Influence of Hormone Receptor Status on Spinal Metastatic Lesions in Patients with Breast Cancer

ObjectiveBony metastasis predominantly affects the spinal column and has been commonly associated in patients with breast cancer. There are two types of lesions that can occur with spine cancer—osteolytic or osteoblastic. Some patients may have mixed lesions, which include lytic and blastic in one vertebra or lytic and blastic in different vertebrae. Previous studies have shown that patients with breast cancer have an increased likelihood for development of lytic spinal metastases.MethodsA retrospective chart review was conducted to more closely examine the association between hormone receptor status and spinal lesion type. A total of 195 patients were initially identified through the City of Hope Cancer Registry. Of the 195, only 153 patients had hormone receptor marker status available. Associations between spinal lesion and hormone receptor status were evaluated using χ2 tests with alpha = 0.05 significance level. In a secondary analysis, the Oncomine Platform was used, which integrated The Cancer Genome Atlas (TCGA) datasets, to identify osteogenic genes that may be relevant to invasive breast cancers.ResultsContrary to previous studies, our findings revealed progesterone receptor positive (PR+) patients were significantly more likely to present with blastic than lytic or mixed lesions. Furthermore, using TCGA analysis, COL1A1 and COL1A2 were found to be up-regulated, which could provide a molecular explanation for the development of blastic metastases.ConclusionsBy integrating clinical and bioinformatic techniques, this study provides a novel discovery of the relationship between blastic and PR + breast cancers, which may have important implications for diagnostic strategies concerning vertebral metastases.