Molecular mechanisms and clinical value of the correlation between depression and cancer.

According to the World Health Organization, cancer remains the primary cause of death of millions of individuals annually and the foremost cause of mortality worldwide. Cancer imposes substantial economic and mental challenges on patients and their families and strains healthcare systems. Depression, one of the most prevalent mental health conditions, affects approximately 3.8% of the global population and is a significant global health challenge. Research indicates increasing incidence rates of depression among patients with cancer. Depression also appears to influence cancer development and progression, worsening patient prognosis and quality of life, thereby creating additional challenges for clinical treatment. Correlation of depression and cancer is a complicated yet promising field with fast-paced progression and vital clinical values. Therefore, we discussed in this review the associations between depression and cancer and their potential mechanisms by analyzing the specific role of depression in the development and progression of tumors from the perspective of suppressing tumor immunity, inhibiting tumor cell apoptosis, inducing DNA damage, promoting tumor cell mesenchymal transition, enhancing tumor cell stemness, and promoting tumor angiogenesis. This review also discusses how tumors influence the development of depression via inflammatory factors and the significance of identifying and treating depression to enhance the quality of life and prognosis of patients with cancer. Promising biomarkers and effective treatments are also highlighted. Despite available data, limited research exists on how treating depression affects cancer prognosis, and whether timely treatment can reduce cancer risk remains unclear, which necessitates further investigation. This review summarizes the molecular mechanisms involved in the relationship between cancer and depression to help identify new biomarkers and provide precise medical care for patients with depression. We hope this review will lay the foundation for future research, advancing new biomarkers and therapies for early diagnosis of cancer and depression comorbidity.