Associations of breast cancer development in patients with systemic sclerosis: an exploratory study

The goal of this study was to describe the clinical characteristics of patients with a diagnosis of systemic sclerosis who develop breast cancer and to identify associations for this relationship. From 769 patients followed at the scleroderma center of our institution over the past 16 years, 24 patients developed a diagnosis of breast cancer. The demographics and clinical characteristics of these patients will be compared to those of a randomly selected group of scleroderma patients without a diagnosis of cancer. A further analysis will compare the patients who developed their breast cancer before the diagnosis of systemic sclerosis to those diagnosed after. Twenty-four patients developed 25 breast cancers with 13 patients diagnosed before the diagnosis of systemic sclerosis and 11 after. Compared to 48 randomly selected systemic sclerosis patients without a diagnosis of cancer, the patients with breast cancer were diagnosed with systemic sclerosis at an older age (53.5 +/- 15.2) as compared to those without (42.4 +/- 12.5) (p=0.002). A relatively equal amount of patients had the diffuse and limited form of systemic sclerosis, while pulmonary fibrosis (p=0.015) and the lack of antinuclear antibody (ANA) positivity (p=0.02) were more commonly seen in patients with breast cancer. Patients who developed breast cancer before the diagnosis of systemic sclerosis were older at systemic sclerosis diagnosis (61.6 +/- 11.3) compared to those after (43.9 +/- 13.5) (p=0.03). An older age at diagnosis of systemic sclerosis, a lack of ANA positivity, and the presence of pulmonary fibrosis were more commonly seen in patients with systemic sclerosis who have a diagnosis of breast cancer.