Life after cancer diagnosis and treatment is full of uncertainties for the patients and their caregivers. The possibility of cancer returning is hard to dismiss at least in the first few years after the end of treatment. Life has often changed in many imperceptible and subtle ways for people who have undergone cancer treatment, as well as their loved ones.

The research on psychological health of long-term cancer survivors gives us a mixed picture. While some studies show high rates of cancer-related intrusive thoughts, others find low rates of depression and good quality of life. Psychological distress experienced by carers is also of concern as that can be even higher than the issues faced by patients.

Mitchell et al (2013) have recently completed a systematic review and meta-analysis that aims to answer the following questions:

• Is the prevalence of mood disorders significantly different in long-term cancer patients compared to their spouses?
• Do the high rates of distress return to a similar rate as in the general population for cancer patients in the long-term?

Methods

The authors carried out an extensive search for studies that reported depression and anxiety prevalence in adults with cancer two years after the treatment. They excluded studies that used the same sample (duplicate publications) and also studies conducted on patients in palliative settings. They found high heterogeneity so they used random-effects rather than fixed-effect meta-analysis.

Results

Out of 1886 results that the systematic review found, they included 43 studies (26 long-term comparisons with healthy controls and 17 long-term comparisons with spouses). They found no publication bias in terms of depression or anxiety in the literature.

The prevalence of depression was 11.6% among cancer survivors compared with 10.2% among healthy people – the difference was not statistically significant. However, the results differed depending on the depression scale used (the relative risk of depression was significantly higher for studies that used the Center for Epidemiologic Studies Depression Scale and not significantly lower for those that used the Hospital Anxiety and Depression Scale).

The prevalence of depression was 26.7% among cancer survivors whereas among their spouses it was 26.3% showing that the risk of depression is not different in spouses of long-term cancer survivors as in the survivors themselves.

Results for anxiety, on the other hand, presented a different picture. The prevalence for anxiety was 17.9% among cancer survivors compared to 13.9% among healthy people. The relative risk of anxiety was higher in cancer survivors than healthy controls. However, a significant difference emerged when it comes to comparing anxiety prevalence between cancer survivors and their spouses: 28% vs 40.1%, respectively.

In addition, the relative risk for depression was significantly higher for cancer survivors who were diagnosed within the past 2 years (1.74) compared with those diagnosed 2-10 years or 10 years ago or more (2.09). In the case of anxiety, relative risks for less than 2 years versus 2-10 years and less than 2 years versus more than 10 years did not differ significantly.

Discussion

The authors conclude that

…after diagnosis of cancer, increased rates of anxiety tend to persist compared with healthy controls, whereas increased rates of depression are less long-lasting (p. 9).

They highlight that anxiety can impact quality of life negatively and that screening for anxiety has not received the same attention as screening for depression and distress.

It is important to note the drawbacks of this meta-analysis. As they indicate, the studies had high heterogeneity and the quality varied. However, a bigger problem is that they ignored a very important factor in their analyses: the importance of gender. As Hagedoorn et al (2008) clearly showed in their meta-analysis of distress in couples coping with cancer, women reported more distress than men, regardless of whether they were the patient or the partners. So, it is surprising that Mitchell et al. did not take gender into account or even cite this work. Given this caveat, we end up wondering what the results would be like if gender was accounted for in the analyses.

Links

Mitchell, AJ et al Depression and anxiety in long-term cancer survivors compared with spouses and healthy controls: a systematic review and meta-analysis (PDF). The Lancet Oncology – 5 June 2013. DOI: 10.1016/S1470-2045(13)70244-4

Hagedoorn, M., R. Sanderman, et al. (2008). Distress in couples coping with cancer: a meta-analysis and critical review of role and gender effects. Psychol Bull 134(1): 1-30. [PubMed abstract] [PowerPoint presentation from lead author PDF]