The most common cause of cutaneous metastasis of an internal malignancy is breast cancer with an incidence of 23.9%. Objective: to identify tumor antigens as markers of cutaneous metastases in breast cancer patients. Materials and methods: A total of 54 patients were included; 24 belonged to patients with cutaneous metastases in which samples of cutaneous metastases, primary tumors and metastatic lymph nodes were studied; 30 breast cancer patients with lymph nodes metastases and without cutaneous metastases were studied as controls. An immunohistochemical approach following standard procedures was performed employing two anti-MUC1 MAbs (HMFG1 and SM3 MAbs), anti-sLex (KM93 MAb), anti-Lex (KM380 MAb), and an anti-TF MAb (Dako). An extensive statistical analysis was performed. Results: in samples belonging to patients with cutaneous metastases, all samples expressed MUC1; 50% of primary tumors and 54% of metastatic lymph nodes were positive to sLex while 23% of cutaneous metastatic samples showed reactivity; a significant difference was found between primary tumors and cutaneous metastatic samples and also between metastatic lymph nodes and cutaneous metastases (p<0.05). Lex showed expression in 75% of primary tumors, 64% of lymph nodes and 45% of cutaneous metastases while TF showed expression in 12.5%, 25% and 10%, respectively. In controls, results were: in primary tumors MUC1 was positive in 95%, sLex in 27%, Lex in 50% and TF in 25% while in metastatic lymph nodes MUC1 stained positively in 50%, sLex in 40%, Lex in 30%, and TF in 20%. A higher expression of sLex and Lex was found in primary tumors and metastatic lymph nodes belonging to patients with cutaneous metastasis compared with samples from breast cancer patients without cutaneous metastasis. Conclusion: breast cancer cutaneous metastasis may be associated with sLex and Lex antigenic expression in primary tumors. Associations between MUC1 and sLex and Lex antigens show the complexity of the dissemination behavior that these antigens modulate in breast cancer.
Breast cancer cutaneous metastases: implications of MUC1 and carbohydrate associated antigens in tumor dissemination.