Addressing overtreatment of screen detected DCIS; the LORIS trial

Research output: Contribution to journalArticlepeer-review


  • Adele Francis
  • Jeremy Thomas
  • Lesley Fallowfield
  • Matthew Wallis
  • John M S Bartlett
  • Claire Gaunt
  • Jennie Young
  • David Dodwell
  • Andrew Hanby
  • Sarah E Pinder
  • Andrew Evans
  • Malcolm Reed
  • Valerie Jenkins
  • Lucy Matthews
  • Maggie Wilcox
  • Patricia Fairbrother
  • Daniel Rea


Overdiagnosis, and thus overtreatment, are inevitable consequences of most screening programmes; identification of ways of minimising the impact of overdiagnosis demands new prospective research, in particular the need to separate clinically relevant lesions that require active treatment from those that can be safely left alone or monitored and only need treated if they change characteristics. Breast cancer screening has led to a large increase in ductal carcinoma in situ (DCIS) diagnoses. This is a widely heterogeneous disease and most DCIS detected through screening is of high cytonuclear grade and therefore likely to be important clinically. However, the historic practice of surgical treatment for all DCIS is unlikely to be optimal for lower risk patients. A clearer understanding of how to manage DCIS is required. This article describes the background and development of 'The low risk' DCIS trial (LORIS), a phase III trial of surgery versus active monitoring. LORIS will determine if it is appropriate to manage women with screen detected or asymptomatic, low grade and intermediate grade DCIS with low grade features, by active monitoring rather than by surgical treatment.


Original languageEnglish
Pages (from-to)2296-2303
Number of pages8
JournalEuropean Journal of Cancer
Issue number16
Early online date18 Sep 2015
Publication statusPublished - Nov 2015


  • DCIS, Low grade DCIS, Breast screening, Over treatment, Clinical trial, Breast cancer

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