RESUMO
Purpose: Chlamydia trachomatis (C. trachomatis) is associated with several gynecological tumors; yet its prognostic role in breast cancer remains unclear. Thus, we investigated the prognostic role of anti-C. trachomatis immunoglobulin G (IgG) in breast cancer patients and the modification effects of pro-inflammatory cytokines. Methods: The serum levels of C. trachomatis IgG and four pro-inflammatory cytokines were measured. Cox regression was used to calculate hazard ratios (HRs) and 95% confidence intervals (CIs), including product terms to assess the modification effects of pro-inflammatory cytokines on the association between C. trachomatis IgG and breast cancer prognosis. Results: From 2008 to 2018, 1121 breast cancer patients were recruited and followed up until December 31, 2021, with a median follow-up time of 63.91 months (interquartile range: 39.16-90.08 months). Patients positive for C. trachomatis IgG showed HRs of 1.09 (95% CI, 0.67-1.78) for overall survival (OS) and 1.24 (0.87-1.78) for progression-free survival (PFS), compared to those who were negative. These associations became statistically significant in women aged 50 years or younger (HR=1.43, 95% CI=0.79-2.58 for OS; HR=1.79, 95% CI=1.16-2.77 for PFS). Positive C. trachomatis IgG serology was associated with adverse prognostic effects among patients with higher levels of pro-inflammatory cytokines (IL-6, TNF-α, IL-8, and IL-1ß), but with favorable prognostic effects for those with low levels. These interactions were particularly significant in those aged 50 years or younger. Conclusion: In breast cancer patients younger than 50 years of age or with higher levels of pro-inflammatory cytokines, C. trachomatis infection appeared to have a negative prognostic impact. These findings highlight the significance of C. trachomatis in predicting prognosis and personalized therapy for breast cancer patients.
RESUMO
Background: Animal experiments have shown the anticancer activity of Toxoplasma gondii (T. gondii), but its effect on the prognosis of cancer patients is unclear. Thus, the present study aimed to investigate the prognostic role of anti-T. gondii IgG in breast cancer patients and the modification effect of cytokines. Methods: A total of 1121 breast cancer patients were recruited between 2008 and 2018 and followed up until December 31, 2021. Anti-T. gondii IgG and cytokines were measured using an enzyme-linked immunosorbent assay (ELISA) kit and a multiplex assay platform. Endpoints were overall survival (OS) and progression-free survival (PFS). Survival and multiplicative interaction analyses were performed using multivariate Cox regression models. Results: According to the cutoff value of optical density (OD=0.111), 900 (80.29%) and 221 (19.71%) patients were divided into two groups: low or high anti-T. gondii IgG. Compared to patients with a low anti-T. gondii IgG level, the adjusted hazard ratios (HRs) of OS and PFS for patients with high anti-T. gondii IgG levels were 0.60 (95% confidence interval (CI): 0.37-0.99) and 0.67 (0.46-0.98), respectively. These associations were profound among patients with a high cytokine score (HR=0.29, 95% CI: 0.10-0.82 for OS; HR=0.30, 95% CI: 0.13-0.69 for PFS), accompanied by a significant interaction between the level of anti-T. gondii IgG and the cytokine score (P interaction=0.019 for PFS); interleukin-17 (IL-17) and interleukin-9 (IL-9) were the main contributors to the interaction. Conclusion: Anti-T. gondii IgG was found to be beneficial to breast cancer survival, especially in women with systematic inflammation and high IL-17 or IL-9 levels, suggesting the potential of T. gondii as a prognostic marker and a novel immunotherapy approach for cancer patients.