Clinical and Pathological Features of Breast Cancer in Systemic Sclerosis: Results from the Sclero-Breast Study

Systemic Sclerosis (SSc) is a chronic disease associated with a 1.5-fold increase in cancer risk, including lung cancer, hematological malignancies, and breast cancer (BC). This is a retrospective study aiming to explore the clinical and pathological features of BC developed by SSc patients. A total of 54.5% of patients developed BC before SSc (median interval: 5 years), whereas 45.5% of patients developed BC after SSc (median delay: 8 years). A total of 93.1% of patients were diagnosed with an early stage tumor. Among invasive carcinomas, 70.8% presented with a low Mib1, 8.3% with a tubular histotype, and 42.8% with a Luminal A-like phenotype. A total of 66.6% of patients underwent breast-conserving surgery and 55.5% RT. A total of 40% of patients developed interstitial lung disease after RT and 20% diffuse cutaneous SSc. The cause of death of the six deceased patients was PAH. A significant association was observed between the use of immunosuppressive therapy and diffuse skin extension, negative ACA, positive Anti-Scl-70, and interstitial lung disease, but not BC status. SSc patients developed BC at a good prognosis, suggesting a de-escalation strategy of cancer therapies. In particular, ionizing radiation and chemotherapeuticals should be limited to higher-risk cases. Finally, proper screening is mandatory in order to allow for early cancer detection in SSc patients.