Non-cancer multimorbidity in people diagnosed and living with and beyond cancer: a retrospective cohort study

Abstract Background Multimorbidity is common at cancer diagnosis, and both cancer and its treatment can lead to new long-term conditions. However, evidence on the prevalence of multimorbidity, particularly mental-physical multimorbidity, at both diagnosis and five years after cancer diagnosis remains limited. This study describes the prevalence of, and factors associated with, non-cancer multimorbidity in people newly diagnosed with cancer and those living with and beyond cancer. Methods Retrospective cohort study of people aged 18 years and older diagnosed with, or surviving five years with one of breast, prostate, colorectal or lung cancer in 2018. For 46 long-term conditions, multimorbidity (≥ 2 non-cancer conditions), mental-physical multimorbidity (≥ 1 non-cancer physical and ≥ 1 mental health condition) and condition count (0 - ≥6 non-cancer conditions) were measured in incident and survivor cohorts, and examined by age, sex, deprivation and ethnicity. Odds of multimorbidity by cancer type was calculated using logistic regression, stratified by sex and adjusted for age, deprivation and ethnicity. Results Analysis included 33,258 people with incident cancer and 16,807 people living with and beyond cancer (PLWBC). Multimorbidity ranged from 60 to 86% at cancer diagnosis to 70–90% in PLWBC, dependent on cancer type. Less than 20% had no additional long-term conditions at diagnosis (< 5.3% in lung cancer specifically) and less than 15% in PLWBC (< 2.3% in lung cancer). Mental-physical multimorbidity affected 24–39% at diagnosis and 27–44% in PLWBC. Both types of multimorbidity were higher in those living in the most deprived areas across all age groups. Compared with colorectal cancer, people with lung cancer had higher odds of multimorbidity at both diagnosis (in women adjusted OR 2.15 95%CI 1.86–2.49; in men aOR 1.71 95%CI 1.50–1.94) and in PLWBC (in women aOR 2.11 95%CI 1.45–3.12; in men, aOR 2.20 95%CI 1.51–3.30), whereas women with breast cancer and men with prostate cancer had lower odds. Conclusions Most people with cancer have additional long-term conditions, with the highest prevalence in lung cancer. Clear socioeconomic inequalities in multimorbidity persist into survivorship. Cancer pathways need to ensure coordinated management of non-cancer long-term conditions between primary and secondary care across the whole cancer journey, from diagnosis through treatment and into survivorship.