Clinicopathological features of inflammatory versus noninflammatory locally advanced nonmetastatic breast cancer

Inflammatory breast cancer (IBC) is a rare but aggressive form of breast cancer. It is mainly a clinical diagnosis. The aim of this study was to compare IBC to clinically diagnosed noninflammatory locally advanced nonmetastatic breast cancer, also called cLABC.

One hundred and eight patients were studied: 49 with IBC and 59 with cLABC. The following features were analyzed: age at diagnosis, body mass index (BMI), axillary lymph node status (cN), estrogen receptor status (ER), progesterone receptor status (PR), HER2 status, histological tumor grade and subtype. Short-term disease-free (DFS) and overall survival (OS) were also assessed in both groups.

Compared with cLABC, IBC was less often PR positive (41.7 vs. 66.1%, p = 0.01) and showed a trend to be more often HER2 positive (34.7 vs. 19.3%, p = 0.07). The 3-year DFS was 63 and 77%, respectively, for IBC and cLABC (p = 0.01); these figures were 83 and 85% for OS (p = 0.17). No significant differences in age at diagnosis, ER, cN, BMI, histological tumor grade or subtype were demonstrated.

Compared to cLABC, IBC are more frequently PR negative, have a worse DFS, and have a tendency to be more often HER2 positive. These data reinforce the idea of IBC being a distinct biological entity compared to noninflammatory breast cancer.