Cervical cytology after 2000: where to go?

Since the introduction of the Pap smear by George Papanicolaou, cervical cytology has become the main diagnostic tool to detect cervical cancer. Nowadays cervical cytology is not only used for the detection of overt cancer cells, but also for finding precursor lesions of cervical cancer—that is, cervical intraepithelial lesions grades I–III (CIN). The success of cervical cytology has often been demonstrated by the decrease in the prevalence of cervical cancer in countries where population based organised cervical cancer screening programmes have been introduced. However, it should be realised that the use of the Pap smear to detect cervical cancer and its precursor lesions is in fact also its tragedy, because the smears read as false negative are often precursor lesions. Principally, cervical cytology can be used in the following ways: + for the detection of cervical cancer and its precursor lesions, either in indicative cervical smears or in population based screening programmes; + for the management of women with abnormal cytology; and + to detect residual or recurrent cervical lesions after treatment. The limited sensitivity and specificity of cervical cytology for detecting cervical cancer and its precursor lesions has been the subject of considerable debate in the last decades. To overcome these problems, several measures have already been taken to improve the end results of smear reading. These include the use of brushes instead of wooden spatulas, optimisation of staining techniques, better training of technicians, and rescreening of smears. These measures have resulted in some improvement in the quality of reading cervical smears. However, it has now become clear that even in high quality laboratories with carefully controlled cervical smear reading, the presence of false positive and false negative smear results cannot entirely be prevented. Given these limitations of cervical cytology the question is whether we can improve the reading of cervical smears. The use of two new technologies may achieve such improvement: 1. The development of liquid based cytology preparations; 2. Automated cervical cytology screening on the basis of morphology, using advanced neural network technology.