Most patients with cancer who are not diagnosed by screening will be diagnosed after symptoms develop, so timely referral of patients to specialists is essential. In this week's BMJ Potter and colleagues assess the long term impact of the “two week wait” rule in the United Kingdom for breast cancer on referral patterns, diagnoses of cancer, and waiting times.1 Their study found that the diagnosis of cancer in people referred within two weeks significantly decreased in the period 1999-2005 (12.8% v 7.7%, P<0.001) and diagnoses in people referred through the routine route increased (2.5% v 5.3%, P<0.001). The study suggests that the current cancer referral policy in the UK—whereby patients with a given set of symptoms are seen within two weeks—results in more patients who have cancer being seen on routine waiting lists than on the fast track list. This means diagnosis is delayed even further. Why is this so, and how can it be rectified?

In formulating such rules, it is important to remember that …