Pathologists at the Yale University School of Medicine in New Haven, Conn., studied the relationship between the Oncotype Dx recurrence score and the cell cycle-related antigen Ki-67 in 32 breast carcinomas and evaluated for a potential association.
Previous studies have shown that patients with a high-risk recurrence score will most likely benefit from adjuvant chemotherapy, but there is no proven advantage for patients with a low-risk recurrence score, who still face an average recurrence risk of 7%, according to the investigators (Int J Surg Pathol 174:303-310, 2009).
Comparison of the recurrence score with tumor type, grade, and the Ki-67 proliferation index (PI) revealed an overall concordance. However, some tumors with a low recurrence score revealed a surprisingly high Ki-67 PI. These cases may correspond to the 7% of low-risk carcinomas that recur, they wrote, and proposed that a combined evaluation of the recurrence score and Ki-67 PI be used to identify tumors with high recurrence potential from the low-risk and intermediate-risk groups.