Retrospective Cohort Study
Copyright ©The Author(s) 2017. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastrointest Oncol. Sep 15, 2017; 9(9): 363-371
Published online Sep 15, 2017. doi: 10.4251/wjgo.v9.i9.363
Characterisation and risk assessment of venous thromboembolism in gastrointestinal cancers
Robert L Metcalf, Eamon Al-Hadithi, Nicholas Hopley, Thomas Henry, Clare Hodgson, Antony McGurk, Wasat Mansoor, Jurjees Hasan
Robert L Metcalf, Eamon Al-Hadithi, Wasat Mansoor, Jurjees Hasan, Department of Medical Oncology, the Christie NHS Foundation Trust, Manchester M20 4BX, United Kingdom
Nicholas Hopley, Thomas Henry, the University of Manchester, Manchester M13 9PL, United Kingdom
Clare Hodgson, Department of Biostatistics, the Christie NHS Foundation Trust, Manchester M20 4BX, United Kingdom
Antony McGurk, Department of Quality and Standards, the Christie NHS Foundation Trust, Manchester M20 4BX, United Kingdom
Author contributions: Metcalf RL and Hasan J designed the research; Hopley N, Henry T and McGurk A performed the data collection; Al-Hadithi E analysed the data and co-wrote the paper; all authors contributed to data analysis and manuscript preparation.
Institutional review board statement: This study was conducted as part of the Christie NHS Foundation Trust’s on-going process of clinical audit including the analysis of the occurrence of thromboembolism and subsequent management and was reviewed and approved by the Institutional Clinical Audit Committee.
Informed consent statement: All data were anonymised prior to analysis and no patient identifiable data were included in the analysis or subsequent presentation of the results. This analysis was performed on a retrospective cohort of 2209 patients treated between 2006 and 2012 as part of the Trust’s process of clinical audit and the analysis was approved by the department of clinical audit. Individual participant informed consent was therefore not sought for this retrospective analysis of non-identifiable population level data.
Conflict-of-interest statement: No authors declare any conflict of interest relating to the work submitted for publication.
Data sharing statement: All data has been stored in an anonymised format in excel spreadsheets which is suitable for sharing upon request.
Open-Access: This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/
Correspondence to: Jurjees Hasan, MSc, MD, FRCP, Department of Medical Oncology, the Christie NHS Foundation Trust, Wilmslow Road, Manchester M20 4BX, United Kingdom. jurjees.hasan@christie.nhs.uk
Telephone: +44-161-4463000
Received: December 24, 2016
Peer-review started: December 28, 2016
First decision: February 4, 2017
Revised: March 16, 2017
Accepted: July 7, 2017
Article in press: July 10, 2017
Published online: September 15, 2017
Abstract
AIM

To characterise venous thromboembolism (VTE) in gastrointestinal cancer and assess the clinical utility of risk stratification scoring.

METHODS

We performed a retrospective analysis using electronic patient records of 910 gastro-oesophageal (GO) cancer and 1299 colorectal cancer (CRC) patients referred to a tertiary cancer centre to identify the incidence of VTE, its relationship to chemotherapy and impact on survival. VTE risk scores were calculated using the Khorana index. Patients were classified as low risk (0 points), intermediate risk (1 to 2 points) or high risk (3 points). Data was analysed to determine the sensitivity of the Khorana score to predict VTE.

RESULTS

The incidence of VTE was 8.9% for CRC patients and 9.7% for GO cancer patients. Pulmonary emboli (PE) were more common in advanced than in localised CRC (50% vs 21% of events respectively) and lower limb deep vein thrombosis (DVT) were more common in localised than in advanced CRC (62% vs 39% of events respectively). The median time to VTE from cancer diagnosis was 8.3 mo for CRC patients compared to 6.7 mo in GO cancer. In localised CRC median time to VTE was 7.1 mo compared with 10.1 mo in advanced CRC. In contrast in GO cancer, the median time to VTE was 12.5 mo in localised disease and 6.8 mo in advanced disease. No survival difference was seen between patients with and without VTE in this cohort. The majority of patients with CRC in whom VTE was diagnosed had low or intermediate Khorana risk score (94% for localised and 97% in advanced CRC). In GO cancer, all patients scored either intermediate or high risk due to the primary site demonstrating a limitation of the risk assessment score in discriminating high and low risk patients with GO cancers. Additional risk factors were identified in this cohort including surgery, chemotherapy or hospital admission. Overall, 81% of patients with CRC and 77% of patients with GO cancer had one or more of these factors within 4 wk prior to diagnosis VTE. These should be factored into clinical risk assessment scores.

CONCLUSION

The Khorana score has low sensitivity for thrombotic events in CRC and cannot discriminate low risk patients in high risk cancer sites such as GO cancer.

Keywords: Thrombo-embolism, Deep venous thrombosis, Pulmonary embolism, Colorectal cancer, Oesophageal cancer, Gastro-oesophageal cancer

Core tip: Analysis of clinical outcomes in 2209 patients with gastrointestinal cancers demonstrated that the Khorana score to assess venous thromboembolism (VTE) risk may have inadequate sensitivity to be clinically useful beyond short term VTE risk.