Colorectal cancer metastatic to the breast: A case report.

Background: Breast metastases from colorectal cancer (CRC) are very uncommon. There is no unanimous consensus regarding the best treatment for this rare condition, and management is, especially in elderly patients, limited to diagnosis and palliative care. Capecitabine, an oral fluoropyrimidine derivative, might be helpful in controlling the disease and may be a treatment option for patients unable to receive more aggressive chemotherapy.

Case Summary: We report a case of synchronous massive breast metastasis from CRC in an 85 year old patient who came to the hospital presenting a huge mass originating from the axillary extension of the right breast. A whole body computed tomography also showed a mass in the right colon. The patient underwent a simple right mastectomy along with right hemicolectomy. The resected breast showed massive metastasis from CRC with intense and homogeneous nuclear CDX2 staining, while the colon specimen revealed poorly differentiated adenocarcinoma stage pT4a pN0 pM1 (breast) (Tumor Node Metastasis 2017). Three months later she developed a subcutaneous mass at the site of the previous mastectomy. An ultrasound guided biopsy was carried out again and revealed a metastasis from CRC. The patient then started treatment with capecitabine plus bevacizumab, obtaining stable disease (RECIST criteria) and a clinical benefit after 3 mo of therapy.

Conclusion: In our experience, capecitabine and bevacizumab may be a useful treatment option for breast metastases from primary CRC in elderly patients.