Prevalence, severity, and predictors of insomnia in advanced colorectal cancer

An article written by Dr Aaron K Wong, Peter MacCallum Cancer Centre and The Royal Melbourne Hospital

Colorectal cancer is the third commonest cancer, and its incidence is increasing worldwide, particularly for those aged under 50 years. Advanced colorectal cancer is associated with a high symptom burden and constitutes a large portion of patients within palliative care cohorts. Insomnia, defined as distressing difficulty initiating or maintaining sleep, is commonly reported by people with cancer (53%), and this prevalence increases as cancer advances. Insomnia is an under-recognised and undertreated symptom in palliative care and advanced cancer cohorts.

We report on a study based on a large national consecutive cohort study of 18,302 patients with advanced colorectal cancer seen by palliative care services from the Palliative Care Outcomes Collaborative (PCOC) database (2013-2019). [1] Insomnia was prevalent in just over half of patients (50.5%). We then defined clinically significant insomnia as a score ≥3/10 on the Symptom Assessment Score, evidence [2] indicating that the patient specific goal for sufficiently controlled insomnia is rated at 2/10. Clinically significant insomnia was seen in over a third of the cohort (35.6%).

Younger patients were proportionally more likely to report any insomnia, and clinically significant insomnia (both p <.01). Clinically significant insomnia was reported by almost half (48.6%) of those aged <45 years compared to 28.5% in those aged ≥85 years. Insomnia severity was also greater in those in the younger age group (mean score 4.97 (SD 1.90) vs 4.54 (SD 1.66)). Based on the Problem Severity Score (PSS), those with moderate-severe psychological symptoms reported the greatest prevalence of clinically significant insomnia (32.2%). Younger patients with advanced cancer experience greater anxiety, loneliness, and a loss of self, contributing to insomnia. Cancer progression may force a degree of unwanted dependence, with younger adults challenged to grapple with the foreign concept of dependence at a young age. Grief over loss of current and future career productivity, difficulty managing young children, and new relationships are all common to those in younger age groups, where insomnia is linked with subjective anxiety surrounding unfinished business and care of family in younger patients. 

Insomnia was also more prevalent in those who were more mobile (AKPS score ≥70) or physically capable (RUG-ADL score ≤5) (both p <.01). This likely captures patients earlier in the disease trajectory where the adjustment to a new terminal cancer diagnosis is greatest. Patients with higher functional and physical capabilities are also more likely to notice the daytime consequences of insomnia including social and vocational disturbance, reduced motivation and mood disturbance. In contrast, those with poorer functional capability may be more fatigued and somnolent at baseline, with insomnia less of a reported problem towards the more advanced stages of debility. Alternatively, the experience of insomnia may simply take a lower priority in this setting.

More recently, the concept of ‘total or integral insomnia’ has been introduced, meaning that insomnia should be considered within a biopsychosocial-spiritual model of care. This is similar to the more familiar concept of ‘total pain’, where successful pain management often requires the clinician to address those similar facets of the person’s life. Guideline recommendations support evidence-based non-pharmacological approaches (mindfulness, exercise, and cognitive behaviour therapy) and pharmacological interventions (melatonin, benzodiazepines, non-benzodiazepine receptor modulators, and orexin receptor antagonists) which each work towards mitigating this symptom by addressing the multidimensionality of insomnia.

Our findings of several groups at greater risk of suffering from insomnia (younger, greater physical capacity, living at home, and those with greater psychological distress) may guide earlier recognition and management of insomnia to allow clinicians time to recognise, diagnose, and treat insomnia to improve the overall quality of life for this population of patients.

Authors:

Dr Aaron K Wong, MBBS, BMedSci, FRACP, FAChPM, GCertClinTeach

References

1. Wong AK, Wang D, Marco D, Le B, Philip J. Prevalence, severity, and predictors of insomnia in advanced colorectal cancer. J Pain Symptom Manage. 2023 Sep;66(3):e335-e342.
    
2. Hui D, Shamieh O, Paiva CE, Perez-Cruz PE, Kwon JH, Muckaden MA, et al. Minimal clinically important differences in the Edmonton Symptom Assessment Scale in cancer patients: A prospective, multicenter study. Cancer. 2015;121(17):3027-35.