Understanding the Effects of Cancer-Related Factors on the Association Between Physical Activity and Quality of Life in Breast Cancer Survivors.

BACKGROUND

Breast cancer survivors often experience physical and mental side effects posttreatment, compromising their quality of life (QoL). The increasing number of survivors coping with long-term side effects creates public health concerns, emphasizing the need for supportive interventions. Although physical activity (PA) benefits cancer survivors, few studies examine the effect that cancer-related factors have on the relationship between PA levels and QoL among breast cancer survivors. Understanding the associations that cancer-related factors may have on the QoL response to PA is crucial for developing effective interventions.

METHODS

Baseline data from 341 postprimary treatment breast cancer survivors enrolled in a web-based diet and/or exercise intervention randomized controlled trial were analyzed. PA measures included accelerometry and self-reported moderate to vigorous PA (MVPA). QoL was assessed using Patient-Reported Outcomes Measurement Information System (PROMIS) global QoL and EuroQOL-5D-5L questionnaires. Pearson correlation coefficient tests and multiple linear regression assessed associations between MVPA and QoL and whether cancer-related factors moderated these associations.

RESULTS

The EuroQOL-5D-5L QoL index (and 4 out of 5 domains) showed statistically significant associations with self-reported MVPA. PROMIS physical health was correlated with both MVPA measures. Survivors > 24 months postdiagnosis had stronger associations between accelerometry-measured MVPA levels and EuroQOL-5D-5 L QoL index (β = 0.0004, P = .003). Survivors receiving hormone therapy exhibited stronger associations between self-reported MVPA levels and PROMIS-physical health QoL domain compared with those not (β = 0.0121, P = .028).

CONCLUSION

Greater MVPA was modestly associated with better QoL, with stronger associations observed in survivors receiving hormone therapy or >24 months postdiagnosis. There are potential QoL benefits in implementing interventions immediately postdiagnosis and tailoring to treatment histories.