AIM: Though about 20% of working age breast cancer survivors do not return to work after treatment, few studies have addressed risk factors for unemployment. The majority of studies on occupational consequences of breast cancer focus on non-employment, which is a mixture of sickness absence, unemployment, retirement pensions and other reasons for not working. Unemployment in combination with breast cancer may represent a particular challenge for these women. The aim of the present study is therefore to analyze the risk for unemployment in the years following diagnosis and treatment for breast cancer.

METHOD: This study included 14,750 women diagnosed with breast cancer in Denmark 2001-2009 identified through a population-based clinical database and linked with information from Danish administrative population based registers for information on labour market affiliation, socio-demography and co-morbid conditions. Multivariable analyses were performed by Cox's proportional hazard models.

RESULTS: Two years after treatment, 81% of patients were still part of the work force, 10% of which were unemployed. Increasing duration of unemployment before breast cancer was associated with an adjusted HR = 4.37 (95% CI: 3.90-4.90) for unemployment after breast cancer. Other risk factors for unemployment included low socioeconomic status and demography, while adjuvant therapy did not increase the risk of unemployment.

CONCLUSIONS: Duration of unemployment before breast cancer was the most important determinant of unemployment after breast cancer treatment. This allows identification of a particularly vulnerable group of patients in need of rehabilitation.