Long-term outcomes of a randomized, open-label, phase II study comparing cabazitaxel versus paclitaxel as neoadjuvant treatment in patients with triple-negative or luminal B/HER2-negative breast cancer (GENEVIEVE)

BACKGROUND

The GENEVIEVE study, comparing neoadjuvant cabazitaxel versus paclitaxel in triple-negative breast cancer (TNBC) and luminal B/human epidermal growth factor receptor 2 (HER2)-negative breast cancer (BC), previously reported significant differences in pathological complete response (pCR) rates. Effects on long-term outcome are unknown.

PATIENTS AND METHODS

GENEVIEVE randomized patients with cT2-3, any cN or cT1, cN+/pNSLN+, centrally confirmed TNBC or luminal B/HER2-negative BC (latter defined as estrogen/progesterone receptor-positive and >14% Ki-67-stained cells) to receive either cabazitaxel 25 mg/m2 q3w for four cycles or paclitaxel 80 mg/m2 weekly for 12 weeks. Anthracycline-containing chemotherapy was allowed in case of histologically proven invasive residuals as neoadjuvant treatment or after surgery as adjuvant treatment. Here we report the secondary endpoints invasive disease-free survival (iDFS), distant disease-free survival (DDFS), and overall survival (OS).

RESULTS

Of the 333 patients randomized, 74.7% and 83.2% completed treatment in the cabazitaxel and paclitaxel arms, respectively. After a median follow-up of 89.3 months (interquartile range 68.8-97.3 months), 80 iDFS events (43 after cabazitaxel and 37 after paclitaxel) and 47 deaths (23 after cabazitaxel and 24 after paclitaxel) were reported. IDFS rates were not significantly different between the cabazitaxel and paclitaxel arms after a 3-year (83.6% versus 85.0%) and 5-year follow-up (76.2% versus 78.3%) [hazard ratio (HR) = 1.27, 95% confidence interval 0.82-1.96, P = 0.294], respectively. DDFS rates at 3 years (88.6% versus 87.8%) and 5 years (82.1% versus 82.8%) for cabazitaxel and paclitaxel were comparable (HR = 1.15, P = 0.573). Similarly, OS rates at 3 years (91.6% versus 91.8%) and 5 years (89.2% versus 86.8%) showed no significant differences (HR = 1.05, P = 0.872). Subgroup analysis for TNBC and luminal B/HER2-negative BCs indicated no significant variations in 3- or 5-year iDFS, DDFS, or OS.

CONCLUSIONS

The significant differences in pCR rates observed in both treatment arms did not significantly impact long-term outcomes for patients treated with cabazitaxel versus paclitaxel in the GENEVIEVE trial.

Optimization of Radiolabeling of a [90Y]Y-Anti-CD66-Antibody for Radioimmunotherapy before Allogeneic Hematopoietic Cell Transplantation

For patients with acute myeloid leukemia, myelodysplastic syndrome, or acute lymphoblastic leukemia, allogeneic hematopoietic cell transplantation (HCT) is a potentially curative treatment. In addition to standard conditioning regimens for HCT, high-dose radioimmunotherapy (RIT) offers the unique opportunity to selectively deliver a high dose of radiation to the bone marrow while limiting side effects. Modification of a CD66b-specific monoclonal antibody (mAb) with a DTPA-based chelating agent should improve the absorbed dose distribution during therapy. The stability and radioimmunoreactive fraction of the radiolabeled mAbs were determined. Before RIT, all patients underwent dosimetry to determine absorbed doses to bone marrow, kidneys, liver, and spleen. Scans were performed twenty-four hours after therapy for quality control. A radiochemical purity of >95% and acceptable radioimmunoreactivity was achieved. Absorbed organ doses for the liver and kidney were consequently improved compared to reported historical data. All patients tolerated RIT well with no treatment-related acute adverse events. Complete remission could be observed in 4/5 of the patients 3 months after RIT. Two patients developed delayed liver failure unrelated to the radioimmunotherapy. The improved conjugation and radiolabeling procedure resulted in excellent stability, radiochemical purity, and CD66-specific radioimmunoreactivity of ⁹⁰Y-labeled anti-CD66 mAb. RIT followed by conditioning and HCT was well tolerated. Based on these promising initial data, further prospective studies of [⁹⁰Y]Y-DTPA-Bn-CHX-A″-anti-CD66-mAb-assisted conditioning in HCT are warranted.

Correlation of background parenchymal enhancement on breast MRI with breast cancer

AIM

To evaluate the prognostic value of background parenchymal enhancement (BPE) in breast magnetic resonance imaging (MRI) in women referred to radiological department as a high risk for breast cancer.

MATERIALS AND METHODS

A retrospective, cross-sectional study included 327 consecutive patients (mean age: 60 years, age range: 30-90 years) who underwent breast MRI and tissue biopsy between 2007 and 2016. All MRI images (T1, T2, and subtraction images) were evaluated visually. The relationship of BPE with patient age, fibroglandular tissue (FGT), Breast Imaging Reporting and Data System (BIRADS) categories, presence of breast cancer, and expression of human epidermal growth factor receptor 2 (HER2), progesterone receptor (PR), oestrogen receptor (ER), and Ki67 were analysed. Furthermore, all variables were correlated with pre- and postmenopausal status.

RESULTS

BPE of bilateral breast showed a weak correlation with FGT (right BPE: r=-0.14, p=0.004; left BPE: r=0.16, p=0.003), a weak negative correlation with patient age (right BPE: r=-0.14, p=0.007; left BPE: r=-0.15, p=0.006), and significant correlation with HER2 (right BPE, p=0.02), left BPE with HER2 was not significant. Among the correlations between BPE and BIRADS, only between right BPE and right BIRADS was significant (p=0.031). No clear evidence of an association between breast MRI BPE and breast cancer in premenopausal and postmenopausal status was observed, and no difference was found between the right and left breasts.

CONCLUSIONS

The results of the present study showed no significant correlations between BPE and breast cancer. In addition, there was no significant difference between the right and left breast. Hence, BPE of MRI may not be a reliable biomarker of breast cancer development.

Genomic characterisation of hormone receptor-positive breast cancer arising in very young women

BACKGROUND

Very young premenopausal women diagnosed with hormone receptor-positive, human epidermal growth factor receptor 2-negative (HR+HER2-) early breast cancer (EBC) have higher rates of recurrence and death for reasons that remain largely unexplained.

PATIENTS AND METHODS

Genomic sequencing was applied to HR+HER2- tumours from patients enrolled in the Suppression of Ovarian Function Trial (SOFT) to determine genomic drivers that are enriched in young premenopausal women. Genomic alterations were characterised using next-generation sequencing from a subset of 1276 patients (deep targeted sequencing, n = 1258; whole-exome sequencing in a young-age, case-control subsample, n = 82). We defined copy number (CN) subgroups and assessed for features suggestive of homologous recombination deficiency (HRD). Genomic alteration frequencies were compared between young premenopausal women (<40 years) and older premenopausal women (≥40 years), and assessed for associations with distant recurrence-free interval (DRFI) and overall survival (OS).

RESULTS

Younger women (<40 years, n = 359) compared with older women (≥40 years, n = 917) had significantly higher frequencies of mutations in GATA3 (19% versus 16%) and CN amplifications (CNAs) (47% versus 26%), but significantly lower frequencies of mutations in PIK3CA (32% versus 47%), CDH1 (3% versus 9%), and MAP3K1 (7% versus 12%). Additionally, they had significantly higher frequencies of features suggestive of HRD (27% versus 21%) and a higher proportion of PIK3CA mutations with concurrent CNAs (23% versus 11%). Genomic features suggestive of HRD, PIK3CA mutations with CNAs, and CNAs were associated with significantly worse DRFI and OS compared with those without these features. These poor prognostic features were enriched in younger patients: present in 72% of patients aged <35 years, 54% aged 35-39 years, and 40% aged ≥40 years. Poor prognostic features [n = 584 (46%)] versus none [n = 692 (54%)] had an 8-year DRFI of 84% versus 94% and OS of 88% versus 96%. Younger women (<40 years) had the poorest outcomes: 8-year DRFI 74% versus 85% and OS 80% versus 93%, respectively.

CONCLUSION

These results provide insights into genomic alterations that are enriched in young women with HR+HER2- EBC, provide rationale for genomic subgrouping, and highlight priority molecular targets for future clinical trials.

Evaluation of the EPR Effect in the CAM-Model by Molecular Imaging with MRI and PET Using 89Zr-Labeled HSA

Mouse models are commonly used to study the biodistribution of novel radioligands, but alternative models corresponding to the 3Rs principles, such as the chorioallantoic membrane (CAM) model, are highly required. While there are promising data from the CAM model regarding target-specific radiolabeled compounds, its utility for assessing macromolecule biodistribution and analyzing the EPR effect remains to demonstrated. Using ⁸⁹Zr-labeled human serum albumin, the accumulation of nontarget-specific macromolecules in CAM and mouse xenograft models was studied using PET and MRI. Therefore, the radioligand [⁸⁹Zr]Zr-DFO-HSA was analyzed in both chicken embryos (n = 5) and SCID mice (n = 4), each with TZM-bl and PC-3 tumor entities. Dynamic PET and anatomical MRI, as well as ex vivo biodistribution analyses, were performed to assess ligand distribution over 24 h. Histological staining and autoradiography verified the intratumoral accumulation. The tumors were successfully visualized for CAM and mouse models by PET, and the albumin influx from the blood into the respective tumors did not differ significantly. The accumulation and retention of HSA in tumors due to the EPR effect was demonstrated for both models. These results highlight that the CAM model is a potential alternative to the mouse model for initial studies with novel radiolabeled macromolecules with respect to the 3Rs principles.

203 Pb-VMT-α-NET Scintigraphy of a Patient With Neuroendocrine Tumor

ABSTRACT

In an end-stage midgut neuroendocrine tumor patient with carcinoid heart disease, right ventricular dysfunction, mildly reduced renal function, and refractory to 6 cycles of 177 Lu-HA-DOTATATE therapy, planar, and 22 hours SPECT/CT images were acquired after injection of 224 MBq of 203 Pb-VMT-α-NET to assess the feasibility of performing 212 Pb-VMT-α-NET therapy. A comparison of the 1.5 and 22 hours SPECT/CT images with 68 Ga-HA-DOTATATE PET/CT showed high uptake of 203 Pb-VMT-α-NET in liver metastases matching with the results of the PET/CT investigation.

Preclinical PET and MR Evaluation of 89Zr- and 68Ga-Labeled Nanodiamonds in Mice over Different Time Scales

Nanodiamonds (NDs) have high potential as a drug carrier and in combination with nitrogen vacancies (NV centers) for highly sensitive MR-imaging after hyperpolarization. However, little remains known about their physiological properties in vivo. PET imaging allows further evaluation due to its quantitative properties and high sensitivity. Thus, we aimed to create a preclinical platform for PET and MR evaluation of surface-modified NDs by radiolabeling with both short- and long-lived radiotracers. Serum albumin coated NDs, functionalized with PEG groups and the chelator deferoxamine, were labeled either with zirconium-89 or gallium-68. Their biodistribution was assessed in two different mouse strains. PET scans were performed at various time points up to 7 d after i.v. injection. Anatomical correlation was provided by additional MRI in a subset of animals. PET results were validated by ex vivo quantification of the excised organs using a gamma counter. Radiolabeled NDs accumulated rapidly in the liver and spleen with a slight increase over time, while rapid washout from the blood pool was observed. Significant differences between the investigated radionuclides were only observed for the spleen (1 h). In summary, we successfully created a preclinical PET and MR imaging platform for the evaluation of the biodistribution of NDs over different time scales.

Comparison of PSMA-TO-1 and PSMA-617 labeled with gallium-68, lutetium-177 and actinium-225

BACKGROUND

PSMA-TO-1 ("Tumor-Optimized-1") is a novel PSMA ligand with longer circulation time than PSMA-617. We compared the biodistribution in subcutaneous tumor-bearing mice of PSMA-TO-1, PSMA-617 and PSMA-11 when labeled with ⁶⁸Ga and ¹⁷⁷Lu, and the survival after treatment with ²²⁵Ac-PSMA-TO-1/-617 in a murine model of disseminated prostate cancer. We also report dosimetry data of ¹⁷⁷Lu-PSMA-TO1/-617 in prostate cancer patients.

METHODS

First, PET images of ⁶⁸Ga-PSMA-TO-1/-617/-11 were acquired on consecutive days in three mice bearing subcutaneous C4-2 xenografts. Second, 50 subcutaneous tumor-bearing mice received either 30 MBq of ¹⁷⁷Lu-PSMA-617 or ¹⁷⁷Lu-PSMA-TO-1 and were sacrificed at 1, 4, 24, 48 and 168 h for ex vivo gamma counting and biodistribution. Third, mice bearing disseminated lesions via intracardiac inoculation were treated with either 40 kBq of ²²⁵Ac-PSMA-617, ²²⁵Ac-PSMA-TO-1, or remained untreated and followed for survival. Additionally, 3 metastatic castration-resistant prostate cancer patients received 500 MBq of ¹⁷⁷Lu-PSMA-TO-1 under compassionate use for dosimetry purposes. Planar images with an additional SPECT/CT acquisition were acquired for dosimetry calculations.

RESULTS

Tumor uptake measured by PET imaging of ⁶⁸Ga-labeled agents in mice was highest using PSMA-617, followed by PSMA-TO-1 and PSMA-11. ¹⁷⁷Lu-PSMA tumor uptake measured by ex vivo gamma counting at subsequent time points tended to be greater for PSMA-TO-1 up to 1 week following treatment (p > 0.13 at all time points). This was, however, accompanied by increased kidney uptake and a 26-fold higher kidney dose of PSMA-TO-1 compared with PSMA-617 in mice. Mice treated with a single-cycle ²²⁵Ac-PSMA-TO-1 survived longer than those treated with ²²⁵Ac-PSMA-617 and untreated mice, respectively (17.8, 14.5 and 7.7 weeks, respectively; p < 0.0001). Kidney, salivary gland, bone marrow and mean ± SD tumor dose coefficients (Gy/GBq) for ¹⁷⁷Lu-PSMA-TO-1 in patients #01/#02/#03 were 2.5/2.4/3.0, 1.0/2.5/2.3, 0.14/0.11/0.10 and 0.42 ± 0.03/4.45 ± 0.07/1.8 ± 0.57, respectively.

CONCLUSIONS

PSMA-TO-1 tumor uptake tended to be greater than that of PSMA-617 in both preclinical and clinical settings. Mice treated with ²²⁵Ac-PSMA-TO-1 conferred a significant survival benefit compared to ²²⁵Ac-PSMA-617 despite the accompanying increased kidney uptake. In humans, PSMA-TO-1 dosimetry estimates suggest increased tumor absorbed doses; however, the kidneys, salivary glands and bone marrow are also exposed to higher radiation doses. Thus, additional preclinical studies are needed before further clinical use.

Neoadjuvant durvalumab improves survival in early triple-negative breast cancer independent of pathological complete response

BACKGROUND

Addition of immune checkpoint inhibitors (CPI) to neoadjuvant chemotherapy (NACT) is a promising strategy in early breast cancer, but the optimal duration of therapy is currently unknown. In the GeparNuevo (NCT02685059) trial, addition of durvalumab to NACT as previously reported led to a moderate increase in pCR rate by absolute 9% (p=0.287).

PATIENTS AND METHODS

Durvalumab or placebo 1.5g/placebo q4 weeks plus nab-paclitaxel 125mg/m² weekly for 12 weeks, followed by 4 cycles durvalumab/placebo plus epirubicin/cyclophosphamide (EC) q2 weeks was given to cT1b-cT4a-d TNBC patients. Durvalumab was not continued after surgery. Primary objective was pathological complete response (pCR). Secondary endpoints included invasive disease-free survival (iDFS), distant disease-free survival (DDFS) and overall survival (OS).

RESULTS

174 patients were randomised between June 2016 and October 2017. After a median follow-up of 43.7 months, 34 events had occurred. Despite a non-significant increase in the pCR rate, significant differences were observed for 3-year iDFS, DDFS and OS: iDFS was 85.6% with durvalumab vs 77.2% with placebo (HR 0.48, 95%CI 0.24-0.97, stratified log-rank p=0.036); DDFS 91.7% vs 78.4% (HR 0.31, 95%CI 0.13-0.74, p=0.005); OS 95.2% vs 83.5% (HR 0.24, 95%CI 0.08-0.72, p=0.006). pCR patients had 3-year iDFS of 95.5% with durvalumab and 86.1% without (HR 0.22, 95% CI 0.05-1.06). In non-pCR cohort 3-year iDFS was 76.3% vs 69.7% (HR 0.67, 95% CI 0.29-1.54). Multivariable analysis confirmed durvalumab effect independent of the pCR effect. No new safety signals occurred.

CONCLUSION

Durvalumab added to NACT in TNBC significantly improved survival despite a modest pCR increase and no adjuvant component of durvalumab. Additional studies are needed to clarify the optimal duration and sequence of CPIs in the treatment of early TNBC.

Quantitative analysis of regional distribution of tau pathology with 11C-PBB3-PET in a clinical setting

PURPOSE

The recent developments of tau-positron emission tomography (tau-PET) enable in vivo assessment of neuropathological tau aggregates. Among the tau-specific tracers, the application of 11C-pyridinyl-butadienyl-benzothiazole 3 (11C-PBB3) in PET shows high sensitivity to Alzheimer disease (AD)-related tau deposition. The current study investigates the regional tau load in patients within the AD continuum, biomarker-negative individuals (BN) and patients with suspected non-AD pathophysiology (SNAP) using 11C-PBB3-PET.

MATERIALS AND METHODS

A total of 23 memory clinic outpatients with recent decline of episodic memory were examined using 11C-PBB3-PET. Pittsburg compound B (11C-PIB) PET was available for 17, 18F-flurodeoxyglucose (18F-FDG) PET for 16, and cerebrospinal fluid (CSF) protein levels for 11 patients. CSF biomarkers were considered abnormal based on Aβ42 (< 600 ng/L) and t-tau (> 450 ng/L). The PET biomarkers were classified as positive or negative using statistical parametric mapping (SPM) analysis and visual assessment. Using the amyloid/tau/neurodegeneration (A/T/N) scheme, patients were grouped as within the AD continuum, SNAP, and BN based on amyloid and neurodegeneration status. The 11C-PBB3 load detected by PET was compared among the groups using both atlas-based and voxel-wise analyses.

RESULTS

Seven patients were identified as within the AD continuum, 10 SNAP and 6 BN. In voxel-wise analysis, significantly higher 11C-PBB3 binding was observed in the AD continuum group compared to the BN patients in the cingulate gyrus, tempo-parieto-occipital junction and frontal lobe. Compared to the SNAP group, patients within the AD continuum had a considerably increased 11C-PBB3 uptake in the posterior cingulate cortex. There was no significant difference between SNAP and BN groups. The atlas-based analysis supported the outcome of the voxel-wise quantification analysis.

CONCLUSION

Our results suggest that 11C-PBB3-PET can effectively analyze regional tau load and has the potential to differentiate patients in the AD continuum group from the BN and SNAP group.

Comparison of MRI-based and PET-based image pre-processing for quantification of 11C-PBB3 uptake in human brain

PURPOSE

Quantification of tau load using ¹¹C-PBB3-PET has the potential to improve diagnosis of neurodegenerative diseases. Although MRI-based pre-processing is used as a reference method, not all patients have MRI. The feasibility of a PET-based pre-processing for the quantification of ¹¹C-PBB3 tracer was evaluated and compared with the MRI-based method.

MATERIALS AND METHODS

Fourteen patients with decreased recent memory were examined with ¹¹C-PBB3-PET and MRI. The PET scans were visually assessed and rated as either PBB3(+) or PBB3(-). The image processing based on the PET-based method was validated against the MRI-based approach. The regional uptakes were quantified using the Mesial-temporal/Temporoparietal/Rest of neocortex (MeTeR) regions. SUVR values were calculated by normalizing to the cerebellar reference region to compare both methods within the patient groups.

RESULTS

Significant correlations were observed between the SUVRs of the MRI-based and the PET-based methods in the MeTeR regions (r_Me=0.91; r_Te=0.98; r_R=0.96; p<0.0001). However, the Bland-Altman plot showed a significant bias between both methods in the subcortical Me region (bias: -0.041; 95% CI: -0.061 to -0.024; p=0.003). As in the MRI-based method, the ¹¹C-PBB3 uptake obtained with the PET-based method was higher for the PBB3(+) group in each of the cortical regions and for the whole brain than for the PBB3(-) group (PET-based_Global: 1.11 vs. 0.96; Cliff's Delta (d)=0.68; p=0.04; MRI-based_Global: 1.11 vs. 0.97; d=0.70; p=0.03). To differentiate between positive and negative scans, Youden's index estimated the best cut-off of 0.99 from the ROC curve with good accuracy (AUC: 0.88±0.10; 95% CI: 0.67-1.00) and the same sensitivity (83%) and specificity (88%) for both methods.

CONCLUSION

The PET-based pre-processing method developed to quantify the tau burden with ¹¹C-PBB3 provided comparable SUVR values and effect sizes as the MRI-based reference method. Furthermore, both methods have a comparable discrimination accuracy between PBB3(+) and PBB3(-) groups as assessed by visual rating. Therefore, the presented PET-based method can be used for clinical diagnosis if no MRI image is available.

Multi-Modal PET and MR Imaging in the Hen's Egg Test-Chorioallantoic Membrane (HET-CAM) Model for Initial in Vivo Testing of Target-Specific Radioligands

The validation of novel target-specific radioligands requires animal experiments mostly using mice with xenografts. A pre-selection based on a simpler in vivo model would allow to reduce the number of animal experiments, in accordance with the 3Rs principles (reduction, replacement, refinement). In this respect, the chick embryo or hen’s egg test–chorioallantoic membrane (HET-CAM) model is of special interest, as it is not considered an animal until day 17. Thus, we evaluated the feasibility of quantitative analysis of target-specific radiotracer accumulation in xenografts using the HET-CAM model and combined positron emission tomography (PET) and magnetic resonance imaging (MRI). For proof-of-principle we used established prostate-specific membrane antigen (PSMA)-positive and PSMA-negative prostate cancer xenografts and the clinically widely used PSMA-specific PET-tracer [⁶⁸Ga]Ga-PSMA-11. Tracer accumulation was quantified by PET and tumor volumes measured with MRI (n = 42). Moreover, gamma-counter analysis of radiotracer accumulation was done ex-vivo. A three- to five-fold higher ligand accumulation in the PSMA-positive tumors compared to the PSMA-negative tumors was demonstrated. This proof-of-principle study shows the general feasibility of the HET-CAM xenograft model for target-specific imaging with PET and MRI. The ultimate value for characterization of novel target-specific radioligands now has to be validated in comparison to mouse xenograft experiments.

Interobserver variability, detection rate, and lesion patterns of 68Ga-PSMA-11-PET/CT in early-stage biochemical recurrence of prostate cancer after radical prostatectomy

PURPOSE

⁶⁸Ga-PSMA-11-PET/CT is increasingly used in early-stage biochemical recurrence of prostate cancer to detect potential lesions for an individualized radiotherapy concept. However, subtle findings especially concerning small local recurrences can still be challenging to interpret and are prone to variability between different readers. Thus, we analyzed interobserver variability, detection rate, and lesion patterns systematically in a homogeneous patient population with low-level biochemical recurrence.

METHODS

We analyzed ⁶⁸Ga-PSMA-11-PET/CTs in 116 patients with status post-prostatectomy and PSA levels up to 0.6 ng/ml. None of them received ADT or radiotherapy beforehand. Images were interpreted and blinded by two nuclear medicine physicians (R1 and R2). Findings were rated using a 5-point scale concerning local recurrence, lymph nodes, bone lesions, and other findings (1: definitely benign, 2: probably benign, 3: equivocal, 4: probably malignant, 5: definitely malignant). In findings with substantial discrepancies of 2 or more categories and/or potentially leading to differences in further patient management, a consensus reading was done with a third reader (R3). Interobserver agreement was measured by Cohens Kappa analysis after sub-categorizing our classification system to benign (1 + 2), equivocal (3), and malignant (4 + 5). Time course of PSA levels after salvage treatment of patients rated as positive (4 + 5) was analyzed.

RESULTS

The overall detection rate (categories 4 and 5) was 50% (R1/R2, 49%/51%) and in the PSA subgroups 0-0.2 ng/ml, 0.21-0.3 ng/ml, and 0.31-0.6 ng/ml 24%/27%, 57%/57%, and 65%/68%, respectively. Local recurrence was the most common lesion manifestation followed by lymphatic and bone metastases. The overall agreement in the Cohens Kappa analysis was 0.74 between R1 and R2. For local, lymphatic, and bone sites, the agreement was 0.76, 0.73, and 0.58, respectively. PSA levels of PSMA PET/CT-positive patients after salvage treatment decreased in 75% (27/36) and increased in 25% (9/36). A decrease of PSA, although more frequent in patients with imaging suggesting only local tumor recurrence (86%, 18/21), was also observed in 67% (10/15) of patients with findings of metastatic disease.

CONCLUSIONS

In a highly homogeneous group of prostate cancer patients with early-stage biochemical recurrence after radical prostatectomy, we could show that ⁶⁸Ga-PSMA-11-PET/CT has a good detection rate of 50% which is in accordance with literature, with clinically relevant findings even in patients with PSA < 0.21 ng/ml. The interobserver variability is low, particularly concerning assessment of local recurrences and lymph nodes. Therefore, PSMA-PET/CT is a robust diagnostic modality in this patient group for therapy planning.

Modelling the internalisation process of prostate cancer cells for PSMA-specific ligands

INTRODUCTION

In prostate-specific membrane antigen (PSMA)-targeting radioligand therapy, small molecules are regularly internalised by the tumour cells. To determine the effectiveness of these ligands, the internalised fraction over time is derived from cell studies. Parameters, such as the ligand concentration and the number of cells, are experiment-specific and therefore a comparison between ligands is difficult. A more objective approach that allows better comparison is desirable. Therefore, the aim of this work was to develop a compartmental model that fully describes all relevant pharmacokinetic interactions of PSMA-specific ligands with prostate cancer cells.

METHODS

Internalisation studies were performed using the lymph node carcinoma of the prostate cell line LNCaP C4-2 and the prostatic carcinoma cell line PC-3. A new protocol was established for the determination of the PSMA-binding specificity by surface plasmon resonance (SPR). The experimental data in combination with parameters from literature were used for the modelling approach.

RESULTS

A compartmental model which includes the relevant physiological mechanisms was developed. The basic model structure and some parameters originate from the literature. The PSMA-specific association and dissociation rates of Ga-PSMA-11 were measured using surface plasmon resonance technology. The ligand-induced internalisation and PSMA synthesis rates were estimated by fitting the developed model to experimental data obtained using LNCaP C4-2 cells. For all [⁶⁸Ga]Ga-PSMA-11 concentrations and including four various incubation times, the ligand-induced internalisation was determined to be (3.6 ± 0.1) % min^-1.

CONCLUSIONS

The presented approach is a prerequisite for better estimation and thus comparison of important ligand-cell interaction parameters, by combining SPR measurements, cell experiments and mathematical modelling.

ADVANCES IN KNOWLEDGE AND IMPLICATIONS FOR PATIENT

A compartmental model was developed for evaluation and comparison of PSMA-binding small molecules. A SPR protocol was established for the determination of PSMA-binding specificity.

Abstract P3-10-01: Single-cell profiling identifies hypoxic carcinoma cells as source of an immunosuppressive VEGFA metagene

Background:

We have previously shown that expression of the IL8/VEGFA-metagene eliminates the good prognostic effect of TILs in TNBC (PMID 21978456, 28750120). We also showed that the VEGFA metagene predicted response to neoadjuvant bevacizumab in the GeparQuinto trial (Karn 2017 SABCS #851166). The main cellular sources of the transcripts that comprise the VEGFA metagene are unknown since mRNA profiling of bulk biopsies contains signals from different cell types.

Methods:

Individual genes that comprise the VEGFA metagene were measured in bulk tissue- and single cell-RNA-Seq from breast cancer subtypes and normal cells on different platforms (Affymetrix n=4915, Agilent n=597, Illumina n=2433, RNA-Seq n=1215, Exome Capture RNA-Seq n=226, HTG-Seq n=243, sc-RNA-Seq n=24710). For blinded, orthogonal validation we performed immunohistochemistry. Effect of neoadjuvant chemotherapy with or without bevacizumab was studied by RNA-Seq and IHC on samples from GeparQuinto trial. SWOG S0800 (GSE114403), PROMIX (GSE87455), and GeparSixto trials were used for validation. TCGA was mined for mutations and somatic CNA. RNA-Seq from GeparNuevo was used for correlation with checkpoint inhibitor treatment.

Results:

We identified a stable core of six genes (VEGFA, ANGPTL4, ADM, NDRG1, DDIT4, CSTB) in different cohorts. Strong expression of this signature was mainly restricted to TNBC subtype and associated with poor prognosis within this subgroup. Single cell RNA-Seq of breast epithelial cells from 4 reduction mammoplasties and 4 TNBC revealed that these genes are coexpressed in individual epithelial cells and not associated with endothelial cells. In line with their presumed functions in cellular stress and hypoxia, immunohistochemistry revealed strong para-necrotic expression in TNBC. Moreover, high gene expression in TNBC was associated with mutations in DNA damage control pathways, somatic copy number alterations, and lower TILs. While chemotherapy led to downregulation, bevacizumab increased expression. In multivariate analysis, high pretreatment values predict pCR to both bevacizumab and chemotherapy (OR 2.40, P=0.006), which may be explained by sensitivity of tumors which are already under cellular stress. On the other hand, expression of the VEGFA metagene seems to create an immunosuppressive environment that counteracts the positive prognostic effect of TILs. In pre-treatment biopsies from the GeparNuevo checkpoint inhibitor trial we found a negative correlation of VEGFA metagene expression with the amount of the recently identified tissue-resident memory T cell subset (CD8TRM, PMID 29942092; P=0.002), while the subsequent increase of CD8TRM during treatment was larger in tumors with high VEGFA (P=0.019).

Conclusions:

Perinecrotic carcinoma cells under stress from hypoxia and or chromosomal instability are the source of the VEGFA metagene signature. Its predictive value in TNBC suggests estimating and reporting the amount of necrosis in the pathology report may be helpful in predicting response to preoperative chemotherapy, and could be used as stratification factor in clinical trials. The signature indicates an immunosuppressive environment and should be further studied in the context of immune therapies in combinations with anti-angiogenic treatment.

Citation Format: Karn T, Denkert C, Sinn BV, Weber K, Nekljudova V, Rody A, Meissner T, Hatzis C, El-Balat A, Becker S, Solbach C, Untch M, Schneeweiss A, von Minckwitz G, Loibl S, Pusztai L, Holtrich U. Single-cell profiling identifies hypoxic carcinoma cells as source of an immunosuppressive VEGFA metagene [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 P3-10-01.

Abstract P2-08-01: Factors predicting relapse in early breast cancer patients with a pathological complete response after neoadjuvant therapy – Results of a pooled analysis based on the GBG meta-database

Background

Even though patients with a pCR following neoadjuvant chemotherapy have an excellent prognosis still some of these patients will eventually relapse. A better identification of pts with an increased risk of relapse despite a pCR would be helpful to select these patients for additional post-neoadjuvant treatment strategies. Thus, the rationale of this retrospective analysis was to identify factors predicting relapse despite a pCR.

Methods

This pooled retrospective analysis based on the GBG meta-database includes the neoadjuvant trials GeparTrio, GeparQuattro, GeparQuinto, GeparSixto and GeparSepto. In these trials 2188 (27%) of 7933 pts had a pCR according to ypT0/ypTis ypN0 Definition and were included. The primary endpoint was disease-free survival (DFS), secondary endpoints were distant DFS (DDFS) and overall survival (OS). A multivariate Cox proportional hazards model was used to report hazard ratios with 95% confidence interval (CI). The two-sided significance level was set to α=0.05. Endpoints were analysed for all pts and in subgroups defined by intrinsic subtypes. The potential risk factors intrinsic subtype (HER2 negative/hormone receptor (HR) positive, triple negative, HER2 positive/HR positive, HER2 positive/HR negative), histological tumor type (lobular vs other), grade (G1/G2 vs G3), KI67 (≤20% vs higher), initial cT and cN stadium (cT1 vs cT2 vs cT3/4; cN0 vs cN+), age (≤40 vs 41-59 vs ≥60), BMI (&lt; 25 vs 25-29 vs ≥ 30), planned number of cycles of chemotherapy (≤6 vs &gt; 6), menopausal status (pre- vs postmenopausal) and clinical response after 2-4 cycles (SD vs PR vs CR vs PD) were included as covariates in multivariate Cox regression models as well as study identification.

Results

From 2188 evaluable patients DFS, DDFS and OS events were observed in 290/197/130 pts respectively; the median follow-up over all studies was 59 months. In multivariate analysis including study and all potential risk factors DFS was significantly different with regard to the initial cN status (cN+ vs cN0, hazard ratio (HR) 1.70; 95% CI [1.2, 2.4], p=0.002). Of borderline significance was histological type (non-lobular vs lobular, HR 0.52 95% CI [0.3, 1.1]; p=0.076) and initial tumor stage (cT3/4 vs cT1, HR 1.61 95% CI [1.0, 2.7]; p=0.064). In terms of DDFS significant differences were seen for the initial cN status (cN+ vs cN0, HR 2.34; 95% CI [1.5, 3.6], p&lt;0.001) and initial tumor stage (cT3/4 vs cT1, HR 1.83 95% CI [1.0, 3.3]; p=0.044); histological type was again close to significance (non-lobular vs lobular, HR 0.46 95% CI [0.2, 1.1]; p=0.067). Multivariate analysis showed significantly worse OS with initial cT3/4 tumors (cT3/4 vs cT1, HR 2.48 95%CI [1.1, 5.7]; p=0.030), and the lobular type (non-lobular vs lobular, HR 0.35 95% CI [0.1, 0.9]; p=0.026) and a trend for worse OS in pts with cN+ (cN+ vs cN0, HR 1.67 95% CI [1.0, 2.9]; p=0.067).

Conclusions

Initial tumor load before start of neoadjuvant chemotherapy (tumor stage and nodal status) and lobular subtype were predictors of long term outcome after a pCR following neoadjuvant chemotherapy. Intrinsic subtype, KI67, grade and planned number of cycles were not predictive for a relapse.

Citation Format: Huober J, Schneeweiss A, Blohmer J-U, Denkert C, Tesch H, Hanusch CA, Salat C, Rhiem K, Rezai M, Solbach C, Fasching PA, Jackisch C, Mehta K, Nekljudova V, Seither F, von Minckwitz G, Loibl S, Untch M. Factors predicting relapse in early breast cancer patients with a pathological complete response after neoadjuvant therapy – Results of a pooled analysis based on the GBG meta-database [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 P2-08-01.

Abstract OT1-06-02: Oncotype DX®-REMAR(Rhein-Main-Registry)-study: Use of the oncotype DX® assay in early breast cancer in certified breast cancer centers in Rhine-Main Region, Germany

A brief background discussion:

The OncotypeDX® multigene assay is recommended by several international guidelines as a predictive and prognostic factor for HR+/HER2- early breast cancer (EBC). Several trials have shown the necessity of OncotypeDX® Recurrence Score (RS) as a decision tool for HR+/HER2- EBC with 0-3 lymph nodes (LN) involved. At present, though, only limited data from the routine setting are available on the impact of treatment decision making process based on the usage of classical proliferation marker Ki67 with or without knowing the individual RS prior and after a treatment decision from a multidisciplinary tumor board (MTB) for the decision making of the adjuvant therapy of EBC. The Oncotype DX® assay is still not reimbursed by every insurance, therefore we expect that this registry will have an impact on reimbursement in Germany.

Trial design:

The OncotypeDX®-REMAR(Rhein-Main-Registry) study is a prospective, non-interventional, multicenter and non-randomized, study. 13 certified breast cancer (BC) centers in the Rhine-Main region in Germany participate. The sponsor of this trial is the AGAPLESION, Markus Hospital Frankfurt, Genomic Health provides the financial support.

After registration, the patient´s case will be discussed in the respective institution's MTB, before and after the RS result. The adjuvant treatment will be recommended based on available clinical and histopathological data according to the guidelines and the RS result. After each meeting, the physician and patient will fill in a questionnaire. In addition to the local determination of Ki67 and nuclear grading, a central pathology assessment of these two markers will be provided in a blinded fashion. Only the sponsor has access to these results. Consequently, this independent test has no influence both on the local histopathology result and on the recommended treatment.

Eligibility criteria:

Inclusion criteria:

Female patients, ≥18 years, with a hormone-receptor positive, HER2-negative EBC and 0-3 positive LN, T1-3, nuclear grading 1-3, Ki67:10-40%, cM0.

Specific aims:

Primary endpoint is the decision impact of the RS result in patients with mid-range Ki67 on adjuvant chemotherapy in EBC.

Secondary endpoints include the correlation of Ki67 with tumor grade and RS result. Moreover, an economic subanalysis will be done.

Statistical methods:

The change in physicians' treatment recommendations will be measured pre-assay vs. post-assay. The proportion of patients for whom the treatment recommendation changed and the 95% confidence interval will be reported overall and by select groups. McNemar's test will be used to compare the proportion of patients' recommended chemo-hormonal therapy pre-assay vs. post-assay.

Present accrual and target accrual:

Thirteen participating centers recruited 97 patients by the end of April 2017. 600 patients are planned in total.

Contact information for people with a specific interest in the trial:

In case of interest you can contact Ms. Louiza Anastasiadou, Tel: +4969-9533-66395, Fax: +4969-9533-2385, email: louiza.anastasiadou@fdk.info

Citation Format: Anastasiadou L, Aulmann S, Falk S, Baier P, Giesecke D, Buchen S, Hurst U, Krapfl E, Moebus V, Mosch D, Schulmeyer E, Solbach C, Ackermann S, Gabriel B, Jackisch C, Thill M. Oncotype DX®-REMAR(Rhein-Main-Registry)-study: Use of the oncotype DX® assay in early breast cancer in certified breast cancer centers in Rhine-Main Region, Germany [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 OT1-06-02.

Abstract P2-09-02: Blinded molecular subtyping analysis from RNA-Seq of FFPE samples in the GeparQuinto trial reveals predictive value of VEGFA metagene for bevacizumab treatment

Background:

RNA-Seq from total RNA in FFPE tissue can be more challenging due to limited capture of partially degraded RNA. Exome-capture based RNA-Seq may circumvent such problems and allow reproducible complete molecular characterization of low-quality RNA from small clinical samples.

Methods:

HER2 negative patients within the GeparQuinto trial were treated with neoadjuvant anthracycline-taxane-based chemotherapy +/- bevacizumab. Patients with bevacizumab therapy had a significantly higher pCR rate, especially within the triple negative subgroup. We performed exome-capture RNA-Seq on 5µm FFPE sections from pre-therapeutic cores of 400 HER2 negative samples from this trial. In a prospectively planned, blinded study we correlated molecular subtypes and metagenes for proliferation, stroma, MHC2, and VEGFA with clinical and histopathological data. Molecular subtypes were defined using the AIMS methods. Metagenes were calculated as mean values corresponding to previously described gene clusters after platform transfer (Rody et al. 2011 PMID 21978456, Hu et al. 2009 PMID 19291283) and then z-transformed.

Results:

296 samples with RNA-Seq data were classified as either of high (n=226) or of limited quality (n=70). For 22 samples RNA yield was insufficient and 82 did not pass initial QC. 121 (41%), 63 (21%), 34 (11.5%), 46 (15.5%), and 32 (11%) samples were defined as basal-like, HER2-enriched, luminal A, luminal B, and normal-like, respectively. Subtyping was robust with regard to gene filtering, normalization, and sample quality. ER and PR status from local IHC strongly correlated with gene expression (overall correctness 84% and 80% for ER, and 85% and 74% for PR, in samples with high and limited quality, respectively) and luminal subtypes (95% ER positive). Proliferation metagene correlated with histological grade (median -0.73, -0.39, and 0.53 in G1, G2, and G3, respectively; P&lt;0.001) and MHC2 metagene correlated strongly with TIL counts (Rho=0.53, P&lt;0.001). Among the high quality samples response rates (49.3% pCR overall) differed significantly by subtype, with higher pCR rates in basal-like (68.9%) and HER2-enriched (45.5%) than in luminal B (35.7%), luminal A (17.9%), and normal-like (20.0%). MHC2- (OR 1.60, 95%CI 1.21-2.12, P=0.001), proliferation- (OR 2.88, 95%CI 2.00-4.16, P&lt;0.001), and VEGFA-metagenes (OR 1.92, 95%CI 1.41-2.60, P&lt;0.001) were significant predictors for pCR. In a multivariate logistic regression (adjusted for bevacizumab treatment and hormone receptor status) both VEGFA metagene (OR 2.59, 95%CI 1.40-4.77, P=0.002) and the interaction between the VEGFA-metagene and bevacizumab treatment arm (P=0.023) significantly predicted pCR.

Conclusions:

Exome-capture RNA-Seq allows robust genomic characterization of clinical samples with limited FFPE material from core biopsies, and molecular subtypes and immune metagenes are predictive for pCR. The VEGFA metagene is a specific predictor for response to neoadjuvant bevacizumab treatment.

Citation Format: Karn T, Meissner T, Weber K, Sinn B, Denkert C, Budczies J, Nekljudova V, Fasching PA, Holtrich U, Schem C, Solbach C, Hartmann A, Röcken C, Untch M, Young BM, Willis S, Leyland-Jones B, von Minckwitz G, Loibl S. Blinded molecular subtyping analysis from RNA-Seq of FFPE samples in the GeparQuinto trial reveals predictive value of VEGFA metagene for bevacizumab treatment [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 P2-09-02.

Abstract P1-17-01: Development of brain metastases in breast cancer patients treated in the neoadjuvant trials Geparquinto and Geparsixto

Background: The incidence of brain metastases (BM) in breast cancer patients is rising and has become a major clinical challenge. So far, the incidence of BM after modern neoadjuvant treatment is not clear.

Materials and Methods: In Geparquinto, patients with untreated HER2-positive breast cancer (n=615) received either lapatinib or trastuzumab, patients with HER2 negative breast cancer (n=1925) received bevacizumab in addition to an anthracycline and taxane-containing regimen and those not responding paclitaxel and everolimus (n=32). In Geparsixto, patients with HER2-positive tumors (n=273) received trastuzumab and lapatinib and patients with triple-negative tumors (n=315) received bevacizumab in addition to chemotherapy. We analyzed clinical factors associated with the occurrence of BM as first site of metastatic relapse after neoadjuvant treatment in both trials (n=3160).

Results: After a median follow-up of 61 months, 108 (3%) of a total of 3160 patients developed BM as first site of recurrence and 411 (13%) patients had distant metastases outside the brain. Brain metastases as first site of recurrence occurred later than other metastases (3--year-relapse free-rate 96.7% for patients who developed BM and 89.5% for patients who developed metastases outside the brain). Regarding subtypes of the primary tumor, 1% of luminal A (11/954), 2% of luminal B (7/381), 4% of HER2 positive (34/809) and 6% of triple-negative patients (56/1008) developed BM as first site of recurrence. In multivariate analysis, risk factors for the development of BM were larger tumor size (cT3-4; HR 1.9, 95%-CI 1.3-2.8, p=0.0022), node positive disease (HR 2.8, 95% CI 1.8-4.4, p&lt;0.0001), no pCR after neoadjuvant chemotherapy (HR 2.7, 95% CI 1.6-4.7, p=0.0003) and HER2 positive (HR 3.8, 95% CI 1.9-7.8, p=0.0002) or triple-negative subtype (HR 8.1, 95% CI 4.2 – 15.8, p&lt; 0.0001). Breast cancer subtype remained the most relevant risk factor for BM. Patients who developed BM were more often HER2 positive or triple-negative tumors compared with patients who developed metastases outside the brain (HER2 positive subtype 32 vs. 19%, triple-negative subtype 52 vs. 40%, p&lt; 0.001).

Conclusion: Especially patients with HER2-positive and triple negative tumors are at risk of developing BM despite active systemic treatment. A better understanding of the underlying mechanisms is required in order to develop potential preventive strategies.

Citation Format: Witzel ID, Laakmann E, Fasching PA, Rezai M, Schem C, Solbach C, Tesch H, Klare P, Schneeweiss A, Zahm D, Blohmer J, Ingold-Heppner B, Huober J, Hanusch C, Jackisch C, Reinisch M, Untch M, von Minckwitz G, Müller V, Loibl S. Development of brain metastases in breast cancer patients treated in the neoadjuvant trials Geparquinto and Geparsixto [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 P1-17-01.

Quantitative and correlative biodistribution analysis of 89Zr-labeled mesoporous silica nanoparticles intravenously injected into tumor-bearing mice

The biodistribution of ⁸⁹Zr-labeled mesoporous silica nanoparticles (MSNs) was evaluated in detail using a prostate cancer mouse model bearing LNCaP C4-2 and PC-3 tumor xenografts with focus on passive targeting. PEGylation of radiolabeled MSNs significantly improved the blood circulation times and radically enhanced the accumulation in tumors comparable to the accumulation levels previously reported for similar but actively targeted particles. The distribution of the passively targeted MSNs was related to the degree of vascularization of the tumors and did not follow the trends observed in vitro. Correlative analyses of organ-to-blood ratios revealed that little or no accumulation of the particles is observed in the lungs, heart, and brain, and that the particles detected were present in the blood pool. On the other hand, clear accumulation was observed in the liver and spleen, in addition to the uptake in the tumors. The accumulation of particles in the kidney did not correlate with the MSN concentration in the blood, but indicated a rather steady level of particles in the kidney. The results, which partly contradict previous studies, highlight the importance of correlative analyses in order to evaluate the organ accumulation of particles.

Radiofluorination of PSMA-HBED via Al(18)F(2+) Chelation and Biological Evaluations In Vitro

PURPOSE

Ga-68-labeled prostate-specific membrane antigen (PSMA) ligands have been used clinically for positron emission tomography (PET) imaging of prostate cancer. However, F-18-labeled compounds offer several advantages, including the potential for delayed imaging, high starting activities enabling multidose preparation, and improved spatial resolution in PET. For F-18 labeling of peptides conjugated with a suitable chelator, a fast and feasible method is the use of [Al(18)F](2+). In the present study, the radiofluorinations of a well-known PSMA ligand Glu-NH-CO-NH-Lys(Ahx)-HBED-CC (PSMA-HBED) via [Al(18)F](2+) were performed with respect to various reaction parameters, along with the biological evaluations in a cell experiment.

PROCEDURES

[Al(18)F]PSMA-HBED was prepared by adding Na[(18)F]F into a vial containing 0.026 μmol peptide (in 0.05 M NaOAc buffer) and 0.03 μmol AlCl3⋅6H2O (in 0.05 M NaOAc buffer). Then, it was stirred at different temperatures from 1 to 30 min. Afterwards, purification was carried out by solid phase extraction. Biological evaluations were performed in PSMA-positive cell lines LNCaP C4-2, along with a negative control using PC-3 cell lines.

RESULTS

The best labeling results (81 ± 0.5 %, n = 4) were observed with 0.026 μmol peptide (30 °C, 5 min). For preclinical experiments, the production of [Al(18)F]PSMA-HBED at 35 °C including purification by solid phase extraction (SPE) succeeded within 45 min, resulting in a radiochemical yield of 49 ± 1.2 % (decay-corrected, n = 6, radiochemical purity ≥98 %) at EOS. The labeled peptide revealed serum stability for 4 h as well as a promising binding coefficient (K D) value of 10.3 ± 2.2 nM in cell experiments with PSMA-positive LNCaP C4-2 cells.

CONCLUSION

An efficient and one-pot method for the radiosynthesis of [Al(18)F]PSMA-HBED was developed (0.26 μmol of precursor at 35 °C). In cell culture studies, the K D suggests [Al(18)F]PSMA-HBED as a potential PSMA ligand for future investigations in vivo and clinical applications afterwards.

Survival after neoadjuvant chemotherapy with or without bevacizumab or everolimus for HER2-negative primary breast cancer (GBG 44-GeparQuinto)†

BACKGROUND

The GeparQuinto study showed that adding bevacizumab to 24 weeks of anthracycline-taxane-based neoadjuvant chemotherapy increases pathological complete response (pCR) rates overall and specifically in patients with triple-negative breast cancer (TNBC). No difference in pCR rate was observed for adding everolimus to paclitaxel in nonearly responding patients. Here, we present disease-free (DFS) and overall survival (OS) analyses.

PATIENTS AND METHODS

Patients (n = 1948) with HER2-negative tumors of a median tumor size of 4 cm were randomly assigned to neoadjuvant treatment with epirubicin/cyclophosphamide followed by docetaxel (EC-T) with or without eight infusions of bevacizumab every 3 weeks before surgery. Patients without clinical response to EC ± Bevacizumab were randomized to 12 weekly cycles paclitaxel with or without everolimus 5 mg/day. To detect a hazard ratio (HR) of 0.75 (α = 0.05, β = 0.8) 379 events had to be observed in the bevacizumab arms.

RESULTS

With a median follow-up of 3.8 years, 3-year DFS was 80.8% and 3-year OS was 89.7%. Outcome was not different for patients receiving bevacizumab (HR 1.03; P = 0.784 for DFS and HR 0.974; P = 0.842 for OS) compared with patients receiving chemotherapy alone. Patients with TNBC similarly showed no improvement in DFS (HR = 0.99; P = 0.941) and OS (HR = 1.02; P = 0.891) when treated with bevacizumab. No other predefined subgroup (HR+/HER2-; locally advanced (cT4 or cN3) or not; cT1-3 or cT4; pCR or not) showed a significant benefit. No difference in DFS (HR 0.997; P = 0.987) and OS (HR 1.11; P = 0.658) was observed for nonearly responding patients receiving paclitaxel with or without everolimus overall as well as in subgroups.

CONCLUSIONS

Long-term results, in opposite to the results of pCR, do not support the neoadjuvant use of bevacizumab in addition to an anthracycline-taxane-based chemotherapy or everolimus in addition to paclitaxel for nonearly responding patients.

CLINICAL TRIAL NUMBER

NCT 00567554, www.clinicaltrials.gov.

Synthesis, characterization, and biodistribution of multiple 89Zr-labeled pore-expanded mesoporous silica nanoparticles for PET

Functional nanoparticles are highly interesting imaging agents for positron emission tomography (PET) due to the possibility of multiple incorporation of positron emitting radionuclides thus increasing the signal strength. Furthermore, long-term nanoparticle biodistribution tests with increased signal-to-noise ratio can be achieved with nanoparticles carrying long-lived isotopes. Mesoporous silica nanoparticles, MSNs, have recently attracted a lot of interest as both imaging agents and carriers for drugs in vitro and in vivo. Here we present results related to the synthesis of PET imageable MSNs carrying the long-lived (89)Zr isotope (half-life of 78.4 hours). Here, (89)Zr(4+) was immobilized through covalent attachment of the complexing agent p-isothiocyanatobenzyldesferrioxamine (DFO-NCS) to large-pore MSNs. Due to the presence of the high DFO content on the MSNs, quantitative (89)Zr(4+) labeling was achieved within just a few minutes, and no subsequent purification step was needed in order to remove non-complexed (89)Zr(4+). The stability of the (89)Zr-labeled MSNs against leaching of (89)Zr(4+) was verified for 24 hours. The high signal strength of the (89)Zr-DFO-MSNs was evidenced by successful PET imaging using a mouse model at particle loadings one order of magnitude lower than those previously applied in PET-MSN studies. The biodistribution followed the same trends as previously observed for MSNs of different sizes and surface functionalities. Taken together, our results suggest that (89)Zr-DFO-MSNs are promising PET imaging agents for long-term in vivo imaging.

Abstract P3-14-04: The choice of the indicator lesion impacts on the pCR rate – An analysis of 114 bilateral breast cancer patients treated within neoadjuvant trials

Background: Patients with bilateral breast cancer are usually excluded from participating in clinical trials. The German Breast Group has traditionally included these patients into their neoadjuvant trials. However, little is known about the outcome of the non-indicator lesion.

Methods: We prospectively captured the information on bilateral breast cancer in our database and collected retrospectively the information from the original histological and surgical reports on tumor size, nodal status, histology, grading, hormone receptor and HER2 status as well as type of surgery and pathological complete response defined as ypT0 ypN0 and ypT0/is ypN0 because both definitions have been used in our clinical studies. The treating physician decided on clinical presentation, which side to be the indicator lesion on which response was assessed for the purpose of the study. The synchronous carcinoma in the contralateral breast is considered as the non-indicator lesion.

Results: From the 6727 patients treated within the Gepartrio, Geparquattro, Geparquinto, and Geparsixto study 157 (2.3%) patients have been identified with the diagnosis of bilateral carcinoma. From the 114 bilateral patients with any information on the non indicator lesion 104 with information on pCR on both sides were used for further analysis. The median age was 51 (range 29-74) years. There were more cT1 (48.5% vs 9.6%, p&lt;0.001) and cN0 (60.0% vs 38.4%, p = 0.004) tumors in the group of the non-indicator lesion compared to the indicator lesion group. In 56% the molecular subtype was identical 86% had a luminal A like tumor of indicator as well as the non-indicator lesion, none of the luminal B-like indicator lesions were identical, 27% of the HER2+/ HR +, 58% in the HER2+/ HR- group and 66% of the triple negative indicator lesions had an identical non indicator lesion. In general the tumor tended to be of lower malignant potential in the non- indicator lesion. Lobular carcinomas (23.4% vs 16.7%, p = 0.205); grade 3 (26% vs 36.7%, p = 0.101), ER positive (72% vs 67%, p = 0.427), HER2-positive (23.9 vs. 35.7%, p = 0.068). Overall the pCR rate (ypT0 ypN) was 20.2% in the non-indicator lesion group vs 13.9% the indicator lesion group (p = 0.276) and ypT0/is ypN0 was 30.8% and 17.6%, respectively (p = 0.0388). 64.4% had no pCR in the indicator as well as the non-indicator lesion, 11.5% had a pCR in the indicator as well as the non-indicator lesion, 4.8% in the indicator alone and 19.2% in the non-indicator alone. Breast conserving surgery was performed more often for non-indicator lesions than for indicator lesions (59% vs 44.4%, p = 0.144).

Conclusion: In general the selection for the indicator lesion was based on tumor size, nodal status and inclusion criteria. Probably, some of the indicator lesions would not have qualified for trial participation. The pCR rate including non-invasive residuals was significantly higher for the non-indicator lesions probably due to smaller tumors and less nodal involvement at baseline. However, based on our data bilateral breast carcinomas should not be excluded from neoadjuvant clinical trials.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P3-14-04.

Neoadjuvant bevacizumab and anthracycline-taxane-based chemotherapy in 678 triple-negative primary breast cancers; results from the geparquinto study (GBG 44)

BACKGROUND

We evaluated the pathological complete response (pCR) rate after neoadjuvant epirubicin, (E) cyclophosphamide (C) and docetaxel containing chemotherapy with and without the addition of bevacizumab in patients with triple-negative breast cancer (TNBC).

PATIENTS AND METHODS

Patients with untreated cT1c-4d TNBC represented a stratified subset of the 1948 participants of the HER2-negative part of the GeparQuinto trial. Patients were randomized to receive four cycles EC (90/600 mg/m(2); q3w) followed by four cycles docetaxel (100 mg/m(2); q3w) each with or without bevacizumab (15 mg/kg; q3w) added to chemotherapy.

RESULTS

TNBC patients were randomized to chemotherapy without (n = 340) or with bevacizumab (n = 323). pCR (ypT0 ypN0, primary end point) rates were 27.9% without and 39.3% with bevacizumab (P = 0.003). According to other pCR definitions, the addition of bevacizumab increased the pCR rate from 30.9% to 41.8% (ypT0 ypN0/+; P = 0.004), 36.2% to 46.4% (ypT0/is ypN0/+; P = 0.009) and 32.9% to 43.3% (ypT0/is ypN0; P = 0.007). Bevacizumab treatment [OR 1.73, 95% confidence interval (CI) 1.23-2.42; P = 0.002], lower tumor stage (OR 2.38, 95% CI 1.24-4.54; P = 0.009) and grade 3 tumors (OR 1.68, 95% CI 1.14-2.48; P = 0.009) were confirmed as independent predictors of higher pCR in multivariate logistic regression analysis.

CONCLUSIONS

The addition of bevacizumab to chemotherapy in TNBC significantly increases pCR rates.

Influence of additives to the formulation of n.c.a. [¹¹C]PiB on sterile filter performance

The influence of different additives (PEG 300, PEG 400, PG) to the product solution of [(11)C]PiB was investigated with regard to tracer retention for a number of commonly used sterile filters for aseptic manufacturing of PET-tracers. The effect of the amount of additive with regard to tracer retention and the resulting viscosity of the filtration solution was determined. Recommendations for the individual combinations of filters and amounts of additives suitable for the different filtration methods that are implemented in commercially available synthesis modules are given as well.

Abstract P2-10-13: CD4 positive tumor-infiltrating lymphocytes are associated with improved prognosis in node-negative breast cancer

Background: The prognostic significance of CD8 positive cytotoxic lymphocytes in breast cancer is well accepted. However, the role of CD4 positive lymphocytes is ambiguous. We examined the prognostic relevance of CD4 positive tumor-infiltrating lymphocytes in previously published node-negative breast cancer cohorts using RNA expression.

Methods: Microarray based gene-expression data for CD4 (203547_at) were analyzed in four previously published cohorts (Mainz, Rotterdam, Transbig, Yu) of node-negative breast cancer patients not treated with adjuvant therapy (n = 824). A meta-analysis of previously published cohorts was performed using a random effects model. Prognostic significance of CD4 on metastasis-free survival (MFS) was examined in the whole cohort and in different molecular subtypes (ER+/HER2−, ER−/HER2−, HER2+). Independent prognostic relevance was analyzed using multivariate Cox regression.

Results: Higher RNA expression of CD4 was related to better MFS in a meta-analysis of the whole cohort (HR 0.66, 95% CI 0.49–0.90, p = 0.0074). Prognostic significance was most pronounced in the HER2+ positive molecular subtype (HR 0.32, 95% CI 0.14–0.75, p = 0.0091) as compared to ER+/HER2− (HR 0.62, 95% CI 0.29–1.32, P&gt;0.05) and ER−/HER2− (HR 0.61, 95% CI 0.28–1.35, P&gt;0.05) carcinomas of the breast. CD4 showed independent prognostic significance (HR 0.60, 95% CI 0.37–0.96, p = 0.032) in multivariate analysis. In addition to CD4, only histological grade of differentiation (HR 2.43, 95% CI 1.50–3.94, P &lt; 0.001) and tumor size (HR 1.87, 95% CI 1.19–2.94, p = 0.007), but not age, HER2 status or hormone receptor status retained an independent prognostic association with MFS.

Conclusion: CD4 positive tumor-infiltrating lymphocytes have independent prognostic significance in node-negative breast cancer. A higher expression is associated with improved outcome.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P2-10-13.