Trajectories of health-related quality of life after cancer diagnosis in a cohort of Australian women: a longitudinal study

Background: With increasing cancer survival rates, optimising health-related quality of life (HRQL) has become a major priority. However, longitudinal assessments of HRQL outcomes in people with cancer are limited. This study aimed to examine changes in HRQL outcomes following a cancer diagnosis and to identify the long-term trajectories of HRQL outcomes and associated factors. Methods: This study included 1414 women diagnosed with primary invasive cancer from 1996 to 2019 and 2828 women without cancer from a large cohort (born in 1946-51) of the Australian Longitudinal Study on Women’s Health, linked to the Australian Cancer Database. Generalised linear models were used to estimate changes in HRQL outcomes, adjusting for sociodemographic factors and other health conditions. Group-based multitrajectory modelling was applied to identify HRQL trajectories over time. Results: In the short-term (≤ 3 years), we found a significant decline in the adjusted mean difference (AMD) across all HRQL domains from pre-cancer to post-cancer surveys, with the largest decrease in general health (AMD − 10.3, 95% CI: -11.43, -9.18). The corresponding changes within the same period among women without cancer were not significant at p < 0.05, except for physical functioning. In the long-term (≤ 15 years), four HRQL trajectory groups were identified: very low HRQL trajectory (n = 184, 13%), moderate HRQL trajectory (n = 355, 25%), moderate-high HRQL trajectory (n = 532, 38%), and high HRQL trajectory (n = 343, 24%). In the control sample, a greater proportion of women belonged to the high HRQL trajectory group (29% versus 24%). Cancer survivors in the very low or moderate HRQL trajectory groups had significantly lower HRQL domain scores than the corresponding trajectory groups in the control group (p < 0.05). Compared with the high HRQL trajectory group, the very low HRQL trajectory group experienced greater difficulties in managing their available income (60% versus 22%, p < 0.01) and had ≥ 2 comorbidities (42% versus 9%, p < 0.01). Conclusions: Our findings suggest the importance of measuring HRQL soon after diagnosis as a baseline measure and considering both baseline and ongoing HRQL when guiding supportive care for women cancer survivors. Additionally, targeted initiatives that prevent and manage comorbidities and financial hardship in those with low HRQL at baseline are critical for equitable care.