The impact of cytological cervical screening and its changing role in the future

Cervical cancer screening in Brazilian Amazon Indigenous women: Towards the intensification of public policies for prevention

BACKGROUND

Indigenous women are vulnerable to cervical cancer. Screening is a strategy to reduce the burden of the disease.

OBJECTIVE

To evaluate the prevalence profile of cervical cancer screening cytological results in Brazilian indigenous women by age and frequency of tests compared to non-indigenous women.

METHODS

A cross-sectional study evaluating the prevalences of screening test results in indigenous women assisted in the Brazilian Amazon from 2007 to 2019 (3,231 tests), compared to non-indigenous women (698,415 tests). The main outcome was the cytological result. Other variables were frequency, age groups, and population. The frequency was categorized as "1st test", the first test performed by the women in their lifetime, or "screening test," tests from women who had previously participated in screening. Analyzes were based on prevalences by age group and population. We used Prevalence Ratios (PR) and 95% Confidence Intervals for risks and linear regression for trends.

RESULTS

Data from the 1st test showed a higher prevalence of Low-grade Squamous Intraepithelial Lesion (LSIL) in indigenous women. Peaks were observed in indigenous under 25, 35 to 39, 45 to 49, and 60 to 64. The prevalence of High-grade Squamous Intraepithelial Lesion or more severe (HSIL+) was low in both groups in women younger than 25. The indigenous HSIL+ prevalence curve showed a rapid increase, reaching peaks in women from 25 to 34 years, following a slight decrease and a plateau. In screening tests, HSIL+ was more prevalent in indigenous from 25 to 39 (PR 4.0,2.3;6.8) and 40 to 64 (PR 3.8,1.6;9.0). In indigenous, the PR of HSIL+ results in screening tests over 1st tests showed no screening effect in all age groups. In non-indigenous, there was a significant effect toward protection in the age groups over 25.

CONCLUSION

This screening study of indigenous women from diverse ethnicities showed a higher prevalence of cytological LSIL and HSIl+ than in non-indigenous women. The protective screening effect in reducing HSIL+ prevalence was not observed in indigenous.

Protection against squamous cell carcinoma and cervical adenocarcinoma afforded by cervical cytology screening: a cross-sectional study

OBJECTIVE

The objective of this study was to evaluate the impact of cervical cytology screening on the prevalence of cervical cytological results in women, as a function of age and test interval.

METHODS

This is a cross-sectional study of cytology screening data of 2,002,472 tests obtained from previously screened women and 217,826 tests from unscreened women. The central cytopathology laboratory database was analyzed. The tests were collected for screening purposes from Campinas metropolitan region, Brazil. A prevalence ratio (PR) with a 95% confidence interval was calculated for the screened women, in relation to the unscreened women, and for different tests intervals. Protection afforded by screening (1-PR) was calculated.

RESULTS

For high-grade squamous intraepithelial lesion, the PR was 0.97 (0.83-1.13) for women aged 20 years or younger and 0.99 (0.86-1.14) for women aged 20 to 24 years, decreasing significantly in women aged 25 to 29 years (PR, 0.63 [0.52-0.76]). The PR for squamous cell carcinoma, adenocarcinoma in situ (AIS), and invasive adenocarcinoma showed a significant reduction in all age groups older than 30 years. For the age group ranging from 30 to 59 years, protection for squamous cell carcinoma, AIS, and invasive adenocarcinoma was 83% or higher for screening intervals from 1 to 5 years. Protective effect was not demonstrated for screening intervals longer than 5 years for AIS and invasive adenocarcinoma.

CONCLUSIONS

Cytology screening is effective at preventing cytological high-grade squamous intraepithelial lesion, squamous cell carcinoma, AIS, and invasive adenocarcinoma. On the basis of cytological results, protection against AIS and invasive adenocarcinoma was observed with screening intervals shorter than 5 years. Cytological screening in women 25 years or younger should be critically evaluated.

Teenage cervical screening in a high risk American population

BACKGROUND

The new 2009 ACOG guideline for cervical cytology screening changed the starting age to 21 years regardless of the age of onset of sexual intercourse. However, many recent studies have shown a dramatic increase in the incidence of cervical epithelial abnormalities among adolescents within the past two decades.

MATERIALS AND METHODS

For this study, the reports of 156,342 cervical cytology were available of which 12,226 (7.8%) were from teenagers. A total of 192 teenagers with high grade intraepithelial lesion (HSIL) cervical cytology were identified. The ages ranged from 13 to 19 years with a mean of 17.7 years and a median of 18 years. Among them, 31.3% were pregnant, 12.0% were postpartum, and 13.5% were on oral contraceptive. Ninety-eight had prior cervical cytology.

RESULTS

The teenagers had statistically significant higher detection rates of overall abnormal cervical cytology (23.6% vs. 6.6%, P = 0), with 15.4% vs. 3.2% (P = 0) of low grade intraepithelial lesion (LSIL) and 1.8% vs. 1.0% (P = 2.56 × 10(-13) ) of HSIL compared to women ≥20 years. The teenage group had the highest abnormal cytology among all age groups. The LSIL/HSIL ratio was 8.5:1 for teenagers and 3.1:1 for women ≥20 years. A total of 131 teenagers had cervical biopsies within 12 months of the HSIL cytology, with diagnoses of 39 CIN 3, 1 VAIN 3, 15 CIN 2, 62 CIN 1, and 14 had a negative histology (CIN 0). Only in 19 of these 39 women, the CIN 2/3 lesion proved to be persistent.

CONCLUSION

We conclude that cytology screening of high risk teenagers is effective in detecting CIN 2/3 lesions. Moreover, treatment and careful follow-up can be realized.