The impact of changing risk thresholds on the number of people in England eligible for urgent investigation for possible cancer: an observational cross-sectional study

BACKGROUND: Expediting cancer diagnosis may be achieved by targeted decreases in referral thresholds to increase numbers of patients referred for urgent investigation. METHODS: Clinical Practice Research Datalink data from England for 150,921 adults aged ≥40 were used to identify participants with features of possible cancer equating to risk thresholds ≥1%, ≥2% or ≥3% for breast, lung, colorectal, oesophago-gastric, pancreatic, renal, bladder, prostatic, ovarian, endometrial and laryngeal cancers. RESULTS: The mean age of participants was 60 (SD 13) years, with 73,643 males (49%). In 2016, 8576 consultation records contained coded features having a positive predictive value (PPV) of ≥3% for any of the 11 cancers. This equates to a rate of 5682/100,000 patients compared with 4601/100,000 Suspected Cancer NHS referrals for these cancers from April 2016–March 2017. Nine thousands two hundred ninety-one patient-consultation records had coded features equating to a ≥2% PPV, 8% more than met PPV ≥ 3%. Similarly, 19,517 had features with a PPV ≥ 1%, 136% higher than for PPV ≥ 3%. CONCLUSIONS: This study estimated the number of primary-care patients presenting at lower thresholds of cancer risk. The resource implications of liberalising this threshold to 2% are modest and manageable. The details across individual cancer sites should assist planning of English cancer services.