Clinical characteristics of breast cancer patients with mental disorders

Background Severe mental disorders are thought to affect the diagnosis and treatment of breast cancer because of their lower awareness and understanding of the disease and their reduced ability to cooperate with medical staff. We analyzed the clinical features of patients with breast cancer and pre-existing mental disorders such as schizophrenia, dementia, and intellectual disability. Patients and methods: We reviewed the records of 46 patients who were diagnosed with schizophrenia, dementia, or intellectual disability, before being diagnosed with breast cancer. Three patients had more than 2 mental disorders. All patients underwent curative surgical treatment between September 1992 and January 2015. Patients' clinicopathological information was compared with a control group of 727 breast-cancer patients without mental disorders seen during the same period. Results Patients with mental disorders were less likely to be aware of their own breast cancer; the lesions were often found by other people such as family, care staff, and medical staff. Breast cancer patients with mental disorders had significantly more advanced T factors and overall stage at the time of surgery than their counterparts without mental illness, more patients underwent total mastectomy, and fewer patients underwent postoperative adjuvant chemotherapy and radiation. Biological markers such as estrogen receptor, progesterone receptor, and human epidermal growth factor receptor 2 (HER2) expression were not significantly different between groups. Disease-free survival and overall survival were not significantly different between groups. Conclusion Patients with mental disorders receive less postoperative adjuvant chemotherapy; however, their outcomes were not worse than those of patients without mental disorders.