We use cookies necessary to giving you a better online experience. By using our website you consent to all cookies in accordance with our Privacy Policy.
Yes, I accept
Menu
Search Opener

Session Item

Clinical track: Breast
Poster
Clinical
00:00 - 00:00
Neuroendocrine Tumors of the Breast: an international series of the Rare Cancer Network
PO-0956

Abstract

Neuroendocrine Tumors of the Breast: an international series of the Rare Cancer Network
Authors: Grellier-Adedjouma|, Noémie(1)*[grellier.noemie@gmail.com];Paix|, Adrien(1);Franco|, Pierfrancesco(2);Kirova|, Youlia Maria(3);De Bari|, Berardino(4);Pasquier|, David(5);Meijer|, Hanneke(6);Oksüz|, Didem Colpan(7);Peignaux-Casasnovas|, Karine(8);Huguet|, Florence(9);De Caluwé|, Alex(10);Khanfir|, Kaouthar(11);Vargas|, Andres(12);Thariat|, Juliette(13);Vargo|, John Austin(14);Ozsahin|, Esat Mahmut(15);Belkacemi|, Yazid(1);
(1)Hopital Henri Mondor, Oncology Radiotherapy, Creteil, France;(2)Università degli Studi di Torino, Oncology Radiotherapy, Torino, Italy;(3)Institut Curie, Oncology Radiotherapy, Paris, France;(4)CHRU Jean Minjoz, Oncology Radiotherapy, Besançon, France;(5)Centre Oscal Lambret, Oncology Radiotherapy, Lille, France;(6)Radboudumc, Oncology Radiotherapy, Nijmegen, The Netherlands;(7)University-Cerrahpaşa, Oncology Radiotherapy, Istanbul, Turkey;(8)Centre Georges François Leclerc, Oncology Radiotherapy, Dijon, France;(9)Hopital Tenon, Oncology Radiotherapy, Paris, France;(10)Institut Jules Bordet, Oncology Radiotherapy, Bruxelles, Belgium;(11)Hôpital du Valais, Oncology Radiotherapy, Sion, Switzerland;(12)Instituto de radiomedicina, Oncology Radiotherapy, Santiago, Chile;(13)Centre François Baclesse, Oncology Radiotherapy, Caen, France;(14)West Virginia University, Oncology Radiotherapy, Morgantown, USA;(15)Centre Hospitalier universitaire Vaudois, Oncology Radiotherapy, Lausanne, Switzerland;
Show Affiliations
Purpose or Objective

Primary neuroendocrine tumors (NET) of the breast are rare breast tumor, representing less than 1% of breast cancers.Their prognosis appears to be poorer than that of classical invasive breast carcinomas, with shorter OS and DFS at equal stage. There are no specific therapeutic guidelines for those tumors.
The aim of this study was to analyze the histological, prognostic and therapeutic specificities of this rare disease.

Material and Methods

All women with primary NET of the breast from 14 different centers and 8 countries between 1995 and 2015 were included. Clinical, pathological and therapeutic data were collected retrospectively.

Statistical analyses were performed using R v3.4.3 . Survival analysis was determined using the Kaplan-Meier method. Factors influencing overall survival and disease-free survival were first evaluated with a univariate Cox analysis with a significant cutoff of p<0.2. Multicollinearity was also checked using a VIF threshold of 4. A stepwise backward procedure was used to build the multivariate Cox model to evaluate the impact of potential variables on survival.

Results

Among the 97 women included, median age was 66 (33-93). At diagnosis, 36% were stage I, 41 II, 14% III and 8% IV. Lymphovascular invasion was found in 39% of tumors, perineural invasion in 8%, fibrosis in 18% and necrosis in 19%. NETs were well differentiated in 40% of cases, poorly differentiated in 12%, and it was carcinoma with neuroendocrine differentiation in 47% of cases. Expression of synaptophysine was found in 84% of cases, chromogranine in 66% and HR in 88%.

The majority of the patients (95%) had breast surgery (57% of partial mastectomy, 43% of total mastectomy), with axillary dissection (56%). Chemotherapy, endocrine therapy and radiotherapy were administrated before surgery in 14%, 10% and 2% of cases respectively, and after surgery in 28%, 73% and 64% of cases.

Chemotherapy regimens were heterogeneous: most of patients received taxans and/or anthracyclins (86% in neoadjuvant situation, 69% in adjuvant situation), but several patients had platinum, etoposide, bevacizumab or somatostatin.

With a median follow up of 89 months (95CI 68-110 months), OS and DFS at 5 years were respectively 66.5% (95CI 57.0-77.6) and 75.0% (95CI 66.2-85.1) (Figures 1 and 2). Age, stage and Ki67 were significantly correlated with OS in multivariate analysis.

 

Conclusion

The management of primary TNE of the breast is heterogeneous, especially concerning chemotherapy regimens. TNM stage and Ki67 are important prognostic factors. Prospective studies are needed to determine specific therapeutic guidelines.