Traditional Prognostic Factors Used for Adjuvant Chemotherapy (Ct) Decisions in Early Stage Hr + , Her2– Breast Cancer in a Large International Survey (Magic) Among Breast Cancer Specialists

Aim: The MAGIC survey aimed to identify how physicians use the most common traditional parameters and histopathology markers in clinical treatment decisions in early stage HR + , HER2– breast cancer. The data presented here describe how physicians use tumor size, grade, nodal status, estrogen receptor (ER), progesterone receptor (PR), and Ki67 expression, and age for CT recommendations. Methods: The online MAGIC survey was available to physicians working in multidisciplinary breast cancer teams (≥5 years' experience). The survey evaluated respondent demographics, criteria considered for CT decisions, and treatment recommendations in a wide variety of patient cases and captured how physicians use traditional parameters for making CT recommendations. Results: Between August 2013 and January 2014, 911 respondents (52 countries) completed the survey. The results for key parameters are presented in the table. There was substantial heterogeneity in how all parameters were considered for decisions about CT, with a majority of respondents reaching agreement to strongly consider CT only in patients with Grade 3 tumors (70.1%), tumors larger than 3 cm (63.7%), and in patients with 2 or more positive nodes (63.1%). A majority would strongly consider CT in patients with low ER and high Ki67 expression but there was no consensus on the definition of low ER expression ( 20% [33.9%], > 30% [31.9%]). Conclusions: The results reveal substantial differences in how physicians use traditional prognostic parameters for CT decisions. The data highlight the need for implementation of additional criteria or biomarkers that are predictive of CT benefit and can help physicians and patients make more informed treatment decisions. Is there a specific tumor size above which you would strongly consider CT? > 1 cm 13.8% > 2 cm 35.5% > 3 cm 14.4% > 4 cm 4.7% > 5 cm 9.4% Not considered 22.2% Is there a specific tumor grade above which you would strongly consider CT? Grade 1 or above 0.6% Grade 2 or above 20.9% Grade 3 or above 70.1% Not considered 8.4% Would you be inclined to give CT to most patients with low expression of ER? Yes 83.4% No 8.4% Not considered 8.2% Would you be inclined to give CT to patients with low PR? Yes 41.9% No 21.3% Not considered 36.9% What percentage of ER+ cells would you consider low and would make you strongly consider CT? 26.2% 46.8% 20.0% Not considered 7.1% At which Ki67 percentage would you strongly consider giving CT? ≥ 14% 27.2% > 20% 33.9% > 30% 31.9% Not considered 7.1% What number of positive nodes would make you strongly consider CT? Node negative 3.6% 1 (including isolated tumor cells or nodal micrometastases) 38.6% 2 20.9% 3 10.8% 4 or more 21.0% Not considered 5.0% Is there an age above which you would strongly consider not giving adjuvant CT? > 50 years 1.4% > 60 years 0.7% > 70 years 16.8% > 80 years 48.4% Age is not considered 32.8% Disclosure: M. Aapro: Advisory board: Genomic Health Corporate-sponsored research: Genomic Health; C. Markopoulos: Other substantive relationships: Genomic Health – Speaker's Honoraria; T. Mamounas: Advisory board: Genomic Health Inc. Other substantive relationships: Speaker's Bureau: Genomic Health Inc.; R. Rouzier: Advisory board: consultant for Genomic Health; C. Thomssen: Advisory board: Genomic Health Speaker for Genomic Health (under other substantive relationships); D. Rea: Advisory board: Genomic Health; B. Linderholm: Board of directors: Steering Committee for the BIG/EORTC/NABCG Male breast cancer project; V. Smit: Advisory board for Genomic Health Inc.; C. Svedman: Other substantive relationships: I am an employee of Genomic Health working in the medical department; M. De Laurentiis: Advisory board: Genomic Health. All other authors have declared no conflicts of interest.