Cervical Cancer in New Zealand —A Failure of Cytology?—

Incidence rates (1948 – 1977) and mortality rates (1941 – 1978) for invasive cervical cancer, together with reporting rates for in situ cancer and cytology screening rates, are considered for New Zealand to find whether the predictions which can be made from the current general biological model of cervical cancer, i.e. normal epithelium ⇄ dysplasia ⇄ carcinoma in situ invasive cancer, are verifiable or not. The results, notably significant rises in mortality and incidence in women 20–34 years old, barely significant falls in incidence in older women, a failure of the proportion of early-stage invasive cancers to rise, and an enormous increase in reported in situ cancer in the later years without an increase in screening to account for this, cast doubt on the validity of the model and the value of cytological screening in the control of cervical cancer.