Thyroid Peroxidase Antibody Cost-Effective Biomarker for predicting metastasis in breast cancer: Study

While breast carcinoma remains the leading global malignancy among women, the relationship between elevated thyroid peroxidase antibody levels and clinical outcomes has been marked by controversy and remains underexplored, particularly regarding its role in tumorigenesis and its prognostic value in predicting axillary spread. To address this clinical gap and build upon previous research suggesting these antibodies might predict lower metastatic prevalence in specific subtypes, Nitesh Kumar and colleagues from a tertiary care center conducted the investigation to clarify the predictive impact of thyroid peroxidase antibody status across various molecular subtypes.

Therefore, the prospective observational investigation, conducted at a tertiary care center from 2024 to 2025, analyzed 92 newly diagnosed patients using multivariate logistic regression to evaluate the primary endpoint of axillary involvement while excluding stage IV cases to focus on a final cohort of 81 individuals with stage I through III disease. By assessing thyroid peroxidase antibody levels alongside receptor status and molecular subtyping, the study provides a concise and clear look at how these biological markers correlate with disease staging and nodal involvement.

Key Clinical Findings of the Study Include:

• Reduced Metastatic Frequency: The investigation revealed that axillary lymph node metastasis was significantly less frequent in patients positive for the thyroid peroxidase antibody at a rate of 23.1%, compared to 49.1% in antibody-negative individuals (p=0.018; OR=0.45; 95% confidence interval [CI]: 0.16–0.98).

• Enhanced Receptor Expression: Data from the study indicated that antibody positivity correlated with significantly higher expression of estrogen receptor (ER) (OR=3.98, 95% CI: 1.05–15.1, p=0.036) and progesterone receptor (PR) (OR=3.78, 95% CI: 1.14–12.5, p=0.031).

• Subtype Specificity: The research identified a strong association between the presence of these antibodies and luminal A or B molecular subtypes, yielding a substantial odds ratio of 10.6 (95% CI: 2.3–48.7, p=0.001).

• Independent Prediction: Multivariate analysis within the study confirmed that thyroid peroxidase antibody positivity independently predicts reduced odds of axillary lymph node metastasis, with an adjusted odds ratio of 0.44 (95% CI: 0.19–0.96, p=0.021).

• Cohort Positivity Rates: Among the non-metastatic patients evaluated in the study, 32.1% were found to be antibody-positive, while the disease distribution included 34.6% in stage I, 38.3% in stage II, and 27.1% in stage III.

The results suggest that thyroid peroxidase antibody positivity correlates with a reduced occurrence of axillary lymph node metastasis and is closely linked to hormone receptor positivity and luminal molecular subtypes. These findings indicate that the presence of these antibodies may define a specific biological profile associated with more favourable prognostic indicators in breast cancer patients

Thus, the study concludes that clinicians might consider utilizing thyroid peroxidase antibody levels as a cost-effective adjunct biomarker for enhancing prognostic assessments, particularly in cases of luminal cancers, which are common in the Indian population

While these results are promising, the study's single-center scope is a limitation, highlighting a need for larger multicenter trials involving long-term survival analysis to further validate these predictive relationships in a broader clinical context.

Reference

Kumar N, Pankaj D, Vishwendu V, Bhushan V, Kumari S, Madhawi R, Pawar S. Role of Thyroid PEroxidase (TPO) Antibody Levels in Predicting Axillary Lymph Node Metastasis (ALMN) in Different Molecular Subtypes of Breast Cancer. Indian Journal of Surgery. Published April 11, 2026.