SUMMARY

In this study, we observed that compared to women with no prior cancer, breast cancer survivors had higher risk of anxiety, depression, sleep problems, sexual dysfunction, fatigue, receipt of opioid analgesics, and pain. Relative risks estimates tended to decrease over time, but anxiety and depression were significantly increased for 2 and 4 years after breast cancer diagnosis, respectively, while associations for fatigue, pain, and sleep disorders were elevated for at least 5–10 years after diagnosis. Early diagnosis and increased awareness among patients, healthcare professionals, and policy makers are likely to be important to mitigate the impacts of these raised risks.

RATIONALE

Large numbers of women around the world are currently living beyond a breast cancer diagnosis, including over 2.9 million in the United States and 570,000 in the UK, with numbers projected to rise further [1,2]. Women with a history of breast cancer may experience long-term physical consequences of treatment, worries about cancer recurrence, employment or financial difficulties, and other challenges, with potential negative consequences for broader mental health [3,4]. However, little evidence is available from large-scale population-based studies to quantify the impact of a history of cancer on long-term mental health.

In a recent systematic review [5], anxiety and depression were found to be more common in breast cancer survivors than in women with no cancer history, but, evidence was often drawn from studies at high risk of selection and information bias, likely to be confounded by age and socioeconomic status, and lacking generalisability. Only a few population-based studies have been done, finding conflicting effect sizes, with relative risks of clinically diagnosed depression or anxiety ranging from no association to a doubling of risk in cancer survivors [5–7]. Increased risks of other mental health outcomes including suicide and neurocognitive and sexual dysfunctions have also been observed; existing evidence on sleep disturbance is insufficient to draw conclusions [5]. The overall burden of mental health disorders is remarkably high, particularly in high-income settings [8], and the efficient planning and delivery of cancer support and mental health services that suit the needs of the largest group of cancer survivors in the population requires timely and robust estimates on the risk of clinically assessed outcomes at population level.

We therefore aimed to quantify the associations between breast cancer history and the primary outcomes of anxiety and depression and the secondary outcomes of cognitive dysfunction, fatigue, sleep disorder, sexual dysfunction, fatal and nonfatal self-harm, pain, and opioid analgesics prescription using population-based electronic health records data from UK primary care. Pain and fatigue were included due to their likely links with both cancer history and mental health.

Citation: Carreira H, Williams R, Funston G, Stanway S, Bhaskaran K (2021) Associations between breast cancer survivorship and adverse mental health outcomes: A matched population-based cohort study in the United Kingdom. PLoS Med 18(1): e1003504. https://doi.org/10.1371/journal.pmed.1003504