Residual thymic activity in adults with lung cancer

Background: The role of the thymus in adulthood remains unclear. Recent studies suggest that thymus might still hold a role in the health of the immune system in adulthood but its significance is not yet confirmed. This study aims to investigate the prevalence and potential clinical significance of residual thymic tissue in adults with lung cancer. Methods: A prospective observational study was conducted on patients aged over 40 who underwent thoracic surgery for either lung cancer or benign thoracic conditions at San Luigi Hospital between November 2023 and May 2024. Thymic tissue samples were collected during surgery and analyzed histologically. Preoperative CT scans were assessed for signs of thymic tissue and correlated with histological findings. Additionally, lymphocyte counts and Neutrophil to Lymphocyte Ratio (NLR) were evaluated preoperatively to explore potential systemic immune correlations. Results: Histological analysis identified thymic tissue residues in 61% of lung cancer patients and 33% of patients with benign thoracic conditions. The average age of the lung cancer group was significantly higher than the control group. The majority of patients with thymic residues were male. Among lung cancer patients, those with more advanced stages (IB or greater) had a higher prevalence of thymic residues compared to those with earlier stages. Radiological findings were inconclusive for detecting thymic tissue. The presence of thymic tissue was associated with higher lymphocyte counts and lower NLR, although these differences were not statistically significant. Conclusions: This study demonstrates a notable presence of residual thymic tissue in adults over 40, particularly among lung cancer patients. The higher incidence of thymic remnants in older adults with lung cancer and those with advanced disease stages suggests a possible interplay between lung cancer and thymic activity, indicating a possible "reactivation" of the thymus in response to oncological disease. These findings suggest potential avenues for further research into the role of thymic activity in oncology and immunotherapy. Future studies should aim to elucidate the relationship between thymic activity, cancer progression, and therapeutic interventions.