IMMUNOCYTOCHEMICAL AND MOLECULAR ANALYSIS OF LIQUID-BASED CERVICAL CYTOLOGY SPECIMENS IN AHMADU BELLO UNIVERSITY TEACHING HOSPITAL ZARIA, NORTHERN NIGERIA

IMMUNOCYTOCHEMICAL AND MOLECULAR ANALYSIS OF LIQUID-BASED CERVICAL CYTOLOGY SPECIMENS IN AHMADU BELLO UNIVERSITY TEACHING HOSPITAL ZARIA, NORTHERN NIGERIA

Abstract:

Cervical cancer is a common and important public health problem for adult women in developing countries. Many industrialized countries have achieved significant successes in reducing invasive cervical cancer burden over the past six decades mainly due to introduction of screening programmes. On the other hand, cervical cancer is not only the second most common malignancy in adult women, but is also the most common malignancy of the female genital tract in sub-Saharan Africa.The aim of this study was to analyse liquid-based cervical cytology specimens among women attending Family Planning/Gynaecology Clinics in Ahmadu Bello University Teaching Hospital (ABUTH), Zaria using immunocytochemical and molecular techniques.Five hundred (500) consenting women between the ages of 18 – 59 years attending the Family Planning and Gynaecology Clinics of the Ahmadu Bello University Teaching Hospital Zaria, Nigeria were recruited consecutively. Cervical smears were reported using the Bethesda System and all abnormal smears had HPV DNA testing done after extraction of the DNA. The extracted HPV DNA was amplified using Polymerase Chain Reaction (PCR) with GP5+/GP6+ and MY09/MY11 consensus primers which amplifies a 150bp fragment of the L1 Hr-HPV genomic region and positive ones had genotyping done by sequencing. Dual immunocytochemical staining using p16INK4a and Ki67 were done on LSIL and borderline cases. All cases classified as high grade had biopsy and histology done.Five hundred (500) women were screened and the mean age was 40.5 ± 9.7 years. The prevalence of abnormal smears was 5% and the cytological diagnoses comprise Negative (95.0%), Low Grade Squamous Intraepithelial Lesion (LSIL, 2.6%), High Grade Squamous Intraepithelial Lesion (HSIL, 1.4%) and Atypical Squamous Cells of Undetermined Significance (ASC-US, 1.0%). Hr-HPV DNA was prevalent among subjects with abnormal smears andtypes 16, 18 and 33were the most prevalent. No case of co-infection was seen in this study. The evaluation of p16INK4a and Ki67 biomarkers in LSIL vii and borderline smears revealed that 33.3% of cases were positive and subsequently reclassified to HSIL. All the associated risk factors examined were all found to be within the 95% confidence interval but only parity and STDs were found to be statistically significant (P<0.05).Abnormal smears are not uncommon and cytology was found to have good sensitivity and specificity to detect them. One third of LSIL/borderline cases were reclassified high grade due to positivity to p16INK4a/ki67 dual stain. Mass screening for cervical cancer should be encouraged by the State and Federal governments to come up with reliable prevalence from the community and dual immunocytochemical stain with p16/Ki67 should be considered in triage for LSIL and borderline lesions of the cervix. HPV vaccination against the most common subtypes are encouraged among the target population

IMMUNOCYTOCHEMICAL AND MOLECULAR ANALYSIS OF LIQUID-BASED CERVICAL CYTOLOGY SPECIMENS IN AHMADU BELLO UNIVERSITY TEACHING HOSPITAL ZARIA, NORTHERN NIGERIA