Abstract P5-16-27: Variation in the use of neoadjuvant chemotherapy for breast cancer in the Netherlands. A lack of consensus

Abstract

Abstract Introduction Neoadjuvant chemotherapy (NAC) is an important initial strategy in the management of stage III locally advanced breast cancer (LABC) as being advised in our national guidelines. Furthermore, NAC is increasingly being used in stage II BC for downsizing the tumour in order to enable breast conservation therapy (BST). The aim of this study was to examine which patient-, tumour- and hospital related factors influence its use in clinical daily practice. In addition, we investigated the preferences of the surgical- and medical- oncologist as well as the patients'. Methods (1) All operated women [aged 18-70] from January 2011 to September 2015 were selected from the multidisciplinary NABON Breast Cancer Audit (NBCA). Multivariable logistic regression was used to assess significant independent predictors of NAC use. (2) Both specialists and ex-patients were provided with a survey about decision-making. Results Overall, 21% of stage II (N=18011) and 70% of stage III patients (N=1715) received NAC. Factors associated with NAC utilization included young age, a diagnostic MRI, histology, large tumour size, more advanced nodal disease, hormone-receptor negative tumours and participation in neoadjuvant trials.After case mix correction variation between hospitals remained (range 10% – 90%). Evidenced by additional survey research, reasons for indication of NAC vary widely among specialists (response rate of 24%; N=100). From the patient survey (response rate of 52%; N=390) it appears that in patients where chemotherapy is recommended, 50% was not informed about the option of NAC. Conclusion There is considerable variation in the use of NAC for BC in the Netherlands. Although various patient, tumor and institutional factors are associated with the use of NAC, these can only explain part of the observed variation in treatment patterns between hospitals. Survey research shows a need for uniformity of selection criteria in the use of NAC between specialists. Also, the information necessary for patients to decide on which treatment option they prefer seems far from complete in clinical practice. Citation Format: Spronk PER, Bommel van ACM, Siesling S, Vrancken Peeters M-JT, Smorenburg CM. Variation in the use of neoadjuvant chemotherapy for breast cancer in the Netherlands. A lack of consensus [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P5-16-27.