br Table br Length of stay with confidence
Length of stay with 95% confidence intervals in the sick leave states during the first five years after diagnosis and cause-specific hazard ratio of sick leave with 95% confidence intervals in women of working age diagnosed with breast cancer 2005e2012.
Cause Women with breast cancer Breast cancer-free women
a Estimates are controlled for matching factors (age and region) but otherwise unadjusted.
b Hazard ratio comparing women with breast cancer with breast cancer-free women (reference group), adjusted for age at diagnosis, calendar year of diagnosis, highest level of education, region, prior sick leave and prior hospitalization for the medical condition of interest.
Cause-specific hazard ratios of disability pension with 95% confidence intervals in women of working age diagnosed with breast cancer 2000e2012.
Breast cancer No 1 (Ref.)
Abbreviations: ALND, axillary lymph node dissection; ER, Angiotensin II receptor; SNB, sentinel node biopsy.
Hazard ratios were adjusted for age at diagnosis, calendar year of diagnosis, highest level of education, region, prior sick leave, and prior hospitalization for the medical condition of interest. Hazard ratios for tumor and treatment characteristics were also adjusted for each other. A model adjusted for only tumor characteristics is presented in Supplementary Table 4. The distribution of events over the various categories is presented in Supplementary Table 5.
Fig. 2. Hazard ratio with 95% confidence intervals of being granted disability pension by time since diagnosis, comparing women with breast cancer (diagnosed 2000e2012) to breast cancer-free women (reference group). Hazard ratios were adjusted for age at diagnosis, calendar year of diagnosis, highest level of education, region, prior sick leave, and prior hospitalization for the medical condition of interest. Due to few events in the first year, hazard ratios are plotted from year one onward.
lymph node dissection, which increases the risk of lymphedema and pain, has also been associated with a higher risk of disability pension [7,21]. Other studies have reported that fatigue, a well-known side effect of cancer treatment, strongly affects ability to work [10,11,13,22]. In addition to side effects, our study provides further support to the notion that factors not directly related to cancer treatment, such as education and previous sick leave, also increases the risk of work-related outcomes after a breast cancer diagnosis .
To our knowledge, our study is the first to find evidence of an increased risk of sick leave and disability pension because of mental disorders in women with breast cancer. This is not surprising, given that earlier studies have reported increased rates of depression, anxiety, and stress-related disorders following a breast cancer diagnosis [24e28]. The risk of psychological problems has been reported to be highest in the first two years , which is likely to reflect immediate reactions to the cancer diagnosis. Our study provides evidence that women with breast cancer of all disease stages are at an increased risk of mental health problems affecting working life for several years after diagnosis.
Previous studies have found an increased risk of cardiovascular events in women with breast cancer [24,29e32]. We found that it was more common for women with breast cancer than for control women to leave the labor market because of cardiovascular disease. The cardiotoxic effects of certain breast cancer treatments are well-known; anthracycline-based chemotherapy, trastuzumab, and radiotherapy are associated with an increased risk of cardiovascular events . Breast cancer and cardiovascular disease also share common risk factors such as tobacco use, physical inactivity, and diabetes, which may also explain the coincidence of the diseases .
We also observed an increased risk of disability pension due to inflammatory diseases. It has been suggested that treatment for breast cancer can induce autoimmune or inflammatory diseases,
such as rheumatoid arthritis, systemic lupus erythematosus, and psoriasis [34,35]. Rheumatoid symptoms of joint pain and joint swelling are common following breast cancer treatment, but do not necessarily involve systemic inflammation . It cannot be excluded that the association may be the opposite; many chronic inflammatory diseases (and their treatments) are associated with increased cancer risks , although current literature point to-wards no increased risk of breast cancer in some of the most common inflammatory diseases [38,39].