The Consensus Project: Participation in cervical cancer screening by the first cohorts of girls offered HPV vaccination at age 15-16 years in Italy

OBJECTIVE

To evaluate the association between human papillomavirus vaccination status and participation in cervical cancer screening (at age 25) by the first cohorts of girls who were offered vaccination at the age of 15 to 16 years in Italy.

METHODS

Women born in 1993, 1994 and 1995 were invited to participate in cervical cancer screening between 2018 and 2020. We report participation in screening by vaccination status in three large areas, Florence province, Piedmont region and Savona province, where the Consensus Project was carried out. The relative risk of participation among vaccinated (≥2 doses) and unvaccinated women was estimated. Odds ratios (OR) of participation by vaccination status were estimated by logistic regression, adjusted by birthplace and birth cohort.

RESULTS

Overall, 34,993 women were invited for screening: 13,006 (37.2%) participated and 10,062 of these agreed to participate in the Consensus intervention study. Among the invited women and screening participants, vaccinated women were 51.0% and 60.6%, respectively. Comparing vaccinated and unvaccinated women, the adjusted OR of screening participation was 1.80 (95% confidence interval (CI): 1.72-1.89), 2.17 (95% CI: 1.94-2.42), 1.59 (95% CI: 1.50-1.68) and 1.15 (95% CI: 0.86-1.54) for overall, Florence, Piedmont and Savona, respectively. About 33% of the invited women were unvaccinated and did not participate in screening: 25.8%, 59.5% and 64.2% of women born in Italy, in high migration pressure countries and in advanced development countries, respectively.

CONCLUSIONS

Screening participation was higher among vaccinated than unvaccinated women. Active policies are needed to reduce inequalities, targeting the unscreened and unvaccinated population, particularly non-native women, to accelerate cervical cancer elimination in Italy.

Assessment of the feasibility of pool testing for SARS-CoV-2 infection screening

BACKGROUND

SARS-CoV-2 pandemic represented a huge challenge for national health systems worldwide. Pooling nasopharyngeal (NP) swabs seems to be a promising strategy, saving time and resources, but it could reduce the sensitivity of the RT-PCR and exacerbate samples management in terms of automation and tracing. In this study, taking advantage of the routine implementation of a screening plan on health workers, we evaluated the feasibility of pool testing for SARS-CoV-2 infection diagnosis in the presence of low viral load samples.

METHOD

Pools were prepared with an automated instrument, mixing 4, 6 or 20 NP specimens, including one, two or none positive samples. Ct values of positive samples were on average about 35 for the four genes analyzed.

RESULTS

The overall sensitivity of 4-samples and 6-samples pools was 93.1 and 90.0%, respectively. Focussing on pools including one sample with Ct value ≥35 for all analyzed genes, sensitivity decreased to 77.8 and 75.0% for 4- and 6-samples, respectively; pools including two positive samples, resulted positive in any size as well as pools including positive samples with Ct values <35.

CONCLUSION

Pool testing strategy should account the balance between cost-effectiveness, dilution effect and prevalence of the infection. Our study demonstrated the good performances in terms of sensitivity and saving resources of pool testing mixing 4 or 6 samples, even including low viral load specimens, in a real screening context possibly affected by prevalence fluctuation. In conclusion, pool testing strategy represents an efficient and resources saving surveillance and tracing tool, especially in specific context like schools, even for monitoring changes in prevalence associated to vaccination campaign.

Interobserver reproducibility of cytologic p16INK4a /Ki-67 dual immunostaining in human papillomavirus-positive women

BACKGROUND

The accumulation of cyclin-dependent kinase inhibitor 2A (p16^ink4a ) protein in a cell is associated with neoplastic progression in precancerous cervical lesions. Dual staining for p16^ink4a and Ki-67 has been proposed as a triage test in cervical cancer screening for women who test positive for human papillomavirus DNA. In this study, interobserver reproducibility of the interpretation of this test was assessed.

METHODS

Forty-two immunostained, liquid-based cytology slides were divided into 2 sets and were interpreted by 17 to 21 readers from 9 different laboratories, yielding a total of 816 reports. Immunostaining results were classified as positive, negative, inconclusive, or inadequate. After evaluation of the first set of slides and before circulation of the second set, the results were discussed in a plenary meeting. The 10 slides with the most discordant results were evaluated again by selected expert cytopathologists.

RESULTS

The overall κ value was 0.612 (95% confidence interval [CI], 0.523-0.701), it was higher for the positive and negative categories (κ = 0.692 and κ = 0.641, respectively), and it was almost null for the inconclusive category (κ = 0.058). Considering only readers from laboratories with documented experience, the κ value was higher (κ = 0.747; 95% CI, 0.643-0.839) compared with nonexperienced centers (κ = 0.498; 95% CI, 0.388-0.616). The results were similar in both sets of slides (κ = 0.505 [95% CI, 0.358-0.642] and κ = 0.521 [95% CI, 0.240-0.698] for the first and second sets, respectively). Reinterpretation of the slides with the most discordant results did not provide any improvement (first evaluation, κ = 0.616 [95% CI, 0.384-0.866]; second evaluation, κ = 0.403 [95% CI, 0.182-0.643]).

CONCLUSIONS

Dual staining for p16 ^ink4a and Ki-67 demonstrated good reproducibility, confirming its robustness, which is a necessary prerequisite for its adoption as a triage test in cervical cancer screening programs that use human papillomavirus DNA as a primary test. Cancer Cytopathol 2017;125:212-220. © 2016 American Cancer Society.

Distribution of high and low risk HPV types by cytological status: a population based study from Italy

Background

HPV type distribution by cytological status represents useful information to predict the impact of mass vaccination on screening programs.

Methods

women aged from 25 to 64 who attended cervical cancer screening in five different Italian regions were tested for HPV infection with Hybrid Capture II (HCII) low and high risk probes. Women repeating Pap-test upon unsatisfactory or positive results, or as a post-treatment and post-colposcopy follow-up analysis, were excluded from our study. High risk (HR) HPV positive samples were typed using GP5+/GP6+ primed PCR, followed by Reverse Line Blot for 18 high/intermediate risk HPV types, while low risk (LR) HPV positive samples were tested with type specific primers for HPV6 and HPV11.

Results

3410 women had a valid HCII and Pap-test. The prevalence of HR and LR infections was 7.0% and 3.6%, 29.1% and 13.7%, 68.1% and 31.9%, 60.0% and 0.0%, 65.0% and 12.0%, for negative, ASC-US, L-SIL, ASC-H and H-SIL cytology, respectively. The fraction of ASC-US+ cytology due to HPV 16 and 18 ranged from 11.2 (HPV 16/18 alone) to 15.4% (including HPV 16/18 in co-infection with other virus strains), and that due to HPV 6 and 11 ranged from 0.2% (HPV 6/11 alone) to 0.7% (including HPV 6/11 in co-infection with other LR virus strains).

Conclusions

mass vaccination with bivalent or quadrivalent HPV vaccine would modestly impact on prevalence of abnormal Pap-test in screening.

Comparison of the Digene HC2 assay and the Roche AMPLICOR human papillomavirus (HPV) test for detection of high-risk HPV genotypes in cervical samples

Many different methods with different sensitivity and specificity have been proposed to detect the presence of high-risk human papillomavirus (HR HPV) in cervical samples. The HC2 is one of the most widely used. Recently, a new standardized PCR-based method, the AMPLICOR HPV test, has been introduced. Both assays recognize the same 13 HR HPV genotypes. The performances of these two commercially available assays were compared in 167 consecutive women (for a total of 168 samples) who presented at the Colposcopy Clinic either for a follow-up or for a diagnostic visit. Concordant results were found in 140/168 cervical samples (overall agreement, 83%; Cohen's kappa = 0.63). Twenty-eight samples gave discordant results: 20 were positive with the AMPLICOR HPV test and negative with the HC2 assay, and 8 were negative with the AMPLICOR HPV test and positive with the HC2 assay. The genotyping showed that no HR HPV was detected in the 8 HC2 assay-positive AMPLICOR HPV test-negative samples, while in 8/20 AMPLICOR HPV test-positive HC2 assay-negative samples, an HR HPV genotype was found. The AMPLICOR HPV test scored positive in a significantly higher percentage of subjects with normal Pap smears. All 7 cervical intraepithelial neoplasia grade 3 patients scored positive with the AMPLICOR HPV test, while 2 of them scored negative with HC2. Both tests had positive results in the only patient with squamous cell carcinoma. In conclusion, this study shows that the HC2 assay and the AMPLICOR HPV test give comparable results, with both being suitable for routine use. The differences noted in some cases may suggest a different optimal clinical use.

Clinical impact (cost-effectiveness) of qualifying atypical squamous cells of undeterminate significance (ASCUS) in cases favoring a reactive or dysplastic process

The cost-effectiveness of qualifying ASCUS cases into two different subcategories, favoring a reactive (ASCUS-R) or dysplastic process (ASCUS-S), was evaluated at the Centro per lo Studio e la Prevenzione Oncologica of Florence in a prospective study. The study determined the positive predictive value (PPV) for histologically confirmed cervical intraepithelial neoplasia grade 2 (CIN2) or more (CIN>) severe lesion of the two ASCUS subgroups. ASCUS-S had a PPV (10.78%) comparable to low-grade squamous intraepithelial lesions (LSIL) (11.40%). For ASCUS-R cases, the recommendation of 6-mo repeat cytology prompting colposcopy in cases of persistent ASCUS or more severe cytology was also effective, as it selected a subgroup with a relatively high PPV (10.34%). The cost-effectiveness of a protocol based on ASCUS qualification was compared with two other possible options for nonqualified ASCUS cases: immediate colposcopy and colposcopy in persistent ASCUS at 6-mo repeat cytology. The detection rate of CIN2> was substantially higher using ASCUS qualification (35.9 vs 14.8 or 17.1). The cost per ASCUS subject was euro 24.99, 27.11, or 25.14 and that per CIN2> detected was euro 697, 1,831 or 1,470 for the three options, respectively. The evidence that ASCUS detection option implies a higher detection rate of CIN2> and subsequently a lower cost per CIN2> detection must be considered with caution and deserves confirmation by other comparative studies.

Intralaboratory reproducibility in cervical cytology. Results of the application of a 100-slide set

In order to evaluate the agreement and accuracy of cervical (vaginal) cytologic diagnoses, 16 cytologists from a large laboratory in Florence, Italy, with experience ranging from 2 to 25 years, independently examined a set of 100 slides. A common reporting form based on a seven-category classification system was used. Concordance was calculated for each pairwise comparison between the 16 cytologists and between each cytologist and the target diagnosis. The values of the kappa statistic for the whole laboratory were .49 for the multiple raters comparison and .59 for the target diagnosis comparison, showing a relatively good degree of agreement.