Suicide and women living with and beyond a breast cancer diagnosis

Cancer accounts for a considerable illness burden globally, with an estimated 9.6 million deaths attributed to it in 2018; this equates to one in six deaths (World Health Organization (WHO), 2022a). In the UK, despite extensive population-based interventions in healthy lifestyle promotion and cancer screening, there are approximately 375 000 new cancer diagnoses every year (Cancer Research UK (CRUK), 2019). The incidence of cancer is higher in the UK than in almost two-thirds of countries in Europe, and the most common cancers include breast with 56 987 new cases, prostate with 55 068 and lung with 48 754 (World Cancer Research Fund, 2022).

With early diagnosis and intervention and the use of targeted cancer treatments, mortality from breast cancer has decreased significantly (Odle, 2017; CRUK, 2019).

The difficulties experienced by individuals following a cancer diagnosis may be physical, emotional, psychosocial or a combination of all three (Irons, 2014; Antoni et al, 2017, Kim et al, 2022). Emotional distress following a diagnosis of cancer is an anticipated, normal behaviour; however, in some individuals, it may manifest at some point through a management episode or patient journey as a level of anxiety or depression that impacts significantly on quality of life and coping.

Symptoms of anxiety and depression can range from loss of focus to overwhelming emotions, which affect participation in normal daily activities to varying degrees. In extreme cases, these feelings can move from physical symptoms of low energy and inability to complete basic tasks to despair and hopelessness (Irons, 2014). The physical and emotional effects of relatively benign subclinical levels of depression can have a significant impact on quality of life at all phases in the cancer trajectory (Andersen et al, 2017).

It is questionable whether research needs in relation to mental health morbidity have been met. An initial scoping review of the literature found a substantial volume of empirical evidence and research on long-term mental health outcomes in people living with and beyond a breast cancer diagnosis (Bardwell and Fiorentino, 2012; Zainal et al, 2013; Avis et al, 2015; Brandão et al, 2017; Faller et al, 2017). However, there was a paucity of literature on suicide or suicide attempts in individuals living with and beyond a cancer diagnosis.

Confronting a cancer diagnosis is a life-changing experience; acknowledging it brings with it a sense of vulnerability and may create or precipitate a crisis that threatens to overwhelm the individual. Some people may be unable to deal with the difficulties this brings and, at worst, the end result is suicide or a suicide attempt (Björkenstam et al, 2005; Irons, 2014).

Suicide is an increasingly significant public health concern and a priority on the health agenda worldwide, with more than 800 000 suicides occurring per year (WHO, 2021). Suicide is defined as ‘the act of intentionally ending one's own life’, and suicide ideation can be described as ‘thoughts of engaging in behaviour intended to end one's own life’, and these have active and passive phases (Nock et al, 2008). Passive suicide ideation is where suicide is contemplated but is a low risk. However, it can move to active ideation where suicide is planned and a suicide attempt may subsequently occur. The catastrophic potential end result is for an individual to end their life (Levi, 2003).

Methodology

It was proposed to undertake a review of the literature on suicide in cancer patients or following a cancer diagnosis. The aim of the literature review was twofold:

• To evaluate research or work undertaken in relation to suicide in cancer patients generally and, more specifically, following a breast cancer diagnosis
• To critically appraise studies included in the review.

The time frame for search was 1970–2019 and grey literature was not searched. Both qualitative and quantitative studies were included in search strategy.

A predetermined search strategy was undertaken with a main subject heading of ‘suicide and breast cancer’ and ‘abridged variants’ and ‘females’ as the population of interest. The author initially searched for suicide and breast cancer, then widened the search to suicide and cancer.

The search used terms including exact phrases such as suicide and cancer AND breast cancer OR breast cancer suicide using Boolean operators and truncation*. Exact phrases were used (suicide AND breast cancer). Studies that were not in English or were about palliative care were excluded.

The search was conducted across multiple electronic databases. Peer-reviewed English language articles were sourced electronically across the CINAHL Plus, PsycINFO, Ovid, PubMed/Medline, Embase and ProQuest (Public Health) databases. Reverse citation searching was carried out.

Extraction of relevant studies was undertaken through a process of synthesising information, initially from abstracts initially (Critical Appraisal Skills Programme (CASP), 2022).

Subsequently, full-paper studies considered to be relevant and meeting the inclusion criteria were reviewed and appraised for methodological quality (Atkins et al, 2008). In randomised controlled trials (RCTs) and quantitative research studies, a formalised approach and structured methodology is used to assess quality (Moher et al, 2009; CASP, 2022).

To provide a systematic approach to reviewing the selected articles, an adapted CASP appraisal method was used (CASP, 2022). This method of categorisation is validated and has been used as an appraisal tool in meta-synthesis for a number of years (Dixon-Woods et al, 2007). The appraisal focuses on the methodological quality of the research, in addition to its relevance to the research question and its value regarding how it answered the question.

Studies were appraised using the system of three points in three areas: relevance to the research question; value in relation to answering the research question; and quality of methodological approach. Appraisal rating of papers was numerical as follows: serious methodological issues scored 0; minor methodological issues scored 1; and papers that were robust scored 2.

The CASP (2022) pre-screen checklist is a useful method to appraise abstracts before appraising full study papers, as the first three overarching questions are used to screen them. Abstracts that do not meet the criteria can be excluded at this point.

The initial search identified 1465 articles. Following removal of duplicates and screening of abstracts, 38 articles were assessed for eligibility, with the final numbers included in the review being 19. These were predominantly quantitative, population-based studies (Figure 1 and Table 1).

Literature synthesis

Whitlock (1978), in an early retrospective population-based study, identified a higher than expected incidence of neoplasms in individuals who had died by suicide, more than across the general population. The data analysis was suggestive of a link between suicide and cancer diagnosis. However, it was concluded that the relationship between the two was tenuous due to other variables.

Allebeck and Bolund (1991), in their quantitative, population-based study using International Classification of Disease (ICD) coding, found that suicide numbers were highest among women with lung cancer. There were 169 suicide attempts out of the registry sample of 59 845, with the highest risk in the first 2 years after diagnosis. In the 16 breast cancer patients, the standard mortality ratio (SMR) was 2.0.

Although absolute suicide numbers are low, suicide ideation and risk are high in cancer patients. Björkenstam et al (2005), who examined suicide prevalence in cancer patients and compared rates with the general population, found patients with cancer were at a higher risk of dying by suicide.

A subsequent large, international, population-based study reported a greater risk of suicide in breast cancer survivors at 30 years after diagnosis, with a probability of 0.20% of suicide remaining prevalent in this population group (Schairer et al, 2006).

Although, again, these numbers are comparatively low, the potential mental health comorbidity is concerning. There have been further large, population-based studies, which have found a linear relationship between cause of death by suicide and cancer diagnosis (Schairer et al, 2006; Kendal and Kendal, 2012).

A survey undertaken in an oncology clinic using the Patient Health Questionnaire-9 (PHQ-9) to explore suicide ideation prevalence in cancer patients found a much smaller incidence than initially expected, with 8% of patients attending oncology clinics reporting that they felt they would be better off dead or that they had experienced thoughts of self-harm (Walker et al, 2008).

In contrast, Robson et al (2010) in a systematic review investigating the suicide risk in people with a cancer diagnosis found a completed suicide incidence with an SMR of 1–11. Suicide ideation ranged from 0.8% to 71.4% in patients without a pre-existing psychiatric disorder. Risk factors included sociodemographic issues such as isolation and social support common to both cancer and non-cancer populations. Specific factors associated with cancer patients included cancer site, physical functional capacity and disease prognosis (Robson et al, 2010).

Following a systematic review of the literature on the associations between breast cancer survivorship and adverse mental health morbidity at >1 year, an analysis was carried out to compare the findings with the data for with women who did not have a cancer diagnosis. This study concluded that there was significant and compelling evidence of a positive correlation between people living with and beyond a breast cancer diagnosis and mental health morbidity (Carreira et al, 2018).

Debate remains over where on the cancer journey trajectory the suicide risk is greatest. Some studies have concluded that the risk is significant in the first year after diagnosis (Ahn et al, 2015; Saad et al, 2019). However, Choi et al (2017a) suggested that not only is the risk high in the first year, but that it also remains a significant risk 10 years after diagnosis. This suggests that there is a need to monitor cancer populations on a long-term basis for suicide ideation or attempts.

A study investigating suicide ideation prevalence among, and risk factors in, the breast cancer population found that the prevalence rates were similar in both the short and long term in followed-up patients (Kim et al, 2013). The authors highlighted that risk factors were different at the two evaluation points of 1 week and 1 year after treatment. They suggested that ‘time-specific’ follow-up programmes may be required to identify and manage suicide risk in this population group (Kim et al, 2013).

The literature identifies multiple variables that impact on the prevalence of mental health disorders after a breast cancer diagnosis (Chou et al, 2012; Carreira et al, 2018; McFarland et al, 2018). Djukanovic (2017) found a 15.3% prevalence of suicide ideation in patients at 1 month after a cancer diagnosis. Variables of pain, prognosis and functioning were identified as contributory factors.

Discussion

Population-based studies, which are longitudinal in design, can be data rich because they include sufficient participant numbers. They do, however, have limitations of attrition because of the lengthy nature of follow-up and bias recall response because they are predominantly retrospective in nature.

Information on suicide or suicide ideation was obtained predominantly from large population databases or cancer registries, with ICD coding used and comparative analysis made between individual tumour groups.

Blanchard and Garden (2016) argued that, although population-based studies are resource heavy in relation to implementation, the benefits are that they can potentially provide sufficient information to generate or influence evidence-based practice guidelines.

What is surprising and concerning is that the increased risk of suicide in breast cancer survivors is likely to be under-reviewed. This is because suicide is often classified and coded in the ICD system under ‘other causes of death’, which potentially happens more commonly with women who have had cancer (Carreira et al, 2018; WHO, 2022b).

Information is not routinely collected on suicide and cancer patients because of the multiple variables that impact and may be precursors to a suicide attempt (Information Services Division (ISD), 2017). It is therefore difficult to make an association between the two factors. In this instance, coding for suicides was investigated to see if an additional coding for a cancer diagnosis was present. It cannot, however, be assumed that these two variables are related, hence the problematic nature of measuring the true incidence and association.

Private hospitals may not have links to NHS services or patient information, so data from these institutions would not have been collected. Similarly, it is difficult to establish a conclusive relationship between cancer diagnosis and death by suicide (ISD, 2017).

Table 2 shows the crude rates of death by probable suicide of patients admitted for cancer in the 5 years before death in Scotland, for the period 2009–2015. The crude rate is the number of events divided by population size, so this does not take into account factors other than the disease of interest, so it excludes age and sex, for example.

It would be difficult to link cancer with death by suicide with certainty because multiple variables can directly or indirectly result in an individual choosing to take their own life. Therefore, recognition of extreme distress or other mental health comorbidities and intervention may be the way to address concerns relating to this as a potential outcome in this population.

While the literature identifies several variables that affect the prevalence of mental health disorders after a breast cancer diagnosis (Chou et al, 2012; Carreira et al, 2018; McFarland et al, 2018), there appears to be a lack of guidance at a national level for screening for mental health comorbidities in patients with a cancer diagnosis. While screening recommendations are included within national guidance, there are no specific quality improvement indicators by which healthcare organisations are measured in this domain (Healthcare Improvement Scotland, 2016).

The 2015-2016 Scottish Cancer Patient Experience survey showed that just 45% of respondents said that they had received sufficient care and support following treatment (Scottish Government, 2016). Within the ‘acute-phase diagnosis to completion of treatment’ period, patients are cocooned throughout the experience in the highly intense, expert and supportive environment in which their care is undertaken (Baker et al, 2016). Once discharged into the community, they may be in a less structured environment. The move from the structured care pathway in hospitals from diagnosis and treatment to acute to long-term management in a primary care setting has the potential to lead to a fragmentation in care.

This risk has been mitigated considerably with the development of specialist outreach community services and specialist nurse clinics for this patient population (Luctkar-Flude et al, 2018). Johnston and Campbell (2015) cited the value of initiatives such as a post-cancer diagnosis recovery plan incorporating healthcare needs assessments. Most importantly, cancer needs to be integrated into long-term conditions programmes. Generic rather than disease-specific interventions may be the way forward.

Conclusion

Two clear themes emerge from the literature: a cancer diagnosis, with or without pre-existing mental health comorbidities, is a risk factor for suicide; and there is a significant incidence and prevalence of anxiety and depression in cancer patient populations.

While multiple variables affect mental health after a diagnosis of breast cancer, national guidance for mental health appears to be lacking and there are no specific quality improvement indicators for this.

While the care of breast cancer patients is exemplary and this is reflected in the number of patients living past the 10-year predicted survival, mental health comorbidities are less well managed. Perhaps adoption of similar models to those used in chronic or long-term conditions management may mitigate the risk of just living, rather than living well.

KEY POINTS

• Cancer accounts for a considerable illness burden globally
• Emotional distress following a diagnosis of cancer is an anticipated, normal behaviour; however, in some individuals, for multifactorial reasons, this may progress to clinical manifestations of anxiety and depression
• Confronting a cancer diagnosis is a life-changing experience; it brings with it a sense of vulnerability and may create or precipitate a crisis that threatens to overwhelm the individual. Some people may be unable to cope with this
• There is significant and compelling evidence supporting a positive correlation between people living with and beyond a breast cancer diagnosis and mental health morbidity

CPD reflective questions

• Consider why screening processes for significant mental health comorbidities do not have greater prominence in care and management pathways for breast cancer patients and in national guidance
• Should mental health screening feature at identified follow-up trajectories, not only during treatment phases?
• Consider whether there is a need for greater recognition and methodology for data extrapolation and visibility of suicide rates in individuals with a cancer diagnosis