Computer-aided clinical management: microscopic cancer of the ectocervix

The main value of decision analysis is that it makes the trade-offs involved in a decision explicit. When depth of invasion is less than 3 mm with no vascular or lymphatic involvement, the risk of spread is so low that radical surgery is not warranted. When the lesion involves lymphatics but does not penetrate the basement membrane more than 1 mm, conservative therapy is still recommended if the operative mortality rate of radical treatment is at least 3.5 per 1000. However, in units with a low operative mortality rate, radical treatment offers the greatest survival advantage provided that fertility is not an issue. These statements refer only to optimizing survival chances and the decision is one of probabilistic dominance where correct treatment is determined entirely by probabilities rather than utility. For a young potential mother who accepts some risk to preserve fertility, the situation is different. Conservative therapy may be preferable despite lymphatic or vascular involvement provided that there is no more than 1 mm depth of invasion. Where invasion exceeds 5 mm, or where it exceeds 3 mm with vascular involvement, the risk of spread increases exponentially, and there must be very few patients for whom conservative therapy is appropriate.