Background: The goal of this large prospective population-based study was to examine the association between depressive symptoms and all-cause mortality among cancer survivors up to 10 years post-diagnosis.
Methods: All currently alive individuals diagnosed with endometrial or colorectal cancer (CRC) between 1998 and 2007 or with lymphoma or multiple myeloma between 1999 and 2008, as registered in the Eindhoven Cancer Registry, received a questionnaire on depressive symptoms (Hospital Anxiety and Depression Scale (HADS)) in 2008 or 2009, respectively; 69 % (n = 3,080) responded. Survival status was obtained from the Central Bureau for Genealogy.
Results: Clinically elevated levels of depressive symptoms (HADS cutoff value ≥8) were more prevalent in those who died compared to those who survived (38 vs. 19 %, respectively; p < 0.0001). This was also evident across different types of cancer. After adjustment for independent predictors of all-cause mortality, 1-10-year survivors with depressive symptoms had an increased risk of death (hazard ratio (HR) 2.07; 95 % confidence interval (CI) 1.56-2.74; p < 0.0001), and this was also found among 1-2-year survivors (HR, 2.20; 95 % CI, 1.41-3.43; p < 0.001). Sub-analyses among CRC survivors gave the opportunity to adjust for metastasis and showed that depressive symptoms among 1-10-year CRC survivors and 1-2-year CRC survivors increased the risk of death (HR, 1.88; 95 % CI, 1.24-2.83; p < 0.01 and HR, 2.55; 95 % CI, 1.44-4.51; p < 0.001, respectively).
Conclusions: This study showed that patients with depressive symptoms had twofold risk for all-cause mortality, even after adjustment for major clinical predictors.
Implications for cancer survivors: Paying more attention to the recognition and treatment of depressive symptoms seems warranted since depressive symptoms are often underdiagnosed and undertreated in cancer patients.