Association of social isolation and loneliness with cancer prognosis: an analysis of the UK Biobank.

BACKGROUND

Evidence is scarce for the association between social isolation and loneliness and prognosis of any cancer or other common cancer types.

METHODS

To address this gap, we performed a cohort study from 2006 to 2022 using data from the UK Biobank (UKB). Social isolation and loneliness were identified based on the questionnaire of the UKB. Cases of death were obtained from the death registry, where both primary and contributory causes were recorded using ICD-10 codes. The Cox proportional hazard models were used to estimate hazard ratios (HRs) and associated 95% confidence intervals (CIs) of death in relation to social isolation and loneliness among patients with cancer.

RESULTS

Among cancer patients studied, 6206 (9.6%) were socially isolated and 3130 (4.8%) reported loneliness. Over a median follow-up of 6.7 years, there were 2378 deaths (38.3%) among exposed patients and 16,566 deaths (29.1%) among unexposed patients. Social isolation was associated with poorer cancer prognosis overall (HR 1.21, 95% CI 1.16-1.26, P < 0.001), while loneliness correlated with a similar risk (HR 1.18, 95% CI 1.11-1.25, P < 0.001). Social isolation specifically impacted survival in colon, melanoma, breast, prostate, kidney, and bladder cancers, as well as myeloproliferative neoplasms. Loneliness was linked to poorer outcomes in breast, prostate, and bladder cancers.

CONCLUSIONS

Our findings suggested that social support for these vulnerable patients might have the potential to improve prognosis.