2 positive and 38.6/38.8% having a tumor grade of 3 in the ST arm and DDT arm respectively. 53 events occurred after ST and 46 after DDT. Adjusted hazard ratio (HR) was 0.87 (95%CI: 0.57-1.35; p=0.54). 5 year DFS rates were 85% (ST) vs. 87% (DDT). Hematological toxicities were the most common grade 3 or 4 adverse events. Grade 3/4 neutropenia occurred in 57.2 vs. 28.0%, grade 3/4 anemia in 15.3% vs. 17.1% and grade 3 /4 pain symptoms were seen in 13.2 vs. 12.4% of the patients in the ST arm vs. DDT arm respectively. Other grade 3/4 toxicities were less frequent than 10%. Subgroup analysis showed a significant interaction (p&lt;0.001) between HER2 status and randomization arm with regard to DFS. In HER2 negative patients the HR was 1.53 (95%CI: 0.91-2.59), whereas in HER2 positive patients the HR was 0.22 (95%CI: 0.09-0.55). Patients with HER2 positive disease and DDT had a similar prognosis like HER2 negative patients.

Conclusion

In the overall population a statistically significant improvement of DFS could not be shown for the DDT arm. In patients with HER2 positive breast cancer DDT chemotherapy improved the disease-free survival to a prognosis which was similar to patients with HER2 negative disease.

Citation Format: Fasching PA, Eggemann H, Krocker J, Häberle L, Volz B, Kleine-Tebbe A, Blohmer J-U, Kittel K, Hufnagel M, Janni W, Emons G, Simon E, Köhler U, Thomssen C, Kohls A, Beckmann MW, Hielscher C, Krabisch P, Zeiser T, Brodkorb T, Baier F, Nabieva N, Kellner S, Untch M, Stadie S, Budner M, Breitbach G-P, Keller M, Stickeler E, Kühn T, Tolkmitt M, Belau AK, Schmidt M, Ulm K, Kümmel S. Final results of the ASG1-3 study, a randomized phase III study comparing a standard dose chemotherapy with epirubicin/cyclophosphamide and paclitaxel with a dose dense regimen with epirubicin and paclitaxel [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 P1-13-01.

Carbon and hydrogen stable isotope analysis for characterizing the chemical degradation of tributyl phosphate

Tributyl phosphate (TBP) belongs to the group of trialkyl substituted organophosphate esters. Its chemical reactivity depends on the stability of various chemical bonds. TBP was used as a model compound for the development of a concept using stable isotope fractionation associated with bond cleavage reactions for better understanding the fate of TBP in the environment. Carbon isotope enrichment factors (ε_C) of TBP hydrolysis were found to be pH dependent (-3.8 ± 0.3‰ at pH 2, -4.6 ± 0.5‰ at pH 7, -2.8 ± 0.1‰ at pH 9, no isotope fractionation at pH 12), which is in accordance with the mode of a S_N2 hydrolytic bond cleavage. Hydrogen isotope fractionation was negligible as no H bond cleavage is involved during hydrolysis. The apparent carbon kinetic isotope effect (AKIE_C) ranged from 1.045 to 1.058. In contrast to hydrolysis, both carbon and hydrogen isotope fractionation were observed during radical oxidation of TBP by OH and SO₄^-, yielding ε_C from -0.9 ± 0.1‰ to -0.5 ± 0.1‰ and ε_H from -20 ± 2‰ to -11 ± 1‰. AKIE_C and AKIE_H varied from 1.007 to 1.011 and from 1.594 to 2.174, respectively. The correlation of ²H and ¹³C isotope fractionation revealed Λ values ranging from 17 ± 1 to 25 ± 6. Results demonstrated that the correlation of ²H and ¹³C isotope fractionation of TBP allowed to identify radical reactions and to distinguish them from hydrolysis. The presented dual isotope analysis approach has diagnostic value for characterizing the chemical transformation of TBP in the environment.

Multi-element compound specific stable isotope analysis of chlorinated aliphatic contaminants derived from chlorinated pitches

Tetrachloroethene and trichloroethene are typical by-products of the industrial production of chloromethanes. These by-products are known as "chlorinated pitches" and were often dumped in un-contained waste disposal sites causing groundwater contaminations. Previous research showed that a strongly depleted stable carbon isotope signature characterizes chlorinated compounds associated with chlorinated pitches whereas manufactured commercial compounds have more enriched carbon isotope ratios. The findings were restricted to a single case study and one element (i.e. carbon). This paper presents a multi-element Compound-Specific Stable Isotope Analysis (CSIA, including carbon, chlorine and hydrogen) of chlorinated aliphatic contaminants originated from chlorinated pitches at two sites with different hydrogeology and different producers of chloromethanes. The results show strongly depleted carbon signatures at both sites whereas the chlorine and the hydrogen signatures are comparable to those presented in the literature for manufactured commercial compounds. Multi-element CSIA allowed the identification of sources and site-specific processes affecting chloroethene transformation in groundwater as a result of emergency remediation measures. CSIA turned out to be an effective forensic tool to address the liability for the contamination, leading to a conviction for the crimes of unintentional aggravated public water supply poisoning and environmental disaster.

Calculation of Single Cell Assimilation Rates From SIP-NanoSIMS-Derived Isotope Ratios: A Comprehensive Approach

The nanoSIMS-based chemical microscopy has been introduced in biology over a decade ago. The spatial distribution of elements and isotopes analyzed by nanoSIMS can be used to reconstruct images of biological samples with a resolution down to tens of nanometers, and can be also interpreted quantitatively. Currently, a unified approach for calculation of single cell assimilation rates from nanoSIMS-derived changes in isotope ratios is missing. Here we present a comprehensive concept of assimilation rate calculation with a rigorous mathematical model based on quantitative evaluation of nanoSIMS-derived isotope ratios. We provide a detailed description of data acquisition and treatment, including the selection and accumulation of nanoSIMS scans, defining regions of interest and extraction of isotope ratios. Next, we present alternative methods to determine the cellular volume and the density of the element under scrutiny. Finally, to compensate for alterations of original isotopic ratios, our model considers corrections for sample preparation methods (e.g., air dry, chemical fixation, permeabilization, hybridization), and when known, for the stable isotope fractionation associated with utilization of defined growth substrates. As proof of concept we implemented this protocol to quantify the assimilation of ¹³C-labeled glucose by single cells of Pseudomonas putida. In addition, we provide a calculation template where all protocol-derived formulas are directly available to facilitate routine assimilation rate calculations by nanoSIMS users.

Liquid chromatography/isotope ratio mass spectrometry analysis of halogenated benzoates for characterization of the underlying degradation reaction in Thauera chlorobenzoica CB-1T

RATIONALE

Halogenated benzoic acids occur in the environment due to their widespread agricultural and pharmaceutical use. Compound-specific stable isotope analysis (CSIA) has developed over the last decades for investigation of in situ transformation and reaction mechanisms of environmental pollutants amenable by gas chromatography (GC). As polar compounds are unsuitable for GC analysis we developed a method to perform liquid chromatography (LC)/CSIA for halogenated benzoates.

METHODS

LC/isotope ratio mass spectrometry (IRMS) utilizing a LC-Surveyor pump coupled to a MAT 253 isotope ratio mass spectrometer via a LC-Isolink interface was applied. For chromatographic separation a YMC-Triart C18 column and a potassium hydrogen phosphate buffer (150 mM, pH 7.0, 40°C, 200 μL mL^-1 ) were used, followed by wet oxidation deploying 1.5 mol L^-1 ortho-phosphoric acid and 200 g L^-1 sodium peroxodisulfate at 75 μL mL^-1 .

RESULTS

Separation of benzoate and halogenated benzoates could be achieved in less than 40 min over a concentration range of 2 orders of magnitude. Under these conditions the dehalogenation reaction of Thauera chlorobenzoica 3CB-1^T using 3-chloro-, 3-bromo- and 4-chlorobenzoic acid was investigated resulting in inverse carbon isotope fractionation for meta-substituted benzoic acids and minor normal fractionation for para-substituted benzoic acids. Together with the respective growth rates this led to the assumption that dehalogenation of para-halobenzoic acids follows a different mechanism from that of meta-halobenzoic acids.

CONCLUSIONS

A new LC/IRMS method for the quantitative determination of halogenated benzoates was developed and used to investigate the in vivo transformation pathways of these compounds, providing some insights into degradation and removal of these widespread compounds by T. chlorobenzoica 3CB-1^T .

Influence of side-effects on early therapy persistence with letrozole in post-menopausal patients with early breast cancer: Results of the prospective EvAluate-TM study

BACKGROUND

Endocrine treatment (ET) with an aromatase inhibitor (AI) is the treatment of choice in post-menopausal patients with hormone receptor-positive early breast cancer (EBC). However, adverse events (AEs) often lead to treatment discontinuation. This analysis aimed to identify side-effects that lead to patients failing to persist with letrozole treatment.

PATIENTS AND METHODS

Post-menopausal hormone receptor-positive EBC patients starting ET with letrozole were enroled in EvAluate-TM, a non-interventional study. Information regarding treatment compliance and persistence was gathered in months 6 and 12. Persistence was defined as the time from 30 d after the start to the end of treatment. The influence on persistence of musculoskeletal syndrome, menopausal disorder, sleep disorder and other AEs within the first 30 d was analysed using Cox regression analyses.

RESULTS

Among 3887 patients analysed, the persistence rate after 12 months was >85%. In all, 568 patients (14.6%) discontinued the treatment, 358 of whom (63.0%) did so only because of side-effects. The main AEs influencing persistence were musculoskeletal symptoms (hazard ratio [HR] 2.55; 95% confidence interval [CI], 1.90-3.42), sleep disorders (HR 1.95; 95% CI, 1.41-2.70) and other AEs (HR 2.03; 95% CI, 1.51-2.73). Menopausal disorder was not associated with non-persistence (HR 1.17; 95% CI, 0.74-1.84).

CONCLUSIONS

These results suggest that side-effects of AIs such as musculoskeletal syndrome and sleep disorder lead to ET discontinuation within the first treatment year in significant numbers of EBC patients. Compliance programmes adapted for subgroups that are at risk for early non-persistence might help to ensure the recommended therapy duration.

CLINICAL TRIALS NUMBER

CFEM345DDE19.

Enrichment of ANME-2 dominated anaerobic methanotrophy from cold seep sediment in an external ultrafiltration membrane bioreactor

Anaerobic oxidation of methane (AOM) coupled to sulfate reduction is a microbially mediated unique natural phenomenon with an ecological relevance in the global carbon balance and potential application in biotechnology. This study aimed to enrich an AOM performing microbial community with the main focus on anaerobic methanotrophic archaea (ANME) present in sediments from the Ginsburg mud volcano (Gulf of Cadiz), a known site for AOM, in a membrane bioreactor (MBR) for 726 days at 22 (± 3)°C and at ambient pressure. The MBR was equipped with a cylindrical external ultrafiltration membrane, fed a defined medium containing artificial seawater and operated at a cross flow velocity of 0.02 m/min. Sulfide production with simultaneous sulfate reduction was in equimolar ratio between days 480 and 585 of MBR operation, whereas methane consumption was in oscillating trend. At the end of the MBR operation (day 726), the enriched biomass was incubated with ¹³C labeled methane, ¹³C labeled inorganic carbon was produced and the AOM rate based on ¹³C-inorganic carbon was 1.2 μmol/(g_dw d). Microbial analysis of the enriched biomass at 400 and 726 days of MBR operation showed that ANME-2 and Desulfosarcina type sulfate reducing bacteria were enriched in the MBR, which formed closely associated aggregates. The major relevance of this study is the enrichment of an AOM consortium in a MBR system which can assist to explore the ecophysiology of ANME and provides an opportunity to explore the potential application of AOM.

Distinct Carbon Isotope Fractionation Signatures during Biotic and Abiotic Reductive Transformation of Chlordecone

Chlordecone is a synthetic organochlorine pesticide, extensively used in banana plantations of the French West Indies from 1972 to 1993. Due to its environmental persistence and bioaccumulation, it has dramatic public health and socio-economic impact. Here we describe a method for carbon-directed compound specific isotope analysis (CSIA) for chlordecone and apply it to monitor biotic and abiotic reductive transformation reactions, selected on the basis of their distinct product profiles (polychloroindenes versus lower chlorinated hydrochlordecones). Significant carbon isotopic enrichments were observed for all microbially mediated transformations (ε_bulk = -6.8‰ with a Citrobacter strain and ε_bulk = -4.6‰ with a bacterial consortium) and for two abiotic transformations (ε_bulk = -4.1‰ with zerovalent iron and ε_bulk = -2.6‰ with sodium sulfide and vitamin B₁₂). The reaction with titanium(III) citrate and vitamin B₁₂, which shows the product profile most similar to that observed in biotic transformation, led to low carbon isotope enrichment (ε_bulk =-0.8‰). The CSIA protocol was also applied on representative chlordecone formulations previously used in the French West Indies, giving similar chlordecone δ¹³C values from -31.1 ± 0.2‰ to -34.2 ± 0.2‰ for all studied samples. This allows the in situ application of CSIA for the assessment of chlordecone persistence.

Abstract P6-15-03: Outcome after neoadjuvant chemotherapy in elderly breast cancer patients – a pooled analysis of individual patient data from eight prospectively randomized controlled trials

Introduction: Recent studies showed the high and independent impact of age (&lt;40 years) on pathologic complete remission (pCR) and prognosis for patients undergoing neoadjuvant chemotherapy (NACT). Some physicians might not consider elderly patients (&gt;65 years) for NACT due to poor prognosis or higher toxicity. The aim of this analysis is to help selecting appropriately elderly women who would benefit from NACT. Secondly, survival parameters will be investigated in several clinical and histological subgroups.

Methods: From 1998 to 2010, eight prospectively randomized German Breast Group (GBG) trials of anthracycline- and taxane-based NACT were performed and analyzed in this study.

Results: Compared to the overall average, women older than 65 years had significant larger tumors and more overall lymph node involvement. Also, compared to patients younger than 51 years, they had more lobular invasive tumors. Histologically, they had more G2 tumors, more estrogen-receptor positive tumors. PCR (ypT0 ypN0) was strongly associated with age: &gt;65y: 11.7%; 51-65y: 14.1%; 40-50y: 17.3%; &lt;40y: 20.9%. The multivariable logistic regression analysis of clinical parameters showed that young age, clinical stage T4, invasive ductal cancer and poor differentiated breast cancer are predictive for high pCR. The multivariate analyses of molecular subgroups also showed that age &gt;65years is a predictor of significant (p&lt;0.05) lower pCR in TNBC and HR positive/HER2- breast cancers. Nonetheless, in this cohort, HER2+ patients showed pCR rates as high - and for HR+/HER2+ even higher - pCR rates compared to younger patients.

Discussion: This study underlines the unfavorable impact of higher age on pCR, but it shows nevertheless a realistic chance for pCR if NACT is applied - especially for HER2+ patients. Furthermore, elderly patients in this analysis with non-TNBC have a good prognosis (comparable to younger patients) regarding OS, even if they do not have pCR.

Citation Format: von Waldenfels G, Loibl S, Furlanetto J, Anna M, Lederer B, Denkert C, Hanusch C, Huober J, Jackisch C, Kümmel S, von Minckwitz G, Schneeweiss A, Untch M, Rhiem K, Fasching PA, Blohmer JU. Outcome after neoadjuvant chemotherapy in elderly breast cancer patients – a pooled analysis of individual patient data from eight prospectively randomized controlled trials [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 P6-15-03.

Abstract P6-15-01: Withdrawn

This abstract was withdrawn by the authors.

Abstract P6-13-01: Withdrawn

This abstract was withdrawn by the authors.