We aimed to systematically summarize the empirical evidence on the 4-week-, 12-month-, and lifetime prevalence of affective and anxiety disorders in cancer patients. We evaluated 89 English or German language original papers and systematic reviews that assessed the prevalence of affective and anxiety disorders using structured clinical interviews published between 1995 and 2010. Adjusted prevalence rates were calculated using a random-intercept model. The pooled adjusted 4-week prevalence of affective disorders was 11.1% (95% CI 8.1-15.1), and 10.8% (95% CI 6.8-16.7) based on German studies. The pooled adjusted 4-week prevalence of anxiety disorders was 10.2% (95% CI 6.9-14.8), and 13.5% (95% CI 7.1-24.3) based on German studies. The findings show the need for further research on representative studies that take into account the range of psychosocial stressors and supportive care needs in addition to the prevalence of mental disorders.
