Faecal calprotectin in patients with suspected colorectal cancer: a diagnostic accuracy study.
BACKGROUND
NICE guidance exists for the use of faecal calprotectin (FC) when irritable bowel syndrome or inflammatory bowel disease are suspected. Often, however, colorectal cancer is considered within the differential. Should FC have a high diagnostic accuracy for colorectal cancer, it may be applicable as a primary care screening test for all patients with lower gastrointestinal symptoms.


OBJECTIVE
To determine the negative and positive predictive value (NPV/PPV) of FC in patients referred from primary care with suspected colorectal cancer.


METHODS
A diagnostic accuracy study conducted at a single secondary care site


METHODS
Consenting patients referred with suspected colorectal cancer within the '2-week wait' pathway provided a stool sample for FC prior to investigation. FC levels were reconciled with end diagnoses: cancer, adenomatous polyps ≥10 mm, and all enteric organic disease.


RESULTS
A total of 654 patients completed the evaluation; median age 69 years, female 56%. The NPV for colorectal cancer was 98.6% and 97.2% when including polyps ≥10 mm. The PPV for all organic enteric disease was 32.7%. The diagnostic yield for cancer based on clinical suspicion was 6.3%. By altering the FC cut-off to fix the NPV at 97.0%, the PPV for cancer increased from 8.7% to 13.3%.


CONCLUSIONS
FC has a high NPV for colorectal cancer and significant polyps in patients with suspected cancer. In total, 27.8% of patients had a normal FC and could safely have been spared a '2-week wait' referral. The addition of FC testing into the current symptom-based assessment has the potential to increase colorectal cancer detection rate yet be clinically and cost effective.
Department of Gastroenterology;
James
J
Turvill
Department of Surgery;
Assad
A
Aghahoseini
Department of Surgery;
Nala
N
Sivarajasingham
Department of Surgery;
Kazim
K
Abbas
Department of Surgery;
Murtaza
M
Choudhry
Department of Surgery;
Kostantinos
K
Polyzois
Department of Surgery;
Kostantinos
K
Lasithiotakis
Department of Surgery;
Dimitra
D
Volanaki
Department of Surgery;
Baek
B
Kim
Department of Surgery;
Fiona
F
Langlands
Department of Surgery;
Helen
H
Andrew
Department of Surgery;
Jesper
J
Roos
Department of Clinical Biochemistry, York Teaching Hospital NHS Foundation Trust, York.
Samantha
S
Mellen
Department of Clinical Biochemistry, York Teaching Hospital NHS Foundation Trust, York.
Daniel
D
Turnock
Department of Clinical Biochemistry, York Teaching Hospital NHS Foundation Trust, York.
Alison
A
Jones
D000368:Aged; D015415:Biomarkers / Q000032:analysis; D015179:Colorectal Neoplasms / Q000097:blood / Q000175:diagnosis*; D005243:Feces / Q000737:chemistry; D005260:Female; D006801:Humans; D015212:Inflammatory Bowel Diseases / Q000175:diagnosis; D039841:Leukocyte L1 Antigen Complex / Q000032:analysis* / Q000097:blood; D008297:Male; D009780:Occult Blood; D011237:Predictive Value of Tests; D011320:Primary Health Care; D012017:Referral and Consultation; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D006113:United Kingdom
D015415:Biomarkers; D039841:Leukocyte L1 Antigen Complex
calprotectin; colorectal cancer; diagnostic accuracy; primary care