Evaluating the Role of Faecal Calprotectin in Older Adults.

Background Faecal calprotectin (FC) is a marker of gastrointestinal (GI) inflammation widely used in primary care to identify patients requiring referral for endoscopic assessment. Most guidelines advise against its use in older adults due to higher rates of colorectal cancer. Many studies include only younger adults, despite FC continuing to be used in older adults. Aim This study aimed to evaluate FC performance in identifying IBD and significant organic pathology in adults over 50 years, to help inform its use and interpretation in primary care. Where available, FIT was also analysed. Methods Patients who had FC testing performed followed by a colonoscopy were recruited and grouped into younger adults (aged 18-49 years), and older adults (aged ≥50 years). Results: 669 patients were included; 423 aged 18-49 years and 246 ≥50 years. There were no significant differences in FC levels between the groups (median FC 71g/g vs 85.5g/g, p = 0.29). FC >50g/g showed a high sensitivity for IBD in both groups (94.1% and 93.8%) although a low PPV, particularly in ≥50 years (12.8% vs 20.9%). FC >50g/g outperformed FIT (threshold 10g/g) for the diagnosis of IBD and organic pathology in both groups. However, in the over 50s, FIT outperformed FC at 150g/g for diagnosis of organic pathology including colorectal cancer. Conclusion: These data show that FC remains a sensitive test in older adults. FC may have a role as a "rule out" test in older adults with lower GI symptoms and a negative FIT, where colorectal cancer is not suspected.