MONDAY, Oct. 6, 2025 (HealthDay News) -- For women with early-stage breast cancer, higher levels of protein markers of inflammation are associated with distinct dimensions of fatigue, according to a study published online Oct. 6 in Cancer.Julienne E. Bower, Ph.D., from the University of California-Los Angeles, and colleagues examined biologic mechanisms of fatigue in 192 women recently diagnosed with early-stage breast cancer. Participants completed assessments before and after adjuvant therapy and at six-, 12-, and 18-month posttreatment follow-up. Women completed the Multidimensional Fatigue Symptom Inventory at each assessment and provided blood for evaluating protein markers of inflammation (tumor necrosis factor [TNF] alpha [TNF‐α], soluble tumor necrosis factor receptor type II [sTNF‐RII], interleukin 6 [IL‐6], and C‐reactive protein [CRP]).The researchers found that when controlling for age, race, education, body mass index, and cancer stage, there was a positive within-person association between general fatigue and TNF-α, sTNF-RII, and IL-6 (b = 1.67, 2.77, and 0.86, respectively). In addition, there was a positive within-person association between physical fatigue and TNF-α, sTNF-RII, and CRP (b = 1.58, 2.38, and 0.43, respectively). Negative within-person associations were seen between emotional fatigue and TNF-α and sTNF-RII (b = −1.92 and −2.10, respectively). At the between-person level, general and physical fatigue were positively associated with CRP (b = 0.82 and 0.71 for general and physical fatigue, respectively). There were no significant associations noted between mental fatigue and inflammatory markers."Our findings indicate that inflammation plays a role in some aspects of cancer-related fatigue, but not others, and that these effects persist well after treatment," Bower said in a statement.Several authors disclosed ties to the pharmaceutical and biotechnology industries.Abstract/Full Text.Sign up for our weekly HealthDay newsletter