Risk factors and prognostic factors for inflammatory breast cancer with bone metastasis: A population-based study

Inflammatory breast cancer (IBC) is a rare type of breast cancer with poor prognosis. IBC patients with bone metastasis (BM) often suffer from many complications. This study was performed to identify risk factors with strong capability of predicting high BM risk for IBC patients and find prognostic factors for those patients.

The Surveillance, Epidemiology and End Results (SEER) database was used to collect the clinicopathological and survival information of IBC patients. 966 IBC patients diagnosed between 2010 and 2015 were included to study the risk factors for developing BM by using Multivariable logistic regression. A total of 194 and 176 patients were included to analyze independent prognostic factors for overall survival (OS) and cancer specific survival (CSS) of IBC patients with BM respectively.

Of the 966 IBC patients, 194 (20.1%) patients were with BM. The risk factors for developing BM in IBC patients included unmarried marital status, double breast tumor, N1 stage, N3 stage, and liver metastases had higher risk of BM, while those of uninsured status and triple negative breast cancer (TNBC) were less likely to have BM. Analysis of prognostic factors for OS and CSS of IBC patients with BM showed that TNBC subtype and liver metastases were independently significantly associated with poorer OS and CSS of BM patients, while chemotherapy could serve as an independent prognostic factor for better OS and CSS of BM patients.

Marital status, double breast tumor, N1 stage, N3 stage, and liver metastases should be considered for prediction of BM in IBC patients. TNBC subtype and liver metastases may indicate poor survival and chemotherapy can indicate improved survival for IBC patients with BM.