King's College London

Research portal

Pathological features of 11337 patients with primary ductal carcinoma in situ (DCIS) and subsequent events – results from the UK Sloane project: DCIS pathology and outcome in the Sloane Project

Research output: Contribution to journalArticlepeer-review

on behalf of the Sloane Project Steering Committee

Original languageEnglish
Pages (from-to)1009–1017
JournalBJC: British Journal of Cancer
Early online date17 Nov 2020
Accepted/In press21 Oct 2020
E-pub ahead of print17 Nov 2020
Published17 Nov 2020

King's Authors


Background: The Sloane audit compares screen-detected ductal carcinoma in situ (DCIS) pathology with subsequent management and outcomes. Methods: This was a national, prospective cohort study of DCIS diagnosed during 2003–2012. Results: Among 11,337 patients, 7204 (64%) had high-grade DCIS. Over time, the proportion of high-grade disease increased (from 60 to 65%), low-grade DCIS decreased (from 10 to 6%) and mean size increased (from 21.4 to 24.1 mm). Mastectomy was more common for high-grade (36%) than for low-grade DCIS (15%). Few (6%) patients treated with breast-conserving surgery (BCS) had a surgical margin <1 mm. Of the 9191 women diagnosed in England (median follow-up 9.4 years), 7% developed DCIS or invasive malignancy in the ipsilateral and 5% in the contralateral breast. The commonest ipsilateral event was invasive carcinoma (n = 413), median time 62 months, followed by DCIS (n = 225), at median 37 months. Radiotherapy (RT) was most protective against recurrence for high-grade DCIS (3.2% for high-grade DCIS with RT compared to 6.9% without, compared with 2.3 and 3.0%, respectively, for low/intermediate-grade DCIS). Ipsilateral DCIS events lessened after 5 years, while the risk of ipsilateral invasive cancer remained consistent to beyond 10 years. Conclusion: DCIS pathology informs patient management and highlights the need for prolonged follow-up of screen-detected DCIS.

View graph of relations

© 2020 King's College London | Strand | London WC2R 2LS | England | United Kingdom | Tel +44 (0)20 7836 5454