Factors influencing fatigue in breast cancer patients undergoing breast irradiation.

Abstract

e20690 Background: We are conducting an exploratory, non-randomized, prospective study to investigate factors associated with radiation-induced fatigue in women with early breast cancer undergoing radiation therapy (RT) for breast conservation. Our hypothesis is that the fatigue associated with adjuvant RT is related to tissue damage by apoptosis and inflammation, and partially related to their baseline psychological profiles. This is the first study of which we are aware that attempts to correlate radiation-induced fatigue with inflammatory cytokines, biomarkers of apoptosis and psychological measures in this population. Methods: All subjects are assessed immediately before RT (T1), mid-point of RT (T2), end of RT (T3), 6 months (T4) and 1 year (T5) after completion of RT. Clinical evaluation of cosmesis, skin toxicity and laboratory parameters are performed. Fatigue, distress, depression, anxiety, sleep, energy level and pain are assessed at each time point using validated measures. Results: Twenty-four subjects (target 50) have been enrolled to date; 17 have completed T1-T3 and 11 have completed T1-T4. Our current population is predominantly white, not currently smoking, middle to upper-middle class, with a mean age of 60.5 (range 43-82). Four received prior chemotherapy: 2 adjuvant and 2 neoadjuvant. All received whole breast radiation; 82% had invasive disease. 53% of patients had past or current mental health issues: depression (41%) or anxiety (29%). Clinical scales for radiation toxicity showed expected changes at the end of treatment with 41% of patients having RTOG Acute Skin Toxicity 2 or 3. There appeared to be no change in cosmesis scores beyond that noted after surgery. 24% fell from ECOG 0 to 1 during RT. Sleep was more interrupted. More detailed measures revealed increases in breast pain and fatigue scores in 5 subjects, 3 of whom had increases in acute skin toxicity scores and a history of mental illness and 2 of whom had increases in caspase-1 p17 and hs-CRP. Most IL-1β, IL-4, IL-6 and IL-10 levels were undetectable. Conclusions: Radiation-associated fatigue was associated with a history of mental illness, acute skin toxicity, breast pain, and increases in some but not all biomarkers of inflammation and apoptosis.