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.

CSPG4 expression in soft tissue sarcomas is associated with poor prognosis and low cytotoxic immune response

Background

Soft tissue sarcomas (STS) are heterogeneous and pro-metastatic tumors. Identification of accurate prognostic factors and novel therapeutic targets are crucial. CSPG4 is a cell surface proteoglycan with oncogenic functions. It recently emerged as a potential target for immunotherapy, including cell therapy based on CSPG4-specific chimeric antigen receptor (CAR)-redirected cytokine-induced killer lymphocytes (CSPG4-CAR.CIKs) in STS. However, expression of CSPG4 is poorly known in STS so far.

Methods

We analyzed CSPG4 gene expression in 1378 localized STS clinical samples, and searched for correlations with clinicopathological data, including disease-free survival (DFS), and with tumor immune features.

Results

CSPG4 expression was heterogeneous across samples. High expression was associated with younger patients’ age, more frequent undifferentiated pleomorphic sarcoma and myxofibrosarcoma pathological subtypes, more frequent internal trunk tumor site, and more CINSARC high-risk samples. No correlation existed with pathological tumor size and grade, and tumor depth. Patients with high CSPG4 expression displayed 49% (95% CI 42–57) 5-year DFS versus 61% (95% CI 56–68) in patients with low expression (p = 3.17E−03), representing a 49% increased risk of event in the “CSPG4-high” group (HR = 1.49, 95% CI 1.14–1.94). This unfavorable prognostic value persisted in multivariate analysis, independently from other variables. There were significant differences in immune variables between “CSPG4-high” and “CSPG4-low” tumors. The "CSPG4-low" tumors displayed profiles suggesting higher anti-tumor cytotoxic immune response and higher potential vulnerability to immune checkpoint inhibitors (ICI). By contrast, the "CSPG4-high" tumors displayed profiles implying an immune-excluded tumor microenvironment, potentially induced by hypoxia, resulting from an immature chaotic microvasculature, and/or the presence of contractile myofibroblasts.

Conclusions

Patients with “CSPG4-high” STS, theoretically candidate for CAR.CIKs, display shorter DFS and an immune environment unfavorable to vulnerability to CAR.CIKs, which could be improved by combining anti-angiogenic drugs able to normalize the tumor vasculature. By contrast, “CSPG4-low” STS are better candidates for immune therapy involving ICI.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12967-022-03679-y.

Lack of prognostic impact of sentinel node micro-metastases in endocrine receptor-positive early breast cancer: results from a large multicenter cohort☆

Background

Prognostic impact of lymph node micro-metastases (pN1mi) has been discordantly reported in the literature. The need to clarify this point for decision-making regarding adjuvant therapy, particularly for patients with endocrine receptor (ER)-positive status and HER2-negative tumors, is further reinforced by the generalization of gene expression signatures using pN status in their recommendation algorithm.

Patients and methods

We retrospectively analyzed 13 773 patients treated for ER-positive breast cancer in 13 French cancer centers from 1999 to 2014. Five categories of axillary lymph node (LN) status were defined: negative LN (pN0i−), isolated tumor cells [pN0(i+)], pN1mi, and pN1 divided into single (pN1 = 1) and multiple (pN1 > 1) macro-metastases (>2 mm). The effect of LN micro-metastases on outcomes was investigated both in the entire cohort of patients and in clinically relevant subgroups according to tumor subtypes. Propensity-score-based matching was used to balance differences in known prognostic variables associated with pN status.

Results

As determined by sentinel LN biopsy, 9427 patients were pN0 (68.4%), 546 pN0(i+) (4.0%), 1446 pN1mi (10.5%) and 2354 pN1 with macro-metastases (17.1%). With a median follow-up of 61.25 months, pN1 status, but not pN1mi, significantly impacted overall survival (OS), disease-free survival (DFS), metastasis-free survival (MFS), and breast-cancer-specific survival. In the subgroup of patients with known tumor subtype, pN1 = 1, as pN1 > 1, but not pN1mi, had a significant prognostic impact on OS. DFS and MFS were only impacted by pN1 > 1. Similar results were observed in the subgroup of patients with luminal A-like tumors (n = 7101). In the matched population analysis, pN1macro, but not pN1mi, had a statistically significant negative impact on MFS and OS.

Conclusion

LN micro-metastases have no detectable prognostic impact and should not be considered as a determining factor in indicating adjuvant chemotherapy. The evaluation of the risk of recurrence using second-generation signatures should be calculated considering micro-metastases as pN0.

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LN micro-metastases have no detectable prognostic impact.

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pN1 status, but not pN1mi, significantly impacted overall survival, disease-free survival, metastasis-free survival.

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In the subgroup of patients with known tumor subtype, pN1=1, as pN1>1, but not pN1mi, had a significant prognostic impact on OS.

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LN micro-metastases should not be considered as a determining factor in indicating adjuvant chemotherapy.

Abstract P2-08-08: Isolated ipsilateral local recurrence of breast cancer: Predictive factors and prognostic impact

Background

Tumour features associated with isolated invasive breast cancer ipsilateral local recurrence (ILR) after breast conservative treatment (BCT) and consequences on overall survival (OS) are still debated. The aim of our study was to examine predictive factors of isolated ILR after BCT with in sano resection and whole breast irradiation as well as the impact of such an ILR on overall survival in a large multi-institutional cohort.

Methods

Patients were retrospectively identified from a large cohort of 23,375 consecutive patients who underwent BCT for invasive breast cancer in 16 cancer centres. End-points were ILR rate and OS. The impact of ILR on OS was assessed through multivariate analysis by logistic regression and Cox model, adjusted on ERs/Grade status (ERs+/Grade 1, ERs+/Grade 2, ERs+/Grade 3 and ERs-) and then on tumour subtypes.

Results

Of 15,570 patients, ILR rate was 3.1%. Cumulative ILR rates differed according to ERs/grade (ERs+/Grade2: HR=1.42, p=0.010; ERs+/Grade3: HR=1.41, p=0.067; ERs-: HR=2.14, p<0.0001), endocrine therapy (HR=2.05, p<0.0001) and age<40-years old (HR=2.28, p=0.005) in multivariate analysis. When multivariate analysis was adjusted on tumour subtype, the latter was the only independent factor. OS-after-ILR was significantly different according to ILR-free intervals (HR=4.96 for ILR-free interval between 2-5-years and HR=9.00 when <2-years, in comparison with ≥5-years).

Impact of free interval time on OS among patients with ILR and among all patients  p-valueHRInfSupILRno ILR 1   <2 years0.0172.2551.1594.388 2-5 years0.0012.451.423.89 ≥5 years0.1030.5550.2741.126Tumor subtypesLuminal A G1 1   Luminal A G20.0031.4311.1321.810 Triple negative<0.00012.6992.0553.544 Luminal B ER-<0.00013.1952.4144.229 Luminal B ER+0.021.6081.0762.401 HER2+<0.00012.2791.4523.579

Conclusion

ERs/Grade status, lack of endocrine therapy and tumour subtypes predict isolated ILR risk in patients treated with BCT. Short ILR-free-intervals represent a strong pejorative factor for OS. These results may help selecting initial treatment as well as tailoring ILR systemic chemotherapy.

Citation Format: Houvenaeghel G, de Nonneville A, Cohen M, Classe J-M, Reyal F, Mazouni C, Chopin N, Martinez A, Daraï E, Coutant C, Colombo P-E, Gimbergues P, Chauvet M-P, Azuar A-S, Rouzier R, Tunon de Lara C, Murraciole X, Agostini A, Gonçalves A, Lambaudie E. Isolated ipsilateral local recurrence of breast cancer: Predictive factors and prognostic impact [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P2-08-08.

Cancers du sein triple-négatifs : données actuelles et perspectives d’avenir

Le cancer du sein triple-négatif (CSTN), défini par l’absence d’expression des récepteurs hormonaux et d’HER2 (human epidermal growth factor receptor-2), représente 15 à 20 % des cancers du sein. Cependant, cette définition, essentiellement négative, masque la très grande hétérogénéité des entités biologiques qui constituent ce soustype. Si la chimiothérapie est le principal traitement systémique établi de la maladie à la fois dans la prise en charge des stades précoces et avancés, la compréhension progressive des composantes moléculaires impliquées dans la pathogenèse des CSTN permet des perspectives thérapeutiques novatrices. L’objectif de cette synthèse est de décrire ces cibles potentielles et d’explorer les traitements d’aujourd’hui et de demain qui permettront de lutter contre ce cancer au comportement particulièrement agressif.

Abstract P1-13-04: Impact of hormone receptor status in HER2-Positive early breast cancer in the trastuzumab era: Results of a National multi-institutional study

Background: Recent updated analysis of the HERA (HERceptin Adjuvant) trial indicate that tumor hormone receptor status (HR)remains a major determinant of outcome in HER2-positive (HER2+) early breast cancer (BC) patients, with higher rates of recurrence and death in women with HR-negative (HR-) disease, even after 11 years' median follow-up. Furthermore, data reported from the HERA trial suggest that the timing of recurrences is different, with an initial higher frequency of disease-free survival (DFS) events in patients with HR- disease than those with HR-positive disease (HR+). No evidence of a different trastuzumab efficacy according to the HR of the primary tumor was found. In this study, we examined the impact of HR on outcome in a large, multicenter, “real-world”, retrospective cohort of HER2+ early breast cancer patients

Methods: HER2+ BC were retrospectively identified from a large cohort of 23,375 consecutive patients who underwent primary surgery at 17 French centers between Dec 1987 and Jan 2014. A multivariate Cox model was built including age, tumor size, SBR grade, lymphovascular invasion, lymph node involvement, hormonal receptors status, adjuvant chemotherapy, adjuvant hormone therapy, trastuzumab, radiotherapy and type of surgery.

Results: A total of 1308 cases were identified, including 829 (63%) HR+ and 479 (47%) HR- patients. Median follow-up was 52 months (range 0 to 201). Compared with HR+, HR- patients had significantly smaller tumors (37 vs. 31% ≤ 10mm, p=0.027; information for multifocal tumors was not available), with higher SBR grade (58 vs. 40% grade 3, p<0.001) and had more lymph nodes involvement (41 vs. 32% pN+, p=0.001). HR- patients were more frequently treated by mastectomy (41 vs. 31%, p<0.001), received more trastuzumab (63 vs. 53%, p<0.001) and less radiotherapy (85 vs. 89%, p=0.020). Endocrine therapy was administered in 90% (744) of HR+ patients. No other significant difference in patient, tumor or treatment characteristics was found. HR status impacted DFS, metastasis free-survival (MFS) and BC-Specific survival (BC-SS) (hazard ratios: 0.46 [0.32-0.66]; p<0.001, 0.52 [0.33-0.82]; p=0.004 and 0.56 [0.34-0.90]; p=0.017, respectively), log-rank test) in overall population with higher rates of recurrence and death in women with HR- disease. In multivariate analysis, lymph node involvement and use of trastuzumab but not HR status impacted significantly DFS, MFS and BC-SS. Considering patients by treatment groups (with or without trastuzumab), HR status was not predictive of survival outcomes in the trastuzumab group, as opposed to the group without trastuzumab. Regarding the timing of recurrences, we observed an increased tendency for later relapse in patients with HR+ disease compared with HR- disease, for both DFS and MFS events.

Conclusions: Our results suggest that HR status remains a major determinant of outcome in HER2+ BC, including the timing of recurrence. Yet, this prognostic impact appears to be mitigated by trastuzumab-based adjuvant treatment.

Citation Format: de Nonneville A, Gonçalves A, Cohen M, Reyal F, Classe JM, Giard S, Colombo PE, Muracciole X, Chopin N, Lambaudie E, Houvenaeghel G. Impact of hormone receptor status in HER2-Positive early breast cancer in the trastuzumab era: Results of a National multi-institutional study [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P1-13-04.

Patients with primary localized high-grade sarcomas of the digestive tract excluding GIST : a retrospective study from the French sarcoma group

INTRODUCTION

The natural history of localized high-grade sarcomas of the digestive tract (SDT) excluding GIST has been rarely considered owing to their low incidence and heterogeneity. We describe the histoclinical characteristics of SDT and correlate them with patients' outcomes.

METHODS

We retrospectively collected medical files from a European database covering connective tissue tumors listed in Europe for about twenty years. Only untreated localized primary high-grade SDT were included. A central histological review was performed for each case. Patients' characteristics were compared and correlated with clinical outcomes.

RESULTS

A total of 45 patients were identified. Leiomyosarcomas (LMS) and undifferentiated sarcomas (UDS) were predominant, the former having better overall survival (OS) and progressionfree survival (PFS) while the latter having a worse outcome than the other histological types. Complete remission was obtained in 34 patients (75%) and was associated with male sex, age over 40 years and monofocal tumor. Complete surgery and LMS histology were associated with a better prognosis without any significant difference in baseline characteristics or in treatment modalities.

CONCLUSION

Complete surgery and histological type seem to be prognostic indicators of SDT. These results suggest the importance of treating these patients in a reference center.

Adjuvant chemotherapy in pT1ab node-negative triple-negative breast carcinomas: Results of a national multi-institutional retrospective study

BACKGROUND

Triple-negative breast cancers (TNBCs) are considered as associated with poor outcome, but prognosis of subcentimetric, node-negative disease remains controversial and evidence that adjuvant chemotherapy (CT) is effective in these small tumours remains limited.

PATIENTS AND METHODS

Our objective was to investigate the impact of CT on survival in pT1abN0M0 TNBC. Patients were retrospectively identified from a cohort of 22,475 patients who underwent primary surgery in 15 French centres between 1987 and 2013. As rare pathological types may display very particular prognoses in these tumours, we retained only the invasive ductal carcinomas of no special type according to the last World Health Organisation (WHO) classification which is the most common TNBC histological type. End-points were disease-free survival (DFS) and metastasis-free survival (MFS). A propensity score for receiving CT was estimated using a logistic regression including age, tumour size, Scarff Bloom and Richardson (SBR) grade and lymphovascular invasion.

RESULTS

Of a total of 284 patients with pT1abN0M0 ductal TNBC, 144 (51%) received CT and 140 (49%) did not. Patients receiving CT had more adverse prognostic features, such as tumour size, high grade, young age, and lymphovascular invasion. CT was not associated with a significant benefit for DFS (Hazard ratio, HR = 0.77 [0.40-1.46]; p = 0.419, log-rank test) or MFS (HR = 1.00 [0.46-2.19]; p = 0.997), with 5-year DFS and MFS in the group with CT versus without of 90% [81-94%] versus 84% [74-90%], and 90% [81-95%] versus 90% [83%-95%], respectively. Results were consistent in all supportive analyses including multivariate Cox model and the use of the propensity score for adjustment and as a matching factor for case-control analyses.

CONCLUSIONS

This study did not identify a significant DFS or MFS advantage for CT in subcentimetric, node-negative ductal TNBC. Although current consensus guidelines recommend consideration of CT in all TNBC larger than 5 mm, clinicians should carefully discuss benefit/risk ratio with patients, given the unproven benefits.