Abstract P1-03-04: Visceral fat area as a predictive factor in metastatic HER2 negative breast cancer patients treated by first line chemotherapy with weekly paclitaxel and bevacizumab

Background Obesity has previously been correlated with poorer survival in both early and metastatic breast cancer. Adipose tissues release proangiogenic factors such as Insulin-like Growth Factor and Vascular Endothelial Growth Factor that may ultimately promote tumor growth. CTscan can be used to measure the visceral fat area (VFA) and the subcutaneous fat area (SFA) on the same section. High VFA has been shown to independently predict poorer outcome in patients given first-line bevacizumab-based treatment for metastatic colorectal cancer and metastatic renal cell carcinoma. The prospective multicenter COMET trial included metastatic HER2 negative breast cancer patients receiving bevacizumab and paclitaxel as fist-line chemotherapy. This study was designed to identify and validate reliable factors to predict benefit of bevacizumab and allow for a more personalized use of this antiangiogenic agent. Our aim was to evaluate the prognostic value of BMI (Body Mass Index), VFA and SFA in the COMET cohort and their impact on the quality of life. Patients and Methods Out of the 510 patients included in the COMET trial from 9/2012 to 3/2016, 480 received bevacizumab and paclitaxel as first-line treatment and 360 had available CTscan data. VFA and SFA were measured retrospectively on the CTscans performed before chemotherapy initiation, at the level of the umbilicus with the patient in the supine position. ImageJ software was used to measure pixels with densities in the -190 HU to -30 HU range in order to delineate the subcutaneous and visceral compartments and to compute the cross-sectional area of each in cm2. These measurements were performed by a radiologist blinded to patients’ characteristics and outcomes. For VFA and SFA, we used a threshold at the median value. VFA and SFA levels were tested for their association with progression-free survival (PFS) and overall survival (OS). The impact on quality of life was based on the Global Health Status, the Physical functioning, the Emotional functioning, Fatigue and Pain scores. Results The mean age at inclusion was 57 years (range: 28-83). At initial diagnosis, the main histological type was invasive ductal carcinoma (n = 247, 80.7%). Most patients had received prior neoadjuvant/adjuvant chemotherapy (n = 245, 68.1%) and a large majority (95.4%) had less than 3 metastatic sites. One hundred and forty patients (46.7%) had histological grade II and 41% had grade III tumors. The majority of the patients had positive hormone receptor tumor (n = 238, 79.3 %) and 62 (20.7%) had triple-negative tumor subtype. The median BMI was 24.7 (range : 17-46). After a median follow-up of 60.6 months (95%CI, 60-61.3), median PFS was 9.5 months (95CI, 8.6-10.3). There was no significant correlation between BMI (p = 0.69), VFA (p = 0.24) or SFA (p = 0.58) and PFS in the univariate analysis. The median OS was 29.6 months (95CI, 25.9-32.4). BMI, VFA and SFA were not correlated with OS. Out of the 360 patients, 328 had available data regarding the quality of life. There was no impact of the VFA or the SFA on the different quality of life scores. Conclusions In our prospective cohort of 360 patients with metastatic breast cancer receiving bevacizumab and paclitaxel as first-line treatment, high VFA or high SFA were not associated with a poorer survival. VFA and SFA had no impact on quality of life.

Citation Format: Séverine Guiu, Boris Guiu, Marion Chevrier, Oumar Billa, Christelle Levy, Olivier Trédan, Isabelle Desmoulins, Marc Debled, Jean-Marc Ferrero, Christelle Jouannaud, Anthony Gonçalves, Maria Rios, Marie-Ange Mouret-Reynier, Frédérique Berger, Fatima-Zohra TOUMI, Jérôme Lemonnier, Jean-Yves Pierga, Sandrine Dabakuyo, Sophie Gourgou. Visceral fat area as a predictive factor in metastatic HER2 negative breast cancer patients treated by first line chemotherapy with weekly paclitaxel and bevacizumab [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr P1-03-04.

Abstract GS3-09: GS3-09 Circulating Tumor Cells-driven choice of first line therapy for ER+ HER2- metastatic breast cancer: overall survival analysis of the randomized STIC CTC trial

Background: High circulating tumor cell (CTC) count (CTChigh) is a strong adverse prognostic factor in patients with metastatic breast cancer (mBC). In the STIC CTC trial (NCT01710605), run before the introduction of CDK4/6 inhibitors for ER+/HER2- mBC, we showed that CTC count (CTC arm) was non inferior to clinician’s choice (standard arm) on progression-free survival (PFS) to guide first line treatment selection between chemotherapy (CT) and endocrine therapy (ET) (Bidard et al., JAMA Oncol 2021). Of note, patients who had treatment escalated from ET (a priori clinician choice) to CT in the CTC arm, had a significantly longer PFS. We report here overall survival (OS) results of this multicenter CTC clinical utility trial.

Methods: In the CTC arm, N=377 patients had their treatment determined by baseline CTC count: CT if CTChigh (≥5 CTCs/7.5 mL, CellSearch®), ET if CTClow. In the standard arm (N=378 patients), the choice was left to the investigator: CT if clinical high risk (Clinhigh), ET if clinical low risk (Clinlow). Therefore, patients with discordant Clinlow/CTChigh or Clinhigh/CTClow profiles had their first line treatment escalated from ET (standard arm) to CT (CTC arm) or de-escalated from CT (standard arm) to ET (CTC arm), respectively. Patients with concordant Clinlow/CTClow and Clinhigh/CTChigh profiles received ET and CT in both arms, respectively.

Results: Among 755 randomized patients, N=189 (25.0%) had a Clinlow/CTChigh profile, N=103 (13.6%) Clinhigh/CTClow, N=363 (48.2%) Clinlow/CTClow and N=100 (13.2%) Clinhigh/CTChigh. OS was analyzed after a median follow-up of 57 months and 382 events (50.6%). In the Clinlow/CTChigh subgroup, CT in the CTC arm led a longer OS (mOS: 51.8 months [43.3-NR]) than ET in the standard arm (35.4 months [30.4-45.4]; HR=0.53 [0.36-0.78], p=0.001). In patients Clinhigh/CTClow, no significant difference was observed whether they received CT (standard arm) or ET (CTC arm) (45.9 months [36.3-59.8] vs 49.4 months [35.4-65.4]; HR=0.88 [0.51-1.51], p=0.63). Pooling the two discordant groups (Clinlow/CTChigh or Clinhigh/CTClow), the CTC-driven strategy was superior to the clinician-driven treatment decision (HR=0.63 [0.46-0.86], p=0.02). Pooling all concordant and discordant groups together, a median OS of 45.5 (95%CI=[40.9-51.1]) and 51.3 months [46.8-55.1] was observed in the standard and CTC arms, respectively (HR=0.84 [0.69-1.03], p=0.10).

Conclusions: Prognostic information brought by CTC or standard factors is discordant in 40% of patients with ER+ HER2- mBC. In case of a discordant estimate, the STIC CTC trial shows the superiority on OS of the CTC-driven treatment decision strategy. These results also suggest a possible clinical utility of CTC to adjust systemic treatment for mBC in second and later lines, after progression on CDK4/6 inhibitors.

Funding:The study was funded by Institut Curie; the French National Cancer Institute (INCa), as part of the Programme de Soutien aux Techniques Innovantes Coûteuses 2011 (STIC 2011); and Menarini Silicon Biosystems (Castel Maggiore, Italy).

Phosphoinositide 3-Kinase (PI3K) Inhibitors and Breast Cancer: An Overview of Current Achievements

The phosphatidylinositol 3-kinase (PI3K) pathway is one of the most altered pathways in human cancers, and it plays a central role in cellular growth, survival, metabolism, and cellular mobility, making it a particularly interesting therapeutic target. Recently, pan-inhibitors and then selective p110α subunit inhibitors of PI3K were developed. Breast cancer is the most frequent cancer in women and, despite therapeutic progress in recent years, advanced breast cancers remain incurable and early breast cancers are at risk of relapse. Breast cancer is divided in three molecular subtypes, each with its own molecular biology. However, PI3K mutations are found in all breast cancer subtypes in three main "hotspots". In this review, we report the results of the most recent and main ongoing studies evaluating pan-PI3K inhibitors and selective PI3K inhibitors in each breast cancer subtype. In addition, we discuss the future of their development, the various potential mechanisms of resistance to these inhibitors and the ways to circumvent them.

Influence of HER2 expression on prognosis in metastatic triple-negative breast cancer-results from an international, multicenter analysis coordinated by the AGMT Study Group

BACKGROUND

Triple-negative breast cancer (TNBC) is associated with poor prognosis, and new treatment options are urgently needed. About 34%-39% of primary TNBCs show a low expression of human epidermal growth factor receptor 2 (HER2-low), which is a target for new anti-HER2 drugs. However, little is known about the frequency and the prognostic value of HER2-low in metastatic TNBC.

PATIENTS AND METHODS

We retrospectively included patients with TNBC from five European countries for this international, multicenter analysis. Triple-negativity had to be shown in a metastatic site or in the primary breast tumor diagnosed simultaneously or within 3 years before metastatic disease. HER2-low was defined as immunohistochemically (IHC) 1+ or 2+ without ERBB2 gene amplification. Survival probabilities were calculated by the Kaplan-Meier method, and multivariable hazard ratios (HRs) were estimated by Cox regression models.

RESULTS

In total, 691 patients, diagnosed between January 2006 and February 2021, were assessable. The incidence of HER2-low was 32.0% [95% confidence interval (CI) 28.5% to 35.5%], with similar proportions in metastases (n = 265; 29.8%) and primary tumors (n = 425; 33.4%; P = 0.324). The median overall survival (OS) in HER2-low and HER2-0 TNBC was 18.6 and 16.1 months, respectively (HR 1.00; 95% CI 0.83-1.19; P = 0.969). Similarly, in multivariable analysis, HER2-low had no significant impact on OS (HR 0.95; 95% CI 0.79-1.13; P = 0.545). No difference in prognosis was observed between HER2 IHC 0/1+ and IHC 2+ tumors (HR 0.89; 95% CI 0.69-1.17; P = 0.414).

CONCLUSIONS

In this large international dataset of metastatic TNBC, the frequency of HER2-low was 32.0%. Neither in univariable nor in multivariable analysis HER2-low showed any influence on OS.

Alpelisib and fulvestrant in PIK3CA-mutated hormone receptor-positive HER2-negative advanced breast cancer included in the French early access program

SOLAR-1 and BYLieve trials documented the efficacy of the PI3K-inhibitor alpelisib in pre-treated PIK3CA-mutant, hormone receptor-positive, HER2-negative (HR+/HER2-) advanced breast cancer (ABC) patients. We report here real-life data of patients prospectively registered in the French alpelisib early access program (EAP) opened to PIK3CA-mutant HR+/HER2- ABC patients treated with alpelisib and fulvestrant. Primary endpoint was PFS by local investigators using RECIST1.1. Eleven centers provided individual data on 233 consecutive patients. Patients had received a median number of 4 (range: 1-16) prior systemic treatments for ABC, including CDK4/6 inhibitor, chemotherapy, fulvestrant and everolimus in 227 (97.4%), 180 (77.3%), 175 (75.1%) and 131 (56.2%) patients, respectively. After a median follow-up of 7.1 months and 168 events, median PFS was 5.3 months (95% CI: 4.7-6.0). Among 186 evaluable patients, CBR at 6 months was 45.3% (95% CI: 37.8-52.8). In multivariable analysis, characteristics significantly associated with a shorter PFS were age < 60 years (HR = 1.5, 95% CI = 1.1-2.1), >5 lines of prior treatments (HR = 1.4, 95% CI = 1.0-2.0) and the C420R PI3KCA mutation (HR = 4.1, 95% CI = 1.3-13.6). N = 91 (39.1%) patients discontinued alpelisib due to adverse events. To our knowledge, this is the largest real-life assessment of alpelisib efficacy. Despite heavy pre-treatments, patients derived a clinically relevant benefit from alpelisib and fulvestrant.

MOVIE: a phase I, open-label, multicenter study to evaluate the safety and tolerability of metronomic vinorelbine combined with durvalumab plus tremelimumab in patients with advanced solid tumors

BACKGROUND

Anti-programmed cell death protein 1 (PD1)/programmed death-ligand 1 (PD-L1) agents have only moderate antitumor activity in some advanced solid tumors (AST), including breast cancer (BC), prostate cancer (PC), cervical cancer (CC), and head and neck cancer (HNC). Combining anti-PD-L1 with anti-cytotoxic T-lymphocyte-associated protein (CTLA) and chemotherapy may significantly improve efficacy.

PATIENTS AND METHODS

MOVIE is a multicohort phase I/II study examining the combination of anti-PD-L1 durvalumab (Durv; 1500 mg IV Q4W) plus anti-CTLA tremelimumab (Trem; 75 mg IV Q4W) with metronomic vinorelbine (MVino; 20-40 mg orally daily) in various AST resistant to conventional therapies. The primary objective of the phase I part was to determine the maximum tolerated dose (MTD) and recommended dose for phase II (RP2D).

RESULTS

Among the 14 patients enrolled during phase I, including 13 women and 1 man, 9 had BC, 1 PC, 2 CC, and 2 miscellaneous cancers with high mutational loads. Median age was 53 years. A total of 12 patients were assessable for the dose-escalation part in which only one dose-limiting toxicity (DLT) was observed [one neutropenia without fever, grade (G) 4]. Two (14.3%), four (28.6%), and four (28.6%) patients had G ≥3 adverse events (AEs) related to MVino, Durv, and Trem, respectively. Treatment-related events included mostly clinical AEs with asthenia (eight G2; three G3), colitis (one G2, one G3), diarrhea (one G3), nausea (two G2), dry skin (two G2), maculopapular rash (one G3), and hyperthyroidism (three G2). No toxic death was reported. Preliminary data showed one patient (CC) who presented a complete response and four patients with stable disease (SD).

CONCLUSIONS

MTD was not reached and dose level 2 (MVino 40 mg, Durv 1500 mg, Trem 75 mg) was selected as RP2D. The safety profile of the combination was manageable and consistent with previous reports of Trem + Durv or MVino. Phase II is currently ongoing in BC, PC, CC, HNC, and miscellaneous cohorts.

Mass Cytometry Reveals Classical Monocytes, NK Cells, and ICOS+ CD4+ T Cells Associated with Pembrolizumab Efficacy in Patients with Lung Cancer

PURPOSE

Immune checkpoint inhibitors (ICI) have revolutionized the treatment of non-small cell lung cancer (NSCLC), but predictive biomarkers of their efficacy are imperfect. The primary objective is to evaluate circulating immune predictors of pembrolizumab efficacy in patients with advanced NSCLC.

EXPERIMENTAL DESIGN

We used high-dimensional mass cytometry (CyTOF) in baseline blood samples of patients with advanced NSCLC treated with pembrolizumab. CyTOF data were analyzed by machine-learning algorithms (Citrus, tSNE) and confirmed by manual gating followed by principal component analysis (between-group analysis).

RESULTS

We analyzed 27 patients from the seminal KEYNOTE-001 study (median follow-up of 60.6 months). We demonstrate that blood baseline frequencies of classical monocytes, natural killer (NK) cells, and ICOS+ CD4+ T cells are significantly associated with improved objective response rates, progression-free survival, and overall survival (OS). In addition, we report that a baseline immune peripheral score combining these three populations strongly predicts pembrolizumab efficacy (OS: HR = 0.25; 95% confidence interval = 0.12-0.51; P < 0.0001).

CONCLUSIONS

As this immune monitoring is easy in routine practice, we anticipate our findings may improve prediction of ICI benefit in patients with advanced NSCLC.

Association of Endocrine Therapy for HR+/ERBB2+ Metastatic Breast Cancer With Survival Outcomes

IMPORTANCE

Evidence suggests that patients with human epidermal growth factor receptor 2-positive (ERBB2+ [formerly HER2+]) metastatic breast cancer (MBC) have different clinical characteristics and outcomes according to their hormone receptor (HR) status. The place of endocrine therapy (ET) for patients with HR+/ERBB2+ is still not clearly defined in this setting.

OBJECTIVE

To evaluate the association of HR status and first-line inclusion of ET with outcomes among patients with ERBB2+ MBC.

DESIGN, SETTING, AND PARTICIPANTS

This cohort study was an analysis of clinical data from the French clinical Epidemiological Strategy and Medical Economics (ESME) cohort, including patients with MBC who started treatment between 2008 and 2017. The last date of follow-up was June 18, 2020. Data were analyzed from May 2021 to May 2022.

EXPOSURES

Patients were treated with first-line ERBB2-targeted therapy and either chemotherapy (CT) with or without ET or ET alone. For the study of the association of maintenance ET with outcomes, we included patients treated with first-line ERBB2-targeted therapy with CT and with or without maintenance ET.

MAIN OUTCOMES AND MEASURES

Median overall survival (OS) and median first-line progression-free survival (PFS) were reported using the Kaplan-Meier method. Cox proportional hazards models and a propensity score were constructed to report and adjust for prognostic factors. Multivariable analysis included age at MBC, time to MBC, number of metastatic sites, type of metastases, and Eastern Cooperative Oncology Group performance status.

RESULTS

Among 4145 women with ERBB2+ MBC, 2696 patients had HR+ (median [IQR] age, 58.0 [47.0-67.0] years) and 1449 patients had HR- (56.0 [47.0-64.0] years) tumors. The median OS for patients with HR+ vs HR- tumors was 55.9 months (95% CI, 53.7-59.4 months) vs 42.0 months (95% CI, 38.8-45.2 months), confirmed in multivariable analysis (hazard ratio, 1.40; 95% CI, 1.26-1.56; P < .001). The median PFS for patients with HR+ vs HR- tumors was 12.2 months (95% CI, 11.5-12.9 months) vs 9.8 months (95% CI, 9.2-11.0 months; P = .01), and the HR was 1.15 (95% CI, 1.06-1.26; P < .001). In multivariable analysis, no significant difference was found in OS or PFS for 1520 patients treated with ERBB2-targeted therapy with CT and with or without ET vs 203 patients receiving ERBB2-targeted therapy with ET, regardless of type of ERBB2-targeted therapy (trastuzumab or trastuzumab with pertuzumab). This result was confirmed by matching patients using a propensity score. Using the time-dependent ET variable among patients with ERBB2-targeted therapy with CT, those with maintenance ET had significantly better PFS (hazard ratio, 0.70; 95% CI, 0.60-0.82; P < .001) and OS (hazard ratio, 0.47; 95% CI, 0.39-0.57; P < .001).

CONCLUSIONS AND RELEVANCE

These results suggest that ET-containing first-line regimens may be associated with benefits among a subgroup of patients with HR+/ERBB2+ MBC.

Red and brown seaweeds extracts: A source of biologically active compounds

The biological activities of Porphyra sp., Gracilaria gracilis, Alaria esculenta and Saccharina latissima extracts prepared by enzymatic and ball milling-assisted methods and hot water were evaluated. Enzyme-assisted methods allowed the highest extraction yields. Alcalase-assisted extraction (EAA) was the most effective in the recovery of polyphenolic compounds and Porphyra sp. had the highest content. The efficiency of flavonoids extraction was highly dependent on the used method. Globally, Porphyra sp. and EAA extracts exhibited the highest antioxidant and chelating activities. The highest α-amylase inhibitory activity was determined in HW Porphyra sp. extract while EAA A. esculenta extract had the highest α-glucosidase inhibitory activity. The highest ACE inhibitory activity was obtained in EAA from S. latissima. None of the extracts showed antimicrobial activity against the tested bacteria. The results showed that Porphyra sp. and S. latissima are potentially useful as ingredient in functional foods and nutraceuticals.

Contribution of endocrine therapy in oestrogen receptor-positive pT1a-b breast cancer: Results of a retrospective study

INTRODUCTION

Few data have been reported regarding endocrine therapy (ET) in patients with small pT1a-b ER-postive breast cancer (BC). Thus, we conducted a study to detect possible survival improvements due to ET in such patients.

METHODS

Our retrospective observational study included 5545 patients with pT1a-b ER-positive BC treated in 15 French centres, excluding patients with HER2-positive status, neoadjuvant chemotherapy, ER-negative status, unknown pN status or in situ BC. We estimated disease-free survival (DFS), recurrence-free survival (RFS) and overall survival (OS) via univariate analysis and multivariate Cox regression.

RESULTS

Most patients (80.3%: 4453) received ET and-when compared to those without ET-experienced increases of 2.5% and 3.3% in DFS and 1.9% and 4.3% in RFS after 5 and 7 years of follow-up, respectively, with little difference in OS. In Cox regression analysis, no ET was significantly associated with decreased DFS (hazard ratio, HR = 1.275, p = 0.047, 95% CI[1.003-1.620]) but not OS or RFS in all patients, while in 2363 patients with pT1a-b ER-positive grade 2-3 BC, no ET was significantly associated with decreased DFS (HR = 1.502, p = 0.049, 95% CI[1.001-2.252]), but not OS (HR = 1.361, p = 0.272). ET omission was not significantly associated with decreased survival in 3047 patients with pT1a-b ER-positive grade 1 BC.

CONCLUSION

Our results indicate that while ET provided a beneficial impact on survival to patients with pT1a-bN0 ER-positive BC-and especially in those with grade 2-3 tumours-no such impact was observed in grade 1 tumours. Consequently, ET should be discussed with these patients, particularly in those with pT1a grade 1 tumours.

Genomics to select treatment for patients with metastatic breast cancer

Cancer progression is driven in part by genomic alterations¹. The genomic characterization of cancers has shown interpatient heterogeneity regarding driver alterations², leading to the concept that generation of genomic profiling in patients with cancer could allow the selection of effective therapies^3,4. Although DNA sequencing has been implemented in practice, it remains unclear how to use its results. A total of 1,462 patients with HER2-non-overexpressing metastatic breast cancer were enroled to receive genomic profiling in the SAFIR02-BREAST trial. Two hundred and thirty-eight of these patients were randomized in two trials (nos. NCT02299999 and NCT03386162) comparing the efficacy of maintenance treatment⁵ with a targeted therapy matched to genomic alteration. Targeted therapies matched to genomics improves progression-free survival when genomic alterations are classified as level I/II according to the ESMO Scale for Clinical Actionability of Molecular Targets (ESCAT)⁶ (adjusted hazards ratio (HR): 0.41, 90% confidence interval (CI): 0.27-0.61, P < 0.001), but not when alterations are unselected using ESCAT (adjusted HR: 0.77, 95% CI: 0.56-1.06, P = 0.109). No improvement in progression-free survival was observed in the targeted therapies arm (unadjusted HR: 1.15, 95% CI: 0.76-1.75) for patients presenting with ESCAT alteration beyond level I/II. Patients with germline BRCA1/2 mutations (n = 49) derived high benefit from olaparib (gBRCA1: HR = 0.36, 90% CI: 0.14-0.89; gBRCA2: HR = 0.37, 90% CI: 0.17-0.78). This trial provides evidence that the treatment decision led by genomics should be driven by a framework of target actionability in patients with metastatic breast cancer.

Comparison of Management and Outcomes in ERBB2-Low vs ERBB2-Zero Metastatic Breast Cancer in France

IMPORTANCE

ERBB2-low (ie, ERBB2 immunohistochemistry score of 1+ or 2+ in the absence of ERBB2 gene amplification) breast cancer (BC) is a new entity, with emerging dedicated treatments. Little is known about its prognosis and response to conventional therapy compared with ERBB2-zero breast tumors (ie, those with an immunohistochemistry score of 0).

OBJECTIVE

To compare the outcomes for patients with ERBB2-low metastatic BC (MBC) with those of patients with ERBB2-zero MBC.

DESIGN, SETTING, AND PARTICIPANTS

This cohort study was conducted from the Epidemiological Strategy and Medical Economics MBC platform and included patients with MBC treated between 2008 and 2016 in 18 French comprehensive cancer centers. The data analysis was conducted from July 16, 2020, to April 1, 2022.

MAIN OUTCOMES AND MEASURES

The main outcome was overall survival (OS), and the secondary outcome was progression-free survival under first-line treatments (PFS1).

RESULTS

The median (range) age was 60.0 (22.0-103.0) years. Among 15 054 patients with MBC, 4671 (31%) had ERBB2-low MBC and 10 383 (69%) had ERBB2-zero MBC. The proportion of ERBB2-low cancers was higher among patients with hormone receptor-positive MBC than those with hormone receptor-negative disease (4083 patients [33.0%] vs 588 patients [21.0%]). With a median follow-up of 49.5 months (95% CI, 48.6-50.4 months), the median OS of the ERBB2-low group was 38.0 months (95% CI, 36.4-40.5 months) compared with 33.9 months (95% CI, 32.9-34.9 months) for the ERBB2-zero group (P < .001). After adjustment for age, visceral metastases, number of metastatic sites, de novo disease, period of care, and hormone receptor status, patients with ERBB2-low MBC had slightly better OS compared with patients with ERBB2-zero MBC (adjusted hazard ratio, 0.95; 95% CI, 0.91-0.99; P = .02). In contrast, PFS1 did not differ by ERBB2 status (adjusted hazard ratio, 0.99; 95% CI, 0.95-1.02; P = .45). No significant differences in OS and PFS1 were observed in multivariate analyses by hormone receptor status and types of frontline treatment.

CONCLUSIONS AND RELEVANCE

In this large cohort study, patients with ERBB2-low MBC had a slightly better OS than those with completely ERBB2-zero tumors, but identical PFS1, which could help guide treatment selection.

Interpretable Machine Learning Models to Predict the Resistance of Breast Cancer Patients to Doxorubicin from Their microRNA Profiles

Doxorubicin is a common treatment for breast cancer. However, not all patients respond to this drug, which sometimes causes life-threatening side effects. Accurately anticipating doxorubicin-resistant patients would therefore permit to spare them this risk while considering alternative treatments without delay. Stratifying patients based on molecular markers in their pretreatment tumors is a promising approach to advance toward this ambitious goal, but single-gene gene markers such as HER2 expression have not shown to be sufficiently predictive. The recent availability of matched doxorubicin-response and diverse molecular profiles across breast cancer patients permits now analysis at a much larger scale. 16 machine learning algorithms and 8 molecular profiles are systematically evaluated on the same cohort of patients. Only 2 of the 128 resulting models are substantially predictive, showing that they can be easily missed by a standard-scale analysis. The best model is classification and regression tree (CART) nonlinearly combining 4 selected miRNA isoforms to predict doxorubicin response (median Matthew correlation coefficient (MCC) and area under the curve (AUC) of 0.56 and 0.80, respectively). By contrast, HER2 expression is significantly less predictive (median MCC and AUC of 0.14 and 0.57, respectively). As the predictive accuracy of this CART model increases with larger training sets, its update with future data should result in even better accuracy.

Whole-genome/exome analysis of circulating tumor DNA and comparison to tumor genomics from patients with heavily pre-treated ovarian cancer: subset analysis of the PERMED-01 trial

Introduction

The poor prognosis of ovarian carcinoma (OvC) is due to the advanced stage at diagnosis, a high risk of relapse after first-line therapies, and the lack of efficient treatments in the recurrence setting. Circulating tumor DNA (ctDNA) analysis is a promising tool to assess treatment-resistant OvC and may avoid iterative tissue biopsies. We aimed to evaluate the genomic profile of recurrent heavily pre-treated OvC.

Methods

We performed tumor panel-based sequencing as well as low-coverage whole-genome sequencing (LC-WGS) of tumor and plasma collected in patients with ovarian cancer included in the PERMED-01 trial. Whole-exome sequencing (WES) data of plasma samples were also analyzed and compared to mutation and copy number alteration (CNA) tumor profiles. The prognostic value [progression-free survival (PFS)] of these alterations was assessed in an exploratory analysis.

Results

Tumor and plasma genomic analyses were done for 24 patients with heavily pretreated OvC [67% high-grade serous carcinoma (HGSC)]. Tumor mutation burden was low (median 2.04 mutations/Mb) and the most frequent mutated gene was TP53 (94% of HGSC). Tumor CNAs were frequent with a median of 50% of genome altered fraction. Plasma LC-WGS and WES detected ctDNA in 21/24 cases (88%) with a median tumor fraction of 12.7%. We observed a low correlation between plasma and tumor CNA profiles. However, this correlation was significant in cases with the highest circulating tumor fraction. Plasma genome altered fraction and plasma mutation burden (p = 0.011 and p = 0.041, respectively, log-rank tests) were associated with PFS.

Conclusions

Combination of LC-WGS and WES can detect ctDNA in most pre-treated OvCs. Some ctDNA characteristics, such as genome altered fraction and plasma mutation burden, showed prognostic value. ctDNA assessment with LC-WGS may be a promising and non-expansive tool to evaluate disease evolution in this disease with high genomic instability.

Clinical Trial Registration

https://clinicaltrials.gov/ct2/show/NCT02342158, identifier NCT02342158.

Post-traumatic growth 5 years after cancer: identification of associated actionable factors

BACKGROUND

The number of cancer survivors is growing increasingly worldwide. The long-term negative consequences of the disease are now better known. Cancer may also foster positive outcomes. Some survivors consider life after cancer as the start of a new life and experience positive changes called post-traumatic growth (PTG) measured by a scale developed by Tedeschi and Calhoun.

OBJECTIVE

The purpose of this article was to explore actionable factors affecting PTG, particularly those in relation with health care management and those that reflected health behavior changes.

METHODS

This study included the 1,982 participants in the VICAN cohort who responded to the questionnaire on living conditions 2 and 5 years after diagnosis. Factors associated with a moderate or high PTG (score ≥ 63) were identified using logistic regressions.

RESULTS

Factors positively associated with moderate or high PTG were being satisfied with the time spent by health care team on information (OR:1.35 [1.08;1.70]), increased physical activity (OR:1.42 [1.04;1.95]) and healthier diet (OR:1.85 [1.44;2.36]) since diagnosis, and having benefited from psychological support at diagnosis (OR:1.53 [1.16;2.01]).

CONCLUSION

High PTG is positively associated with health behavior and time spent on information. Our findings suggest that appropriate clinical and educational interventions can help foster growth after the experience of cancer. Even if we do not know what causes what, it is admitted that the interventions leading to an increase of physical activity, for example, are good from all points of view.

P-064 Clinical outcomes of 127 patients with recurrent implantation failure treated with testicular sperm aspiration (TESA)

Study question

Are the embryological, clinical and newborn outcomes using aspirated testicular sperm improved in cases with recurrent implantation failure previously treated with ejaculated sperm?

Summary answer

Aspirated testicular sperm enabled to obtain significant higher embryological, clinical and newborn outcomes in cases with recurrent implantation failure previously treated with ejaculated sperm.

What is known already

High levels of sperm DNA fragmentation (SDF) were associated to poor clinical outcomes (1-Simon et al., 2017). Testicular sperm display lower SDF than ejaculated sperm (2-Sakas and Alvarez, 2010), improving clinical outcomes in cases with abnormal semen parameters (3-Awaga et al., 2018; 4-Kang et al., 2018), recurrent implantation failure (RIF) and pregnancy loss (RPL) (5-Esteves et al., 2017), and elevated SDF (6-Ambar et al., 2021). As only a few studies are specifically dedicated to RIF, we expanded the number of cases and first provided full demographic, stimulation, embryological, clinical and newborn outcomes.

References

1-(https://doi.org/10.4103/1008-682X.182822);

2-(https://doi.org/10.1016/j.fertnstert.2009.10.046);

3-(https://doi.org/10.1016/j.rbmo.2018.08.017);

4-(https://doi.org/10.1038/s41598-018-26280-0);

5-(https://doi.org/10.1016/j.fertnstert.2017.06.018);

6-(https://doi.org/10.5534/wjmh.200084

Study design, size, duration

We retrospectively evaluated during consecutive years (2010-2020) 63 patients with recurrent implantation failure, which accepted to perform testicular sperm aspiration (TESA) as an alternative treatment. These patients presented a long history of failed treatments (153 cycles) using ejaculated sperm. From these cycles, no pregnancy ensued. The present study compares 127 treatment cycles, 80 with testicular sperm (17 cases repeated TESA) and 47 with ejaculated sperm from the same patients performed at the present IVF clinic.

Participants/materials, setting, methods

Patients were screened for karyotype abnormalities, for Y-chromosome microdeletions (7-Gonçalves et al., 2016), and for SDF with the TUNEL assay (8-Sá et al., 2015). Conventional semen analysis was performed according to World Health Organization guidelines (9-WHO, 2010). Male evaluation and TESA was performed by the same experienced urologist (LF) according to established protocols (10-Madureira et al 2014). The procedure was performed entirely on an outpatient basis, with no complications reported.

References

7-(https://doi.org/10.4103/1008-682X.172827);

8-(https://doi.org/10.1016/j.rbmo.2015.06.019);

9-(https://apps.who.int/iris/handle/10665/44261);

10-(https://doi.org/10.1111/j.2047-2927.2014.00231.x).

Main results and the role of chance

The mean ages were 35.5±3.4 (26-42)-female and 38.1±5.7 (29-59)-male. There were 4 abnormal karyotypes (3-female, 1-male), all without known relevance. Most cases had asthenozoospermia and teratozoospermia (65.1%), or oligoasthenoteratozoospermia (41.8%). Of the 19 cases with &lt;5M/ml, none presented Y-chromosome microdeletions. Although we do not routinely perform SDF testing, 15 patients had previous SDF values (12, &gt;20%; 8, &gt;36%). Female basal characteristics and testicular evaluation were under normal values. The TESA procedure took about 15-20 min, and the time of laboratorial search around 30-60 min. Cases using testicular sperm showed significant higher rates of fertilization (64% vs 73%-p=0.005), blastocyst development (47% vs 62%-p=0.010), implantation (6% vs 27%-p=0.000), clinical pregnancy (10% vs 39%-p=0.001), live birth delivery (5% vs 28%-p=0.005) and newborn (5% vs 32%-p=0.000) than ejaculated sperm. No significant differences were observed regarding the rates of embryo cleavage (95% vs 94.8%) and high quality embryos (89.4% vs 94%), in the mean number of transferred embryos (1.8±0.4 vs 1.9±0.4), or in the abortion rate (2 cases-50% vs 7 cases-25.9%). Cases using testicular sperm had 22 frozen-thawed embryo transfer cycles, enabling per initiated cycle a cumulative pregnancy rate of 45%, live birth delivery rate of 31.3% and newborn rate of 37.5% (32 newborn).

Limitations, reasons for caution

Although presenting the higher number of cycles using TESA in the treatment of RIF, this number needs to be increased for drawing more definitive conclusions, as these women present a diversity of conditions, rendering subgrouping difficult. In the future, it would also be important to evaluate SDF in all cases.

Wider implications of the findings

In conclusion, the present results gave further evidence for the superiority of using testicular sperm instead of ejaculated sperm in cases with recurrent implantation failure. Data also evidences the security of using testicular sperm aspiration, as there were no pregnancy or delivery complications, or congenital anomalies among the 32 newborn.

Trial registration number

Not Applicable

Overcoming Resistance to Anti-nectin-4 Antibody-Drug Conjugate

Antibody-drug conjugates (ADCs) represent a fast-growing drug class in oncology. However, ADCs are associated with resistance, and therapies able to overcome it are of utmost importance. Recently, enfortumab vedotin-ejfv (EV) was approved in nectin-4+ metastatic urothelial cancer. We previously described PVRL4/nectin-4, as a new therapeutic target in breast cancer (BC), and produced an efficient EV-like ADC comprising a human anti-nectin-4 monoclonal antibody conjugated to monomethyl auristatin-E (MMAE) named N41mab-vcMMAE. To study the consequence of the long-term treatment with this ADC, we developed a preclinical BC model in mice, and report a mechanism of resistance to N41mab-vcMMAE after a 9- months treatment and a way to reverse it. RNA-sequencing pointed to an upregulation in resistant tumors of ABCB1 expression, encoding the multidrug resistance protein MDR-1/P-glycoprotein (P-gp), associated with focal gene amplification and high protein expression. Sensitivity to N41mab-vcMMAE of the resistant model was restored in vitro by P-gp pharmacological inhibitors, like tariquidar. P-gp is expressed in a variety of normal tissues. By delivering the drug to the tumor more specifically than does classical chemotherapy, we hypothesized that the combined use of ADC with P-gp inhibitors might reverse resistance in vivo without toxicity. Indeed, we showed that the tariquidar/N41mab-vcMMAE combination was well tolerated and induced a rapid regression of ADC-resistant tumors in mice. By contrast, the tariquidar/docetaxel combination was toxic and poorly efficient. These results show that ABC transporter inhibitors can be safely used with ADC to reverse ADC-induced resistance and open new opportunities in the fight against multidrug resistance.

Clinicopathological characteristics and prognosis of breast cancer patients with isolated central nervous system metastases in the multicentre ESME database

Background:

As a result of progress in diagnosis and treatment, there is a growing prevalence of metastatic breast cancer (MBC) with isolated CNS metastases. This study describes the largest-to-date real-life cohort of this clinical setting and compares it to other clinical presentations.

Methods:

We retrospectively analysed the French Epidemiological Strategy and Medical Economics (ESME) MBC database including patients who initiated treatment for MBC between 2008 and 2016. Progression-free survival (PFS) and overall survival (OS) were estimated using the Kaplan–Meier method. Descriptive statistics and multivariate Cox model were used.

Results:

Of 22,266 patients, 647 (2.9%) and 929 (4.2%) patients had isolated first-site CNS metastases or combined with extra-CNS metastases, with longer OS for the group with isolated CNS metastases (16.9 versus 13.9 months, adjusted HR = 1.69 (95% CI: 1.50–1.91), p < 0.001). Among the 541 (2.4%) patients with isolated CNS metastases and no intrathecal therapy (excluding leptomeningeal metastases), HER2+ cases were preponderant over TN or HR+ /HER2− cases (41.6% versus 26.1% versus 28.5%, respectively, p < 0.01). The treatment strategy consisted of a combination of local treatment and systemic therapy (49.2%), local treatment only (35.5%) or systemic therapy only (11.4%), or symptomatic therapy only (3.9%). Median PFS was 6.1 months (95% CI: 5.7–6.8). Median OS was 20.7 months (95% CI: 17.3–24.3), reaching 37.9 months (95% CI: 25.9–47.6) in the HR+ /HER2+ subgroup. Older age, TN subtype, MBC-free interval of 6–12 months, lower performance status, and WBRT were associated with poorer survival. Patients who received systemic therapy within 3 months from MBC diagnosis had longer OS (24.1 versus 16.1 months, p = 0.031), but this was not significant on multivariate analysis [HR = 1.0 (95% CI: 0.7–1.3), p = 0.806].

Conclusions:

Patients with isolated CNS metastases at MBC diagnosis represent a distinct population for which the role of systemic therapy needs to be further investigated in prospective studies.

Abstract P5-13-08: Identification of PD-L1+ status as a candidate predictive biomarker of response to talazoparib (TALA) in the phase 3 EMBRACA study

Background: Loss-of-function mutations in genes encoding components of the homologous recombination DNA damage response (DDR) machinery, notably BRCA1/2, are associated with tumor sensitivity to poly(ADP-ribose) polymerase inhibitors (PARPi). In EMBRACA, the PARPi TALA improved progression-free survival (PFS) (HR [95% CI] 0.54 [0.41-0.71], P&lt;0.001) vs chemotherapy (CT) in germline BRCA-mutated (gBRCAm) HER2− advanced breast cancer. BRCA1/2 deficiency is associated with elevated PD-L1 expression in ovarian cancers, and PARP inhibition has been associated with PD-L1 upregulation in nonclinical models (Stewart et al, Cancer Res 2018;78:6717-25). Little is known about the potential for PD-L1 expression to modulate sensitivity to PARPi monotherapy in the clinic. Recently, a neoadjuvant study of olaparib in unselected, primary triple-negative breast cancer (TNBC), demonstrated a significant correlation between PD-L1 expression (using the 22C3 antibody) and response to olaparib (Eikesdal et al, Ann Oncol 2021;32:240-9). In contrast, this EMBRACA analysis assessed the contribution of PD-L1 status to TALA sensitivity in a uniformly gBRCAm patient (pt) population. Methods: Available baseline tumor tissue blocks from 120 of 431 EMBRACA pts (28% of intent-to-treat) were sectioned and slides immunostained using SP142/Ventana anti-PD-L1 at HistoGeneX (Naperville, Illinois). PD-L1 immunohistochemistry (IHC) status was assessed as the proportion of tumor area occupied by PD-L1 stained immune cells (IC) of any intensity, with ≥1% defined as PD-L1+. The overall response rate (ORR), defined as unconfirmed complete or partial response (CR/PR), was assessed by investigators. PFS was assessed by an Independent Review Facility. Results: 92/120 (77%) tumors were evaluable for PD-L1 IHC status. Of these 92 evaluable tumors, 9/36 (25%) TNBC and 15/56 (27%) hormone receptor-positive (HR+) tumors were PD-L1+ (24/92, 26% combined TNBC and HR+). In the TALA arm, the ORR was similar for PD-L1+ and PD-L1− tumors for TNBC pts: 2/5 (40%) and 6/19 (32%), respectively. In contrast, the ORR was higher for PD-L1+ vs PD-L1− tumors for HR+ pts: 11/12 (92%) vs 12/31 (39%), exact P value=0.002 (for combined TNBC and HR+, 13/17 [76%] vs 18/50 [36%], P=0.005). For the CT arm, the limited numbers evaluable for both PD-L1 and response (n=25 total), with only one response, precluded similar analysis. Based on the imbalanced results in ORR according to PD-L1 status in pts with HR+ disease, Cox regression analysis was used to explore potential associations of PD-L1 status with PFS. In the TALA arm, median PFS was similar for TNBC independent of PD-L1 status (6.3 mo and 7.0 mo, respectively; HR [95% CI] 1.207 [0.371-3.929]). Median PFS was numerically longer for PD-L1+ vs PD-L1− for HR+ tumors; this difference was not significant (20.2 mo vs 9.2 mo; HR [95% CI] 1.154 [0.395-3.367]). In the CT arm, PD-L1 status was not associated with PFS, although the PD-L1 subgroups were small (For HR+: PD-L1+, n=3; PD-L1−, n=10). Conclusions: Based on these exploratory, retrospective subgroup analyses, PD-L1 positivity by SP142/Ventana was lower in EMBRACA than previously reported in TNBC using the same scoring algorithm: 24/92 (26%) vs 369/902 (41%) in IMpassion130 (Schmid et al, Lancet Oncol 2020;21:44-59). PD-L1+ status was associated with higher ORR in HR+ EMBRACA pts receiving TALA. Interestingly, the enhanced responsiveness for PD-L1+ was not associated with improved PFS, although this assessment is complicated by low pt numbers. Further research is warranted to explore the relationship between baseline tumor PD-L1 status and sensitivity to PARPi, particularly in light of ongoing clinical studies evaluating combinations of immunotherapy and PARPi.

Citation Format: Hope S. Rugo, Joanne L. Blum, A. Douglas Laird, Sara A. Hurvitz, Johannes Ettl, Lida A. Mina, Kyung-Hun Lee, Anthony Gonçalves, Rinat Yerushalmi, Young-Hyuck Im, Miguel Martin, Louis Fehrenbacher, Henri H. Roché, Ying Chen, Silvana Lanzalone, Jijumon Chelliserry, Wolfgang Eiermann, Jennifer K. Litton. Identification of PD-L1+ status as a candidate predictive biomarker of response to talazoparib (TALA) in the phase 3 EMBRACA study [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr P5-13-08.

Abstract GS1-10: Clinical utility of molecular tumor profiling: Results from the randomized trial SAFIR02-BREAST

Background: While studies have shown feasibility and reported preliminary evidence of utility, there is no evidence that multigene sequencing improves outcome in patients with metastatic cancer. The aim of the present study was to assess the clinical utility of multigene sequencing and DNA copy number analyses.. Methods: In SAFIR02-BREAST (NCT: 02299999) and SAFIR-PI3K (NCT: 03386162), open-label multicentric phase II randomized trials, patients were selected if they had a Her2-negative metastatic breast cancer eligible to 1st or 2nd line chemotherapy. Patients underwent a pre-treatment biopsy of metastatic disease when feasible, followed by genomic analysis by next generation sequencing and SNParray. After 6 to 8 cycles of induction chemotherapy, patients without progressive disease and presenting an actionable genomic alteration, were randomized between targeted therapies matched to genomic alterations or maintenance chemotherapy. The primary objective was to evaluate whether targeted therapies guided by genomics improves progression-free survival (PFS) as compared to maintenance chemotherapy, in a pooled analyses of SAFIR02-BREAST and SAFIR-PI3K populations. A hierarchical testing was applied. The efficacy of targeted therapies matched to genomic alterations was first tested in patients presenting an ESCAT I/II alteration (ESMO Scale of Actionability of Molecular Targets). If a p value &lt;0.1 was observed in the first step, analyses were then performed in the Intent-to-treat population. Results: Out of the 1462 patients included, 238 (16%) were subsequently randomized between maintenance chemotherapy (n=81) and targeted therapy (n=157). In 115 patients presenting an ESCAT I/II genomic alteration, the median PFS was 9.1 months (90%CI: 7.1-9.8) and 2.8 (90%CI: 2.1-4.8) in matched targeted therapy and maintenance chemotherapy arms respectively (adjusted HR for stratification factors =0.41;90%CI: 0.27-0.61, p&lt;0.001). In the overall population, there was no significant difference in the duration of PFS between the two arms (adjusted HR: 0.77 (95%CI: 0.56- 1.06, p=0.109). ESCAT classification was highly predictive for the benefit of targeted therapies matched to genomic alterations (interaction test, p= 0.004). Targeted therapies matched to genomic alterations were not effective in patients without ESCAT I/II alteration (HR: 1.15, 95%CI: 0.76-1.75). The SNP array analyses (n=926) identified 21 genes altered more frequently in metastases as compared to primary tumors (TCGA+ METABRIC). Of these, focal TERT amplifications were associated with a poor outcome. Focal CDK4 amplifications were observed after resistance to CDK4 inhibitors. Finally, high HRD was associated with longer PFS in patients with BRCA mutation treated with olaparib (HR: 0.32 [95%CI: 0.12;0.83], p=0.013).. Conclusion: SAFIR02/PI3K trials report that the clinical use of multigene sequencing must be driven by a framework of actionability, and identifies new genomic alterations associated with metastatic evolution and drug resistance or sensitivity.

Citation Format: Fabrice André, Anthony Gonçalves, Thomas Filleron, Florence Dalenc, Amélie Lusque, Mario Campone, Marie-Paule Sablin, Hervé Bonnefoi, Ivan Bieche, Ludovic Lacroix, Alicia Tran-Dien, Marta Jimenez, Alexandra Jacquet, Qing Wang, Etienne Rouleau, David Gentien, Isabelle Soubeyran, Alain Morel, Monica Arnedos, Thomas Bachelot. Clinical utility of molecular tumor profiling: Results from the randomized trial SAFIR02-BREAST [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr GS1-10.

Real-world evidence of the management and prognosis of young women (⩽40 years) with de novo metastatic breast cancer

Background:

Breast cancer (BC) in young women merits a specific approach given the associated fertility, genetic and psychosocial issues. De novo metastatic breast cancer (MBC) in young women is an even more serious condition, with limited data available.

Methods:

We evaluated management of women aged ⩽40 years with de novo MBC in a real-life national multicentre cohort of 22,463 patients treated between 2008 and 2016 (NCT0327531). Our primary objective was to compare overall survival (OS) in young women versus women aged 41–69 years. The secondary objectives were to compare first-line progression-free survival (PFS1) and to describe treatment patterns.

Results:

Of the 4524 women included, 598 (13%) were ⩽40 years. Median age at MBC diagnosis was 36 years (range = 20–40). Compared with women aged 41–69 years, young women had more grade III tumours (49% versus 35.7%, p < 0.0001), human epidermal growth factor receptor 2 amplified (HER2+) disease (34.6% versus 26.4%, p < 0.0001) and HR–/HER2– disease known as “triple negative breast cancer” (TNBC) (17.1% versus 12.7%, p < 0.0001). BRCA testing was performed for 260 young women, with a BRCA1/2 mutation in 44 (17% of those tested) In young HR+/HER2– patients, chemotherapy (CT) was given as the frontline treatment more frequently compared with older ones (89.6% versus 68.8%, respectively, p < 0.0001). After median follow-up of 49.7 months (95% confidence interval, CI = 48.0–51.7), the median OS of young women was 58.5 months, 20.7 months and not attained in HR+/HER2–, TNBC and HER2+ subgroups, respectively. After adjustment for histological subtype, tumour grade, and number and type of metastasis, young women had significantly better OS compared with older ones, except for the TNBC subgroup, for which the outcome was similar. PFS1 was statistically different only in the TNBC subgroup, with 7.8 months for young women and 6.3 months for older women ( p = 0.0015).

Conclusion:

De novo MBC affects a significant proportion of young women. A subgroup of these patients achieves long OS and merits multidisciplinary care.

Neoadjuvant Chemotherapy for Breast Cancer: Evolution of Clinical Practice in a French Cancer Center Over 16 Years and Pathologic Response Rates According to Tumor Subtypes and Clinical Tumor Size: Retrospective Cohort Study

We examined characteristics trends in early breast cancer patients receiving neoadjuvant chemotherapy (NAC) over a 16-year period. Our primary objective was to analyze variations in tumor stage and subtype over time. Secondary objectives included analyses of type of surgery and pathological response, from January 2005 to May 2021, 1623 patients receiving NAC were identified. Three periods were determined: 2005-2009 (P1), 2010-2014 (P2), 2015-2021 (P3). Correlations between periods and patient features with cT stage, pathological breast and axillary node response, pathological complete response (pCR), and type of surgery were assessed in univariate and multivariate analyses. We observed a significant increase in cT0-1 and N0 stages with periods (from 6.8% at P1 to 21.2% at P3, and from 43.2% at P1 to 55.9% at P3, respectively) and in the proportion of HER2+ and triple negative (TN) subtypes. In a multivariate analysis, a decrease of cT2-3-4 tumors during P3 was observed for HER2+ (OR:0.174; p=0.004) and TN tumors (OR:0.287; p=0.042). In-breast pCR and pCR were observed in 40.8% and 34.4% of all patients, respectively, with strong association with tumor subtypes, but not with tumor size in multivariate analysis (37.0% pCR for cT0-1 tumors, 36.4% for cT2 tumors, 29.1% for cT3 tumors (cT0-1 versus cT≥2; p=0.222)). pCR was negatively associated with cN1 stage (OR:1.499; p<0.001 for cN1 patients compared to cN0). We observed an increase in the proportion of small cT0-1 and N0 stages treated with NAC, especially in HER2+ and TN subtypes. No significant impact of tumor size on pCR rates was found.