Loneliness and social isolation linked to heightened risk of death in those with cancer

Loneliness and social isolation are linked to a heightened risk of death from cancer as well as from all causes among those with the disease, finds a pooled data analysis of the available research published online in the open access journal BMJ Oncology.

Globally, new cases of cancer are projected to rise to 35 million, and associated deaths to 18.5 million by 2050, note the researchers. 

Loneliness is relatively common among people with cancer, and while loneliness is associated with various health issues, including cognitive problems, sleep disorders, immune system dysfunction, and pain, it’s not clear if it might also be linked to a heightened risk of death from cancer, they add.

To explore this further, the researchers scoured research databases for relevant studies published up to September 2024. Out of an initial haul of 148, 16 involving 1,635,051 patients (average age 63) were reviewed, 13 of which were included in a pooled data analysis.

The studies were carried out in Canada, England, Finland, France, Ireland, Japan and the USA and included many different types of cancer.

The potential impact of loneliness (as measured most often by the Social Network Index and UCLA Loneliness Scale) on death from any cause was reported for 1,570,918 patients in 12 studies, and pooled data analysis showed that it was associated with a 34% heightened risk, after adjusting for small study sizes. 

The potential impact of loneliness on death from cancer was reported for 2,142,338 patients in nine studies, and pooled data analysis showed that it was associated with an 11% heightened risk of death from the disease, after adjusting for small study sizes.

The three studies excluded from pooled data analysis due to differing outcome measures also consistently reported strong associations between social isolation and a heightened risk of death.

“These findings collectively suggest that loneliness and social isolation may influence cancer outcomes beyond traditional biological and treatment-related factors,” suggest the researchers.

But the variations in study design, methodology, and outcome measures; the limited allowance made for potentially influential factors; and the fact that the included studies were all observational in nature, warrant cautious interpretation of the findings, they highlight.

Nevertheless, they go on to say: “Despite these limitations, our findings are consistent with prior research linking psychosocial stressors to adverse health outcomes. Social isolation and loneliness are thought to increase mortality risk in patients with cancer through interconnected biological, psychological, and behavioural mechanisms.” 

They add: “Biologically, the stress response triggered by loneliness may lead to immune dysregulation and heightened inflammatory activity, ultimately contributing to disease progression.”

And they explain: “Psychosocially, the unique burden of cancer survivorship often includes forms of isolation stemming directly from disease and treatment experiences, including the inability of loved ones to fully understand cancer-associated fears, stigma around visible treatment effects, and survivorship-related anxieties. 

“Treatment-induced physical changes (fatigue, cognitive impairments) may further limit social participation, while prolonged medicalisation of life can erode pre-illness identity and community connections.”

And they conclude that if the findings are confirmed in further methodologically sound studies, they would indicate the need to routinely incorporate psychosocial assessments and targeted interventions into cancer care to improve outcomes.