P J Toliman1, S Phillips2, S de Jong3, T O'Neill3, G Tan4, J M L Brotherton5, M Saville6, J M Kaldor7, A J Vallely8, S N Tabrizi9. 1. Papua New Guinea Institute of Medical Research, Goroka, Papua New Guinea; The Kirby Institute, UNSW Sydney, Australia. Electronic address: ptoliman@kirby.unsw.edu.au. 2. Department of Microbiology, The Royal Women's Hospital, Parkville, Victoria, Australia; Murdoch Children's Research Institute, Parkville, Victoria, Australia. 3. Anatomical Pathology, The Royal Children's Hospital, Melbourne, Australia. 4. VCS Foundation, Melbourne, Victoria, Australia. 5. VCS Foundation, Melbourne, Victoria, Australia; Melbourne School of Population and Global Health, University of Melbourne, Victoria, Australia. 6. VCS Foundation, Melbourne, Victoria, Australia; Department of Obstetrics and Gynaecology, University of Melbourne, Victoria, Australia. 7. The Kirby Institute, UNSW Sydney, Australia. 8. Papua New Guinea Institute of Medical Research, Goroka, Papua New Guinea; The Kirby Institute, UNSW Sydney, Australia. 9. Department of Microbiology, The Royal Women's Hospital, Parkville, Victoria, Australia; Murdoch Children's Research Institute, Parkville, Victoria, Australia; Department of Obstetrics and Gynaecology, University of Melbourne, Victoria, Australia.
Abstract
OBJECTIVES: To compare the performance of dual immunostaining of p16INK4a and Ki-67 proteins performed on self-collected vaginal specimens and clinician-collected cervical specimens, and to evaluate the performance of this technique in predicting high-grade disease. METHODS: Women aged 30-59 years (n = 1005) were recruited at two well-women clinics in Papua New Guinea. Each woman provided both cervical and vaginal specimens that were tested for high-risk human papillomavirus (hrHPV) DNA using the Xpert HPV Test (Cepheid) at point of care. A subset of paired cervical and vaginal specimens (n = 243) were selected to undergo CINTec® PLUS (Roche) p16/Ki-67 dual-stain cytology and liquid-based cytology (LBC). RESULTS: Fifty-five pairs (22%) were excluded from further analysis because the smears were not assessable. Of the 189 remaining paired specimens, 74 pairs (39.1%) were positive for one or more hrHPV genotypes. When comparing results of the dual stain, the overall percent agreement, positive and negative percent agreements and κ value between the cervical and vaginal specimens were 87.8% (CI 82.3-92.1%), 64.6% (CI 49.5-77.8%), 95.7% (CI 91.0-98.0%) and 0.65 (CI 0.51-0.79%) respectively. The sensitivity of the dual stain performed on the cervical specimen to predict high-grade disease, determined by LBC, was superior to that of the dual stain performed on the vaginal specimen: 100% (CI 84.6-100%) versus 68.2% (CI 45.1-86.1%). CONCLUSION: Although further evaluation may be warranted, these findings indicate that dual-stain testing of vaginal specimens cannot be advocated as part of cervical screening programmes in low- and middle-income countries. However, dual-stain cytology performed on cervical specimens may have a role in quality assurance in such settings.
OBJECTIVES: To compare the performance of dual immunostaining of p16INK4a and Ki-67 proteins performed on self-collected vaginal specimens and clinician-collected cervical specimens, and to evaluate the performance of this technique in predicting high-grade disease. METHODS:Women aged 30-59 years (n = 1005) were recruited at two well-women clinics in Papua New Guinea. Each woman provided both cervical and vaginal specimens that were tested for high-risk human papillomavirus (hrHPV) DNA using the Xpert HPV Test (Cepheid) at point of care. A subset of paired cervical and vaginal specimens (n = 243) were selected to undergo CINTec® PLUS (Roche) p16/Ki-67 dual-stain cytology and liquid-based cytology (LBC). RESULTS: Fifty-five pairs (22%) were excluded from further analysis because the smears were not assessable. Of the 189 remaining paired specimens, 74 pairs (39.1%) were positive for one or more hrHPV genotypes. When comparing results of the dual stain, the overall percent agreement, positive and negative percent agreements and κ value between the cervical and vaginal specimens were 87.8% (CI 82.3-92.1%), 64.6% (CI 49.5-77.8%), 95.7% (CI 91.0-98.0%) and 0.65 (CI 0.51-0.79%) respectively. The sensitivity of the dual stain performed on the cervical specimen to predict high-grade disease, determined by LBC, was superior to that of the dual stain performed on the vaginal specimen: 100% (CI 84.6-100%) versus 68.2% (CI 45.1-86.1%). CONCLUSION: Although further evaluation may be warranted, these findings indicate that dual-stain testing of vaginal specimens cannot be advocated as part of cervical screening programmes in low- and middle-income countries. However, dual-stain cytology performed on cervical specimens may have a role in quality assurance in such settings.