Article Text

Download PDFPDF
Original article
Development and external validation of a nomogram and online tool to predict bowel dysfunction following restorative rectal cancer resection: the POLARS score
  1. Nick J Battersby1,2,
  2. George Bouliotis3,
  3. Katrine J Emmertsen4,
  4. Therese Juul4,
  5. Rob Glynne-Jones5,
  6. Graham Branagan6,
  7. Peter Christensen4,
  8. Søren Laurberg4,
  9. Brendan J Moran1,2
  10. on behalf of the UK and Danish LARS Study Groups
    1. 1The Pelican Cancer Foundation, The Ark, Basingstoke, Hampshire, UK
    2. 2Department of Colorectal and Peritoneal Malignancy Surgery, Hampshire Hospitals NHS Foundation Trust, Basingstoke, Hampshire, UK
    3. 3Department of Clinical Statistics, Imperial College London, London, UK
    4. 4Department of Surgery, Aarhus University Hospital, Aarhus, Denmark
    5. 5Radiotherapy Department, Mount-Vernon Cancer Centre, Mount-Vernon Hospital, Northwood, UK
    6. 6Department of Colorectal Surgery, Salisbury NHS Foundation Trust, Salisbury, Wiltshire, UK
    1. Correspondence to Brendan J Moran, Hampshire Hospitals NHS Foundation Trust, Aldermaston Road, Basingstoke, Hampshire RG24 9NA, UK; Brendan.Moran{at}


    Objective Bowel dysfunction is common following a restorative rectal cancer resection, but symptom severity and the degree of quality of life impairment is highly variable. An internationally validated patient-reported outcome measure, Low Anterior Resection Syndrome (LARS) score, now enables these symptoms to be measured. The study purpose was: (1) to develop a model that predicts postoperative bowel function; (2) externally validate the model and (3) incorporate these findings into a nomogram and online tool in order to individualise patient counselling and aid preoperative consent.

    Design Patients more than 1 year after curative restorative anterior resection (UK, median 54 months; Denmark (DK), 56 months since surgery) were invited to complete The European Organisation for Research and Treatment of Cancer Quality of Life Questionnaire - Core 30 version3 (EORTC QLQ-C30 v3), LARS and Wexner incontinence scores. Demographics, tumour characteristics, preoperative/postoperative treatment and surgical procedures were recorded. Using transparent reporting of a multivariable prediction model for individual prognosis or diagnosis (TRIPOD) guidelines, risk factors for bowel dysfunction were independently assessed by advanced linear regression shrinkage techniques for each dataset (UK:DK).

    Results Patients in the development (UK, n=463) and validation (DK, n=938) datasets reported mean (SD) LARS scores of 26 (11) and 24 (11), respectively. Key predictive factors for LARS were: age (at surgery); tumour height, total versus partial mesorectal excision, stoma and preoperative radiotherapy, with satisfactory model calibration and a Mallow's Cp of 7.5 and 5.5, respectively.

    Conclusions The Pre-Operative LARS score (POLARS) is the first nomogram and online tool to predict bowel dysfunction severity prior to anterior resection. Colorectal surgeons, gastroenterologist and nurse specialists may use POLARS to help patients understand their risk of bowel dysfunction and to preoperatively highlight patients who may require additional postoperative support.


    Statistics from

    Request Permissions

    If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.


    • Previous communication: These data were orally presented in part at the Digestive Disorders Federation Conference, London, 2015.

    • Twitter Follow Nick Battersby @BattersbyNick

    • Collaborators The Low Anterior Resection Syndrome (LARS) Study Group consisted of the following centres and investigators (listed in alphabetical order, the principal investigator at each centre is indicated by*): UK Airedale NHS Foundation Trust: R Basit Khan*, C Kurasz, E Waldron; Basingstoke and North Hampshire Hospitals: NJ Battersby, Z Janjau, BJ Moran*, T Shahir; East and North Hertforshire NHS Trust (Lister Hospital): K Chan, R Hughes*, S Kelly; (Mount Vernon Hospital): K Evans, R Glynne-Jones*, F Smith; Harrogate District Hospital: B Heath, D Leinhardt*, A Norton; Leeds Teaching Hospital (St James): D Jayne*, C Moriarty; Luton and Dunstable NHS Trust: E Laing, S Mawdsley*; Mid Yorkshire Hospitals NHS Trust (Pinderfields Hospital): L Bourner, N Narula*, J Ward; Royal Shrewsbury Hospital: J Lacy-Colson*, H Moore, S Potts; Salisbury NHS Foundation Trust: G Branagan*, L Bell, H Chave; Wolverhampton NHS Trust: V Carter, N Mirza*, G Pereira, JG Williams; York NHS Foundation Trust: K Last*, J Todd, N Woodcock*. Denmark: The Danish Colorectal Cancer Group.

    • Contributors NJB, GeBo and BJM: conception, design and manuscript draft. NJB and KJE: data extraction. NJB, BJM, RG-J, GrBr, TJ and KJE contributed to patient recruitment. GeBo and NJB: analysis of the data. All authors contributed to revising the article for important intellectual content and approved the final manuscript.

    • Funding The Pelican Cancer Foundation, Basingstoke, UK funded this study and the Danish Cancer Foundation funded collection of the Danish data.

    • Competing interests None declared.

    • Patient consent Obtained.

    • Ethics approval NRES Committee West Midlands—The Black Country.

    • Provenance and peer review Not commissioned; externally peer reviewed.