Psychiatric disorders, including recurrent unipolar depression and bipolar disorder, are associated with increased cancer risk and premature mortality. Alcohol use disorder (AUD) and immune dysregulation may underlie these associations.

This exploratory study investigated whether inflammatory and neuroplasticity-related biomarkers differ according to cancer history and alcohol abstinence in patients with AUD and depressive disorders.

We conducted a retrospective analysis of 172 patients from a French clinical cohort, including 53 participants with longitudinal inflammatory and neuroplasticity biomarkers assessed over six months.

Among the study sample (mean age: 45.7 years; 134 men/38 women), 12.8% had cancer history, predominantly ear, nose and throat (27.3%) and breast cancers (22.7%), with psychiatric diagnoses preceding cancer onset by approximately 15 years. IL-8 (Interleukin-8) levels were significantly higher in participants with cancer history and depressive disorders, independently of alcohol abstinence, suggesting a stable cancer-associated inflammatory signature. In contrast, TNF-α (Tumor Necrosis Factor-alpha) levels varied according to alcohol abstinence status over time, distinguishing abstinent from non-abstinent individuals independently of cancer history. BDNF (Brain-Derived Neurotrophic Factor) levels did not differ according to cancer history or abstinence.

These findings suggest that distinct inflammatory pathways may characterize cancer history and alcohol abstinence in patients with AUD and depressive disorders. IL-8 and TNF-α may represent candidate biomarkers associated with cancer-associated inflammation and alcohol abstinence status, respectively. Given the small cancer subgroup, these results should be interpreted as exploratory and hypothesis-generating. Future studies integrating genetic, epigenetic, and molecular markers are needed to refine these associations and support personalized approaches.