The Relationship of Race, Oncotype DX, and Ki67 in a Population Highly Screened For Breast Cancer

Abstract

Oncotype DX recurrence score (ODX) can predict risk of invasive breast cancer recurrence and benefit of chemotherapy. Literature is limited on the relationship of ODX and race in women with hormone receptor positive and node negative/positive disease. Our study examines the relationship between race and clinical characteristics within a population of highly screened women with newly diagnosed breast cancer. The institutional Breast Cancer Database was queried for patients with newly diagnosed breast cancer between January2010 and March2015. We analyzed clinical and tumor characteristics including ODX. Statistical analyses included Pearson's Chi-Square and Fisher's Exact Tests. There were 2,092 women in our study cohort. The majority had college-level education (84%), regular screening (78%), and clinical breast exams (88%). The majority had invasive ductal carcinoma (IDC) (62%), early stage (0, I, II) tumors (93%), ER+ (84%), PR+ (71%), Her2 negative (86%), and node negative disease (83%). There was a significantly higher proportion of later stage disease among African-Americans (p = 0.001) and Asians (p = 0.006) and more triple negative breast cancers among African-Americans (p < 0.0001). A majority of patients had a low ODX (56%). While ODX was not different among the race categories (p = 0.97), there were significant racial differences in Ki-67 (p < 0.0001). In a population of highly screened women, differences were found between races regarding tumor histology. No statistical difference between race and ODX was noted, but there were racial differences in Ki67. Therefore we recommend that further research be focused on refining management algorithms by ethnicity.

Ethnicity, recurrence score distribution, and clinical outcomes in ER + HER2‐negative breast cancer patients in Israel: A registry analysis

“…This is the first study comparing RS distribution, chemotherapy use, and clinical outcomes between ethnic groups in Israel. RS distribution was not impacted by ethnicity, consistent with the observation in TAILORx, 1 and a single‐center US cohort study (N = 2092), 3 and in contrast, to a recent US cohort study (N = 2216) which did demonstrate significant racial differences in RS distribution 4 . Interestingly, in our larger cohort, the proportion of RS 26‐100 patients was numerically higher in the Jewish group which may be related to the higher rate of BRCA1/2 founder mutations reported in Jews vs other ethnicities, and the observed association between BRCA1/2 mutations and higher RS results 5,6 .…”

Breast cancer subtype and clinical characteristics in women from Peru

“…The distribution of tumor subtypes is similar to what has been previously described in other Latin American countries (95), with differences being partially explained by the inclusion of KI-67 expression and tumor grade for subtype classification (95), as indicated by the 2013 St. Gallen consensus (96). This classification criterion was not used in this report since KI-67 was not available for more than 20% of patients, and parameters for subtype determination based on this marker tend to be unstable across populations and studies (97). A study describing patient and tumor characteristics from Peruvian breast cancer patients at INEN diagnosed between 2000 and 2002 (80) (PEGEN-BC patients were recruited if diagnosed in 2010 or later) reported a lower proportion of HR+ tumors compared with PEGEN-BC (62.5% vs. 71.1%).…”

Identification of metabolic pathways contributing to ER+ breast cancer disparities using a machine-learning pipeline

“…Breast cancer mortality rates in African American (AA) women are 40% higher than in Non-Hispanic White (NHW) women 1 , stemming from complex and multifaceted factors 2 . AA women experience earlier disease onset, exhibit biologically aggressive tumor phenotypes 1 – 3 , present with higher stages at diagnosis (4), experience increased likelihood of distant metastases 4 , and have lower survival rates post-diagnosis 4 – 6 . These disparities are particularly pronounced in individuals with estrogen receptor-positive (ER + ) breast cancer 1 .…”