Tumour growth is more dispersed in pancreatic head cancers than in rectal cancer: implications for resection margin assessment

Authors

  • Caroline Sophie Verbeke,

    1. Department of Histopathology, St James’s University Hospital, The Leeds Teaching Hospitals NHS Trust, Leeds, UK and currently at Department of Pathology, Karolinska University Hospital, Stockholm, Sweden
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  • Johannes Knapp,

    1. School of Physics and Astronomy, University of Leeds, Leeds, UK
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  • Ivar Prydz Gladhaug

    1. Department of Hepatic and Gastrointestinal Surgery, Oslo University Hospital, Rikshospitalet, Norway and Institute of Clinical Medicine, Faculty of Medicine, University of Oslo, Oslo, Norway
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  • Presented in part at the 8th World Congress of the International Hepato-Pancreato-Biliary Association, Mumbai, India, 27 February–2 March 2008.

Dr C S Verbeke, Department of Pathology, Karolinska University Hospital, F42, SE-141 86 Stockholm, Sweden.e-mail: cverbeke@doctors.org.uk

Abstract

Verbeke C S, Knapp J & Gladhaug I P
(2011) Histopathology 59, 1111–1121
Tumour growth is more dispersed in pancreatic head cancers than in rectal cancer: implications for resection margin assessment

Aims:  The UK definition of microscopic resection margin involvement (R1) in pancreatic head cancer, based on tumour lying <1 mm from the margin, has been adopted from rectal cancer, but has never been validated. The aim of this study was to assess the adequacy of the R1 definition for pancreatic head cancers by comparing the growth patterns of rectal (RC), pancreatic (PC), ampullary (AC) and distal bile duct (DBC) adenocarcinomas.

Methods and results:  Distances between tumour cells and tumour cell density in the tumour centre and periphery were quantified by Minimum Spanning Tree (MST) analysis in 10 cases of the four cancer groups. In RC, the MST distance was similar throughout the entire width of the tumour, whereas in PC, DBC and AC it was significantly larger at the periphery than at the tumour centre ( 0.003). While results were similar for PC and DBC, however, distances at the centre and periphery of both cancers were larger compared to AC ( 0.046). Tumour cell density dropped at the periphery of PC to 31% of that at the centre, compared to 83% in RC (< 0.0002).

Conclusions:  Tumour growth in pancreatic head cancers is more dispersed than in RC, particularly in the tumour periphery. Revision of the R1 definition for pancreatic head cancer may therefore need to be considered.

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