Abstract P3-13-19: Isolated sternal metastases: The place of surgical resection
Authors: Berliere M , Taburiaux L , Lacroix V , Gerday A , Coyette M , Lecouvet F , Piette P , Galant C , Duhoux F , Lengele B 
Published: May 2019

Abstract
Background: Solitary sternal metastases from breast cancer are found in approximately 1.9 to 2.5 % of all advanced breast cancer cases. According to the latest AJCC classification, they are still considered as stage IV disease, but their prognosis is better in the absence of other foci of metastatic disease. Their treatment still remains controversial.
Material and methods: This is a monocentric retrospective study performed in our breast clinic and approved by our ethics committee. Twelve patients were included in this study between 2010 and 2015; 11 had a metachronous solitary sternal metastasis and 1 had a synchronous metastatic sternal lesion. Complete restaging was negative in all patients for other metastatic lesions. The extent of resection (different parts of the sternum and frequently also adjacent rib cartilages) necessary to obtain free margins was estimated preoperatively on MRI images focused with adequate sequences. All the patients underwent a large sternal resection and a chest wall reconstruction integrated in a multimodal approach.
Characteristics of the patients and of the tumors were studied.
The major outcomes studied were disease-free (DFS) and overall survival (OS).
Results: The mean interval between the initial diagnosis of breast cancer and the discovery of sternal metastasis was 115 months. After surgical resection, free margins were obtained in 10 patients. No post-operative complications were observed except for persistent thoracic pain in one patient with a medical history of chronic pain. Excellent cosmetic and functional outcomes were obtained without significant impairment of respiratory function. Ten patients received chemotherapy pre- or postoperatively. All the tumors expressed ER and /or PgR receptors, and endocrine therapy was administered in all patients.
Mean duration of follow-up was 25 months (9-51 months). Three patients presented distant recurrences: 2 liver lesions and 1 cervical nodal recurrence with pericardic effusion. Out of these 3 patients, 1 died after 51 months. Currently the DFS of this small study is 75 % and the OS is 91.6 %.
Conclusion: Treatment of isolated sternal metastases of breast cancer must be based on a multidisciplinary strategy.
Sternectomy and multilayered chest wall reconstruction (with different types of meshes and flaps) could be a curative approach in highly selected patients with no other metastatic lesions. In this group of patients, the good prognosis observed could be due to a different mechanism of dissemination, based on lymphatic rather than hematogenic diffusion.
Longer follow-up and prospective studies are needed to confirm these encouraging results.
Citation Format: Berliere M, Taburiaux L, Lacroix V, Gerday A, Coyette M, Lecouvet F, Piette P, Galant C, Duhoux F, Lengele B. Isolated sternal metastases: The place of surgical resection [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P3-13-19.