br RESULTS The models show and
RESULTS: The models show and quantify the diminishing returns for prevalent screens with increasing biopsy rates. A biopsy rate increase from 10 to 20 per 1,000 increases the cancer detection rate by 2.13 per 1,000 with four extra biopsies per extra cancer detected. Increasing the biopsy rate from 40 to 50 per 1,000, increases the cancer detection rate by only 0.25 per 1,000, with 40 extra biopsies per extra cancer detected. Although diminishing returns are also seen at incident screens, screening Tacrolimus generally more efficient.
CONCLUSIONS: Increasing needle biopsy rates leads to rapidly diminishing returns in cancer detection and a marked increase in non-malignant/benign needle biopsies. Much of the harms associated with screening in terms of false-positive recall rates and non-cancer biopsies occur at prevalent screens with much lower rates at incident screens. Needle biopsy rate targets should be considered together with recall rate targets to maximise benefit and minimise harm.
2019 The Royal College of Radiologists. Published by Elsevier Ltd. All rights reserved.
* Guarantor and correspondent: R. G. Blanks, Cancer Epidemiology Unit, Nuffield Department of Population Health, Oxford University, Richard Doll Building,
The English National Health Service Breast Screening Programme (NHSBSP) started in 1987 following the Forrest report.1 The programme currently undertakes two-view mammography on women aged 50e70 years at intervals of 3 years. Following the AgeX trial, invitations now occur from age range 47e73 years as the trial involves random-ising women aged 47e49 and 71e73 to receive an invitation to screening.2
There has been controversy for many years related to the optimum balance between benefits and harms in screening for breast cancer.3 In the UK, invasive cancer detection rate targets are informed by the Swedish Two-County rando-mised controlled trial, which detected nearly all cancers as invasive and are age standardised.4,5 In Europe, targets are set at three times the underlying incidence rate for first screen and 1.5 for subsequent screens.6
Targets for recall rates range from 2% in Holland7 to a recommended upper threshold of 12% in the United States.8 Europe and the NHSBSP set separate targets for recall rate. At prevalent (first) screens, <5% in Europe with a minimum standard of <7% (but <7% and <10% respectively in the NHSBSP). At incident (subsequent) screens the European
Percutaneous needle biopsy has essentially replaced open surgical biopsy for the diagnosis of both palpable and impalpable abnormalities.10 The NHSBSP has targets to reduce the rate of women referred for benign surgical bi-opsy, repeat operation rates, and targets to avoid early surveillance/follow-up9; however, no target is set for needle (cytology/core) biopsy rates. There has been some upward drift in needle biopsy rates over the years as units try to increase cancer detection and ensure diagnosis of malig-nancy prior to referral for surgery. In addition, there is marked variation in unit needle biopsy rates by a factor of three times at prevalent screens and a factor of about two times at incident screens.11
The aim of the present study was to examine the asso-ciation between cancer detection and needle biopsy rates and provide information that could potentially enable the setting of evidence-based needle biopsy rate ranges.
Materials and methods
Information on cancer detection, recall, and needle biopsy rates were taken from the national Korner (KC62) returns sent to Public Health England (PHE) annually and published by NHS Digital.10 Data in barriers to gene flow paper are from 80 screening units over the 7 screening years 2009/10 to 2015/16. The KC62 datasets are based on women as the denominator and the needle biopsy rate is interpreted as the number of screened women who have at least one needle biopsy. There is no information on repeat or multiple biopsies in these returns. Similarly the KC62 returns record no information on multiple or bilateral cancers.