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©2012 Baishideng Publishing Group Co., Limited. All rights reserved.
Similar fecal immunochemical test results in screening and referral colorectal cancer
Sietze T van Turenhout, Leo GM van Rossum, Frank A Oort, Robert JF Laheij, Anne F van Rijn, Jochim S Terhaar sive Droste, Paul Fockens, René WM van der Hulst, Anneke A Bouman, Jan BMJ Jansen, Gerrit A Meijer, Evelien Dekker, Chris JJ Mulder
Sietze T van Turenhout, Frank A Oort, Jochim S Terhaar sive Droste, Chris JJ Mulder, Department of Gastroenterology and Hepatology, VU University Medical Center, 1081 HV Amsterdam, The Netherlands
Leo GM van Rossum, Department of Epidemiology Biostatistics and HTA, Radboud University Nijmegen Medical Center, 6500 HB Nijmegen, The Netherlands
Robert JF Laheij, Jan BMJ Jansen, Department of Gastroenterology and Hepatology, Radboud University Nijmegen Medical Center, 6500 HB Nijmegen, The Netherlands
Anne F van Rijn, Paul Fockens, Evelien Dekker, Department of Gastroenterology and Hepatology, Academic Medical Center, 1105 AZ Amsterdam, The Netherlands
René WM van der Hulst, Department of Gastroenterology and Hepatology, Kennemer Gasthuis, 2035 RC Haarlem, The Netherlands
Anneke A Bouman, Clinical Chemistry, VU University Medical Center, 1081 HV Amsterdam, The Netherlands
Gerrit A Meijer, Department of Pathology, VU University Medical Center, 1081 HV Amsterdam, The Netherlands
Author contributions: van Turenhout ST, van Rossum LGM, Meijer GA, Dekker E, Mulder CJJ were responsible for study concept and design; van Turenhout ST, van Rossum LGM, Oort FA, Laheij RJF, van Rijn AF, Terhaar sive Droste JS, van der Hulst RWM, Fockens P, Jansen JBMJ, Meijer GA, Dekker E, Mulder CJJ obtained and interpreted the data; Bouman AA provided technical and material support for acquisition of test analysis; van Turenhout ST, van Rossum LGM analyzed the data; van Turenhout ST, van Rossum LGM drafted the manuscript; Oort FA, Laheij RJF, van Rijn AF, Terhaar sive Droste JS, van der Hulst RWM, Fockens P, Jansen JBMJ, Meijer GA, Dekker E, Mulder CJJ critically revised the manuscript for important intellectual content; van Rossum LGM, Meijer GA, Dekker E, Mulder CJJ supervised the study; all authors approved the final version of the manuscript.
Supported by A Research Grant of Center for Translational Molecular Medicine, The Netherlands, to van Turenhout ST; Grant of Nycomed B.V., Hoofddorp to “the Amsterdam Gut-club”, The Netherlands; The Netherlands Organization for Health Research and Development, ZonMW, No. 50-50115-98-060, project 63000004; The original trial was registered under ISRCTN57917442 at Current Controlled Trials (www.controlled-trials.com)
Correspondence to: Sietze T van Turenhout, MD, Department of Gastroenterology and Hepatology, VU University Medical Center, PO Box 7057, 1081 HV Amsterdam, The Netherlands.
s.vanturenhout@vumc.nl
Telephone: +31-20-4440613 Fax: +31-20-4440554
Received: January 15, 2012
Revised: June 21, 2012
Accepted: June 28, 2012
Published online: October 14, 2012
AIM: To improve the interpretation of fecal immunochemical test (FIT) results in colorectal cancer (CRC) cases from screening and referral cohorts.
METHODS: In this comparative observational study, two prospective cohorts of CRC cases were compared. The first cohort was obtained from 10 322 average risk subjects invited for CRC screening with FIT, of which, only subjects with a positive FIT were referred for colonoscopy. The second cohort was obtained from 3637 subjects scheduled for elective colonoscopy with a positive FIT result. The same FIT and positivity threshold (OC sensor; ≥ 50 ng/mL) was used in both cohorts. Colonoscopy was performed in all referral subjects and in FIT positive screening subjects. All CRC cases were selected from both cohorts. Outcome measurements were mean FIT results and FIT scores per tissue tumor stage (T stage).
RESULTS: One hundred and eighteen patients with CRC were included in the present study: 28 cases obtained from the screening cohort (64% male; mean age 65 years, SD 6.5) and 90 cases obtained from the referral cohort (58% male; mean age 69 years, SD 9.8). The mean FIT results found were higher in the referral cohort (829 ± 302 ng/mL vs 613 ± 368 ng/mL, P = 0.02). Tissue tumor stage (T stage) distribution was different between both populations [screening population: 13 (46%) T1, eight (29%) T2, six (21%) T3, one (4%) T4 carcinoma; referral population: 12 (13%) T1, 22 (24%) T2, 52 (58%) T3, four (4%) T4 carcinoma], and higher T stage was significantly associated with higher FIT results (P < 0.001). Per tumor stage, no significant difference in mean FIT results was observed (screening vs referral: T1 498 ± 382 ng/mL vs 725 ± 374 ng/mL, P = 0.22; T2 787 ± 303 ng/mL vs 794 ± 341 ng/mL, P = 0.79; T3 563 ± 368 ng/mL vs 870 ± 258 ng/mL, P = 0.13; T4 not available). After correction for T stage in logistic regression analysis, no significant differences in mean FIT results were observed between both types of cohorts (P = 0.10).
CONCLUSION: Differences in T stage distribution largely explain differences in FIT results between screening and referral cohorts. Therefore, FIT results should be reported according to T stage.
