Abstract:
Objectives. To investigate the density, spatial distribution (intra- vs. peritumoral), and prognostic significance of tumor-infiltrating CD45RO⁺ memory T lymphocytes (TILs) in invasive ductal breast carcinoma. A primary aim was to elucidate the modulatory impact of concomitant type 2 diabetes mellitus (T2DM) on this immune infiltrate and its correlation with established clinico-pathological indicators of tumor aggressiveness.Methods. We conducted a retrospective study on archived tissue from 60 cases of invasive ductal breast carcinoma, stratified into two groups: patients with T2DM (n = 30) and a non-diabetic control group (n = 30). CD45RO expression was evaluated by immunohistochemistry. Positive-cell density was assessed separately in intra- and peritumoral stromal compartments. Correlations between CD45RO⁺ cells density and histologic grade, molecular subtype, Ki-67 proliferation index, and lymph node status were analyzed using Spearman’s rank correlation coefficient. Statistical significance was set up at p < 0.05.Results. Analysis revealed a statistically significant difference in intratumoral CD45RO⁺ lymphocyte density (CD45RO-IT) between the two cohorts. The T2DM group showed a significantly lower CD45RO-IT density. In the non-diabetic cohort, higher CD45RO-IT density correlated negatively with histologic grade and Ki-67, indicating a protective association. These correlations were attenuated or absent in the T2DM cohort. Moreover, within the T2DM group, a negative correlation emerged between CD45RO-IT density and lymph-node metastasis, suggesting an alteration in immune function.Conclusions. Infiltration by CD45RO⁺ memory T cells is an important prognostic indicator in invasive ductal breast carcinoma. The presence of T2DM is associated with quantitative—and potentially functional—impairment of the antitumor memory immune response, characterized by diminished CD45RO⁺ infiltrates that align with a more aggressive tumor phenotype. Routine evaluation of CD45RO⁺ TILs—particularly in patients with metabolic comorbidities—is warranted to refine prognostic assessment.
