Cervical acid phosphatase detection: A guide to abnormal cells in cytology smear screening for cervical cancer

Abstract

<b>Background:</b> Cervical acid phosphatase-Papanicolaou (CAP-PAP) test has recently been described for detection of acid phosphatase enzyme in abnormal squamous cells, and has been proposed as a biomarker-based technology for the screening of cervical cancer.<br><b>Materials and Methods:</b> Eighty-one consecutive cervical smears were subjected to routine Papanicolaou (Pap) staining as well as CAP-PAP, which combined cytochemical staining for acid phosphatase with modified Pap stain. Statistical evaluation of its utility was examined.<br><b>Results:</b> Of 81 smears, 16 (19.75%) showed the presence of mature squamous cells with acid phosphatase by CAP-PAP technique and were considered positive. Of these 16, atypical squamous cells of undetermined significance (ASCUS) or above were initially diagnosed in five of the corresponding routine Pap smears. After re-evaluation with CAP-PAP, eight of the routine Pap smears were considered to have ASCUS or above. Of these eight, three were reported as low-grade squamous intraepithelial lesions and five as ASCUS on conventional Pap smears. The remaining 8/16 CAP-PAP-positive cases were negative for atypical squamous cells on the corresponding Pap smears. None of the CAP-PAP-negative smears were positive on routine Pap smear screening.<br><b>Conclusions:</b> This study highlights the efficacy of CAP-PAP in quality assurance of cervical smear screening. It is also an inexpensive method for segregating smears for subsequent re-screening. In the absence of trained cytologists in peripheral laboratories, this technique can be adopted for identifying smears that would require proper evaluation.