Proof of causation: a new approach in cases of breast cancer delay in diagnosis.

Until now, proof of causation in cases of breast cancer delay has relied on being able to show that a delay in treatment has reduced the prospects of 10-year survival from above 50% to below 50%. As survival from breast cancer continues to improve, with 10-year survival close to 80% in England, more and more patients move away from the 50% threshold even with a delay in diagnosis. This effectively excludes the majority of cases from ever proving causation using the balance of probability principle.

In an article recently published in Clinical Risk1, authors Professor Gordon Wishart & Andrew Axon discuss how with use of epidemiological breast cancer data and prognostic models it is now possible to estimate loss of life expectancy as a result of a delay in diagnosis. The authors suggest that this may provide a fairer assessment of the impact of the delay and in many cases where redress is not currently available, better reflect the duty of the treating doctor(s).