Patterns of Care and Efficacy of Chemotherapy and Radiotherapy in Skin-Involved Breast Cancers of All Sizes

The management of small skin-involved (SI) invasive breast cancers is controversial because although they are considered unresectable, their prognosis is far better than their stage III classification. This study was undertaken to determine how SI lesions are treated in the United States and to discern the benefit of systemic therapy.

Data of patients diagnosed with stage I-III breast cancer in the National Cancer Data Base between 2004 and 2011 were reviewed. Treatment patterns were examined and overall survival assessed.

A total of 3485 patients had SI and 456,287 patients had non-SI breast cancers. Chemotherapy was administered to 68.5% of SI and 45.9% of non-SI tumors (P < .001), including 77.2% of SI and 33% of non-SI tumors < 2 cm (P < .001). After adjusting for patient and tumor characteristics, SI patients were 19.4% more likely to receive chemotherapy than non-SI patients. Radiotherapy was provided to 61.1% of SI and 64.3% of non-SI tumors (P < .001), including 65.5% of SI and 66.5% non-SI tumors < 2 cm (P = .711). After adjusting for patient and tumor characteristics, SI patients were 76.6% more likely to receive radiotherapy than non-SI patients. Chemotherapy and radiotherapy provided an overall survival benefit for stage II and III SI and non-SI tumors.

Despite controversy regarding staging and prognosis of SI tumors, the majority of patients are provided systemic therapy and radiotherapy. Varied patterns of chemotherapy administration for SI tumors suggests that further treatment guidance and standardization are required, especially because chemotherapy and radiotherapy are equally efficacious in SI and non-SI tumors alike.