The University of Tennessee Medical Center, USA
Dr. Heather Gage received a Bachelor of Arts degree in Physics from Bryn Mawr College, Pennsylvania in 2008, and received her medical degree from University College Cork, Ireland in 2013. Currently, Dr. Gage is a PGY 1 resident in the Anatomic and Clinical Pathology Residency Program at the University of Tennessee Medical Center in Knoxville, Tennessee. Research interests include breast cancer, biomarkers, and outcomes.
Large randomized trials have shown that adjuvant anti-HER2 therapy is efficient in reducing the risk of recurrence and improving the survival in patients with HER2+ breast cancer (BC). We evaluated whether the introduction of adjuvant anti-HER2 therapy for treatment of HER2+ BC patients in an academic institution settings outside of clinical trials had similar effect on overall survival (OS). Two-hundred-fifteen of 309 Caucasian females diagnosed with HER2+ invasive BC at our academic institution from 1998-2009 were studied. They were divided into 2 groups based on the time of diagnosis (before or after 11/2005, the start date of adjuvant anti-HER2 therapy administration as standard practice for operable HER2+ BC at our institution). Group 0 (G0) included 119 HER2+ patients diagnosed before 11/2005; Group 1 (G1) included 95 HER2+ patients diagnosed after 11/2005. Both groups were further subdivided based on ER/PR/HER2 subtype: G0 had 72 ER+/PR+/HER2+ and 48 ER-/PR-/HER2- patients. G1 had 56 ER+ PR+/HER2+ and 39 ER-/PR-/HER2+ patients. Ninety-four patients from G0 followed for >120 months were excluded from the study, to balance the G0 and G1 groups’ follow-up time. OS was measured by Kaplan-Meier curve. Although only 2/3 of G1 patients received anti-HER2 therapy, OS significantly improved (p<.003), largely due to an effect on the ER-/PR-/HER2+ group. This was also reflected in five-year survival (G0:ER-/PR-/HER2+=68.8%, G1:ER-/PR-/HER2+=84.6%; G0:ER+/PR+/HER2+=83.3%, G1:ER+/PR+/HER2+=85.7%). Our results are comparable to results from the clinical trials for anti-HER2 therapy in adjuvant settings. Similarities and differences will be discussed including the role of ER/PR positivity in HER2+ BC.