The prognostic significance of skin involvement in breast cancer patients with chest wall recurrence.

PURPOSE:To assess the prognostic significance of skin involvement in breast cancer patients with chest wall recurrence (CWR). METHODS:We retrospectively analyzed the clinicopathological data of breast cancer patients with CWR who were diagnosed pathologically between January 2000 and April 2020. Disease-free survival (DFS) was the time from radical resection for CWR to disease recurrence. Progression-free survival (PFS) was defined as the time from the diagnosis of locally unresectable CWR to the first sign of disease progression. Persistent chest wall progression was defined as three consecutive chest wall progressions with no distant organ involvement. RESULTS:A total of 476 patients with CWR were included in this study. Skin involvement was confirmed in 345 patients. Skin involvement was significantly correlated with a high T stage (p = 0.003), more positive nodes at initial examination (p < 0.001) and lymphovascular invasion (p < 0.001). Kaplan-Meier analysis showed that skin involvement was a predictor of shorter DFS (p < 0.001), including both local disease progression (p < 0.001) and distant disease progression (p = 0.022). Multivariate analysis showed that skin involvement was an independent biomarker for DFS (p = 0.043). Patients with skin involvement were more likely to experience persistent chest wall progression (p = 0.040). After eliminating the potential deviation caused by an insufficient follow-up time, persistent chest wall progression was more likely to be associated with a high N stage (p = 0.002), negative progesterone receptor (PR; p = 0.001) and positive human epidermal growth factor receptor 2 (HER2; p = 0.046) of the primary site, and negative oestrogen receptor (ER; p = 0.027) and PR (p = 0.013) of the chest wall lesion and skin involvement (p = 0.020). CONCLUSION:Skin involvement was a predictor of poor disease control in patients with CWR and was closely related to persistent chest wall progression. We stratified the prognosis of individualized treatment for breast cancer patients with CWR to provide new insights into the biological behaviours of the disease.