Significance of full-thickness chest wall resection as a local treatment for sternum metastasis of breast cancer

Bone metastasis of breast cancer generally tends to be multiple. However, breast cancer frequently metastasizes to the sternum as solitary metastasis. Resection of the sternum was reported to be an effective surgical technique for sternum metastasis which could not be remarkably improved by chemo-endocrine therapy and locoregional recurrent breast cancer invading the skin. A first patient was diagnosed with sternum metastasis invading the skin 44 months after radical mastectomy for breast cancer of stage II. A second patient had breast cancer of stage IV simultaneously with metastases to the sternum and the lung. Only the lung metastasis was successfully controlled by chemo-endocrine therapy, but the sternum metastasis was progressive, following radical mastectomy. Both patients manifested solitary bone metastases and underwent full-thickness chest wall resection. The defect of the chest wall was reconstructed with the mucocutaneous flap using the dorsal latissimus muscle in case 1 and with the abdominal rectus muscle in case 2. Twenty months after the resection of the sternum, the first patient suffered from supraclavicular lymph node metastasis, and the multidisciplinary treatment including radiation therapy was indicated. This therapeutic procedure was effective, and the patient survived for 63 months after resection of the sternum. The second patient has made good progress for six months in maintaining complete remission with chemo-endocrine therapy. These findings suggested that surgical resection was a useful local treatment for solitary sternum metastasis.