[Ki67 in young patients with breast cancer]

Abstract

The aim of the study was to compare KI67 in young breast cancer patients (pts) (35 years or less), and in older ones. Forty-three young pts treated between January 1, 2006 and December 31, 2008 as well as pts more than 35 years treated in the same institution in 2006 were considered. Biomarker studies were carried out on a surgical specimen or on a biopsy before neoadjuvant chemotherapy if any. Young pts had a higher median value of KI67 (30% [3-95] versus 10% [0-90] P<0.0001) a higher rate of SBR3 (44 versus 28% P<04), of mitotic index 3 (35 versus 13% P<0.001). ER was less frequently positive (56 versus 87%, P<0.001) as well as PR (38 versus 68% P<0.001). HER2 was more frequently amplified in young pts (24 versus 10% P<0.007). Young pts more frequently had a triple negative breast cancer (TNBC) (31 versus 8% P<0.001). In TNBC pts, KI67 was higher in younger pts (70% [10-95] versus 38% [2-80] P=0.06). Among young pts, TNBC had a higher KI67 than non TNBC (70% [10-95 versus 20% [3-60] P<0.001).

Conclusion: KI67 is significantly higher in young pts than in older ones. TNBC is significantly more frequent; among young pts, and KI67 is significantly higher in TNBC.