Objective:

To compare tumor characteristics of screen-detected and interval cancers, their relationship with breast density, and AJCC prognostic criteria of interval cancers, particularly focusing on time to diagnosis and retrospective radiological classification.

Key Findings:

• Interval cancers are typically larger, have higher histologic grade, and more frequently exhibit a triple-negative phenotype compared to screen-detected cancers, indicating a need for targeted screening.
• Mammographic density is a significant risk factor for interval cancers, with high-density breasts showing a masking effect that may lead to missed diagnoses.
• AJCC prognostic pathologic stage IIA or higher is identified as the optimal threshold for predicting breast cancer death, emphasizing the importance of accurate staging in screening.

Interpretation:

The study highlights the need for improved screening strategies that consider breast density and the characteristics of interval cancers to enhance early detection and treatment outcomes, particularly for high-risk populations.

Limitations:

• The study did not include race and ethnicity data, which may limit the generalizability of the findings across diverse populations.
• The method of detection for interval cancers was not recorded in the NBSS, potentially affecting the understanding of detection efficacy.

Conclusion:

Understanding the differences in tumor characteristics between screen-detected and interval cancers can inform breast cancer screening programs and improve early detection strategies.