The changing face of cervical screening. Challenges for the future

A three-armed trial of the ThinPrep Imaging System

We compared the performance of the ThinPrep (TP) Imaging System (TIS) with manual reading of TP slides (TPM) and with manual reading of the paired conventional Pap smear (PS) in terms of sensitivity for and positive predictive value (PPV) of high-grade disease and productivity. The study consisted of 11,416 routine PS and paired TP slides as well as 103 confirmed abnormal TP slides. In terms of sensitivity for the detection of biopsy-confirmed high-grade disease, overall there was no statistically significant difference between TIS-screened TP (TPI) and TPM (81.1% vs. 86.8%). For the routine cases, TPI was significantly more sensitive than PS (73.4% vs. 57.8%). In terms of PPVs for the cytologic prediction of high-grade disease, there was no statistically, significant difference among TPI, TPM, and PS (75.6%, 73.9%, and 84.6%). For cytologic reports of possible high-grade disease, the PPVs were equivalent for TPI (45.0%) and TPM (37.0%) and there was no significant difference in PPVs between TPI and PS (61.3%). For TP slides, TIS screening showed a 27% productivity gain when compared with manual screening and a 54% productivity gain when compared with manual screening of PS slides. Use of TIS showed productivity benefits when compared with TPM and both productivity and sensitivity benefits over use of PS.

Prevalence and predictors of squamous intraepithelial lesions of the cervix in HIV-infected women in Lusaka, Zambia

OBJECTIVES

HIV-infected women living in resource-constrained nations like Zambia are now accessing antiretroviral therapy and thus may live long enough for HPV-induced cervical cancer to manifest and progress. We evaluated the prevalence and predictors of cervical squamous intraepithelial lesions (SIL) among HIV-infected women in Zambia.

METHODS

We screened 150 consecutive, non-pregnant HIV-infected women accessing HIV/AIDS care services in Lusaka, Zambia. We collected cervical specimens for cytological analysis by liquid-based monolayer cytology (ThinPrep Pap Test) and HPV typing using the Roche Linear Array PCR assay.

RESULTS

The median age of study participants was 36 years (range 23-49 years) and their median CD4+ count was 165/microL (range 7-942). The prevalence of SIL on cytology was 76% (114/150), of which 23.3% (35/150) women had low-grade SIL, 32.6% (49/150) had high-grade SIL, and 20% (30/150) had lesions suspicious for squamous cell carcinoma (SCC). High-risk HPV types were present in 85.3% (128/150) women. On univariate analyses, age of the participant, CD4+ cell count, and presence of any high-risk HPV type were significantly associated with the presence of severely abnormal cytological lesions (i.e., high-grade SIL and lesions suspicious for SCC). Multivariable logistic regression modeling suggested the presence of any high-risk HPV type as an independent predictor of severely abnormal cytology (adjusted OR: 12.4, 95% CI 2.62-58.1, p=0.02).

CONCLUSIONS

The high prevalence of abnormal squamous cytology in our study is one of the highest reported in any population worldwide. Screening of HIV-infected women in resource-constrained settings like Zambia should be implemented to prevent development of HPV-induced SCC.