title: Very low local recurrence rates after breast-conserving therapy: analysis of 8485 patients treated over a 28-year period.
abstract: The purpose of this study was to study the impact of changes in clinical practice on outcome in patients treated with breast-conserving therapy (BCT) over a period of 28 years. Patients with early invasive breast cancer, who were treated with BCT at the Netherlands Cancer Institute between 1980 and 2008, were studied. Clinical characteristics, treatment and outcome were compared between groups (1980-1987; 1988-1998; 1999-2008). The main endpoint analyzed was ipsilateral breast tumor recurrence (IBTR). 8485 patients with a median follow-up of 9 years (IQR 6-14 years) were analyzed. The cumulative 5- and 10-year IBTR incidences were, respectively, 2 and 5 % for the whole cohort and 4 and 9 % in patients ≤40 years. Young age was a significant risk factor for IBTR in multivariable analysis. IBTR-free interval was better for patients who received a RT boost (HR 0.65) or systemic therapy (HR 0.52). In later years, patients less often received a boost and more often underwent adjuvant systemic treatment. 761 patients (9.0 %) underwent a re-excision; the tumor resection margins were tumor free for 85 %. In later years (1999-2008), 89 % of patients had a tumor-free margin. The margin status of invasive carcinoma did not influence IBTR, DM rate, or OS. Between 1980 and 2008, locoregional control after BCT remained stable with low IBTR rates, even in young patients. These good results were achieved under the policy of accepting close or focally positive margins, indicating this is a safe approach. The results of this study may help in lowering the re-excision rates, which are high in many centers.
authors.affiliation: Department of Radiation Oncology, The Netherlands Cancer Institute, Plesmanlaan 121, 1066 CX, Amsterdam, The Netherlands.
authors.forename: S C J
authors.identifier: http://orcid.org/0000-0001-9923-4736
authors.initials: SC
authors.lastname: Bosma
authors.affiliation: Department of Radiation Oncology, The Netherlands Cancer Institute, Plesmanlaan 121, 1066 CX, Amsterdam, The Netherlands.
authors.forename: F
authors.initials: F
authors.lastname: van der Leij
authors.affiliation: Statistics Department, The Netherlands Cancer Institute, Plesmanlaan 121, 1066 CX, Amsterdam, The Netherlands.
authors.forename: E
authors.initials: E
authors.lastname: van Werkhoven
authors.affiliation: Department of Radiation Oncology, The Netherlands Cancer Institute, Plesmanlaan 121, 1066 CX, Amsterdam, The Netherlands.
authors.forename: H
authors.initials: H
authors.lastname: Bartelink
authors.affiliation: Department of Pathology, The Netherlands Cancer Institute, Plesmanlaan 121, 1066 CX, Amsterdam, The Netherlands.
authors.forename: J
authors.initials: J
authors.lastname: Wesseling
authors.affiliation: Department of Medical Oncology, The Netherlands Cancer Institute, Plesmanlaan 121, 1066 CX, Amsterdam, The Netherlands.|Department of Pathology, University Medical Center Utrecht, Heidelberglaan 100, Utrecht, The Netherlands.
authors.forename: S
authors.initials: S
authors.lastname: Linn
authors.affiliation: Department of Surgery, The Netherlands Cancer Institute, Plesmanlaan 121, 1066 CX, Amsterdam, The Netherlands.
authors.forename: E J
authors.initials: EJ
authors.lastname: Rutgers
authors.affiliation: Department of Pathology, Academical Medical Center, Meibergdreef 9, 1105 AZ, Amsterdam, The Netherlands.
authors.forename: M J
authors.initials: MJ
authors.lastname: van de Vijver
authors.affiliation: Department of Radiation Oncology, The Netherlands Cancer Institute, Plesmanlaan 121, 1066 CX, Amsterdam, The Netherlands. p.elkhuizen@nki.nl.
authors.forename: P H M
authors.initials: PH
authors.lastname: Elkhuizen
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D001943:Breast Neoplasms / Q000188:drug therapy / Q000532:radiotherapy / Q000601:surgery*; D017024:Chemotherapy, Adjuvant; D003131:Combined Modality Therapy; D005260:Female; D006801:Humans; D015412:Mastectomy, Segmental / Q000379:methods*; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000453:epidemiology*; D009426:Netherlands / Q000453:epidemiology; D016019:Survival Analysis; D016896:Treatment Outcome; D055815:Young Adult
keywords: Breast cancer; Breast-conserving therapy; Local control; Tumor-free margins