"Abstract

Background

The IBIS/Tyrer-Cuzick [version 8 (TC8)] risk model is widely used to estimate breast cancer risk, and to inform the allocation of magnetic resonance imaging (MRI) screening for high-risk breast patients. No study to date has evaluated the latest TC model in diverse populations.

Objective

To assess the predictive value of the TC8 Risk Model across diverse racial and ethnic groups in an urban American population.

Methods

Retrospective data analysis from five sites within a single urban health care system from January 1, 2018-November 1, 2022. The sample included 73,435 patients; 639 had a history of breast cancer. Average TC risk scores were calculated by racial and ethnic groups for the overall sample, and then for those with a history of breast cancer. Analyses were conducted to evaluate relationships between TC8 risk scores, cancer rates, ethnicity and race.

Results

As expected, analyses revealed that TC8 scores were significantly associated with increased risk of cancer, with each percentage point increase in TC8 score the odds of cancer caseness increased by 2 %; (OR = 1.02, 95 % CI [1.01, 1.03]). Black/AA patients were less likely to be diagnosed with cancer than Whites; OR = 0.72, 95 % CI [0.59, 0.89]. Hispanic patients were less likely to be diagnosed with cancer than Non-Hispanic patients; OR = 0.49, 95 % CI [0.39, 0.61]. White patients had the highest TC8 scores, followed by Asian, Black/AA, and Other patients. Among cancer patients, White patients had higher TC8 scores than Black/AA patients (p < 0.02). Interestingly, we also found a stronger effect of TC8 scores on cancer caseness among Hispanic patients than Non-Hispanic patients [χ²(1) = 5.1, p < 0.024]. White patients had a greater odds of reaching the TC8 threshold of 20 than Black/AA (OR = 0.49, 95 % CI [0.46, 0.53]), Asian (OR = 0.62, 95 % CI [0.57, 0.68]), and Other (OR = 0.44, 95 % CI [0.41, 0.47]) patients. Similarly, Hispanic patients were significantly less likely to meet TC8 threshold scores than Non-Hispanic patients; χ²(1) = 390.6, p < 0.001, OR = 0.53, 95 % CI [0.50, 0.57].

Conclusion

A higher TC8 risk score is significantly associated with increased odds of cancer across demographic groups. White patients exhibited the highest TC8 scores, and White patients have the highest odds of reaching the TC8 threshold for qualifying for breast MRI, while the relationship between TC8 scores and caseness was highest for Hispanic patients.Among cancer patients, Black/AA patients continued to have lower TC8 scores, raising the question of whether the cut-off of TC8 = 20 is appropriate for all groups.

Clinical impact

TC8 scores guide decisions for MRI screening, but the predictive value of the TC8n score may differ based on ethnicity. Furthermore, due to potential score bias, Black and other minority patients may receive fewer breast MRIs than their White counterparts. Such potential bias could potentially contribute to racial disparities in breast cancer care including delayed diagnosis, or increased mortality and morbidity."