The doctrine of early intervention

When assessing interventions, context is more important than doctrine

The principle of early intervention in a disease process is intuitively appealing. Clearly, where early intervention is synonymous with primary prevention, the principle is sound. You need only to look at the fall in recorded cases of poliomyelitis or meningitis caused by Haemophilus influenzae type B after the introduction of their respective vaccines for confirmation of the value of appropriate early intervention.1 But when early intervention means secondary prevention the issue is less clear. We know now that a combination of exercise, diet, and intensive treatment with insulin can delay the start of microvascular complications in patients with insulin dependent diabetes mellitus.2 On the other hand, considerable debate surrounds the treatment and surveillance of patients diagnosed with ductal carcinoma of the breast,3 prostate cancer,4 or malignant melanoma.5

A recent editorial in the New England Journal of Medicine appraising a paper by Weinberger et al6 presented what its author called the …