Abstract P2-01-02: Heterogeneity and variability of human epidermal growth factor receptor 2 (HER2) expression on circulating tumor cells (CTC) in HER2 negative metastatic breast cancer patients treated with first line weekly paclitaxel and bevacizumab in a prospective cohort from the French Breast Cancer InterGroup Unicancer (UCBG): COMET study

Background: It has been reported in women with advanced estrogen-receptor (ER)-positive/(HER2)-negative breast cancer the acquisition of a HER2-positive CTC subpopulation during therapy (Jordan NV Nature 2016). The clinical significance of acquired HER2 heterogeneity during the evolution of metastatic breast cancer is unknown. We report here the analysis of HER2 status of CTC before and after one cycle of treatment in HER2 negative metastatic breast cancer patients treated with first line weekly paclitaxel and bevacizumab.

Patients & methods:The French cohort COMET is a prospective study including first line HER2 negative patients (pts) receiving weekly paclitaxel and bevacizumab according to EMA approved combination. The aim of this cohort is to evaluate clinical, biological and radiological parameters associated with pts outcome. We confirmed previously the outcome of patients with high CTC count at base line and after one cycle of treatment (Bidard et al, Lancet Oncol 2014). We present here the analysis on 203 pts evaluated for the expression of HER2 on CTC using the FDA cleared CellSearch method. The HER2 expression of CTCs (CB11 clone) was categorized (class 0–3) as described by Riethdorf et al.CCR2010.

Results: At base line, 144 out of 203 pts had at least one detectable CTC (71%), (median 4, and range 1- 30,000). Among them, 104 (72%) had one or more HER2 positive CTC (1-21,484). In 25 patients with HER2 2+ primary tumor with FISH or CISH non amplified, the incidence of CTC HER2+ cases (13/25, 52%) was similar than in pts with HER2 0 or HER2 1+ (51%) primary tumor. In each case, 3 to 100% of detectable CTC could be HER2+ stained (median 50% of CTC). Only 12 cases (8% of all CTC cases) had 2+ HER2 staining score on CTC and none 3+. After one cycle of treatment, the number of pts with detectable CTC dropped to 64, including 42 with HER2+ CTC (65%). Out of these cases, 14 were 3+ or 2+ HER2 score (22% of CTC+ cases). This was a significant increase compared to baseline (8%) (p<0.001), including 6 cases with 100% of HER2+ CTC. To note, 7 patients without HER2+ CTC at baseline, had detectable HER2+ CTC after one cycle of treatment. With a median follow-up of 2 years, correlation of CTC variations with pts outcome is planned.

Conclusion: HER2 staining on CTC was heterogeneous with HER2 positive and negative subpopulations in the same patient with primary HER2 negative breast cancer. We observe a variability of HER2 CTC status with an increased intensity or appearance of immunostaining in few cases during treatment. We hypothesize that these phenotypes changes within patient-derived circulating tumor cells could contribute to progression of breast cancer and acquisition of drug resistance.

Citation Format: Pierga J-Y, Proudon C, Tredan O, Decraene C, Dubot C, Lorgis V, Jacot W, Goncalves A, Debled M, Levy C, Ferrero J-M, Jouannaud C, Luporsi E, Mouret-Reynier M-A, Dalenc F, Lemonnier J, Berger F, Bidard F-C. Heterogeneity and variability of human epidermal growth factor receptor 2 (HER2) expression on circulating tumor cells (CTC) in HER2 negative metastatic breast cancer patients treated with first line weekly paclitaxel and bevacizumab in a prospective cohort from the French Breast Cancer InterGroup Unicancer (UCBG): COMET study [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 P2-01-02.

Abstract OT3-04-01: A phase I of olaparib with radiation therapy in patients with inflammatory, loco-regionally advanced or metastatic TNBC (triple negative breast cancer) or patient with operated TNBC with residual disease

Background and discussion: TNBC shares clinical and pathological features with hereditary BRCA1-related breast cancers, and in sporadic TNBC; dysregulation of BRCA1 has been frequently observed together with other defects in homologous recombination pathways. Preclinical studies have shown that breast cancer cell lines with a triple-negative phenotype are more sensitive to PARP1 inhibitors compared with non-TNBC cells. These lines of evidence provide a strong rationale for developing a new therapeutic approach to TNBC based on targeting the DNA-repair defects via PARP inhibition in these cancers that the most aggressive are the inflammatory, loco-regional advanced and metastatic breast cancer, as well as operated patients with residual disease (after primary systemic treatment-PST).

The aim of this study is to determine the Maximal Tolerated Dose of Olaparib administered with concurrent loco regional RT in the previously described population of patients.

Trial design: Olaparib (oral administration) will be administered at a starting dose of 50 mg bid. The other dose levels will be: 100 mg bid, 150 mg bid, 200 mg bid. The 25 mg bid dose will be included in the model to deal with unexpected high toxicity of the starting dose. Seven days prior to their first fraction of radiation therapy, patients will begin taking Olaparib at the assigned dose twice daily each day. All patients will receive radiotherapy on day 8 after the start of Olaparib of 50 Gy to the whole breast (or chest wall) with or withour lymph nodes (LN) in 25 daily fractions and 5 weeks.

Eligibility Criteria: Women aged >18 years with histologically confirmed TNBC with loco-regional RT indication as :

Non-operated:

Inflammatory and/or advanced BC (T≥3 and/or N≥1) BC in progression during PST (containing anthracyclines or taxanes or the combination of both or containing platinium-based chemotherapy) or inoperable after PST.

Non operable metastatic BC (all T, all N, M1; with evaluable disease).

Or patients operated after PST and surgery with residual disease (non-pCR and pN+ disease, evaluable according to RECIST 1.1 criteria).

Specific aims

To assess the safety profile of Olaparib administered with concurrent RT.

This study should be completed by a methylation study of BRCA1 and RAD51 promoters.

Statistics Phase I dose-finding based on toxicity will be conducted in a sequential and adaptive Bayesian scheme, using the method of Time-to-event Continual Reassessment Method to determine the Maximum Tolerated Dose (MTD) of Olaparib associated with RT. The primary endpoint is Dose-Limiting Toxicity (DLT) occurring within 6 weeks after the end of RT (12 -13 weeks from the first drug intake, depending on the period of the radiotherapy treatment). Dose allocation will be centrally defined, based on DLT observed in all patients previously evaluated, by modeling the probability of DLT. An empiric model will be used for the dose-toxicity relationship. No intra-patient dose-escalation is permitted. No dose skipping in escalation is permitted. The MTD is defined as the dose associated with 25% of DLT.

Target accrual: Twenty-four to 30 pts are expected to be enrolled.

Contact: youlia.kirova@curie.fr

Citation Format: Kirova YM, Ezzalfani M, Rodrigues M, Pierga J-Y, Salomon A, Stern M-H, Laki F, Mosseri V, Berger F, Neffrati S, Armanet S, Fourquet A. A phase I of olaparib with radiation therapy in patients with inflammatory, loco-regionally advanced or metastatic TNBC (triple negative breast cancer) or patient with operated TNBC with residual disease [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 OT3-04-01.

Abstract P4-09-02: Disseminated tumor cells as predictive factor of benefit of lymph node irradiation to prevent loco-regional relapse

Background:

Early stage breast cancer patients with micrometastatic spread (cM0(i+) per the 2010 TNM staging), detected either in the bone marrow (disseminated tumor cells, DTC) or in the blood (circulating tumor cells, CTC) are at higher risk of distant relapse and death. Loco-regional relapses were also more frequently observed in patients with DTC and, recently, with CTC (IMENEO study, Bidard et al, SABCS 2016). In that context, we analyzed whether DTC detection would be a predictive factor for the benefit of comprehensive loco-regional irradiation.

Methods:

Patients with localized breast cancer were eligible for this IRB-approved prospective cohort after informed written consent. DTC status was prospectively assessed by trained pathologists after immunocytostaining following ISHAGE criteria, at time of surgery or prior to any primary systemic therapy. Irradiation volumes (breast or chest wall +/- regional lymph nodes) were defined per standard of care. Locoregional relapse was defined as documented ipsilateral invasive relapse occurring in the breast, chest wall and/or in regional lymph nodes, prior to any distant metastatic relapse. Locoregional relapse-free interval (LRFI) was defined as the time elapsed between breast surgery and locoregional relapse. Cumulative incidence rates and hazard ratio were obtained using both Cox and Fine-Gray models, taking into account metastatic relapse and death as competitive events. Interaction tests were performed to confirm the predictive value of DTC status in a multivariate analysis.

Results:

From 11.1998 to 09.2005, a total of 620 patients with non-metastatic breast cancer were included in this prospective cohort. Median FU was 11.7 years. Overall, 94 patients (15.1%) were DTC-positive and 50 patients (8.1%) experienced a locoregional relapse during follow-up. DTC detection was significantly associated with shorter LRFI in univariate and multivariate analyses (Cox, HR=2.6 [1.4;4.8], p=0.004 ; Fine-Gray, HR=1.76 [1.04;3.0], p=0.04). In the multivariate subgroup analysis, locoregional lymph node irradiation was associated with a longer LRFI for DTC-positive patients, but not for DTC-negative patients (interaction test in multivariate analysis: p=0.03). Similar results were obtained when taking locoregional relapses synchronous with distant metastatic disease into account (interaction test: p=0.02). Importantly, the predictive value of DTC status for the benefit of locoregional irradiation was independent of other clinical and pathological characteristics, including locoregional nodal (pN) status.

Conclusion:

This long term analysis confirms the independent long-term prognostic value of DTC on locoregional relapses. Moreover, the finding that cM0(i+) status is a predictive marker for the efficacy of locoregional lymph node irradiation promises a new opportunity to better tailor adjuvant radiation therapy in early stage breast cancer patients.

Citation Format: Bidard F-C, Mignot F, Poortmans P, Dureau S, Berger F, Loirat D, Proudhon C, Vincent-Salomon A, Pierga J-Y, Kirova Y. Disseminated tumor cells as predictive factor of benefit of lymph node irradiation to prevent loco-regional relapse [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 P4-09-02.

Abstract P2-11-08: Risk factors for fibrosis after whole breast radiation therapy in lateral position : A large scale single center experience

Background and Purpose: We previously confirmed the efficacy and safety of our technique of whole breast radiation therapy (WBRT) in isocentric lateral decubitus (ILD) position. The purpose of this work is to evaluate the risk factors for long-term fibrosis in patients treated in ILD position.

Material and methods: We studies 832 consecutive female patients with early stage BC treated by conservative surgery followed by 3D-conformal WBRT at Institut Curie between 2005 and 2010. Fibrosis and deformation were evaluated at the end of the treatment and subsequently every 6 months during at least 5 years, using NCI CTC v3.0 scale. Different fractionation schedules were used: 66Gy in 33 fractions, 50Gy in 25 fractions, 40Gy in 15 fractions, 41.6Gy in 13 fractions and 30Gy in 5 weekly fractions.

Results: Median age is 61.5 years (range: 29 - 90); median follow up is 6.4 years (range: 1.5 - 12.4). During the follow-up, 308 patients (38.9%) had grade 1 fibrosis, and 36 patients (4.3%) only, had grade 2-3 fibrosis. Among patients with grade 1 to 3 fibrosis, the median time to development of fibrosis was 1.6 years (range: 9 days – 8.3 years). In univariate and multivariate analysis, age, cup size and chemotherapy administration had no significant influence on development of breast fibrosis. The hypo fractionated schedule of 30Gy in 5 fractions significantly increased the fibrosis rate (OR=12.5; [2.7; 57.1] p=0.001). On the other hand, 40 Gy/15 fr and 41.6 Gy/13 fr had no significative influence (OR=2.2 [0.5; 11.1] p=0.32) as well as the 66 Gy/33 fr schedule (OR=3.6 [0.8; 15.4] p=0.09) compared to standard scheme of 50 Gy/25 fr. The cosmetic result was good or excellent for 84.8% of cases at the first evaluation. The 30 Gy in 5 fractions schedule significantly influenced the cosmetic result in the multivariate analysis (OR=11.2 [3.1; 43.9]; p<0.001), with increased rates of breast deformation. The risk of breast deformity was also worse for large breast size (OR=2.7 [1.3; 5.8]; p=0.02).

Conclusion: Whole breast radiation therapy in ILD position is well tolerated with good cosmesis and low rates of fibrosis, except for the 30 Gy in 5 weekly fractions schedule. Large breast size has a significantly negative influence on cosmetic results and fibrosis.

Citation Format: Bronsart E, Dureau S, Xu HP, Costa E, Poortmans P, Chilles A, Berger F, Stilhart A, Fourquet A, Kirova Y. Risk factors for fibrosis after whole breast radiation therapy in lateral position : A large scale single center experience [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 P2-11-08.

Advantages and limitations of whole-body bone marrow MRI using turbo-STIR sequences in comparison to planar bone scans

At modern MRI tomographs the whole body can be screened for bone marrow metastases within 45 min. Aim of this study was to evaluate the diagnostic advantages and disadvantages of a whole-body bone marrow MRI protocol using Turbo Short Tau Inversion Recovery [STIR] sequences in comparison to planar bone scintigraphy (SZ). Patients and methods: In order to screen for bone metastases within two weeks SZ and whole-body MRI with Turbo-STIR-sequences were performed in 20 patients with known breast cancer. For further evaluation five regions were defined: scull, spine including the pelvis, femora, humeri and ribs including scapulae and sternum. Results: In 9/20 patients neither with SZ nor with MRI bone metastases were detected (staging M0). Among the remaining 11 patients SZ detected 109 and MRI 150 lesions which were typical for bone metastases. All of these 11 patients were staged Ml correspondingly with both methods. Within the thorax (ribs, sternum, scapulae) MRI discovered only 6/17 and within the scull 0/6 lesions which were suspicious for metastases in SZ. Inversely MRI identified much more metastatic lesions than SZ within the femora (20/16), the humeri (14/12) and the spine including the pelvis (110/58). Conclusions: Susceptibility-, truncation*, chemical-shift-, third arm- and particularly pulsation artifacts along with the impossibility to chose slice orientation equally advantageous for all regions of the body cause impaired image quality of MRI whole body scanning. Therefore, concerning the detection rate of bone metastases within the thorax (ribs, sternum and scapulae) and the scull, conventional Turbo-STIR-MRI whole-body scans are even less accurate than conventional planar bone scintigraphy in those regions.

A pharmacological study of Arabidopsis cell fusion between the persistent synergid and endosperm

Cell fusion is a pivotal process in fertilization and multinucleate cell formation. A plant cell is ubiquitously surrounded by a hard cell wall, and very few cell fusions have been observed except for gamete fusions. We recently reported that the fertilized central cell (the endosperm) absorbs the persistent synergid, a highly differentiated cell necessary for pollen tube attraction. The synergid-endosperm fusion (SE fusion) appears to eliminate the persistent synergid from fertilized ovule in Arabidopsis thaliana Here, we analyzed the effects of various inhibitors on SE fusion in an in vitro culture system. Different from other cell fusions, neither disruption of actin polymerization nor protein secretion impaired SE fusion. However, transcriptional and translational inhibitors decreased the SE fusion success rate and also inhibited endosperm division. Failures of SE fusion and endosperm nuclear proliferation were also induced by roscovitine, an inhibitor of cyclin-dependent kinases (CDK). These data indicate unique aspects of SE fusion such as independence of filamentous actin support and the importance of CDK-mediated mitotic control.

Towards Implementation of OMOP in a German University Hospital Consortium

Background  In 2015, the German Federal Ministry of Education and Research initiated a large data integration and data sharing research initiative to improve the reuse of data from patient care and translational research. The Observational Medical Outcomes Partnership (OMOP) common data model and the Observational Health Data Sciences and Informatics (OHDSI) tools could be used as a core element in this initiative for harmonizing the terminologies used as well as facilitating the federation of research analyses across institutions.

Objective  To realize an OMOP/OHDSI-based pilot implementation within a consortium of eight German university hospitals, evaluate the applicability to support data harmonization and sharing among them, and identify potential enhancement requirements.

Methods  The vocabularies and terminological mapping required for importing the fact data were prepared, and the process for importing the data from the source files was designed. For eight German university hospitals, a virtual machine preconfigured with the OMOP database and the OHDSI tools as well as the jobs to import the data and conduct the analysis was provided. Last, a federated/distributed query to test the approach was executed.

Results  While the mapping of ICD-10 German Modification succeeded with a rate of 98.8% of all terms for diagnoses, the procedures could not be mapped and hence an extension to the OMOP standard terminologies had to be made.

Overall, the data of 3 million inpatients with approximately 26 million conditions, 21 million procedures, and 23 million observations have been imported.

A federated query to identify a cohort of colorectal cancer patients was successfully executed and yielded 16,701 patient cases visualized in a Sunburst plot.

Conclusion  OMOP/OHDSI is a viable open source solution for data integration in a German research consortium. Once the terminology problems can be solved, researchers can build on an active community for further development.

Comprehensive genomic profiling of head and neck squamous cell carcinoma reveals FGFR1 amplifications and tumour genomic alterations burden as prognostic biomarkers of survival

BACKGROUND

We aimed at identifying deleterious genomic alterations from untreated head and neck squamous cell carcinoma (HNSCC) patients, and assessing their prognostic value.

PATIENTS AND METHODS

We retrieved 122 HNSCC patients who underwent primary surgery. Targeted NGS was used to analyse a panel of 100 genes selected among the most frequently altered genes in HNSCC and potential therapeutic targets. We selected only deleterious (activating or inactivating) single nucleotide variations, and copy number variations for analysis. Univariate and multivariate analyses were performed to assess the prognostic value of altered genes.

RESULTS

A median of 2 (range: 0-10) genomic alterations per sample was observed. Most frequently altered genes involved the cell cycle pathway (TP53 [60%], CCND1 [30%], CDKN2A [25%]), the PI3K/AKT/MTOR pathway (PIK3CA [12%]), tyrosine kinase receptors (EGFR [9%], FGFR1 [5%]) and cell differentiation (FAT1 [7%], NOTCH1 [4%]). TP53 mutations (p = 0.003), CCND1 amplifications (p = 0.04), CDKN2A alterations (p = 0.02) and FGFR1 amplifications (p = 0.003), correlated with shorter overall survival (OS). The number of genomic alterations was significantly higher in the HPV-negative population (p = 0.029) and correlated with a shorter OS (p < 0.0001). Only TP53 mutation and FGFR1 amplification status remained statistically significant in the multivariate analysis.

CONCLUSION

These results suggest that genomic alterations involving the cell cycle (TP53, CCND1, CDKN2A), as well as FGFR1 amplifications and tumour genomic alterations burden are prognostic biomarkers and might be therapeutic targets for patients with HNSCC.

Heterochromatin and DNA damage repair: Use different histone variants and relax

Repair of damaged DNA requires the activation of kinases, which in turn phosphorylate diverse proteins including histone H2A.X, an event conserved from yeast to human. By combining genetics, biochemical, and cytological approaches, we recently reported that, in addition to H2A.X, phosphorylation of histone variant H2A.W.7 is required for DNA damage response in Arabidopsis. This work provides direct evidence for the functional diversification of plant-specific H2A.W histone variants, which are tightly associated with heterochromatin. We place our findings in perspective of other recent reports and discuss how DNA damage is being recognized and repaired in heterochromatin.

Insights into Land Plant Evolution Garnered from the Marchantia polymorpha Genome

The evolution of land flora transformed the terrestrial environment. Land plants evolved from an ancestral charophycean alga from which they inherited developmental, biochemical, and cell biological attributes. Additional biochemical and physiological adaptations to land, and a life cycle with an alternation between multicellular haploid and diploid generations that facilitated efficient dispersal of desiccation tolerant spores, evolved in the ancestral land plant. We analyzed the genome of the liverwort Marchantia polymorpha, a member of a basal land plant lineage. Relative to charophycean algae, land plant genomes are characterized by genes encoding novel biochemical pathways, new phytohormone signaling pathways (notably auxin), expanded repertoires of signaling pathways, and increased diversity in some transcription factor families. Compared with other sequenced land plants, M. polymorpha exhibits low genetic redundancy in most regulatory pathways, with this portion of its genome resembling that predicted for the ancestral land plant. PAPERCLIP.

Circulating tumor cell count and thrombosis in metastatic breast cancer

Essentials Tumor cells circulating in blood (CTC) may favor thrombotic events in cancer patients. We assessed the impact of CTC on the risk of thrombosis in metastatic breast cancer. Baseline CTC detection was the only independent factor associated with the risk of thrombosis. CTC detection under therapy may be the hidden link between tumor progression & thrombosis.

SUMMARY

Background Circulating tumor cell (CTC) count is a major prognostic factor in metastatic breast cancer (MBC) and has been reported to be associated with thrombosis in short-term studies on MBC patients. Objective To assess whether CTC detection (CellSearch® ) before first-line chemotherapy impacts the risk of thrombosis throughout the course of MBC. Patients/Methods Among patients included before first-line chemotherapy for MBC in the prospective IC2006-04 CTC detection study (NCT00898014), the electronic medical files of those patients treated at Institut Curie (Paris, France) were searched in silico and manually checked for incident venous or arterial thrombotic events (TE) in the course of MBC. Univariate and multivariate analyses were performed using Cox and Fine-Gray models, adjusted for age and Khorana score. Results/Conclusions With a median follow-up of 64 months (25-81 months), among the 142 patients included, 34 (24%) experienced a TE (incidence rate, 8 TE/100 patient-years). The TE incidence rate was 13 TE/100 patient-years for the 80 patients with ≥ 1 CTC/7.5 mL of blood before initiating first-line chemotherapy, vs. only 4 TE/100 patient-years for the 62 CTC-negative patients. Fine-Gray multivariate analysis (with death as competing event) included age, Khorana score and baseline lactate dehydrogenase and CTC levels: detectable CTC was the only factor significantly associated with an increased risk of TE (sub-distribution hazard ratio [SHR] for patients with [1-4] CTC = 3.1, 95% CI [1.1; 8.6], SHR for patients with ≥ 5 CTC = 1.4, 95% CI [0.5; 4.6]). This study shows that CTC detection before starting first-line chemotherapy is an independent risk factor for TE in MBC patients.