Prevalence of DSM-5 somatic symptom disorder in Chinese patients with breast cancer.

Objective: The aims of this study were to explore the frequency of somatic symptom disorder (SSD) and the relationship between SSD and somatic, psychological, and social factors in Chinese patients with breast cancer.

Methods: This multicenter cross-sectional study enrolled 264 patients with breast cancer from three different departments in Beijing. The structured clinical interview for fifth edition of the Diagnostic and Statistical Manual of Mental Disorders (SCID-5) for SSD. Standardized questionnaires and clinical data were used to compare patients with and without SSD.

Results: Somatic symptom disorder was diagnosed in 21.6% (57/264) of all enrolled patients. No differences were found between SSD patients and non-SSD patients in terms of sociodemographic characteristics and tumor-specific variables, except radiotherapy. However, patients with SSD reported higher levels of depression, anxiety and cancer-related worry. They also showed a longer duration of symptoms, greater impairment in daily life, more concern over their physical complaints and more doctor visits. In a stepwise binary logistic regression analysis, among others, higher health anxiety (WI-8, Exp(B) = 0.107, p = 0.009) and more doctor visits (OR = -1.841, p < 0.001) showed a significant association with SSD; the model explained 53.7% of the variance.

Conclusions: Similar to other physical diseases, there is a high prevalence of SSD in patients with breast cancer. Somatic symptom disorder patients differ from non-SSD patients by exhibiting higher cancer-related emotional distress and dysfunctional illness perception and behavior. There remain substantial challenges in the diagnosis of SSD in patients with cancer and other medical conditions.

Clinical Trial Registration: ChiCTR2100051525.