Comparison of HPV-based assays with Papanicolaou smears for cervical cancer screening in Morelos State, Mexico.
OBJECTIVE
To compare the performance of human papillomavirus (HPV) assays with conventional Pap cytology for cervical cancer (CC) screening in Mexico.


METHODS
Pap smears, self-collected vaginal specimens (SS) for HPV testing, and clinician-collected cervical specimens (CS) for HPV testing were obtained from 7868 women, aged 15-85 years old, attending CC screening at the Mexican Institute of Social Security (IMSS) between May and October, 1999. SS and CS specimens were screened for oncogenic HPV DNA by Hybrid Capture 2. Women who received cytological interpretations of atypical squamous cells of undetermined significance (ASCUS), and/or a positive HPV test were referred for colposcopy and histologic studies. The relative estimates for sensitivity, specificity and predictive values of each test were calculated using histological diagnoses of cervical intraepithelial neoplasia (CIN) grades 2 or 3, or CC histological diagnosis.


RESULTS
Oncogenic HPV detection rate was 11.6% for SS, and 9.3% for CS. Pap smear abnormalities were observed in 2.4% of the women. Of 1147 women who had at least one abnormal test result, 88.5% underwent colposcopy, and 101 biopsy-confirmed CIN2/3 or cancer cases were identified. The relative sensitivity estimates for the Pap test, SS and CS were 59.4% (95% CI: 49.2-68.9), 71.3% (95% CI: 61.3-79.6), and 93.1% (95% CI: 85.8-96.9), respectively, while the specificities were 98.3% (95% CI: 98.0-98.6), 89.2% (95% CI: 88.5-89.9), and 91.8% (95% CI: 91.2-92.4), respectively. The positive predictive values of Pap, SS and CS were 36.1, 9.1 and 14.9, the colposcopy referrals needed to detect a case of CIN2/3 or cancer were 2.8, 11.0 and 6.7, respectively.


CONCLUSIONS
Both HPV assays detected more cases of CIN2/3 or CC than Pap cytology alone. However, the HPV assays increased the number of colposcopy referrals. Our study suggests that HPV testing could be an effective way to improve the performance of CC screening.
Salmerón
Jorge
J
Unidad de Investigación Epidemiológica y en Servicios de Salud, Instituto Mexicano del Seguro Social, Morelos, México. jsalme@prodigy.net.mx
Lazcano-Ponce
Eduardo
E
Lorincz
Attila
A
Hernández
Mauricio
M
Hernández
Pilar
P
Leyva
Ahideé
A
Uribe
Mario
M
Manzanares
Horacio
H
Antunez
Alfredo
A
Carmona
Enrique
E
Ronnett
Brigitte M
BM
Sherman
Mark E
ME
Bishai
David
D
Ferris
Daron
D
Flores
Yvonne
Y
Yunes
Elsa
E
Shah
Keerti V
KV
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003581:Cytodiagnosis; D004279:DNA, Viral / Q000302:isolation & purification; D005260:Female; D006801:Humans; D008403:Mass Screening / Q000379:methods*; D008800:Mexico; D008875:Middle Aged; D065006:Papanicolaou Test; D027383:Papillomaviridae / Q000235:genetics / Q000302:isolation & purification*; D030361:Papillomavirus Infections / Q000175:diagnosis / Q000473:pathology*; D002583:Uterine Cervical Neoplasms / Q000175:diagnosis* / Q000473:pathology / Q000821:virology; D014626:Vaginal Smears; D002578:Uterine Cervical Dysplasia / Q000175:diagnosis* / Q000473:pathology / Q000821:virology
D004279:DNA, Viral