Association between systemic sclerosis and breast cancer: eight new cases and review of the literature

Several studies have demonstrated an increased frequency of cancer in patients with systemic sclerosis (SSc), specially lung and breast cancers. The pathogenesis of the association between SSc and cancer is not fully established. The aim of this study was to describe new cases of the association between SSc and breast cancer and to perform a review of the literature. We retrospectively studied the medical files of eight patients followed in our institution for SSc and breast cancer. We analyzed them with data available in the literature for a total of 46 patients. Cutaneous extension of SSc was clearly mentioned in 17 cases: the SSc was limited in 10 cases and diffuse in 7 cases The median age at the diagnosis of cancer was 54 years (range: 40–71). The median duration between SSc onset and breast cancer diagnosis was 11.5 months (range: 0–288). The duration between SSc onset and breast cancer diagnosis was ≤12 months in 27 of 44 patients (61.4%), and in 11 (25%) of them the diagnosis of both diseases was made simultaneously. It was clearly mentioned for 35 patients whether the diagnosis of breast cancer was made before or after the onset of SSc. The diagnosis of breast cancer was made before SSc onset in 17 of 35 patients (48.6%) and after SSc onset in 18 of 35 patients (51.4%). For 33 patients, the follow-up was available: 18 (54.5%) died, 11 (33.3%) of them within the 1st year after the diagnosis of the cancer. For none of the patients did the anticancer treatment improve the SSc. The close temporal relationship between SSc onset and breast cancer diagnosis is highly suggestive of a pathophysiological link. SSc is probably not a paraneoplastic disease since the anticancer treatment has no influence on the evolution of SSc. However, it can be suggested that SSc could be a disease facilitating breast cancer and/or metastases development.