Abstract
Elevations in cancer treatment-induced circulating inflammatory cytokines may be partially responsible for the development of significant symptom burden (e.g., pain, fatigue, distress, disturbed sleep) during concurrent chemoradiation therapy (CXRT). Sixty-two patients undergoing CXRT for locally advanced non-small cell lung cancer (NSCLC) reported symptoms weekly for 15 weeks via the M. D. Anderson Symptom Inventory (MDASI). Serum inflammatory cytokines were assessed weekly during therapy via enzyme-linked immunosorbent assay. Dynamic changes in cytokines and associated symptom profiles were estimated using mixed-effect models. MDASI symptom severity increased gradually as CXRT dose accumulated and peaked at week 8. Serum concentrations of interleukin (IL)-6, IL-10, and serum soluble receptor 1 for tumor necrosis factor (sTNF-R1) increased significantly by week 8 (all p<.05). During CXRT, controlled for age, sex, race, body mass index, cancer recurrence, previous treatment status, total radiotherapy dose, and CXRT delivery technique, an increase in sTNF-R1 was significantly related to an increase in the mean score for all 15 MDASI symptoms (estimate, 1.74; SE, 0.69; p<.05) and to a larger radiation dose to normal lung volume (estimate, 1.77; SE, 0.71; p<.01); an increase in serum IL-6 was significantly related to increased mean severity for the five most severe symptoms (pain, fatigue, disturbed sleep, lack of appetite, sore throat) (estimate, 0.32; SE, 0.16; p<.05). These results suggest a role for over-expressed pro-inflammatory cytokines in significant worsening of symptoms in NSCLC patients undergoing CXRT, and warrant further study to identify biological targets for ameliorating treatment-related symptom burden.