Spatial predictors of immunotherapy response in triple-negative breast cancer

Immune checkpoint blockade (ICB) benefits some patients with triple-negative breast cancer, but what distinguishes responders from non-responders is unclear1. Because ICB targets cell-cell interactions2, we investigated the impact of multicellular spatial organization on response, and explored how ICB remodels the tumour microenvironment. We show that cell phenotype, activation state and spatial location are intimately linked, influence ICB effect and differ in sensitive versus resistant tumours early on-treatment. We used imaging mass cytometry3 to profile the in situ expression of 43 proteins in tumours from patients in a randomized trial of neoadjuvant ICB, sampled at three timepoints (baseline, n = 243; early on-treatment, n = 207; post-treatment, n = 210). Multivariate modelling showed that the fractions of proliferating CD8+TCF1+T cells and MHCII+ cancer cells were dominant predictors of response, followed by cancer-immune interactions with B cells and granzyme B+ T cells. On-treatment, responsive tumours contained abundant granzyme B+ T cells, whereas resistant tumours were characterized by CD15+ cancer cells. Response was best predicted by combining tissue features before and on-treatment, pointing to a role for early biopsies in guiding adaptive therapy. Our findings show that multicellular spatial organization is a major determinant of ICB effect and suggest that its systematic enumeration in situ could help realize precision immuno-oncology.

Abstract OT3-20-03: Refusal of Breast Surgery in Breast Cancer Patients With cCR After Neoadjuvant Systemic Therapy and Vacuum-assisted Biopsy (VAB) and SLNB Confirmed pCR. An interim report of the prospective non-randomized trial. NCT04293796

Introduction The aim of the study was to prove efficacy and safety of de-escalation of traditional breast surgery in BC patients who develop cCR after neoadjuvant systemic therapy. Refusal of surgery was offered to exceptional responders after vacuum-assisted tumor bed biopsy and sentinel lymph node biopsy confirmed absence of residual disease (pCR). Materials and methods A single-center prospective study was run in the NMRC n.a. N.N. Petrov. Starting from August of 2020, 35 patients with early сT1-2N0-1M0 (stage Ia-IIb) triple-negative and HER2-positive (both ER+ and ER-) unifocal tumours without DCIS in core-biopsy specimen enrolled in the study. Primary lesions were marked with a single clip in the centre. In cases with nodal involvement (cN1) the affected lymph nodes were also clipped. Patients with triple-negative breast cancer received 4 cycles of AC q21d followed by 12 cycles of weekly paclitaxel and carboplatin AUC 2.0. HER2-positive patients received 4 cycles of AC followed by 4 cycles of docetaxel combined with trastuzumab and pertuzumab q21d. Breast US, mammography and SPECT were used at baseline and at response evaluation. Vacuum-assisted biopsy was performed with 7G needle and US-guidance in the OR simultaneously with the SLNB. VAB protocol included retrieval of the tumor clip as first stage. Subsequently surrounding tissues were sampled, and markers were placed to guide radiotherapy. In case residual tumor was found patients received standard breast-conserving surgery. In case the sentinel lymph nodes were found to be positive, standard level II axillary clearance was performed. HER2-positive patients with pCR confirmed by VAB and SLNB received adjuvant trastuzumab up to one year. HER2-positive patients with residual breast or nodal involvement received trastuzumab emtansine up to one year. In case ER+, all patients received appropriate endocrine-therapy. In case of residual in-breast or nodal involvement patients with triple-negative breast cancer received standart capecitabine. Results The interim analysis included 25 patients in both groups. The median follow-up of disease-free survival for patients is 12 months. In the triple-negative group 12 patients achieved cCR. All patients went on to receive VAB and SLNB. After VAB and SLNB pCR was confirmed 11 patients (91.7%). 1 patient had invasive residual tumor with less than 5% cellularity. FNR in this group was 8.3% (1/12). Patient with invasive residual tumor received standard breast-conserving surgery. All the patients in the TNBC group were also found to be (sn)ypN0. In the HER2-positive group cCR was achieved 13 patients. All patients went on to receive VAB and SLNB. After VAB and SLNB pCR was confirmed 10 patients (77%). 3 patients had invasive residual tumor with less than 5% cellularity. FNR in this group was 23% (3/13). Patients with invasive residual tumor received standard breast-conserving surgery. All HER2-positive patients were found to be (sn)ypN0. One patient with HER2-positive subtype experienced a local reccurence in the postoperative zone 16 months after surgery. Initially, this patient achieved cCR and undergone VAB with SLNB. On final pathomorphologic examination isolated focuses of DCIS were found (ypTisN0). Standard breast-conserving surgery was performed and histologically only DCIS was found. This patient recieved 1-year of Trastuzumab and standard radiotherapy with boost. After the histologic confirmation of local reccurence patient underwent nipple-sparring mastectomy with reconstruction and nowadays she is recieveing therapy with trastuzumab emtansine (T-DM1). Conclusion All visualization modalities fail to provide reliable information on the true rate of pCR. Contemporary systemic therapy regimens after accurate selection of patients, following the inclusion criteria, allows to achieve pCR in 75-90%, thereby reducing the risk of FNR after VAB. The trial continues to enroll patients and further follow-up is needed.

Citation Format: Petr Krivorotko, Sergey Yerechshenko, Alexander Emelyanov, Ekaterina Busko, Tengiz Tabagua, Viktoria Mortada, Konstantin Zernov, Alexander Komyakhov, Kirill Nikolaev, Elena Zhiltsova, Larisa Gigolaeva, Roman Pesotsky, Diana Enaldieva, Yana Bondarchuk, Nikolay Amirov, Valentin Channov, Sergey Novikov, Zhanna Bryantseva, Anna Artemyeva, Viktoriya Smirnova, Tatiana Semiglazova, Alexey Belyaev, Vladimir Semiglazov. Refusal of Breast Surgery in Breast Cancer Patients With cCR After Neoadjuvant Systemic Therapy and Vacuum-assisted Biopsy (VAB) and SLNB Confirmed pCR. An interim report of the prospective non-randomized trial. NCT04293796. [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 OT3-20-03.

Abstract P3-04-12: Intraoperative valuation of the resection margin with the usage of digital two-point sectorography (Faxitron BioVision)

Background. Surgical method is fundamental in complex and combined approach of the treatment of the early breast cancer. It is a common fact, that purity of the resection margin is the main indicator of oncological safety of the breast-conserving surgery (BCS). The presence of tumor cells in examined margin is one of the predictors of the development of local recurrence after BCS with breast cancer. Currently the necessity of searching for adequate and quick method of intraoperative valuation of the state of the resection margin is kept. Intraoperative valuation of the resection margin state with the usage of digital two-point sectorography (Faxitron BioVision) appeared as the alternative of urgent histological test, providing the optimum size of the information about adequacy of the carried out surgical treatment. Objective – to evaluate diagnostic features of the digital two-point sectorography Faxitron BioVision in the intraoperative valuation of the resection margin status after the conducted surgical treatment in comparison with planned histologic study. Materials and methods. 368 conducted conservative surgeries were analyzed, patients were divided in two groups depending on carrying out of non-adjuvant chemotherapy (NAC). The first group of patients included 236 patients, who didn`t received NAC before operative treatment stage; second group included 132 patients, who received NAC. Subset analysis of detection rate of the positive resection margin was carried out with the usage of the intraoperative valuation of the resection margin on the X-ray apparatus Faxitron BioVision or without carrying out this method. After each BCS conducted when planned histologic study resection margin were tested for the presence of the tumor cells and the frequency of carrying out of reoperations when positive margin were found. Results. From 368 tested anatomic medications after BCS positive resection margin (R1) is found in 25 cases, which is 6,8 %. From 236 patients of the first group after BCS R1 is found in 20 cases, which is 8,5 %; from 132 conducted operations in the second group in 5 (3,8%) сases – the presence of R1 is found. Reoperations were conducted in 13 cases, when repeated pathomorphological study tumor cells found in 3 cases in the subgroup, which didn`t receive intraoperative valuation on the X-ray apparatus Faxitron BioVision. Conclusion. Assessing the results of our study we can make a conclusion about the positive experience of conducting of BCS and intraoperative evaluation of conservative surgery and intraoperative valuation with the usage of the digital two-point sectorography (Faxitron BioVision) and low frequency of positive margin (3,8%) in comparison with refusal from carrying out of this method (8,5%).

Citation Format: Petr Krivorotko, Yana Bondarchuk, Elena Zhiltsova, Roman Pesotsky, Alexander Emelyanov, Tengiz Tabagua, Larisa Gigolaeva, Sergey Yerechshenko, Alexander Komyakhov, Kirill Nikolaev, Konstantin Zernov, Ruslan Paltuev, Viktoria Mortada, Tatiana Semiglazova, Diana Enaldieva, Nikolay Amirov, Valentin Channov, Antonina Chernaya, Roxanne Ulyanova, Anna Artemyeva, Vladimir Semiglazov, Vladislav Semiglazov. Intraoperative valuation of the resection margin with the usage of digital two-point sectorography (Faxitron BioVision) [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 P3-04-12.

Ten-year survival of neoadjuvant dual HER2 blockade in patients with HER2-positive breast cancer

BACKGROUND

Dual anti-HER2-targeted therapy in breast cancer (BC) significantly increased the rate of pathological complete response (pCR) compared to single blockade when added to chemotherapy. However, limited data exist on the long-term impact on survival of the additional increase in pCR.

METHODS

Neoadjuvant lapatinib and/or trastuzumab treatment optimisation (NCT00553358) is an international, randomised, open-label, phase III study investigating the addition of lapatinib to chemotherapy plus trastuzumab in HER2-positive early BC. Ten-year event-free survival (EFS), overall survival (OS) and safety were assessed on intention-to-treat population. The association between pCR and EFS or OS was investigated in landmark population.

RESULTS

A total of 455 patients were randomised to receive lapatinib (154), trastuzumab (149) or the combination (152). Ten-year EFS estimates were 63% (95% confidence interval [CI], 54%-71%) in the lapatinib group, 64% (95% CI, 55%-72%) in the trastuzumab group and 67% (95% CI, 58%-74%) in the combination group. Ten-year OS rates were 76% (95% CI, 67%-83%), 75% (95% CI, 66%-82%) and 80% (95% CI, 73%-86%) in the lapatinib, trastuzumab and combination groups, respectively. Women who achieved a pCR had improved EFS (hazard ratio 0.48, 95% CI, 0.31-0.73) and OS (hazard ratio 0.37, 95% CI, 0.20-0.63) compared with those who did not. The numerical difference in survival according to pCR status was greater in women treated with the combination and those with hormone-receptor-negative tumours. There were no new or long-term safety concerns.

CONCLUSIONS

Patients with HER2-positive BC showed a durable survival benefit of neoadjuvant anti-HER2, irrespective of treatment arm. Patients who achieve pCR have significantly better outcomes than patients without pCR.

Immunology and immunotherapy in breast cancer

Immuno-oncology is a rapidly developing field in medicine. Drug combination therapies have already been studied in many clinical trials on various tumor types. In recent years, a checkpoint inhibition therapy with monoclonal antibodies targeting PD-1 and its ligand PD-L1 has been developed. Breast cancer had been examined in the field of immune-oncology relatively recently. This review focuses on clinical evidence regarding immune checkpoint inhibition for curative treatment of various breast cancer subtypes. In addition, we present the results of studies demonstrating the prognostic and predictive value of levels of tumorinfiltrating lymphocytes (CD4 and CD8), their quantitative ratios, and their correlation with regulatory genes (PD-1, PD-L1, and FOX-P3).

Axillary surgery after neoadjuvant chemotherapy in breast cancer patients downstaging from cN+ to ycN0

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Background: Axillary lymph node dissection is a redundant method of surgical treatment and axillary staging for a large number of patients receiving neoadjuvant therapy with positive lymph nodes before NCT. Methods: The study included 212 patients with breast cancer (cT1-3N1M0) who received treatment at the breast tumors department of the N.N. Petrov NMRC of Oncology from 2019 to 2021 All patients included in the study had the cN1 initial status of the axillary lymph nodes. All patients underwent neoadjuvant systemic therapy and subsequent sentinel lymph node biopsy (SLNB). In patients with pathomorphologically proven metastatic lymph nodes (cN1) even at the initial diagnosis, lymph node marking was performed before the start of NCT and targeted axillary lymph node dissection after the completion of neoadjuvant systemic therapy. In the same patients, after SLNB and targeted axillary lymph node dissection, a complete (standard) axillary lymph node dissection was performed to determine the false-negative rate and the oncological safety of the procedure. Results: The identification rate of only one sentinel lymph node was 21% (40 out of 193 patients), two sentinel lymph nodes - 30% (58 out of 193 patients), more than 3 - 49% (95 out of 193 patients). When only 1 sentinel lymph node was found, the false-negative rate of SLNB was 20.0% (4 of 20) (95% CI, 5.7 to 43.7). When two sentinel lymph nodes were found, the false-negative rate of SLNB was 20.0% (6 of 30) (95% CI, 7.7 to 38.6). When three sentinel lymph nodes were found, the false negative rate of SLNB was 4.7% (2 of 43) (95% CI, 0 to 15.8). Among 45 patients who had a microseed with the iodine-125 radioisotope installed before the start of treatment, the frequency of identifying a marked node was 100%. In 19 patients, tumor cells were found in the lymph nodes. The false-negative rate of targeted axillary dissection in combination with SLNB was 5.3% (1 of 19) (95% CI, 0 to 26.0). Conclusions: Targeted axillary dissection and sentinel lymph nodes biopsy, provided that 3 SLNs are removed, are reliable methods for identifying patients in whom systemic therapy is guaranteed to achieve complete response of regional lymph nodes (ypN0), thereby relieving patients of the need to perform a crippling complete axillary lymph node dissection. Clinical trial information: 3/198.

Derived Neutrophil-to-Lymphocyte Ratio Predicts Pathological Complete Response to Neoadjuvant Chemotherapy in Breast Cancer

Background

Derived neutrophil-to-lymphocyte ratio (dNLR) is a biomarker associated with clinical outcome in breast cancer (BC). We analyzed the association of dNLR with pathological complete response (pCR) in triple-negative BC (TNBC) patients receiving neoadjuvant chemotherapy (CT).

Methods

This is a retrospective analysis of two randomized studies involving early stage/locally advanced TNBC patients receiving anthracycline/taxane-based CT+/−carboplatin (GEICAM/2006-03) or nab-paclitaxel/paclitaxel followed by anthracycline regimen (ETNA). dNLR was calculated as the ratio of neutrophils to the difference between total leukocytes and neutrophils in peripheral blood before CT (baseline) and at the end of treatment (EOT). Logistic regression analyses were used to explore dNLR association with pCR.

Results

In total, 308 TNBC patients were analyzed, 216 from ETNA and 92 from GEICAM/2006-03. Baseline median dNLR was 1.61 (interquartile range (IQR): 1.25–2.04) and at EOT 1.53 (IQR: 0.96–2.22). Baseline dNLR showed positive correlation with increased tumor size (p-value = 1e−04). High baseline dNLR, as continuous variable or using median cutoff, was associated with lower likelihood of pCR in univariate analysis. High EOT dNLR as continuous variable or using quartiles was also associated with lower pCR rate in uni- and multivariate analyses.

Conclusions

High baseline and EOT dNLR correlates with lower benefit from neoadjuvant CT in TNBC.

Pathologic complete response (pCR) to neoadjuvant treatment with or without atezolizumab in triple negative, early high-risk and locally advanced breast cancer. NeoTRIP Michelangelo randomized study

BACKGROUND

High-risk triple negative breast cancers (TNBC) are characterized by poor prognosis, rapid progression to metastatic stage and onset of resistance to chemotherapy, thus representing an area in need of new therapeutic approaches. PD-L1 expression is an adaptive mechanism of tumour resistance to tumour infiltrating lymphocytes, which in turn are needed for response to chemotherapy. Overall, available data support the concept that blockade of PD-L1/PD-1 check-point may improve efficacy of classical chemotherapy.

PATIENTS AND METHODS

Two-hundred-eighty patients with TNBC were enrolled in this multicentre study (NCT002620280) and randomized to neoadjuvant carboplatin AUC 2 and nab-paclitaxel 125 mg/m² iv on days 1 and 8, without (N = 142) or with (N = 138) atezolizumab 1200 mg iv on day 1. Both regimens were given q3 weeks for 8 cycles before surgery and 4 cycles of an adjuvant anthracycline regimen. The primary aim of the study is to compare event-free survival, an important secondary aim was the rate of pathological complete remission (pCR defined as absence of invasive cells in breast and lymph nodes). The primary population for all efficacy endpoints is the intention-to-treat population.

RESULTS

The intention-to-treat analysis revealed that pCR rate after treatment with atezolizumab (48.6%) did not reach statistical significance compared to no atezolizumab [44.4%: odds ratio (OR) 1.18; 95% CI 0.74-1.89; P = 0.48]. Treatment-related adverse events were similar with either regimen except for a significantly higher overall incidence of serious adverse events and liver transaminases abnormalities with atezolizumab.

CONCLUSIONS

The addition of atezolizumab to nab-paclitaxel and carboplatin did not significantly increase the rate of pCR in women with TNBC. In multivariate analysis the presence of PD-L1 expression was the most significant factor influencing rate of pCR (OR 2.08). Continuing follow up for the event-free survival is ongoing, and molecular studies are under way.

Abstract P2-07-12: Triple negative breast cancer subtypes and early dynamics of the 27-gene IO score predict pCR in the NeoTRIPaPDL1 trial

Background A post-hoc of NeoTRIP trial showed that 27-gene IO score assessed on baseline samples is predictive of increased pathological complete response (pCR) with the addition of atezolizumab to carboplatin/nab-paclitaxel, whereas the LAR subtype has the lowest rate of pCR with and without atezolizumab (Bianchini G ESMO 2021). We evaluated 27-gene IO score and TNBC subtypes on biopsies collected during treatment, assessed biomarker dynamics, and studied the association with pCR. Methods In NeoTRIP, patients randomly received 8 cycles of nab-paclitaxel/carbo alone (CT) or with atezolizumab (CT/A). 258 patients were evaluable for pCR (Per-Protocol Population). We assessed IO score as binary and continuous variable, and the five 101-gene TNBC types (BL1, BL2, LAR, M, and MSL; Ring et al 2016) by RNA-seq on biopsies at baseline and day 1 of second treatment cycle (d1c2) (n: baseline 242/258, 94%; d2c2 161/258, 62%; paired 152/258, 59%). Forty-four paired samples were excluded due to lack of tumor cells at d1c2. PD-L1 (Ventana SP142) and sTILs data were available. We evaluated the association with pCR of biomarkers assessed at d1c2 and their dynamics from baseline. Results Frequency of TNBC types at d1c2 showed minor differences between arms (p = 0.055). TNBC type frequencies were 22.9% BL1, 11.4% BL2, 22.9% LAR, 21.4% M, and 21.4% MSL in the CT/A arm and 43.8% BL1, 6.2% BL2, 11.2% LAR, 21.2% M, and 17.5% MSL in the CT arm. Individual TNBC type changes from baseline to d1c2 were observed, but overall, it was not significant. Frequency of IO positive score at d1c2 was similar in CT and CT/A arm (p = 0.75). Only in CT/A, an increase from baseline to d1c2 was observed (30.9% to 49.3%, p = 0.04).Overall, TNBC types at d1c2 were predictive of pCR (p = 0.00002). Compared to BL1, LAR and M were associated with lower pCR rate in CT (OR = 0.09, 95% CI = 0.01-0.83, p = 0.034 for LAR; OR = 0.16, 95% CI = 0.04-0.66, p = 0.011 for M) and CT/A arm (OR = 0.05, 95% CI = 0.01-0.49, p = 0.010 for LAR; OR = 0.28, 95% CI = 0.06-1.28, p = 0.102). pCR rate in LAR was 11.1% and 6.2% in CT and CT/A arm, respectively. TNBC types were predictive of pCR independently of PD-L1 and sTILs.Continuous IO score at d1c2 was predictive of pCR in both CT/A (p = 0.004) and CT arms (p = 0.009). The binary IO score was significantly associated to higher pCR rate in CT/A arm only (OR = 5.42, 95% CI = 1.95-15.07, p = 0.001). A strong predictive value of the highest quartile of IO score compared to the lowest was observed in CT/A (OR = 14.73, 95% CI = 2.97-73.21, p = 0.001) and CT (OR = 4.38, 95% CI = 1.21-15.81, p = 0.024) arms. pCR rates for the highest and lowest quartiles were 72.2% vs 15.0% in CT/A and 65.2% vs 30.0% in CT arm. In CT/A binary IO score at d1c2 retained significance after adjustment for baseline PD-L1 and sTILs (p = 0.036).Combining baseline and d1c2 IO score, only d1c2 assessment was informative in CT arm. In CT/A arm, both biomarkers were informative, with assessment at d1c2 being more informative than baseline IO score when continuous scores were considered. Baseline binary IO score (OR = 25.0, 95% CI = 3.31-188.9, p = 0.002) and ΔIO score (d1c2-baseline) (OR = 11.3, 95% CI = 1.07-120.1, p = 0.044) retained significance. The combination of baseline and d1c2 binary IO score defined four groups with different likelihood of pCR: 73.7% vs 15.2% in positive/positive and negative/negative groups, respectively (OR = 15.68, 95% CI = 3.88-63.32, p = 0.0001). Conclusions Dynamic of IO score early on treatment was linked to likelihood of pCR independently of baseline biomarkers and may be an early surrogate of treatment benefit especially in atezolizumab arm. LAR and M are associated with lower pCR rate, suggesting that different therapeutic strategies may be beneficial. Combining baseline and on-treatment biomarkers can be more informative than baseline only of the complex tumor/immune co-evolution dynamic and of clinical outcome.

Citation Format: Matteo Dugo, Chiun-Sheng Huang, Daniel Egle, Begoña Bermejo, Claudio Zamagni, Robert S. Seitz, Tyler J. Nielsen, Marc Thill, Antonio Anton, Stefania Russo, Eva Maria Ciruelos, Brock L. Schweitzer, Douglas T. Ross, Barbara Galbardi, Richard Greil, Vladimir Semiglazov, Balázs Gyorffy, Marco Colleoni, Catherine Kelly, Gabriella Mariani, Lucia Del Mastro, Pinuccia Valagussa, Giuseppe Viale, Maurizio Callari, Luca Gianni, Giampaolo Bianchini. Triple negative breast cancer subtypes and early dynamics of the 27-gene IO score predict pCR in the NeoTRIPaPDL1 trial [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 P2-07-12.

Abstract P2-13-17: A phase III, randomized, multicenter, double-blind study to compare efficacy and safety of EG12014 (EirGenix trastuzumab) with Herceptin® as neoadjuvant treatment in combination with anthracycline/paclitaxel-based systemic therapy in patients with HER2-positive early breast cancer - a multinational phase III study conducted during the COVID-19 pandemic

Amplification and/or overexpression of HER2 in breast cancer (BCa) patients is associated with aggressive disease and poor prognosis. Herceptin® (trastuzumab), a monoclonal antibody targeting HER2, has an established role in the treatment of HER2 positive BCa. Addition of trastuzumab to anthracycline- and taxane-based neoadjuvant treatment in women with HER2-positive BCa has resulted in improvements in pathological complete response (pCR, a strong predictor for long-term clinical outcome), event-free survival (EFS) and overall survival (OS). This study is designed to compare efficacy (pCR) and safety between the originator Herceptin and the proposed trastuzumab biosimilar EG12014. The study is conducted during the COVID-19 pandemic (last patient in: March 2020, last patient last visit: planned Jan 2022) in Belarus, Chile, Colombia, Georgia, India, Russia, South Africa, South Korea, Taiwan, and the Ukraine. Methods: Neoadjuvant phase: 807 patients were randomized (1:1) into 2 arms receiving epirubicin (90 mg/m2) and cyclophosphamide (600 mg/m2) every 3 weeks for 4 cycles, followed by EG12014 (arm 1) or Herceptin (arm 2) (both at loading dose: 8 mg/kg and maintenance dose: 6 mg/kg) and paclitaxel (175 mg/m2) every 3 weeks for 4 cycles. Subsequently, the patients underwent surgery, and primary endpoint (pCR [ypT0/is ypN0]) was assessed. Adjuvant phase: After surgery, the patients received EG12014 or Herceptin (both at loading dose: 8 mg/kg and maintenance dose: 6 mg/kg) to complete 12 months of overall trastuzumab treatment. COVID-19 infections in the study population were not expected to affect primary endpoint analysis; thus, no sensitivity analysis was performed regarding COVID-19 status (symptomatic/asymptomatic). Differences between the 2 arms regarding delays in study treatments and procedures due to COVID-19 were assessed. Results (at interim data base lock, blinded as study is ongoing): Study population: the mean age was 50 years, the majority were white Europeans with tumor stage II, estrogen receptor positive and progesterone receptor negative. The median time from date of first diagnosis was 0.5 months. Primary endpoint pCR (ypT0/is ypN0) was reached with relative risk ratio (RR) for the full analysis set: 0.992 (90% CI 0.880 to 1.118) between the 2 treatment arms. Secondary pCR endpoints (defined as ypT0 ypN0 and ypT0/is) were also reached, with RR between the treatment arms: 0.917 and 0.992, respectively. Objective clinical response prior to surgery was similar for the 2 treatment arms: 83.8% and 83.6%, respectively. EFS, OS, safety endpoints (e.g., adverse events [most frequently reported: alopecia], serious adverse events, and deaths), and toxicity assessments, supported similarity between EG12014 and Herceptin. Sixty-two patients (7.7%) were infected with COVID-19; the infections were equally distributed between the 2 treatment arms. COVID-19 did not cause any discontinuations or deaths in the study. Among all reported COVID-19 events, 13 (21%) were asymptomatic, 11 (18%) were graded as 3 (severe), and 1 (1.6%) was graded as grade 4 (life threatening). Conclusion: EG12014 has shown equivalent efficacy to Herceptin in regard to clinical response (pCR) and has also demonstrated a similar safety profile. The impact of the COVID-19 pandemic has been comparable between the two treatment arms. The influence of the pandemic on this clinical study has been relatively low considering timing and the participating countries. For further information, visit ClinicalTrials.gov (NCT03433313).

Citation Format: Barbara Grohmann-Izay, Chiun-Sheng Huang, Giorgi Dzagnidze, Nestor Llinas, Anand Misra, Denys Pominchuk, Alexander Prokhorov, Bernardo Rapoport, Vladimir Semiglazov, Ling-Ming Tseng, Eduardo Yanez Ruiz, Sibylle Loibl. A phase III, randomized, multicenter, double-blind study to compare efficacy and safety of EG12014 (EirGenix trastuzumab) with Herceptin® as neoadjuvant treatment in combination with anthracycline/paclitaxel-based systemic therapy in patients with HER2-positive early breast cancer - a multinational phase III study conducted during the COVID-19 pandemic [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 P2-13-17.

Abstract PD10-06: Predictive value of RT-qPCR 27-gene IO score and comparison with RNA-Seq IO score in the NeoTRIPaPDL1 trial

Background The identification of biomarkers for optimization of immune checkpoint inhibitors (ICI) treatment is an unmet clinical need. In the Phase III randomized trial, NeoTRIPaPDL1, a post-hoc analysis of whole transcriptome RNA-Seq data, previously showed that the 27-gene IO score is a potential predictive biomarker of increased pathological complete response with the addition of atezolizumab to carboplatin/nab-paclitaxel (Bianchini G ESMO 2021). However, the laboratory implementation of gene-expression signatures measured using RNA-seq is challenging. Therefore, we further assessed the predictive value of the IO score using a twenty-seven gene RT-qPCR assay on NeoTRIP samples, and compared to the previously reported RNA-Seq version of the assay. Methods The NeoTRIP study randomized patients to eight cycles of carboplatin/nab-paclitaxel (CT) with or without atezolizumab (CT/A). 258 patients were evaluable for pCR (breast and nodes) as Per-Protocol Population. We assessed the IO score as binary and continuous variables using the CAP/CLIA validated DetermaIO qPCR test (Saltman et al 2021) on pre-treatment core biopsies (n=220/258; 85.3%), all of which have RNA-Seq data available. We evaluated the association between IO score defined by RT-qPCR and RNA-Seq, and the association of the IO score defined by RT-qPCR test with PD-L1 IHC (Ventana SP142), stromal TILs (sTILs), and pCR. Results Comparison of continuous IO scores between the RT-qPCR assay and the RNA-Seq algorithm had a Pearson’s correlation of 0.94 (p < 0.0001). High agreement between categorical IO scores was also observed (Cohens’ kappa = 0.84; 95% confidence interval [CI] = 0.77-0.91; p < 0.0001). RT-qPCR IO score was balanced in the two arms (p = 0.65) with 44% and 40% positive patients in the CT and CT/A arms, respectively. The RT-qPCR IO score was correlated with both PD-L1 (Pearson’s r = 0.64; p < 0.0001) and sTILs (Pearson’s r = 0.67; p < 0.0001). Continuous IO score was significantly predictive of pCR in CT/A (Odds ratio [OR] = 3.12; 95% CI = 1.20-8.10; p<0.019), but not CT arm (OR = 1.28; 95% CI = 0.54-3.01; p = 0.578). Considering the binary IO score, OR were 2.87 [1.27-6.47] (p = 0.011) and 0.91 [0.43-1.93] (p = 0.812), in CT/A and CT, respectively (interaction test p = 0.043). The pCR rate for CT/A vs CT was 69.8% vs 46.9% in IO score positive [+22.9%, p = 0.046, Chi-squared test] and 44.6% vs 49.2% [-4.6%, p = 0.73] in IO score negative. A significant interaction was found between continuous PD-L1 and continuous IO-score (p = 0.006). Among PD-L1-neg, 9 patients were IO score positive (10.1%). The pCR rate in this group was 3/4 (75%) in the CT/A arm and 1/5 (20%) in CT arm. The predictive value of IO score by RT-qPCR was similar to RNA-Seq. Conclusions We observed a high level of agreement and concordance between IO scores assessed by RT-qPCR and RNA-Seq, indicating that the 27-gene IO assay and algorithm is robust and the choice of platform has limited impact. This finding also demonstrates the high quality of NeoTRIP RNA-Seq data. In this post-hoc analysis, IO score assessment by this CLIA validated RT-qPCR test was confirmed to be predictive of atezolizumab benefit over CT alone in a randomized trial.

Citation Format: Matteo Dugo, Chiun-Sheng Huang, Daniel Egle, Begoña Bermejo, Claudio Zamagni, Robert S. Seitz, Tyler J. Nielsen, Marc Thill, Antonio Anton, Stefania Russo, Eva Maria Ciruelos, Brock L. Schweitzer, Douglas T. Ross, Barbara Galbardi, Richard Greil, Vladimir Semiglazov, Balázs Gyorffy, Marco Colleoni, Catherine Kelly, Gabriella Mariani, Lucia Del Mastro, Pinuccia Valagussa, Giuseppe Viale, Maurizio Callari, Luca Gianni, Giampaolo Bianchini. Predictive value of RT-qPCR 27-gene IO score and comparison with RNA-Seq IO score in the NeoTRIPaPDL1 trial [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 PD10-06.

Abstract GS1-00: Single-cell spatial analysis by imaging mass cytometry and immunotherapy response in triple-negative breast cancer (TNBC) in the NeoTRIPaPDL1 trial

Background Immunecheckpoint inhibitors are effective in early and advanced TNBC, however only aminority of patients benefit making precision immune-oncology a major unmetneed. Imaging mass cytometry (IMC) enables high dimensional tissue imaging atsubcellular resolution for assessment of TNBC ecosystems, providing informationon cell type composition, functional status, and spatial organisation. Methods InNeoTRIP patients with TNBC were randomized to eight cycles ofnab-paclitaxel/carbo (CT) with/without atezolizumab (CTA). Forty-four proteinsspanning cancer cells and the tumor microenvironment (TME) were assessed onpre-treatment biopsies (n=243/280; 86.8% evaluable after QC). FFPE samples werelabelled with antibodies conjugated to isotopically pure rare earth metalreporters and profiled at one micron resolution by IMC. For each sample, wehave generated three high dimensional images that encompass the tumor,tumor-stroma interface and adjacent stroma. We investigated the association ofprotein expression assessed separately for epithelial and TME cells, cellphenotypes, and spatial architectures with PD-L1 status (Ventana SP142),stromal TILs, TNBC types and pathological complete response (pCR). 237 patients(84.6%) have both IMC and RNA-seq available allowing for comparison with genesignatures derived from HALLMARK,ConsensusTME immune cell types, and Nanostring. Results Across243 samples we identify just over one million single cells. By supervised clustering,we defined 37 robust cell phenotypes. PD-L1-positive tumors, high stromal TILsand TNBC type were characterized by extreme heterogeneity and unique cell-type andspatial TME composition. Severalbiomarkers demonstrated a significant test for interaction. Considering proteinexpression, GATA3 and CD20 on TME, HLA-DR in epithelial cells and Ki67 assessedboth in epithelial and TME, had a significant test for interaction (p <0.05). For all these biomarkers, high expression (above median) was associatedwith an increase of pCR of >10% in favour of atezolizumab, whereas lowerexpression group demonstrated a similar pCR rate among arms.Two cellphenotypes, PD-L1+IDO+ antigen presenting cells (APCs) and CD56+ neuroendocrine(NE) epithelial cells, had a significant test for interaction. Higherexpression of these biomarkers was associated with higher likelihood of pCR in CTAarm, but not in CT arm. For example, PD-L1+IDO+APCs in the CTA arm wereassociated with pCR proportions of 64.6% and 24.6% for above- and below-mediangroups respectively (OR4.5 [2.01-10.1], p<0.001).Mostof these tests of interaction retained significance after adjustment by PD-L1status and stromal TILs. Notably, none among 61 gene-expression basedimmune-related pathways and 7 proliferation-related signatures demonstrated a significant test ofinteraction. Resultsof systematic multi-tiered image analysis at the levels of cell-cellinteractions and recurrent higher order multicellular complexes defining TNBC ecosystemsidentified by graph-based methods will be presented at the meeting. Conclusions Imaging mass cytometry provides a morecomprehensive overview of TNBC heterogeneity at a single-cell level withspatial resolution. Bulk protein or gene expression might deliver limitedpredictive information because it does not consider the cell compartment ofexpression. Precise cell phenotyping highlights the predictive role ofPD-L1+IDO+APCs and CD56+NE epithelial cells. Overall, we demonstrated that IMCis feasible in a large, randomized trial and provides independent predictiveinformation on immune checkpoint inhibitors benefit to PD-L1, TILs and gene-expressionprofiles.

Citation Format: Giampaolo Bianchini, Xiao Qian Wang, Esther Danenberg, Chiun-Sheng Huang, Daniel Egle, Maurizio Callari, Begoña Bermejo, Claudio Zamagni, Marc Thill, Anton Anton, Matteo Dugo, Stefania Zambelli, Stefania Russo, Eva Maria Ciruelos, Richard Greil, Vladimir Semiglazov, Marco Colleoni, Catherine Kelly, Gabriella Mariani, Lucia Del Mastro, Balázs Győrffy, Olivia Biasi, Pinuccia Valagussa, Giuseppe Viale, Luca Gianni, H Raza Ali. Single-cell spatial analysis by imaging mass cytometry and immunotherapy response in triple-negative breast cancer (TNBC) in the NeoTRIPaPDL1 trial [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 GS1-00.

Abstract P3-18-09: Refusal of breast surgery in breast cancer patients with clinical complete response (cCR) after neoadjuvant systemic therapy and vacuum-assisted biopsy (VAB) and sentinel lymph node biopsy (SLNB) confirmed pathological complete response (pCR). A first report of the prospective non-randomized trial results. NCT04293796

Introduction The aim of the study was to prove efficacy and safety of refusal of traditional breast surgery in BC patients who develop cCR after neoadjuvant chemotherapy. Refusal of surgery was offered to exceptional responders after vacuum-assisted tumor bed biopsy and sentinel lymph node biopsy confirmed absence of residual disease (pCR). Materials and methods A single-center prospective study was run in the NMRC n.a. N.N. Petrov. Starting from August of 2020 20 patients with early сT1-2N0-1M0 (stage Ia-IIb) triple-negative and HER2-positive (both ER+ and ER-) unifocal tumours without in situ component in core-biopsy specimen enrolled in the study. Primary lesions were marked with a single clip in the centre. In cases with nodal involvement (cN1) the affected lymph nodes were also clipped. Patients with triple-negative breast cancer received 4 cycles of AC q21d followed by 12 cycles of weekly paclitaxel and carboplatinum AUC 2.0. HER2-positive patients received 4 cycles of AC followed by 4 cycles of docetaxel combined with trastuzumab and pertuzumab q21d. Breast US, mammography and SPECT were used at baseline and at response evaluation. Vacuum-assisted biopsy was performed with 7G needle and US-guidance in the OR simultaneously with the SLNB under general anesthesia. VAB protocol included retrieval of the tumor clip as first stage. Subsequently surrounding tissues were sampled, and markers were placed to guide radiotherapy. In case residual tumor was found patients received standard breast-conserving surgery. In case the sentinel lymph nodes were found to be positive, standard level II axillary clearance was performed. HER2-positive patients with pCR confirmed by VAB and SLNB received adjuvant trastuzumab up to one year. HER2-positive patients with residual breast or nodal involvement received trastuzumab-emtanzine up to one year. In case ER-positive, all patients received appropriate endocrine-therapy. In case of residual in-breast or nodal involvement patients with triple-negative breast cancer received 6 cycles of capecitabine. Results cCR was achieved in 8 of 10 patients in the HER2-positive group. VAB and SLNB were performed in 7 cases and confirmed pCR in 5 patients. 2 had residual in-breast disease with <10% cellularity. One patient with cCR requested standard surgical approach that confirmed pCR. 2 patients failed to obtain cCR. Both received standard surgery. In one of the cases no residual disease was found, in another one - a residual in-breast tumor was found at section. All HER2-positive patients were found to be sn ypN0. In the triple-negative group cCR was achieved in 6 of 10 patients. 4 patients went on to receive VAB and SLNB. After VAB and SLNB pCR was confirmed in three of them. 1 patient had residual tumor with less than 5% cellularity. Two patients with cCR after NAT opted for standard surgery. In both cases pCR was confirmed. 4 patients with clinically detectable residual in-breast tumor received standard surgery. All turned out to have pCR. All the patients in the TNBC group were also found to be sn ypN0.ConclusionVisualization modalities fail to provide reliable information on the true rate of pCR. Contemporary systemic therapy regimens provide the rate of pCR up to 60-70%. In all cases of NAT tumor bed marking at baseline is an essential procedure to guide future interventions and confirm their success. Discrepancies between radiologic assessment and true rates of pCR are a substrate for further search for the techniques that would challenge the role of surgery in exceptional responders developing cCR. The trial continues to enrol patients.

Citation Format: Petr Krivorotko, Sergey Yerechshenko, Alexander Emelyanov, Ekaterina Busko, Alexander Bessonov, Viktoriya Gukova, Alexander Komyahov, Elena Zhiltsova, Kirill Nikolaev, Tengiz Tabagua, Larisa Gigolaeva, Roman Pesotsky, Sergey Novikov, Zhanna Bryantseva, Anna Artemyeva, Viktoriya Smirnova, Vladimir Kushnarev, Alexey Belyaev, Tatiana Semiglazova, Vladimir Semiglazov. Refusal of breast surgery in breast cancer patients with clinical complete response (cCR) after neoadjuvant systemic therapy and vacuum-assisted biopsy (VAB) and sentinel lymph node biopsy (SLNB) confirmed pathological complete response (pCR). A first report of the prospective non-randomized trial results. NCT04293796 [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 P3-18-09.

The TRAR gene classifier to predict response to neoadjuvant therapy in HER2-positive and ER-positive breast cancer patients: an explorative analysis from the NeoSphere trial

As most erb-b2 receptor tyrosine kinase 2 (HER2)-positive breast cancer (BC) patients currently receive dual HER2-targeting added to neoadjuvant chemotherapy, improved methods for identifying individual response, and assisting postsurgical salvage therapy, are needed. Herein, we evaluated the 41-gene classifier trastuzumab advantage risk model (TRAR) as a predictive marker for patients enrolled in the NeoSphere trial. TRAR scores were computed from RNA of 350 pre- and 166 post-treatment tumor specimens. Overall, TRAR score was significantly associated with pathological complete response (pCR) rate independently of other predictive clinico-pathological variables. Separate analyses according to estrogen receptor (ER) status showed a significant association between TRAR score and pCR in ER-positive specimens but not in ER-negative counterparts. Among ER-positive BC patients not achieving a pCR, those with TRAR-low scores in surgical specimens showed a trend for lower distant event-free survival. In conclusion, in HER2-positive/ER-positive BC, TRAR is an independent predictor of pCR and represents a promising tool to select patients responsive to anti-HER2-based neoadjuvant therapy and to assist treatment escalation and de-escalation strategies in this setting.

Primary results from IMpassion131, a double-blind, placebo-controlled, randomised phase III trial of first-line paclitaxel with or without atezolizumab for unresectable locally advanced/metastatic triple-negative breast cancer

BACKGROUND

In the phase III IMpassion130 trial, combining atezolizumab with first-line nanoparticle albumin-bound-paclitaxel for advanced triple-negative breast cancer (aTNBC) showed a statistically significant progression-free survival (PFS) benefit in the intention-to-treat (ITT) and programmed death-ligand 1 (PD-L1)-positive populations, and a clinically meaningful overall survival (OS) effect in PD-L1-positive aTNBC. The phase III KEYNOTE-355 trial adding pembrolizumab to chemotherapy for aTNBC showed similar PFS effects. IMpassion131 evaluated first-line atezolizumab-paclitaxel in aTNBC.

PATIENTS AND METHODS

Eligible patients [no prior systemic therapy or ≥12 months since (neo)adjuvant chemotherapy] were randomised 2:1 to atezolizumab 840 mg or placebo (days 1, 15), both with paclitaxel 90 mg/m² (days 1, 8, 15), every 28 days until disease progression or unacceptable toxicity. Stratification factors were tumour PD-L1 status, prior taxane, liver metastases and geographical region. The primary endpoint was investigator-assessed PFS, tested hierarchically first in the PD-L1-positive [immune cell expression ≥1%, VENTANA PD-L1 (SP142) assay] population, and then in the ITT population. OS was a secondary endpoint.

RESULTS

Of 651 randomised patients, 45% had PD-L1-positive aTNBC. At the primary PFS analysis, adding atezolizumab to paclitaxel did not improve investigator-assessed PFS in the PD-L1-positive population [hazard ratio (HR) 0.82, 95% confidence interval (CI) 0.60-1.12; P = 0.20; median PFS 6.0 months with atezolizumab-paclitaxel versus 5.7 months with placebo-paclitaxel]. In the PD-L1-positive population, atezolizumab-paclitaxel was associated with more favourable unconfirmed best overall response rate (63% versus 55% with placebo-paclitaxel) and median duration of response (7.2 versus 5.5 months, respectively). Final OS results showed no difference between arms (HR 1.11, 95% CI 0.76-1.64; median 22.1 months with atezolizumab-paclitaxel versus 28.3 months with placebo-paclitaxel in the PD-L1-positive population). Results in the ITT population were consistent with the PD-L1-positive population. The safety profile was consistent with known effects of each study drug.

CONCLUSION

Combining atezolizumab with paclitaxel did not improve PFS or OS versus paclitaxel alone. CLINICALTRIALS.GOV: NCT03125902.

Clinical and pathological response to neoadjuvant chemotherapy (NCT) in patients with triple-negative breast cancer (TNBC)

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Background: Neoadjuvant chemotherapy (NCT), Triple-negative breast cancer (TNBC) including anthracyclines and taxanes for early stages of TNBC, allows to achieve pathological complete response (pCR) in 25-36% of patients. Pathological complete response (pCR) significantly correlates with an increase in disease-free survival (DFS) and overall survival (OS). Methods: Randomized, monocentric trial was conducted in NN Petrov National Medical Research Center of Oncology from 2016 to 2019. 99 patients aged from 28 to 68 years with confirmed TNBC were included in trial: 96 had invasive ductal carcinoma G3, 3 - metaplastic cancer, negative BRCA mutations (a test for Founder mutations was performed).Patients were randomized in 3 groups, depending on the NCT regimen:1st subgroup (24 patients) - Eribulin in combination with Carboplatin AUC 5 x 4 cycles 2nd subgroup (37 patients) - Paclitaxel in combination with Carboplatin AUC 5 x 4 cycles 3rd subgroup (38 patients) –Carboplatin AUC5 + Doxorubicin + Paclitaxel x 6 cycles. Patients 1 and 2 subgroups in an adjuvant mode received 4 cycles of AC. Results: Clinical complete response (cCR) by physical examination (palpation) was achieved in 44 out of 99 patients (44.4%). Clinical complete response (cCR) by ultrasound and MG - in 27 (27.2%) patients. Miller-Payne V regression stage was achieved in 55 out of 99 cases (55.6%). In clinical cT1-T2 stage (n = 70), ypCR was achieved in 49 cases (70%), cT3-T4 (n = 29) ypCR in 6 patients (20.68%). Before NCT, 71 patients had status cN0-N1. Conversion to ypN0 occurred in 57 patients (80.2%). In 28 patients with cN2-N3 status, conversion to ypN0 occurred in 7 patients (25%). The median follow-up was 58 months. Progression was observed in 15.1% of patients, mortality – 6%. Local recurrence - 6 patients (6%), all patients were with residual tumor after NCT. Distant recurrence – 8 patients (8.1 %). Local recurrence rate and distant recurrence rate did not correlate with type of surgery (BCS or ME), but correlated with ypCR. Conclusions: NCT for TNBC is advisable both for locally advanced breast cancer and early breast cancer BC. De-escalation of BC surgery is possible in the future, especially in cT1-T2 stage patients (n = 70) where ypCR rate reaches 70%. It is planned to continue the trial with the vacuum aspiration biopsy of the tumor bed and SLNB after NCT.SLNB after NCT is advisable only in cN0-N1 group of patients (n = 71), since conversion to ypN0 was achieved in 57 patients - 80.2%.

Targeted axillary lymph node dissection in breast cancer patients using I-125 microseeds for prostate cancer brachytherapy

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Background: To date, targeted axillary lymph node dissection is one of the possible methods of de-escalation of surgical aggression on the areas of regional lymph flow in breast cancer patients with confirmed metastases in the axillary lymph nodes prior to the neoadjuvant chemotherapy. There are no specialized microseeds for targeted axillary dissection. The purpose of our study was to determine the possibility of using I-125 microseed for prostate cancer brachytherapy for targeted axillary dissection. Methods: A prospective study of patients with biopsy-confirmed nodal axillary metastases with a I-125 microseed placed in the node was performed. I-125 microseed for prostate cancer brachytherapy was used to mark the axillary lymph node. After neoadjuvant therapy, patients underwent targeted axillary lymph node dissection in combination with SLNB with pathomorphological examination of marked lymph node and total axillary lymph node dissection with pathomorphological examination of over lymph nodes for FNR evaluation. Results: 45 breast cancer patients stage cT1-3N1M0 were enrolled in the study. The frequency of reaching ypN0 was 58%. Residual disease identified in 19 patients. The clipped node revealed metastases in 18 patients, resulting in an FNR of 5.26% (95% CI, to 20.6) for the clipped node. CIs for FNR were calculated using exact (Clopper-Pearson) confidence limits for the binomial proportion. Conclusions: Marking the biopsy-confirmed lymph node using a I-125 microseed prior neoadjuvant chemotherapy and performing targeted axillary lymph node dissection in combination with SLNB is a safe method for diagnosing axillary lymph nodes and allows you to abandon routine ALD for ypN0 patients. Advantages of I-125 microseed for prostate cancer brachytherapy: fixation in the lymph node without migration, the ability to use a standard gamma-probe to locate the microseed during the operation, these microseeds are registered for the treatment of cancer patients.

Abstract PS9-62: Biopsychosocial approach in the rehabilitation of patients with early breast cancer

Relevance: early breast cancer is detected in more than 60% of cases. Maintaining the quality of life of patients with early breast cancer at the highest possible level is a priority, along with the treatment of patients. Under a complex antitumor treatment as well as after its completion, more than 60% of patients with early breast cancer report the occurrence of functional disorders.An important aspect is to improve the effectiveness of the rehabilitation process of patients with early breast cancer taking into account scientifically-based and proven recommendations.Objective: to evaluate the event-free survival rate (EFS) of patients with EBC undergoing rehabilitation within a biopsychosocial approach.Materials and methods: 228 patients with breast cancer who received complex treatment from 2015 to 2019 were included in the study. The prospective part of the study included 114 patients with early breast cancer undergoing rehabilitation measures within the biopsychosocial approach. The control group which was selected retrospectively, using the method of "pairwise selection", included 114 patients with early breast cancer comparable in age, stage of the disease, volume of surgical treatment and menopausal status, undergoing physical and psychological rehabilitation prescribed by a doctor. Patients in both groups were stratified depending on preoperative chemotherapy. EFS was calculated over a 2-year follow-up period. Events that were censored were a disease progression, the appearance of metastases, the occurrence of another cancer, a new concomitant disease, an exacerbation of the concomitant pathology and death.Results: Rehabilitation measures within the biopsychosocial model improve the indicators of EFS in the group of patients with EBC: EFS was 18.3 months against 14.5 months in the control group (HR=0.91, 95% CI [0.83; 0.99]; p=0.0034). In a multi-factor analysis the key factors affecting EFS were neoadjuvant chemotherapy (HR=0.79, 95% CI [0.69; 0.94]; p=0.0025), age (HR=0.87, 95% CI [0.71;1.09]; p=0.0027) and menopausal status (HR=0.85, 95% CI [0.84; 0.95]; p=0.0022) (table 1).

Conclusions: Rehabilitation measures within the biopsychosocial model improve the indicators of EFS in the group of patients with early breast cancer, the key factors affecting EFS were neoadjuvant chemotherapy, age and menopausal status.

Table 1 Multi-factor analysis of event-free survival of patients with early breast cancer in the group of biopsychosocial model of rehabilitation versus control group.CharacteristicNumber of patientsHR (95% CI)Preoperative chemotherapyyes1520,84 (0,77; 1,1)no760,79 (0,69; 0,94)Menopauseyes1300,84 (0,77; 1,04)no980,85 (0,84; 0,95)Age group25-44610,87 (0,71; 1,09)45-601030,89 (0,74; 1,1)61-75641,01 (0,82; 1,24)EventDisease progression281,11 (0,86; 1,26)Exacerbation of the concomitant pathology160,83 (0,74; 0,96)

Citation Format: Valeria Kluge, Tatiana Semiglazova, Petr Krivorotko, Elena Melnikova, Vladislav Semiglazov, Kristina Kondrateva, Svetlana Nazarova, Margarita Tynkasova, Bahtiyar Adhamov, Roman Pesotsky, Konstantin Zernov, Valentina Chulkova, Boris Kasparov, Denis Kovlen, Vladimir Semiglazov, Alexey Belyaev. Biopsychosocial approach in the rehabilitation of patients with early breast cancer [abstract]. In: Proceedings of the 2020 San Antonio Breast Cancer Virtual Symposium; 2020 Dec 8-11; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2021;81(4 Suppl):Abstract nr PS9-62.

Abstract GS4-01: Results from CONTESSA: A phase 3 study of tesetaxel plus a reduced dose of capecitabine versus capecitabine alone in patients with HER2-, hormone receptor + (HR+) metastatic breast cancer (MBC) who have previously received a taxane

Objectives: The key objectives of CONTESSA are to evaluate the efficacy and safety of tesetaxel plus a reduced dose of capecitabine as an all-oral regimen versus capecitabine alone in patients with HER2-, HR+ MBC previously treated with a taxane.

Rationale: Tesetaxel is a novel, oral taxane with several properties that make it unique, including: oral administration with a low pill burden; a long (8-day) terminal plasma half-life in humans, enabling infrequent, once-every-3 weeks (Q3W) dosing; no observed hypersensitivity reactions; and significant activity against chemotherapy-resistant breast cancer cell lines. More than 1,000 patients have been treated with tesetaxel in clinical studies. Tesetaxel had encouraging monotherapy activity in a Phase 2 study in 38 patients with HER2-, HR+ MBC, with a confirmed objective response rate (ORR) per RECIST 1.1 of 45% and median progression-free survival (PFS) of 5.4 months (Seidman et al, 2018 ASCO Annual Meeting).

Methodology: CONTESSA is a multinational, multicenter, randomized (1:1), Phase 3 registration study comparing tesetaxel (27 mg/m2 on Day 1 of a 21-day cycle) plus a reduced dose of capecitabine (1,650 mg/m2/day on Days 1-14 of a 21-day cycle) to the approved dose of capecitabine alone (2,500 mg/m2/day on Days 1-14 of a 21-day cycle) in patients with HER2-, HR+ MBC who have received no more than one chemotherapy regimen for advanced disease and have received a taxane in the (neo)adjuvant setting. There was no restriction on the disease-free interval following taxane therapy. The primary endpoint is PFS assessed by an Independent Radiologic Review Committee (IRC). CONTESSA was designed with 90% power to detect a 2.5-month improvement in median PFS (HR=0.71). Secondary endpoints are overall survival (OS), ORR and disease control rate.

Results: CONTESSA, which enrolled 685 patients, met the primary endpoint of improved PFS as assessed by the IRC. Median PFS was 9.8 months for tesetaxel plus a reduced dose of capecitabine versus 6.9 months for capecitabine alone, an improvement of 2.9 months [HR=0.716 (95% CI: 0.573-0.895); p=0.003]. ORR was 57% for tesetaxel plus a reduced dose of capecitabine versus 41% for capecitabine alone (p=0.0002). OS data are immature. Tesetaxel plus capecitabine was associated with a manageable side effect profile consistent with previous clinical studies. Grade ≥3 treatment-emergent adverse events (TEAEs) that occurred in ≥5% of patients (tesetaxel plus capecitabine vs. capecitabine alone) were: neutropenia (71.2% vs. 8.3%); diarrhea (13.4% vs. 8.9%); hand-foot syndrome (6.8% vs. 12.2%); febrile neutropenia (12.8% vs. 1.2%); fatigue (8.6% vs. 4.5%); hypokalemia (8.6% vs. 2.7%); leukopenia (10.1% vs. 0.9%); and anemia (8.0% vs. 2.1%). TEAEs resulting in treatment discontinuation in ≥1% of patients (tesetaxel plus capecitabine vs. capecitabine alone) were: neutropenia or febrile neutropenia (4.2% vs. 1.5%); neuropathy (3.6% vs. 0.3%); diarrhea (0.9% vs. 1.5%); and hand-foot syndrome (0.6% vs. 2.1%). Treatment discontinuation due to any adverse event occurred in 23.1% of patients treated with tesetaxel plus capecitabine versus 11.9% of patients treated with capecitabine alone. Grade 2 alopecia occurred in 8.0% of patients treated with tesetaxel plus capecitabine versus 0.3% of patients treated with capecitabine alone. Grade ≥3 neuropathy occurred in 5.9% of patients treated with tesetaxel plus capecitabine versus 0.9% of patients treated with capecitabine alone.

Conclusion: An all-oral regimen of tesetaxel plus a reduced dose of capecitabine significantly improved PFS versus capecitabine alone. Neutropenia was the most frequent Grade ≥3 TEAE. Rates of clinically significant alopecia and neuropathy were low.

Citation Format: Joyce O'Shaughnessy, Lee Schwartzberg, Martine Piccart, Hope S. Rugo, Denise A Yardley, Javier Cortes, Michael Untch, Nadia Harbeck, Gail S. Wright, Igor Bondarenko, John Glaspy, Zbigniew Nowecki, Fadi Kayali, Arlene Chan, Christelle Levy, Mei-Ching Liu, Sung-Bae Kim, Julie Lemieux, Alexey Manikhas, Sara Tolaney, Elaine Lim, Andrea Gombos, Agostina Stradella, Mark Pegram, Peter Fasching, Laszlo Mangel, Vladimir Semiglazov, Veronique Dieras, Luca Gianni, Michael A Danso, Jeff Vacirca, Stew Kroll, Joseph O'Connell, Kevin Tang, Thomas Wei, Andrew Seidman. Results from CONTESSA: A phase 3 study of tesetaxel plus a reduced dose of capecitabine versus capecitabine alone in patients with HER2-, hormone receptor + (HR+) metastatic breast cancer (MBC) who have previously received a taxane [abstract]. In: Proceedings of the 2020 San Antonio Breast Cancer Virtual Symposium; 2020 Dec 8-11; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2021;81(4 Suppl):Abstract nr GS4-01.

Modulation by treatment of tumor infiltrating lymphocytes (TILs) and PDL1 expression in triple-negative breast cancer in the ETNA trial

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Background: We assessed TILs and PDL1 expression before, during and after neoadjuvant treatment in TNBC patients enrolled in the ETNA study, and investigated associations with clinical outcome. Methods: In ETNA patients randomly received paclitaxel or nab-paclitaxel followed by 4 cycles of an anthracycline regimen, including 219 centrally confirmed TNBC. We successfully measured stromal and intratumoral TILs (sTILs, iTILs) and PDL1 status (Ventana SP142, IC≥1%) on biopsies before [n = 186/213 (84.9%)], on d1 cycle 2 (d1c2) of therapy [n = 41/186 (22.0%)], and at surgery [SX, n = 65/129 (34.9%)]. We investigated the expression and modulation over time of TILs and PDL1 and their association with pCR and event-free survival (EFS). Results: Prevalence of PDL1+ was 35.5% (baseline), 20.6% (d1c2) and 30.1% (SX). At each time-point sTILs and iTILs were higher in PDL1+ cases (p≤0.01). An effect of age of the tumor blocks (5-7.5 years) or pre-analytical issues could not be ruled out for the relatively low rate of PDL1 positivity. Paired PDL1 at baseline and d1c2 showed conversion in 25.7% (pos to neg [11.4%] or neg to pos [14.3%]). Comparing PDL1 at baseline and SX, the conversion rate was 30% (pos to neg [8.3%] or neg to pos [21.6%]). sTILs and iTILs significantly increased at cycle 2, more significantly in pCR (p≤0.001) than in RD (p≤0.05) cases, and a not significant trend of decrease was observed at surgery PDL1+ tumors had a higher pCR rate (54.7% vs 32.5%, p = 0.004). PDL1 retained significance (OR 2.00 [1.04-3.88], p = 0.039) after adjustment for sTILs (OR 1.21 [1.03-1.42], p = 0.021). High iTILs and sTILs at d1c2, but not PDL1 status, were predictive of pCR. Notably, adjusting for sTILs, PDL1+ tumors at d1c2 showed a trend for association with lower pCR rate (OR 0.06 [0.01-1.15], p = 0.062). sTILs at cycle 2 was the most informative variable (OR 1.61 [1.28-1.61], p = 0.004) and provided independent information to baseline biomarkers. Baseline PDL1 and biomarkers at cycle 2 were not associated with EFS. In surgical samples with RD, higher sTILs, but not iTILs and PDL1 status, were associated with a trend for a lower risk of recurrence (HR 0.19 [0.02-1.39], p = 0.068). Conclusions: sTILs assessment on core biopsies after one cycle of taxane is a promising early biomarker of pCR. PDL1, as well as sTILs and iTILs, provided independent prediction of pCR and were strongly modulated by treatment. The modulation of PDL1 expression should be considered whenever PDL1 is assessed in view of identifying candidates to atezolizumab in 1st line advanced setting.

Pertuzumab, trastuzumab, and docetaxel for HER2-positive metastatic breast cancer (CLEOPATRA): end-of-study results from a double-blind, randomised, placebo-controlled, phase 3 study

BACKGROUND

CLEOPATRA was a phase 3 study comparing the efficacy and safety of pertuzumab, trastuzumab, and docetaxel with placebo, trastuzumab, and docetaxel in patients with HER2-positive metastatic breast cancer. In the primary analysis and subsequent reports, progression-free and overall survival were significantly improved in the pertuzumab group compared with the placebo group. Here, we report the end-of-study analysis of CLEOPATRA.

METHODS

This was a double-blind, randomised, placebo-controlled, phase 3 trial that was done at 204 centres in 25 countries. Eligible patients were 18 years or older, had HER2-positive, metastatic breast cancer, had not received previous chemotherapy or biological treatment for their metastatic disease, and had an Eastern Cooperative Oncology Group performance status of 0 or 1. All study drugs were given intravenously, every 3 weeks. Patients were assigned to receive either pertuzumab or placebo at a loading dose of 840 mg, and 420 mg thereafter; plus trastuzumab at 8 mg/kg loading dose and 6 mg/kg thereafter; and docetaxel at 75 mg/m², escalating to 100 mg/m² if tolerated. Pertuzumab or placebo and trastuzumab were given until disease progression; docetaxel was given for six cycles, or longer at the investigators' discretion. Randomisation (1:1) was done by use of an interactive voice-response system and was stratified by geographical region (Asia, Europe, North America, or South America) and previous treatment (previous adjuvant or neoadjuvant chemotherapy vs none). The primary endpoint was independent review facility-assessed progression-free survival, which has been reported previously. Since the confirmatory overall survival analysis had also occurred before this prespecified end-of-study analysis, analyses presented here are descriptive. Overall survival analyses were based on the intention-to-treat population with crossover patients analysed in the placebo group; analyses were not adjusted for crossover to the pertuzumab group and are likely to be conservative. Safety analyses were based on treatment received; crossover patients were counted in the placebo group up to the day before first pertuzumab dose. This trial is registered with ClinicalTrials.gov, number NCT00567190.

FINDINGS

Between Feb 12, 2008, and July 7, 2010, 1196 patients were assessed for eligibility, of whom 808 were enrolled and randomly assigned. 402 patients were assigned to receive docetaxel plus trastuzumab plus pertuzumab, and 406 patients were assigned to receive docetaxel plus trastuzumab plus placebo. Clinical cutoff for this analysis was Nov 23, 2018. Between July 2012 and clinical cutoff, 50 patients crossed from the placebo to the pertuzumab group. Median follow-up was 99·9 months in the pertuzumab group (IQR 92·9-106·4) and 98·7 months (90·9-105·7) in the placebo group. Median overall survival was 57·1 months (95% CI 50-72) in the pertuzumab group and 40·8 months (36-48) in the placebo group (hazard ratio 0·69, 95% CI 0·58-0·82); 8-year landmark overall survival rates were 37% (95% CI 31-42) in the pertuzumab group and 23% (19-28) in the placebo group. The most common grade 3-4 adverse event was neutropenia (200 [49%] of 408 patients in the pertuzumab group, 183 [46%] of 396 patients in the placebo group). Five (1%) of 408 patients in the pertuzumab group and six (2%) of 396 patients in the placebo group had treatment-related deaths. One new serious adverse event suggestive of congestive heart failure (pertuzumab group) and one new symptomatic left ventricular systolic dysfunction (post-crossover) occurred since the previous analysis.

INTERPRETATION

Our analysis shows that the previously observed improvements in overall survival with pertuzumab, trastuzumab, and docetaxel versus placebo, trastuzumab, and docetaxel were maintained after a median of more than 8 years of follow-up. The long-term safety and cardiac safety profiles of pertuzumab, trastuzumab, and docetaxel were maintained in the overall safety population and within crossover patients. HER2-targeted therapy has changed the natural history of HER2-positive metastatic breast cancer, with the dual blockade of pertuzumab and trastuzumab, with docetaxel, demonstrating an 8-year landmark overall survival rate of 37%.

FUNDING

F Hoffmann-La Roche and Genentech.

Abstract P5-14-23: Preventing alopecia caused by chemotherapy among patients with breast cancer efficacy of applying the cooling hood

Background: Alopecia is one of the most frequent adverse event of chemotherapy (CHT) in patients with breast cancer (BC). Alopecia causes many unpleasant feelings, as well as emotional disorders, including depression, especially in women

Aim: to improve the quality of life among BC patients undergoing CHT.

Materials and methods: alopecia prevention procedures were performed by the Cold Caps and Scalp Cooling Systems during various regimens of CHT for 180 BC patients. The mean age of the BC patients was 43 y.o. (from 21 to 73).

The alopecia prevention procedure was performed during CHT and included 3 steps:

1. The preventive cooling cycle took 20-30 minutes to achieve required temperature before proceeding medications.

2. The cooling cycle last during whole CHT.

3. The cooling cycle were continued after CHT and took from 60 to 120 minutes. The duration of post-CHT cycle was dependent on the type of drug and the period of excretion.

Patients received various regimens of CHT, including: antracyclins (47%), taxanes (32%), Cisplatin (5%), Gemcitabine (3,5%), AT (3,5%), CP (9%).

Local hypothermia during various regimens of CHT (n= 988).

Regimens of CHTPatients, n=180Cycles, n= 988n cycles per patientАT (doxorubicin + paclitaxel)6355 (2-6)АС (doxorubicin + cyclophosphamide)864474 (2-6)СР (Carboplatin+ Paclitaxel)15201 (1-4)Paclitaxel584407 (4-12)Cisplatin9302 (2-4)Gemcitabine6162 (2-4)

Alopecia degree evaluated based on СТСАЕ 4.0:

I degree - hair loss of <50% of normal for that individual that is not obvious from a distance but only on close inspection; a different hair style may be required to cover the hair loss but it does not require a wig or hair piece to camouflage.

II degree - hair loss of >=50% normal for that individual that is readily apparent to others; a wig or hair piece is necessary if the patient desires to completely camouflage the hair loss; associated with psychosocial impact.

Results: Among BC patients who were given antracyclins (n=86), 62 (72%) had I degree alopecia, 24 (28%) - II degree alopecia. Among patients who were given taxanes (n=58), 56 (96%) suffered from I degree alopecia, in 2 (4%) of them developed II degree alopecia. Patients who received treatment with Cisplatin (n=9), 7 (78%) of them had I degree alopecia and 2 - II degree alopecia (22%); patients with gemcitabine-based CHT (n=6), suffered from I degree alopecia in 100%.

Patients with AT (n=6), had I degree alopecia in 3 (50%) patients, 3 (50%) suffered from II degree alopecia. In regimens like CP (n=15), 8 (53%) had I degree alopecia, 7 (47%) - II degree alopecia.

Side effects after procedure: 5 (2,8%) patients had headaches, procedure was discontinued for 3 (1,7%) patients because of intolerance to low temperatures.

Conclusions: hypothermia of the hairy part of the head is an effective method of preventing alopecia among BC patients during chemotherapy with antracyclins (72% of cases), taxanes (96%), Cisplatin (78%) and with gemcitabine (100%).

Citation Format: Veronika Klimenko, Tatiana Semiglazova, Boris Kasparov, Anton Krutov, Margarita Zernova, Kristina Kondrateva, Valeria Kluge, Evgenia Kharchenko, Artem Poltoratsky, Karina Khidishyan, Vladislav Semiglazov, Roman Donskih, Petr Krivorotko, Vladimir Semiglazov, Aleksey Belyaev. Preventing alopecia caused by chemotherapy among patients with breast cancer efficacy of applying the cooling hood [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr P5-14-23.

Abstract P5-06-21: Prognostic and predictive value of PML in the ETNA study and the TCGA

Background. Although long considered a tumor suppressor gene, PML (promyelocytic leukemia) also plays tumor-promoting functions in specific contexts. In vitro and in vivo studies have demonstrated that PML is upregulated by HIF-1α transcriptional activation in triple-negative breast cancer (TNBC) cells and it is implicated in promoting metastasis downstream of HIF-1α. This pro-metastatic function of PML is inhibited by arsenic trioxide, a pharmacological compound currently in use in acute promyelocytic leukemia. However, the clinical relevance of PML expression in BC has not been extensively investigated. In this study, we evaluated the association of PML expression with clinic-pathological factors and outcome (pathological complete response -pCR- and risk of recurrence) in the ETNA trial, and risk of recurrence in the TCGA. Methods. In the ETNA study (NCT01822314) 695 patients with HER2-negative breast cancer (BC) were randomized to receive neoadjuvant paclitaxel or nab-paclitaxel followed by 4 cycles of an anthracycline regimen. In the ITT study population, the two treatments did not show significantly different rates of pCR nor different Event-Free Survival (EFS) (Gianni JAMA Oncol 2018, Gianni ASCO 2019). A central histologic assessment of ER, PgR, HER2 status and Ki67 was mandatory. We evaluated PML expression by immunohistochemistry using the continuous histoscore (H-score) on pre-treatment core biopsies. The H-score is generated from the estimation of the percentage of cells with no (0), light (1+), moderate (2+) and strong (3+) intensity staining, and the corresponding score is generated with the following algorithm: [1 × (% cells 1+) + 2 × (% cells 2+) + 3 × (% cells 3+)]. We evaluated the association of PML with clinic-pathological features and clinical outcomes (pCR and EFS) in triple negative (TN) and in LuminalB-like (ER+ and/or PgR+, Ki67≥14%) groups. We also investigated the association between PML mRNA expression (RNA-seq) and DFS in HER2-negative BC (TN, n=192; ER+/HER2-, n=702) in the TCGA dataset. Results. In the ETNA study, PML was successfully assessed and valuable in 491 pts (70.6%). The average PML expression was 126.3 (median 120, range 0-295). In the ETNA trial, TNBC showed the highest expression of PML (p<1.0E-10). Within LumB-like tumors, the group with intermediate proliferation (Ki67 14-20%, LumB-int) had higher PML expression than the high proliferation group (Ki67>20%, LumB-high) (p=0.0005). However, within the LumB-high group, higher proliferation (Ki67>40%) showed a higher expression of PML (p=0.025), suggesting a non-linear relationship between PML and proliferation in luminal tumors. In LumB-high, PML was higher in PgR-negative tumors (p=1.0E-5). Finally, PML showed a positive association with higher stromal tumor-infiltrating lymphocytes (sTILs) both in LumB-like and TN group (p=0.019 and p=0.001, respectively). PML expression was not significantly associated with pCR and risk of recurrence in LumB-like nor in TN BC.In the TCGA dataset also PML expression was highest in the TN group (p<1.0E-10). No association was found between PML expression and risk of recurrence in any molecular subgroup. Conclusions. PML expression assessed by IHC in the ETNA trial was not predictive of likelihood of pCR nor of risk of recurrence in LumB-like and TN breast cancer. PML mRNA expression was not prognostic in TN and LumB-like tumors also in the TCGA dataset. Some interesting associations with biological features emerged which warrants biological interpretation of the complex role of PML in breast cancer. Supported in part by an unrestricted grant from Celgene Sarl, Swizerland

Citation Format: Stefania Zambelli, Chanel Smart, Giampaolo Bianchini, Isabella Sassi, Mauro Mansutti, Antonio Anton, Lourdes Calvo, Giancarlo Bisagni, Begona Bermejo, Martina Uggè, Barbara Galbardi, Vladimir Semiglazov, Marc Thill, Jose Ignacio Chacon, Arlene Chan, Serafin Morales Murillo, Isabel Alvarez, Ainhara Lahuerta, Patrizia Zucchinelli, Claudio Doglioni, Pinuccia Valagussa, Ignasi Tusquets, Luca Gianni, Rosa Bernardi. Prognostic and predictive value of PML in the ETNA study and the TCGA [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr P5-06-21.

Comparing Neoadjuvant Nab-paclitaxel vs Paclitaxel Both Followed by Anthracycline Regimens in Women With ERBB2/HER2-Negative Breast Cancer-The Evaluating Treatment With Neoadjuvant Abraxane (ETNA) Trial: A Randomized Phase 3 Clinical Trial

Importance

Studies of neoadjuvant chemotherapy regimens using anthracyclines followed by taxanes have reported a doubling of pathological complete remission (pCR) rates compared with anthracycline-based regimens alone. A reverse sequence did not reduce activity. Nab-paclitaxel is an albumin-bound nanoparticle of paclitaxel that allows for safe infusion without premedication, and its use led to a significantly higher rate of pCR in the GeparSepto trial.

Objective

To determine whether nab-paclitaxel improves the outcomes of early and locally advanced human epidermal growth factor receptor 2 (ERBB2/HER2)-negative breast cancer compared with paclitaxel when delivered in a neoadjuvant setting.

Design, Setting, and Participants

In this multicenter, open-label study, in collaboration with Grupo Español de Investigación en Cáncer de Mama (GEICAM) and Breast Cancer Research Center-Western Australia (BCRC-WA), patients with newly diagnosed and centrally confirmed ERBB2/HER2-negative breast cancer were recruited. Participants were randomly allocated to paclitaxel, 90 mg/m2 (349 patients), or nab-paclitaxel, 125 mg/m2 (346 patients). The 2 drugs were given on weeks 1, 2, and 3 followed by 1 week of rest for 4 cycles before 4 cycles of an anthracycline regimen per investigator choice.

Main Outcomes and Measures

The primary end point was the rate of pCR, defined as absence of invasive cells in the breast and axillary nodes (ie, ypT0/is ypN0) at the time of surgery. A secondary end point was to assess tolerability and safety of the 2 regimens.

Results

From May 2013 to March 2015, 814 patients were registered to the study; 695 patients met central confirmation eligibility and were randomly allocated to receive either paclitaxel (349), or nab-paclitaxel (346) (median age, 50 years; range, 25-79 years). The intention-to-treat analysis of the primary end point pCR revealed that the improved pCR rate after nab-paclitaxel (22.5%) was not statistically significant compared with paclitaxel (18.6%; odds ratio [OR], 0.77; 95% CI, 0.52-1.13; P = .19). Overall, 38 of 335 patients (11.3%) 11.3% of patients had at least 1 serious adverse event in the paclitaxel arm and 54 of 337 patient (16.0%) in the nab-paclitaxel arm. Peripheral neuropathy of grade 3 or higher occurred in 6 of 335 patients (1.8%) and in 15 of 337 (4.5%), respectively.

Conclusions and Relevance

The improved rate of pCR after nab-paclitaxel was not statistically significant. The multivariate analysis revealed that tumor subtype (triple-negative vs luminal B-like) was the most significant factor (OR, 4.85; 95% CI, 3.28-7.18) influencing treatment outcome.

Trial Registration

clinicaltrials.gov Identifier: NCT01822314.

Evaluation of mental and social adaptation of patients with breast cancer

e23167

Background: In 2018, in the N.N. Petrov National Medical Research Center of Oncology, there was conducted a study of the effectiveness of a mental and social adaptation of patients to the disease and treatment in the framework of The International Classification of Functioning, Disability and Health (ICF). Methods: The patients with breast cancer (n = 28, mean age 31 ±7) were examined at the stages of diagnosis and admission to the hospital. The basis of the study is the «Narcissism Evaluation Test», EORTC QLQ-C30, as well as the following ICF domains: Body function - global psychosocial functions (b122), temperament and personality functions (b126), energy and drive functions (b130), sleep functions (b134), attention functions (b140), psychomotor functions (b147), emotional functions (b152), thought functions (b160), higher-level cognitive functions (b164). Activity and participation- doing housework (d640), family relationships (d760), intimate relationships (d770), acquiring, keeping and terminating a job (d845). Results: The increase in values (7.26–13.61; p < 0.05) on the “Depersonalization” scale indicates an attempt to dissociate from threatening processes in oneself by means of dissociation and splitting, to preserve the coherence of the personality structure. This tendency can be viewed as an attempt by the patient to deny that destabilization affects his personality and lifestyle, which leads to the experience of melancholia as an attempt at destruction of Self-Concept. Such reactions are classified by us within the framework of psychogenic, i.e. conditionally normal in the situation of cancer, however, it was shown that the pathology of “psychogeny” significantly reduces the quality of life and social adaptation. For example, in 11 patients, there is a decrease in the quality of life (62.85; p < 0.05), disturbed sleep, emotions, energy and drive functions (b134, b152, b130), and there are difficulties in the resumption of labor activities (d845). Conclusions: Experiencing the threat to the integrity of Self-Concept launches psychological defenses, as a result of which a rapid regression of Self-Concept occurs before the primary narcissism. Psychogenic reactions during pathologization contribute to the patient’s social and mental maladjustment.

End-of-study analysis from the phase III, randomized, double-blind, placebo (Pla)-controlled CLEOPATRA study of first-line (1L) pertuzumab (P), trastuzumab (H), and docetaxel (D) in patients (pts) with HER2-positive metastatic breast cancer (MBC)

1020

Background: Progression-free and overall survival (PFS and OS) were significantly improved with 1L P + H + D v Pla + H + D in 808 pts with HER2-positive MBC in CLEOPATRA (NCT00567190). OS was increased by an unprecedented 15.7 mo (median 56.5 mo with P + H + D v 40.8 mo with Pla + H + D; HR 0.68; 95% CI 0.56, 0.84; p < .001) with a median follow-up of 50 mo [Swain et al. NEJM 2015]). Here we report the end-of-study analysis with a median follow-up of 99 mo (max 120 mo). Methods: In this descriptive analysis, OS was compared between arms using the log-rank test, stratified by prior treatment status and geographic region. The Kaplan–Meier approach was used to estimate median OS, and a stratified Cox proportional hazards model was used to estimate the HR and 95% CIs. Subgroup analyses of OS were performed for stratification factors and other baseline characteristics. Results: Clinical cutoff was Nov 23, 2018. Since Jul 2012, 50 pts crossed from the Pla to the P arm. These pts are counted in the Pla arm for efficacy analyses and up to the first dose of P for safety analyses. The OS HR was 0.69 (95% CI 0.58, 0.82), favoring P + H + D. Median OS was 57.1 mo in the P arm (402 pts) and 40.8 mo in the Pla arm (406 pts; Δ 16.3 mo). The 8-year landmark OS rates were 37% and 23%, respectively. The OS benefit in predefined subgroups, including in pts previously treated with H in the (neo)adjuvant setting (88 pts, HR 0.86; 95% CI 0.51, 1.43), remained consistent with the overall result and previous reports. The overall safety profile of P + H + D was consistent with the known P safety profile. There was only one new serious adverse event suggestive of congestive heart failure (onset ~77 mo on treatment in the P arm, resolution in 34 days, pt continued on study medication) and one new symptomatic left ventricular systolic dysfunction (onset ~46 mo after crossing to the P arm, resolution in 34 days) since the previous analysis. Conclusions: The OS improvement with 1L P + H + D v Pla + H + D for pts with HER2-positive MBC was maintained after an additional 4 years of long-term follow-up, as were the safety and cardiac safety profiles. Clinical trial information: NCT00567190.

Event-free survival analysis of the prospectively randomized phase III ETNA study with neoadjuvant nab-paclitaxel (nab-P) versus paclitaxel (P) followed by anthracycline regimens in women with HER2-negative high-risk breast cancer

515

Background: The ETNA study showed that substituting P with nab-P did not significantly increase the overall rate of pathological complete response (pCR) (P 18.6%, nab-P 22.5%, p = 0.19). The multivariate analysis revealed that tumor subtype (triple negative vs luminal B-like) was the most significant factor (OR 4.85) influencing treatment outcome (Gianni L et al, JAMA Oncol 2018). Methods: This multicenter open label study (NCT01822314) in collaboration with GEICAM and BCRC-WA randomized 695 patients with centrally-confirmed HER2-negative breast cancer to nab-P 125 mg/m2 (346 patients) or P 90 mg/m2 (349 patients). The two drugs were given on weeks 1, 2 and 3 followed by 1-week rest for 4 cycles before 4 cycles of an anthracycline regimen as per investigator choice. The primary endpoint was pCR (absence of invasive cells in breast and nodes). A secondary endpoint is event-free survival (EFS) defined as the time from randomization to the first date of disease progression while on primary therapy or disease recurrence (local, regional, distant, invasive contralateral breast cancer) after surgery or death due to any cause. Results: The ITT analysis of the secondary endpoint EFS at 5 years is reported below: Clinical trial information: NCT01822314. Overall 5-year survival was 84.8% after P and 87.3% for nab-P. No serious adverse events were documented during the follow-up. Conclusions: The improved 5-year EFS after nab-P failed to reach statistical significance (unadjusted P = 0.245). In the analysis by subgroup the numerical improvement was almost exclusively observed in luminal B and not in TN tumors. So far the data do not support substitution of P with nab-P in the schedule and doses adopted in the ETNA trial. Additional analyses will be based on ongoing molecular studies.[Table: see text]

The diagnostic accuracy of 12-point core biopsy of a tumor bed compared to the study of surgically obtained breast tissue in patients with locally advanced triple-negative or HER2-positive breast cancer after neoadjuvant systemic and targeted therapy

e12097

Background: Innovative advances in neoadjuvant systemic and targeted breast cancer therapy implicate surgical treatment in specific patient groups can be avoided. The core biopsy of the tumor bed and some diagnostic approaches (breast ultrasound, mammography, SPECT/CT) allow for precise evaluation of the treatment efficacy. Methods: This research started in our department in 2018, we picked two groups of 15 patients each treated for locally advanced TNBC or grade cT1-4N1-3M0 HER2-positive breast cancer: HER2+/ER+ or HER2+/ER- breast cancer. The TNBC group received 6 cycles of NACT of paclitaxel combined with doxorubicin and carboplatin AUC5. The HER2+ group received 4 cycles of АС polychemotherapy followed by 4 cycles of monochemotherapy with the docetaxel and 3-weekly trastuzumab. The HER2+ group is receiving adjuvant trastuzumab for up to one year, where ER-positive patients are also given hormone therapy with tamoxifen or aromatase inhibitors. The response to neoadjuvant treatment was assessed in all patients using standard two-dimensional mammography, ultrasound elastography, and SPECT-CT. The 12-point core biopsy of a tumor bed was performed in the operating room setting by previously marked tumor projections. Then, all patients underwent either breast-conserving surgery or mastectomy with immediate reconstruction with expander/implant. Results: After neoadjuvant therapy, in a group of 15 patients with TNBC in surgically obtained material, the pathologic complete response (pCR) was observed in 8 patients (53.33%), whereas residual disease was found in 7 (46.67%) patients. The core biopsy results showed no tumor cells in 10 (66.67%) patients, and were detected in 5 (33.33%) patients (p = 0.0011), the accuracy of the method in this group was 80%. The overall response rate in the group of 15 patients with HER2-positive breast cancer was 8 (53.33%) patients with residual disease and 7 (46.67%) patients with pCR. According to core biopsy, tumor cells were present in 3 (20%) patients and were absent in 12 (80%) patients (p = 0.0787). Conclusions: Avoiding surgical treatment through not less than 12-point core biopsy of a tumor bed in patients with complete regression after neoadjuvant therapy is a new trend in the treatment of breast cancer. Any new approach in this sphere requires a long-term elaboration, compliance with the safety principles, rethinking standard procedures and following-up patients.

A phase 1b/2, open-label, dose-escalation, and dose-confirmation study of eribulin mesilate in combination with capecitabine

BACKGROUND

Capecitabine and eribulin are widely used as single agents in metastatic breast cancer (MBC) and have nonoverlapping toxicities.

METHODS

In phase 1b (dose escalation), patients with advanced, treatment-refractory, solid tumours received eribulin mesilate intravenously in 21-day cycles according to schedule 1 (day 1) or schedule 2 (days 1, 8) with twice-daily oral capecitabine (1000 mg/m2 days 1-14). In phase 2 (dose confirmation), women with advanced/MBC and ≤3 prior chemotherapies received eribulin mesilate at the maximum tolerated dose (MTD) per the preferred schedule plus capecitabine. Primary objectives were MTD and dose-limiting toxicities (DLTs; phase 1b) and objective response rate (ORR; phase 2). Secondary objectives included progression-free survival (PFS), safety, and pharmacokinetics.

RESULTS

DLTs occurred in 4/19 patients (schedule 1) and 2/15 patients (schedule 2). Eribulin pharmacokinetics were dose proportional, irrespective of schedule or capecitabine coadministration. The MTD of eribulin was 1.6 mg/m2 day 1 for schedule 1 and 1.4 mg/m2 days 1 and 8 for schedule 2. ORR in phase 2 (eribulin 1.4 mg/m2 days 1, 8 plus capecitabine) was 43% and median PFS 7.2 months. The most common treatment-related adverse events were neutropenia, leukopenia, alopecia, nausea, and lethargy.

CONCLUSIONS

The combination of capecitabine and eribulin showed promising efficacy with manageable tolerability in patients with MBC.

Abstract P3-03-39: Sentinel lymph node biopsy after surgery with removal of the primary tumor

Nowadays, sentinel lymph node biopsy (SLNB) is one of the basic methods for

diagnosing the lesion of regional lymph nodes (LN) and it is recommended by

experts as a standard method in determining the prevalence of the disease in breast

cancer patients (BC).

The aim of the study was the possibility of sentinel lymph node biopsy after

surgery with removal of the primary tumor.

Materials and methods

The study was conducted in the N.N. Petrov's National Medical Center of

Oncology from 2013 to 2018. SLNB was performed in patients who had a primary

tumorectomy in another medical institution. The study included patients with the

stage cN0. Radionuclide imaging of the sentinel lymph nodes (SLN) was

performed in 37 patients with breast cancer. The injection of radiopharmaceuticals

in postoperative scar was performed before the biopsy. Median of the period

between the operations was 21 days (14 to 30 days).

Results

After injection, the image of SLN was obtained in 91.9% (34 of 37) of patients.

During the operation, 1-5 sentinel lymph nodes were visualized. The lesion of the

sentinel lymph nodes (N+) was detected in 21.6% (8) patients, N0 in 78.4% (29)

patients, respectively.

There is no data for locoregional relapse for the period of observation from 2014 to

nowadays.

Conclusions

The obtained results are comparable with the results of sentinel lymph node biopsy

in primary patients with breast cancer stage cN0. This indicates the possibility of

biopsy after surgery with removal of the primary tumor.

Citation Format: Zhiltsova E, Krivorotko P, Dashayan G, Emelyanov A, Tabagua T, Bessonov A, Ivanova O, Kanaev S, Novikov S, Krzivickiyi P, Komayachov A, Nikolaev K, Gigolaeva L, Zernov K, Semiglazov V. Sentinel lymph node biopsy after surgery with removal of the primary tumor [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 P3-03-39.