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  • Poster presentation
  • Open Access

A radiological and pathological analysis of screen-detected and interval-detected breast cancers in Belfast

  • 1,
  • 1,
  • 1, 2,
  • 1, 2 and
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Breast Cancer Research201214 (Suppl 1) :P52

  • Published:


  • Breast Cancer
  • Lesion Size
  • Breast Screening
  • Interval Cancer
  • Outer Quadrant


The Belfast Breast Screening Programme serves a population of approximately 25,000 patients. We aimed to analyse radiological and pathological trends between screen-detected and interval breast cancers, and determine our screening lesion miss rate.


Using the Quality Assurance Reference Centre (QARC) database patients were identified with screen-detected or interval breast cancers diagnosed via the Belfast Breast Screening Programme over a fixed period. Film packs and operative specimen reports were analysed for radiological and pathological data.


Screening identified 75% of breast cancers. Only 30% of screen-detected lesions were palpable by breast clinicians. Sixty-one per cent of lesions were in the upper outer quadrant, with equal left-right distribution. Radiological measurements underestimated lesion size by 22%. There was moderate correlation between lesion size and lymph node status. No other correlations were identified. Twenty-three per cent of interval cancers presented in year 1 following screening, 28% in year 2 and 49% in year 3. They were larger at presentation than screen-detected cancers (29.4 mm vs. 18.2 mm mean size) and of pathologically higher grade (39% vs. 13% grade III). Screen-detected cancers were mostly IDC (63%) or DCIS (18%) subtype. Interval lesions were predominantly IDC subtype (87%). Interval lesions showed more nodes positive per patient. Retrospective review of past screening films of interval-detected cancers showed suspicious features present in 17% of cases.


Breast screening identifies three-quarters of breast cancers in the screening population. Interval cancers present with increasing frequency through the screening cycle and are faster growing, pathologically more aggressive lesions.

Authors’ Affiliations

Belfast City Hospital, Belfast, UK
Northern Ireland Breast Screening Programme (Eastern Unit), Belfast, UK


© Malloy et al.; licensee BioMed Central Ltd. 2012

This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.