Background There is an increased focus on multimorbidity among cancer survivors. We aimed to determine whether women experience greater risk of multimorbidity before, during, and after cancer diagnosis compared to women without cancer.
Methods We conducted a prospective 5 to 1 matched cohort analysis of 7499 women from the Australian Longitudinal Study on Women’s Health. Women were followed from 1996 (aged 45-50 years) through 2016. Prevalence and incidence of multimorbidity (developing two or more chronic conditions except cancer) in both cohorts were assessed up to 18 years before and after cancer diagnosis. We estimated the time-varying odds ratios (OR) and 95% confidence interval (CI) for incidence of multimorbidity, adjusted for related predictors (sociodemographic factors, behaviors, and menopause status).
Results Half of women had multimorbidity at the time of cancer diagnosis. The ORs for developing multimorbidity were 1.18 (95% CI, 1.08-1.30), 1.42 (95% CI, 1.22-1.65), and 1.13 (95% CI, 1.02-1.25) for the cancer cohort before, during and after cancer diagnosis, respectively. Similar trends were found among individual cancers, with the highest increased risk noted for women with cervical cancer around diagnosis (OR, 4.8; 95% CI, 3.0-7.5). The associations of incidence of multimorbidity with predictors were similar for cancer and comparison cohorts.
Conclusion Women with cancer experience a higher risk of multimorbidity before, during, and after cancer diagnosis with the difference highest at the time of diagnosis. These findings should be considered when developing strategies and measures for prevention, treatment, and intervention of both cancer and other chronic conditions among cancer survivors.