Prevalence and epidemiologic correlates of atypical squamous cells of undetermined significance in women at low risk for cervical cancer

Prevalence of human papillomavirus (HPV) in Brazil: A systematic review and meta-analysis

OBJECTIVES

This study aimed to estimate the prevalence of genital, anal and oral HPV infection in Brazil through systematic review and meta-analysis.

METHODS

We searched EMBASE, LILACS, MEDLINE, Web of Science and SciELO from inception to December 2018. Original research articles that assessed the prevalence of genital (i.e., cervical, penile), anal and oral HPV infection in Brazil were selected in pairs by independent authors. No sex, age, HPV vaccination, language or date restrictions were applied. HPV prevalence was estimated and stratified according to risk factors population and by geographic area throughout the country. The study prevalence was pooled using a random effects model. Analysis was performed using R (version 3.5.2), packages meta version 4.9-4 and metaphor 2.0-0. This review is registered on PROSPERO under protocol number CRD42016032751.

RESULTS

We identified 3,351 references. After the screening process, 139 of them were eligible for this systematic review (57,513 total participants). Prevalence of cervical HPV was 25.41% (95% CI 22.71-28.32). Additionally, prevalence was 36.21% (95% CI 23.40, 51.33) in the penile region, 25.68% (95%CI 14.64, 41.04) in the anal region, and 11.89% (95%CI 6.26, 21.43) in the oral region. Subgroup analysis showed prevalence in each anatomic site was higher in high-risk populations.

CONCLUSION

The prevalence of HPV is high in the Brazilian population and varies by population risk and anatomic body site, with lower rates in the oral cavity compared to that in the cervical, penile and anal region. Studies on HPV have primarily been developed to evaluate infection and cancer in the cervical region. There is a profound lack of HPV data in many geographic regions of Brazil and for different anatomic sites.

Cervical HPV infection in Brazil: systematic review

OBJECTIVE

To assess the prevalence of human papillomavirus (HPV) infection in women in Brazil.

METHODS

A systematic literature review was conducted with an active search in PubMed and Virtual Health Library databases using the terms "human papillomavirus," "HPV," "prevalence," and "Brazil". Of 155 articles retrieved, 82 were selected after reading their title and abstract. After a thorough examination, 14 articles were included in the study.

RESULTS

The 14 articles selected were published between 1989 and 2008 and comprised studies from four Brazilian macroregions (Southeast - 43%; South - 21.4%; Northeast - 21.4%; and North - 7.1%). Nine were cross-sectional studies. Eight articles used polymerase chain reaction and seven used hybrid capture for HPV detection. The study samples ranged from 49 to 2,329 women. The overall prevalence of HPV cervical infection was between 13.7% and 54.3%; and women with cytologically normal results had 10% to 24.5% prevalence of HPV cervical infection. Four articles described the most common HPV types.

CONCLUSIONS

The cytology techniques available use different classifications leading to different HPV prevalence estimates. However, considering the studies individually according to the detection technique used, the HPV prevalence has increased. HPV16 was the most prevalent type among women, regardless of the cytology result. The concentration of studies in the Southeast region, especially in metropolitan regions, evidences that further investigations are needed to improve information coverage of Brazilian women.

Clinical significance of cytologic atypical squamous cells of undetermined significance

OBJECTIVE

To analyze the screening status, clinical characteristics, and risk of invasive cervical cancer in women with cytologic atypical squamous cells of undetermined significance (ASC-US) in general populations and to make recommendations for these women.

METHODS

The 95,309 women with initial cytologic ASC-US from the national cervical cancer screening database in Taiwan were divided into unscreened and screened groups based on their previous screening history. Newly diagnosed invasive cervical cancer cases in the follow-up period were retrieved for analysis.

RESULTS

There were 860 cases of invasive cervical cancer during the follow-up period of 556,758 person-years, with an overall incidence rate of 154.5 cases per 100,000 person-years. The incidence was 92.3 and 257.2 cases per 100,000 person-years in the screened and unscreened groups, respectively. Previous screening history was a strong risk predictor of invasive cervical cancer (hazard ratio 2.8, 95% confidence interval 2.4-3.1, P<.001) after adjustments for age, educational status, and hospital setting. Age was also a significant risk factor for developing invasive cervical cancer in the unscreened group but not in the screened group.

CONCLUSION

Women with cytologic ASC-US, especially those without a previous Pap test or older women, were more likely to develop invasive cervical cancer and should be followed up aggressively.

LEVEL OF EVIDENCE

II.

Human papillomavirus and abnormal Pap test results in Vietnamese-American women: a pilot case-control study

OBJECTIVE

To evaluate the relationship between abnormal Pap test results and human papillomavirus (HPV) in Vietnamese-American women, who have the highest cervical cancer incidence in the United States.

MATERIALS AND METHODS

In 2001, we obtained specimens from 117 Vietnamese women, 24 with abnormal Pap test results including atypical squamous cells of undetermined significance (cases) and 93 with normal Pap test results (controls), as classified by the 1991 Bethesda System. We used L1 consensus primers MY09/MY11 to perform HPV polymerase chain reaction analysis and type-specific probes to perform genotyping.

RESULTS

Thirteen cases (54%) and 6 controls (6%) were HPV positive (p < .001). Ten of 24 cases (42%) and 0 controls (0%) had high-risk HPV types (16, 18, 45, 53, 56, or 66; p < .001). High-risk HPV types were significantly associated with increasing severity of Pap test results.

CONCLUSIONS

Compared with those with normal Pap test results, Vietnamese-American women with abnormal Pap test results were more likely to have high-risk HPV types. Higher cervical cancer incidence among these women is likely the result of less frequent Pap screening rates and not different biology.

Atypical squamous cells of undetermined significance on cervical smears

BACKGROUND

The current study reports on the significance of cervical smears identified as atypical squamous cells of undetermined significance (ASCUS) in the largest Asian screening population to date.

METHODS

From January 1998 to December 1999, 190,000 cervical smears were evaluated by the cervical cytology laboratory at the University of Hong Kong (Hong Kong, China). From these smears, 5579 ASCUS were identified. Follow-up cytology and histology findings were analyzed.

RESULTS

Follow-up cytology or biopsy results were retrieved for 3601 women (64.5%). Of these, 544 (9.8%) and 96 women (1.7%) were found to have low-grade (LSIL) and high-grade (HSIL) squamous intraepithelial lesions, respectively. Biopsy results were obtained for 198 (36.4%) of the 544 women with LSIL. One hundred seventy-nine (32.9%) and 19 women (3.5%) were confirmed to have cervical intraepithelial neoplasia (CIN)-1 and CIN-2-CIN-3, respectively. Biopsy results were retrieved for 53 (55.2%) women with HSIL. Forty patients (41.7%) were confirmed to have CIN-2-CIN-3, whereas CIN-1 was found in the remaining patients. One woman with squamous cell carcinoma was diagnosed by colposcopic biopsy after immediate referral following a diagnosis of ASCUS. There was a significantly larger proportion of LSIL or HSIL (P < 0.0001) or higher-grade findings in women with ASCUS compared with the general screening population. Infective organisms were identified in 412 women (7.4%) with ASCUS. These women had a decreased risk of subsequent development of LSIL (P < 0.0001) or HSIL (P = 0.027).

CONCLUSIONS

ASCUS smears indicated an increased risk of HSIL or carcinoma. The authors suggested careful patient follow-up in such cases.

The ASCUS : SIL ratio and the reference laboratory pathologist

The atypical squamous cells of undetermined significance (ASCUS) : squamous intraepithelial lesion (SIL) ratio was proposed to monitor laboratory use of the ASCUS diagnosis. This study addresses problems associated with comparing pathologists by this means. An intuitive example showed the ASCUS : SIL ratio depends on the prevalence of smears from patients who actually have SIL. In this study of 2000 cervical smears, each of five pathologists made 400 diagnoses. Differences among proportions of SIL diagnoses were statistically significant; differences among proportions of ASCUS diagnoses were not. Had an ASCUS : SIL ratio upper limit of 3.0 been used, two pathologists would have been misidentified as having high ASCUS diagnosis rates. Unlike the situation for laboratories, potential variability in SIL prevalence requires caution in the use of this ratio in assessing pathologists. An alternative measure that is independent of prevalence, the ASCUS : SIL odds ratio, is posited.