Living with and beyond cancer with comorbid illness: a qualitative systematic review and evidence synthesis

Understanding the challenges experienced by people living after a cancer diagnosis with other chronic conditions such as COPD, diabetes or mental ill health, can give new insights into patient-centred models of care. A systematic review approach provides a comprehensive process to explore the current evidence base and define a research agenda building on prior knowledge [25]. This systematic review aimed to identify and synthesise qualitative evidence on the experience of living with and beyond cancer with one or more additional long-term illnesses. Insights from the review will inform further research in this area. The review seeks to answer the following questions:

A review of qualitative papers was chosen to fit with the aim of exploring people’s experiences, using a person-centred approach to highlight context and generate meaningful and relevant findings [27]. The review used methods of qualitative synthesis to combine, integrate and interpret, where possible, the evidence from the included papers [27, 28]. The review aimed to move beyond the aggregation of available data to provide further interpretive insights into living with complex illness and define where future research can add to what is known [28].

The review method follows the PRISMA statement guidance for conducting a systematic review [29].

This review was exempt from NHS and internal University of Edinburgh Usher Institute for Population Health Sciences and Informatics Ethics Review Committee because no primary data was used.

Articles were included if they were published in English between January 2000–January 2017 to capture the current survivorship agenda while allowing for a broad view of issues as they have developed. Eligible articles included wholly qualitative studies and the qualitative component of mixed methods studies (including unpublished literature) addressing the topic of psychosocial dimensions of living with cancer and comorbid illness (diagnosed before or after the cancer diagnosis but not directly caused by the cancer), including issues of support and experience of service provision from diagnosis to end of life. Adult patients (18 years or over), informal carer and health care professional perspectives were included.

Any cancer type was included along with any comorbidity (as defined by the ISD Scotland report [30]) and listed in Barnett et al.’s paper mapping the epidemiology of multi-morbidity [4], listed in Online Resource 1. Long-term side effects of cancer treatment and second primary cancers were not included. See Online Resource 2 for a summary of inclusion and exclusion criteria.

The review includes physical, social, emotional, psychological and spiritual dimensions of experience of cancer and comorbidity. Full details of the review topic can be found in the study protocol [26].

Literature was identified using a variety of methods, including database searching, citation and snowball searching, known expert consultation via email and related articles searches in PubMed and Google scholar. The databases consulted were Medline, Embase, CINAHL, PsycINFO, ASSIA, Sociological Abstracts, Web of Science, SCOPUS and, for grey literature, OpenGrey and ProQuest Dissertations and Theses Global.

A broad search strategy was developed to reflect the exploratory nature of the review (see Online Resource 3 for an example search strategy for Medline, adapted to each database using free text, MeSH and subject headings where possible for maximum sensitivity and specificity).

Five themes emerged from the analysis. The themes relating to each included study are listed in column 10 of Table 1.

The interaction of having cancer and additional chronic illness reportedly produces a complex and increased burden of ill health for many,

‘They're morbidly obese, they have heart disease, diabetes, they all have orthopedic issues... breast cancer's just one thing’. (Nurse navigator, [33])

There is an indication in the literature reviewed that this complexity influences not only quality of life, and recovery (e.g. Corner et al. [37]), but also treatment decisions,

‘I could not have [general anaesthetic] because it affects my heart, you see’. (Patient 23, [56])

‘If you have got umm a person with reduced mental capacity [because of dementia] living on their own then the safety of giving chemotherapy is a risk’. (Oncologist, [38])

Related to interaction and impact of cancer and comorbidity, experiencing additional chronic ill health as well as cancer brought about a complex symptom burden that appeared to be mediated by stage and severity as well as proximity to diagnosis of the cancer and/or comorbidity. Evidence varied to suggest that some patients prioritised one condition over another; whereas, for others, they appeared to be entwined. Participants in some studies described cancer as merely a ‘bump in the road’; whereas, for others, the symptoms and effects were more enduring. For some, complexity of disease led to a blurring of symptoms and an inability to attribute symptomology to a particular condition; a source of fear of the cancer returning,

‘Dr C said that he doesn't really feel that I got too much to worry about, that they got it in time, but then how do they know if they got everything? ...And when my lungs are bad [asthma], it frightens you’. (Judith, [55])

Ability to adjust and cope with a complex burden of ill health was influenced by past experience of illness (including sequencing of conditions, i.e. whether the cancer or the comorbid condition came first) as well as notions of ageing and expectations of ailing health and functional ability. Expecting illness with advancing age helped to ‘lessen the shock’ of cancer diagnosis for some participants in the included studies [45], captured by those participating in Mason et al as ‘old not ill’ [23].

Maintaining a sense of control and one’s existing personal identity appeared to be an important part of illness experience for participants in many included studies,

‘One feels sorry for oneself, in the sense that one loses one's independence and you become dependent on others’. (91 year old patient with back problems, cancer, heart disease and other conditions, [36])

A smaller number of studies referred to managing medications as being a challenge for people living with cancer and other chronic illness at the same time. In addition to issues such as being refused trial participation due to contraindicated medications and the financial cost of medications in relevant health systems, one of the concerns raised was the ability to self-manage the range of medications needed. Patients also had to look out for contraindications as the communication between primary and secondary care or between different specialists was not always optimal, meaning the patient often had to champion their position,

‘The fact that I'm on this pain control regimen, doctors wanted to ignore it, he didn't want to deal with someone on Fentnyl patch and Oxycodone, just didn't want to deal with that. So if you don't advocate for yourself, forget it...sometimes you get tired of fighting for yourself and trying to educate everybody’. (Cancer patient, [58])

In terms of self-management, studies emphasised the need for shared care or supported self-management (including looking after overall health and well-being), and the need for resources to enable this and to take the pressure off primary care in providing follow-up care and support for this patient group.

The evidence suggests that oncologists do not often see the management of comorbid conditions as being part of their role or within their perceived level of competency. GPs were more likely to regard holistic condition management as part of their role and advocated a patient-centred ‘joined up’ approach. For example, a medical oncologist interviewed by Sada et al. said:

‘I encourage patients to continue the management of their [chronic illness] with their PCP...I'm so subspecialised that I don't really feel comfortable managing [it]’. (Medical oncologist 6, [52])

However, primary care practitioners did not always feel comfortable managing advanced cancer symptoms, potentially leading to a fragmented experience of care, as another study suggests:

‘[The FP (family physician) is] still looking after their diabetes…One kind of doctor does this; he does that: [to] each their own. Symptom control is not in their hands…You leave that to the specialists. She’s just a family physician’. (Cancer patient, [49]).

Managing cancer multi-morbidity in primary care carries many challenges:

‘…Actually most of our patients have five or six issues, and so we’re trying to manage their diabetes or hypertension or renal insufficiency and then end up with a breast issue, and it’s impossible…that’s like more than an hour’s worth of time where you have like four patients scheduled in 15-min increments, and it’s overwhelming’. (Primary Care Professional, [44])

This systematic review of the evidence relating to the experience of living with and beyond cancer with comorbid illness identified a small number of heterogeneous papers with a range of aims and perspectives. Qualitative data on this specific topic was difficult to identify as comorbidities were often mentioned in passing or ‘buried’ in articles with a different dominant focus. From the 31 included studies, a number of themes emerged to give a summary of the current evidence and help identify topics for further investigation (see Fig. 2). These issues relate to the burden of symptoms, the combined impact on one’s illness experience and how adjustment was entwined with previous experience of illness, illness expectations and the severity of the illness burden. Dealing with polypharmacy, self-managing and the related challenges and demand for health services, including the relationship between primary and specialist care, were also identified as important concerns. Overall, there is need to grow the evidence base on this topic, in order to address the support needs of the growing number of cancer survivors living with other chronic conditions, their informal carers and health care professionals.

The findings from the review sit within a wider literature examining experiences of cancer survivors and the role for primary and secondary care, as well as literature around multi-morbidity, e.g. [20, 63‐68]. There have been a number of intervention studies to support patients living with and beyond cancer [69, 70], and to consider the views of health care providers [21, 71]. There is also a recognition that guidance is needed for a model of survivorship care that acknowledges the challenges for and complexity of this patient group, including measuring comorbid conditions and managing them in the treatment and survivorship contexts [12, 13, 72].

A number of potential theoretical positions may provide insight to the emergent themes from the synthesis. Indeed, a small number of included studies refer to theory in order to make sense of their findings. For example, issues of symptom burden and people’s illness expectations and identity relate to experience of illness theory around keeping illness at the boundaries of one’s self concept in an attempt to maintain one’s existing personal identity (Charmaz 2000) and can be understood in the context of biographical disruption, flow and continuity [73, 74] and Frank’s illness narratives [75]. Further in-depth research can revisit the potential contribution of these theoretical insights to the experience of cancer and comorbid illness.

The issue of the pressure on primary care to manage cancer survivor follow-up and for patients to self-manage is one that has been problematised in the sociological literature, marking a shift toward ‘living with and beyond cancer’. It is argued that the term ‘survivor’ is heavily loaded with expectations of optimism in ‘fighting’ the cancer battle with an emphasis on individual responsibility and accountability for lifestyle change and secondary prevention [76, 77], with implications for the ‘burden of treatment’ work expected of patients and their families, and with repercussions for health services [78].

This review brings together studies exploring experience of illness. It focuses on qualitative findings to meet the aims of identifying contextual evidence of psychosocial issues and supportive care needs.

The articles included in the review come from differing settings and foci. Due to the broad exploratory nature of the topic, it was difficult to design a search strategy that was sensitive and specific. Given the ‘snippets’ of qualitative data relating to the topic of cancer and comorbid illness, there may be additional articles containing relevant data that were not identified. Additional methods of snowball referencing and related articles searching as well as expert consultation were undertaken to address this potential limitation. Also, despite the heterogeneity of the studies, it was possible to deduce some common themes, suggesting that a diverse sample of papers from a number of different settings can enable a level of conceptual saturation of ideas [79], and remains true to the aim of producing an abstract synthesis that is ‘faithful to the group of studies from which it was extracted’ [80].

While multi-morbidity in cancer survivors is often highlighted as a key issue in literature and policy, qualitative research to date has yet to focus on it as a substantive concern. Reviewing the qualitative evidence on this topic has identified key themes that warrant further exploration and focus. Variations in symptoms burden and the interaction and impact on one’s illness experience have been indicated in the included studies. Further, qualitative work is needed to explore the influence of stage of survivorship, severity of the concomitant illnesses and the meaning attributed to cancer in relation to other chronic conditions. The challenges for health services have been identified in the literature: there is a call for further work to better understand the difficulties facing primary and secondary care in managing survivorship care in the context of multi-morbidity and what patients want from services in this context. Finally, carers’ views have been largely under-represented and it is important to explore the additional strain that caring for someone with cancer and additional chronic conditions imposes. These issues have also emerged from research prioritisation work carried out by the authors in relation to this topic (in draft), as well as the wider context of the recent National Cancer Research Institute Top 10 research priorities for living with and beyond cancer (www.​NCRI.​org.​uk/​lwbc), and have combined to inform the design (including aims, sampling decisions and interview topic guide) of an in-depth, multi-perspective interview study with patients, carers and health care professionals.