Light microscopy cannot confidently distinguish which cases will progress and which will regress, and clinicians are therefore obliged to treat all. This will result in the destruction of many lesions of uncertain malignant potential. The secondary prevention of cervical cancer, although therapeutically efficacious, is inefficient. A lack of understanding of the natural history of intraepithelial neoplasia has frustrated attempts to develop rational referral criteria, and it is only now that the appropriate trials are being undertaken. The development of outpatient investigative and therapeutic procedures has resulted in many more women being referred for investigation and treatment, with predictable pressure on other services offered by gynaecologists, but no demonstrable saving of life.
Similar uncertainties surround a screening programme for colorectal cancer.
The principal concerns are not about the efficacy of polypectomy in interrupting the polyp cancer sequence, although uncertainties about the frequency with which cancer arises de novo do require that the effectiveness of this intervention is formally tested. To examine the efficacy of cytopathology laboratories in monitoring action following an abnormal cervical smear. Cellular amounts of EGF receptor messenger RNA remained constant until day 3 of the treatment and were substantially reduced after day 7. Chromatin condensations, morphologic evidence for apoptotic cell death, were observed at day 1 by staining. The average total medical costs in women with detected CIN III are Dfl 3700 per woman.