Relationship Among Body Mass Index, Survival, Cancer Treatment and Health-Related Quality of Life Among Older Patients with Bladder Cancer.

BACKGROUND

The relationship between body composition and bladder cancer outcomes is complex. While a higher body mass index (BMI) has been associated with an increased risk of bladder cancer development, its impact on survival outcomes is less clear. This study aimed to explore the association between BMI, survival, health-related quality of life, and the performance of ADLs in a cohort of older patients with bladder cancer.

METHODS

Data were obtained from the Surveillance, Epidemiology, and End Results-Medicare Health Outcomes Survey, including patients diagnosed with bladder cancer who had recorded BMI values. Analysis of variance was used to assess the association between BMI categories and patient demographics as well as cancer/treatment characteristics. Generalized linear models examined the impact of BMI on health-related quality of life, as measured by the physical and mental component summary scores when controlling for confounding variables. Kaplan-Meier survival curves across BMI categories were compared using log-rank tests.

RESULTS

The final cohort consisted of 8013 patients (age ≥ 65) with a mean age of 77.7 ± 7.1 years, the majority of whom were White (85.6%) and male (74.8%). We observed no significant association between BMI and cancer/treatment characteristics. The severely obese subgroup had the highest rate of disability in performing ADLs (18.3%) followed by the underweight subgroup (10.3%). Overweight patients exhibited the highest physical and mental component summary scores, indicating better health-related quality of life. BMI was a significant predictor of overall survival, with overweight, obese, and severely obese patients demonstrating improved survival compared to those with healthy or underweight BMI. These findings remained statistically significant in multivariable analysis.

CONCLUSIONS

Our findings suggest a dual role of BMI in older patients with bladder cancer: higher BMI provides a survival advantage and, to an extent, a QoL advantage. At the same time, severe obesity did lead to the lowest QoL despite improved survival outcomes. These results underscore the complex interplay between BMI, survival, and QoL in this bladder cancer population.