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.

Automated summary

Lowering referral thresholds for suspected cancer can expedite diagnosis and increase the number of patients referred for urgent investigation. Data from England showed a significant number of patients with features of possible cancer at different risk thresholds, suggesting that liberalizing the thresholds may not have a substantial impact on resources.