Clinical Features,Treatment Patterns And Survival Outcomes Of HER2 Dual-Equivocal Breast Tumors

Objectives: To investigate the clinico-pathological characteristics,adjuvant treatment patterns and prognosis of HER2 dual-equivocal breast cancer,to answer whether such patients should be treated as HER2-negative tumors.Methods: Breast cancer patients who underwent surgery from January 2009 to December2014 in our center were retrospectively included.The HER2 status was determined using the 2013 American Society of Clinical Oncology / College of American Pathologists HER2 Detection Guidelines.Chi square test was applied to compare the clinico-pathological features and systemic treatment patterns of HER2 IHC 2+ and FISH positive,dual-equivocal and negative patients.The expression of HER2 gene m RNA was detected by quantitative real-time polymerase chain reaction method.The Kaplan-Meier analysis was used to compare clinical outcomes in each group.Results: Of the 691 patients,HER2 IHC 2+,HER2-positive,dual-equivocal and HER2-negative tumors were found in 133(19.25%),25(3.62%)and 533(77.13%)cases.HER2 dual-equivocal tumors had similar clinico-pathological features(P > 0.05),HER2 m RNA levels(P = 0.26),and adjuvant treatment recommendations(P > 0.05)to HER2 negative ones.None in the HER2 dual-equivocal group received anti-HER2 therapy.There were no significant survival differences between the three groups(P = 0.43).Conclusion: HER2 dual-equivocal breast cancer is similar to HER2-negative tumors in terms of clinico-pathological features,HER2 m RNA expression,adjuvant treatment,and prognosis.HER2 dual-equivocal tumors can be managed as HER2-negative disease.