The Efficiency of Cervical Pap and Comparison of Conventional Pap Smear and Liquid-Based Cytology: A Review.

Cervical cancer is one of the leading health burdens globally with a huge incidence in developing countries like India. Cervical cancer has an extended premalignant stage known as cervical dysplasia or cervical intraepithelial neoplasia (CIN). CIN can be grade 1, 2, or 3 depending on its severity. One of the most effective methods of cervical cancer screening and prevention is detecting these premalignant lesions by cervical cytology. Pioneered by Dr. George Nicholas Papanicolaou, the Papanicolaou (Pap) stain became an important advent for the microscopic evaluation of the exfoliated cervical cells. Over the years, this method of conventional Pap smear became more practiced and yielded excellent results, so much so that the incidence of cervical cancer actually started to decline in developed countries. However, few drawbacks started to become evident with conventional Pap smears like unsatisfactory samples due to obscuring materials, false negative results due to sampling error, and low sensitivity. To overcome these drawbacks of conventional Pap smear, liquid-based cytology (LBC) was introduced in 1996. Thereafter, many investigations and studies have been conducted by many authors to compare the efficacy of conventional Pap smear and LBC. This review puts forward the facts and results of various studies pertaining to efficacy of cervical cytology, comparing conventional Pap smear and LBC, and highlighting the pros and cons of each method based on various studies. For this review, relevant articles under the headings "Conventional PAP smear", "Cervical cancer screening", "Liquid-based cytology" and "Comparison" have been searched in PubMed/MEDLINE and Google Scholar. About 100 articles were studied, and all the facts have been highlighted. While many studies did support LBC over conventional Pap smear for screening of cervical abnormalities, some studies did not find any major difference between the two and preferred the practice of conventional Pap smear in our Indian scenario considering the low-resource setting and low price. This research highlights the various facts of the two types of cervical Pap smear and their comparison.