The Upgrade Risk of B3 Lesions to (Pre)Invasive Breast Cancer After Diagnosis on Core Needle or Vacuum Assisted Biopsy. A Belgian National Cohort Study.

INTRODUCTION: Flat epithelial atypia (FEA), lobular neoplasia (LN), papillary lesions (PL), radial scar (RS) and atypical ductal hyperplasia (ADH) are lesions of uncertain malignant potential and classified as B3 lesions by the European guidelines for quality assurance in breast cancer screening and diagnosis. Current management is usually wide local excision (WE), surveillance may be sufficient for some. We investigated the upgrade rate of B3 lesions to breast malignancy in a subsequent resection specimen after diagnosis on core needle-or vacuum assisted biopsy (CNB-VAB) in a national population-based series. METHODS: Using data from the Belgian Cancer Registry (BCR) between January 1, 2013 and December 31, 2016, inclusion criteria were new diagnosis of a B3 lesion on CNB or VAB with subsequent histological assessment on a wider excision specimen. Histological agreement between first- and follow-up investigation was analyzed to determine the upgrade risk to ductal adenocarcinoma in situ (DCIS) or invasive breast cancer (IC) according to the type of B3 lesion. RESULTS: Of 1855 diagnosed B3 lesions, 812 were included in this study: 551 after CNB-261 after VAB. After diagnosis on CNB and VAB, we found 19.0% and 14.9% upgrade to malignancy respectively. Upgrade risks after CNB and VAB were: FEA 39.5% and 17.6%; LN 40.5% and 4.3%; PL 10.4% and 12.5%; RS 25.7%and 0.0%; ADH 29.5% and 20.0%. CONCLUSION: Based on the observed upgrade rate we propose three recommendations: first, resection of ADH, and FEA with WE; second, resection of RS and classical LN with therapeutic VAB and further surveillance when radio-pathological correlation is concordant; third, surveillance of PL.

Cause of death for patients with breast cancer: discordance between death certificates and medical files, and impact on survival estimates.

BACKGROUND: Registration and coding of cause of death is prone to error since determining the exact underlying condition leading directly to death is challenging. In this study, causes of death from the death certificates were compared to patients' medical files interpreted by experts at University Hospitals Leuven (UHL), to assess concordance between sources and its impact on cancer survival assessment. METHODS: Breast cancer patients treated at UHL (2009-2014) (follow-up until December 31st 2016) were included in this study. Cause of death was obtained from death certificates and expert-reviewed medical files at UHL. Agreement was calculated using Cohen's kappa coefficient. Cause-specific survival (CSS) was calculated using the Kaplan-Meier method and the relative survival probability (RS) using the Ederer II and Pohar Perme method. RESULTS: A total of 2862 patients, of whom 354 died, were included. We found an agreement of 84.7% (kappa-value of 0.69 (95% C.I.: 0.62-0.77)) between death certificates and medical files. Death certificates had 10.7% false positive and 4.5% false negative rates. However, five-year CSS and RS measures were comparable for both sources. CONCLUSION: For breast cancer patients included in our study, fair agreement of cause of death was seen between death certificates and medical files with similar CSS and RS estimations.