AIM: For studies done in Malaysia, to identity the sample sizes and heterogeneity present in the various studies which used p16 in evaluating lesions of the cervix. To evaluate if it would be possible for a single study to answer the various questions posed by the original authors. To highlight areas where the design features of future studies can be optimised.
MATERIALS AND METHODS: Various databases were searched using synonyms for p16 AND cervix AND Malaysia. These were assessed for broad conformity to a Diagnostic Test Accuracy format. Methodological and clinical heterogeneity indicators were extracted into standardised fields.
RESULTS: There were 5 studies eligible for inclusion. Each sought to study different aspects of the disease such as diagnostic grade stratification and pathogenesis. The study type broadly conformed to a Diagnostic Test Accuracy format. The study design used was either consecutive or non-consecutive. Sample size ranged from 75 to 201. Clinical heterogeneity was present in the choice of controls with some using normal and some using inflamed tissue. Methodological heterogeneity in applying the reference test, index test and different antibody clones were present.
CONCLUSION: There was both clinical and methodological heterogeneity making synthesis of studies difficult. It is possible to design a study which would be able to answer all the questions posed by the original authors with internal validity while at the same time increasing sample size.
METHODS: Liquid based cervico-vaginal cytology specimens with squamous abnormalities and corresponding histology from 97 women with subsequent colposcopy and biopsy were included. The specimens were then subjected to the dual stain and Roche Cobas 4800 multiplex real time PCR HPV DNA testing. The sensitivity and specificity of the dual stain and HPV testing were calculated using CIN 2+ on histology as a reference standard.
RESULTS: The sensitivity and specificity of the dual stain in detecting histology proven CIN 2+ was 93.7% and 76.5% while HPV testing was 85.7% and 14.7% respectively. Of the 44 women with ASCUS or LSIL on cytology, the dual stain also reduced the number of unnecessary colposcopy referrals from 27 to 7 when used as a triage marker compared to HPV testing.
CONCLUSION: p16/Ki-67 dual stain was more sensitive and specific than HPV testing in determining the presence of CIN 2+ on histology. It could triage low grade cervico-vaginal specimens more effectively and potentially help women avoid unnecessary colposcopies. Future studies are needed to further evaluate its role in cervical cancer screening programmes.