title: Adjuvant systemic therapy in early breast cancer: impact of guideline changes and clinicopathological factors associated with nonadherence at a nation-wide level.
abstract: Over recent years, adjuvant systemic treatment guidelines (AST) for early-stage breast cancer have changed considerably. We aimed to assess the impact of these guideline changes on the administration of AST in early-stage breast cancer patients and to what extent these guidelines are adhered to at a nation-wide level. We used Netherlands Cancer Registry data to describe trends in AST prescription, adherence to AST guidelines, and to identify clinicopathological determinants of nonadherence. Between 1990 and 2012, 231,648 Dutch patients were diagnosed with early breast cancer, of whom 124,472 received AST. Adjuvant endocrine treatment (ET) use increased from 23 % of patients (1990) to 56 % (2012), and chemotherapy from 11 to 44 %. In 2009-2012, 8 % of patients received ET and 3 % received chemotherapy without guideline indication. Conversely, 10-29 % of patients did not receive ET and chemotherapy, respectively, despite a guideline indication. Unfavorable clinicopathological characteristics generally decreased the chance of undertreatment and increased the chance for overtreatment. Remarkable was the increased chance of ET undertreatment in younger women (RR < 35 vs 60-69 years 1.79; 95 % CI 1.30-2.47) and in women with HER2+ disease (RR 1.64; 95 % CI 1.46-1.85). Over the years, AST guidelines expanded resulting in much more Dutch early breast cancer patients receiving AST. In the majority of cases, AST administration was guideline concordant, but the high frequency of chemotherapy undertreatment in some subgroups suggests limited AST guideline support in these patients.
authors: Department of Epidemiology, Julius Center for Health Sciences and Primary Care, University Medical Centre Utrecht, Universiteitsweg 100, P.O. Box 85500, 3508 GA, Utrecht, The Netherlands.
authors: A M F
authors: AM
authors: Verschoor
authors: Department of Surgery, Diakonessenhuis Utrecht, Bosboomstraat 1, 3582 KE, Utrecht, The Netherlands.|Department of Radiology, University Medical Center Utrecht, Universiteitsweg 100, P.O. Box 85500, 3508 GA, Utrecht, The Netherlands.
authors: A
authors: A
authors: Kuijer
authors: Department of Research, Netherlands Comprehensive Cancer Organization, Postbus 19079, 3501 DB, Utrecht, The Netherlands.
authors: J
authors: J
authors: Verloop
authors: Department of Epidemiology, Julius Center for Health Sciences and Primary Care, University Medical Centre Utrecht, Universiteitsweg 100, P.O. Box 85500, 3508 GA, Utrecht, The Netherlands.
authors: C H
authors: CH
authors: Van Gils
authors: Department of Medical Oncology, Netherlands Cancer Institute, Plesmanlaan 121, 1066 CX, Amsterdam, The Netherlands.
authors: G S
authors: GS
authors: Sonke
authors: Department of Medical Oncology, Erasmus Medical Cancer Institute, Postbus 2040, 3000 CA, Rotterdam, The Netherlands.
authors: A
authors: A
authors: Jager
authors: Department of Surgery, Diakonessenhuis Utrecht, Bosboomstraat 1, 3582 KE, Utrecht, The Netherlands.
authors: T
authors: T
authors: van Dalen
authors: Department of Epidemiology, Julius Center for Health Sciences and Primary Care, University Medical Centre Utrecht, Universiteitsweg 100, P.O. Box 85500, 3508 GA, Utrecht, The Netherlands. s.elias@umcutrecht.nl.
authors: S G
authors: http://orcid.org/0000-0002-6666-1368
authors: SG
authors: Elias
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D018931:Antineoplastic Agents, Hormonal / Q000627:therapeutic use*; D001943:Breast Neoplasms / Q000188:drug therapy*; D017024:Chemotherapy, Adjuvant; D004358:Drug Therapy; D005260:Female; D019983:Guideline Adherence; D006801:Humans; D008875:Middle Aged; D009367:Neoplasm Staging; D009426:Netherlands; D012042:Registries; D016896:Treatment Outcome; D055815:Young Adult
chemical_list: D018931:Antineoplastic Agents, Hormonal
keywords: Adjuvant systemic therapy; Breast cancer; Chemotherapy; Endocrine therapy; Guideline adherence; Overtreatment; Undertreatment