RESUMO
INTRODUCTION: The aim of this study was to assess faecal immunochemical test (FIT) negativity in terms of its effect on cancer risk in the local symptomatic two-week wait (2WW) population. FIT was introduced to the colorectal 2WW pathway at the start of the pandemic. This study analyses the FIT-negative (<10µg Hb/g) cohort and calculates the relative risk and odds ratio associated with a negative FIT test. METHODS: FIT tests were sent to symptomatic 2WW patients without rectal bleeding, iron-deficient anaemia or palpable mass. Where FIT was <10µg Hb/g investigations were moved to a radiology protocol. RESULTS: The test return rate was 91% with a FIT-negative (<10µg Hb/g) rate of 82%. The FIT-negative group in the symptomatic referral pathway in Cornwall have a low (1.4%) risk of colon cancer but a significant risk (6.6%) when all cancer types are considered. The impact of a negative quantitative FIT changes the odds ratio of a patient having a luminal cancer by 0.26. The odds ratio for 'all cancer' risk was affected by 0.83. CONCLUSION: A negative FIT test within the local NG12 symptomatic patient group signifies a low risk of colon cancer and identifies patients who can be initially investigated with cross-sectional imaging. However, when all cancer types are considered, cancer prevalence in this group remains above 6%. In relative risk terms a negative FIT represents a small change in overall risk and this patient group still qualify for investigation through 2WW pathways.
