Abstract B22: Fatigue among long-term survivors of breast cancer: A prospective cohort study with longitudinal follow-up

Abstract

Abstract Background: Fatigue is a common side effect of cancer treatment, but the longer terms effects of cancer diagnosis and treatment on fatigue are not well quantified. Study population: Participants from the prospective Nurses' Health Study who completed the Medical Outcomes Short-Form-36 (SF36) in 1992, 1996, and 2000. Outcomes: The 5-item Fatigue subscale from the SF36. A score of ≤ 50 is considered to represent fatigue: Results: 46,851 women without a history of cancer, 1015 women diagnosed with invasive breast cancer between 1984 and 1991, and 187 women diagnosed with in situ breast cancer between 1984 and 1991 were included in this analysis. All fatigue assessments were performed at least one year after diagnosis. Using the three time points, several fatigue trajectories were investigated including: persistently fatigued at all three time points, persistently non-fatigued at all time points, and developing fatigue over time. In age-adjusted analyses, the frequencies of the different fatigue trajectories were similar across the three groups: cancer free women, breast cancer survivors with invasive breast cancer, and survivors with in situ disease. That is, the chances of being persistently fatigued, persistently non-fatigued, or developing fatigue was similar across all three groups (p>0.09). Instead, the strongest predictor of fatigue trajectories was age. The prevalence of persistent fatigue and persistent non-fatigue varied strongly with age with a U-shaped curve (p<0.01). Specifically, the women aged 55–59.9 and 60–64.9 (when categorizing participants by 5 year age groups) had the lowest incidence of persistent fatigue and highest incidence of non-fatigue compared to older (65+) or younger women (<55). Conclusions: After a cancer diagnosis, the prevalence of persistent fatigue or developing fatigue is similar comparing cancer-free women compared to breast cancer survivors. Self-assessments of fatigue appear to be more strongly related to age. Age needs to be carefully considered in all fatigue analyses and would provide a useful way to target interventions to improve fatigue. Citation Information: Cancer Prev Res 2011;4(10 Suppl):B22.