p16, COX-2, and Ki67 Protein Expression in DCIS and Risk of Ipsilateral Invasive Breast Cancer

Area of Science:

• Oncology
• Biomarkers
• Breast Cancer Research

Background:

• Limited prior research exists on the association between p16, COX-2, and Ki67 immunopositivity in ductal carcinoma in situ (DCIS) tissue and the risk of subsequent ipsilateral invasive breast cancer (IBC).
• Understanding these associations is crucial for improving risk stratification and treatment strategies for DCIS patients.

Purpose of the Study:

• To investigate the association between p16, COX-2, and Ki67 immunopositivity in DCIS tissue and the risk of developing subsequent ipsilateral IBC.
• To determine if these biomarkers, individually or in combination, can predict the risk of invasive breast cancer recurrence in the ipsilateral breast.

Main Methods:

• A nested case-control study was conducted using a cohort of women diagnosed with DCIS.
• Immunostaining for p16, COX-2, and Ki67 was performed on DCIS tissue from cases (n=146) who developed ipsilateral IBC and matched controls (n=273) who did not.
• Conditional logistic regression was used to estimate odds ratios (ORs) and 95% confidence intervals (CIs) for the associations.

Main Results:

• No significant association was found between p16, COX-2, or Ki67 immunopositivity, whether assessed individually or collectively, and the risk of ipsilateral IBC.
• The multivariable OR for women who were triple positive for all three markers was 1.16 (95% CI: 0.38-3.54), indicating no increased risk.

Conclusions:

• p16, COX-2, and Ki67 immunopositivity are not associated with an altered risk of ipsilateral IBC in women diagnosed with DCIS.
• These markers may not serve as prognostic indicators for predicting ipsilateral IBC development in this patient population.