Abstract
Despite concerns about the mental health of breast cancer patients, little is known regarding the temporal
risk pattern and risk factors of common mental disorders among these patients. We estimated
standardized incidence ratios (SIRs) of depression, anxiety and stress-related disorders in a Swedish
nationwide cohort of 40,849 women with invasive and 4,402 women with in-situ breast cancer (2001-
2010, median follow-up = 4.5 years). The impact of patient, tumor and treatment characteristics was
analyzed using flexible parametric survival models in a regional cohort of 7,940 invasive breast cancer
patients (2001-2013, median follow-up = 7.5 years). Women with invasive breast cancer showed
increased rates of depression, anxiety and stress-related disorders [overall SIR (95% CI) = 1.57 (1.46-
1.69), 1.55 (1.43-1.68) and 1.77 (1.60-1.95), respectively]. SIRs were highest shortly after diagnosis, but
remained increased up to 5 years. Younger age at diagnosis, comorbidity, higher-grade disease, lymph
node involvement and chemotherapy were independently associated with the risk of depression and
anxiety in invasive cancer patients, with chemotherapy and higher-grade disease conferring short-term
risk only, while comorbidities were mainly associated with late-onset events. No clinical risk factors were
identified for stress-related disorders except for a greater risk associated with younger age. Patients with
in-situ cancer only showed an increased incidence of stress-related disorders during the first six months
after diagnosis [SIR (95% CI) = 2.76 (1.31-5.79)]. The time-dependent risk profile of invasive cancer
patients may guide health care professionals for timely and targeted psycho-oncologic interventions.
