Sensitivity, effect and overdiagnosis in screening for cancers with detectable pre-invasive phase

Contributions of Liquid-Based (Papanicolaou) Cytology and Human Papillomavirus Testing in Cotesting for Detection of Cervical Cancer and Precancer in the United States

Objectives

Given the recent debate challenging the contribution of cytology in cervical screening, we evaluated results of liquid-based cytology (LBC) and human papillomavirus (HPV) testing in cotesting preceding cervical cancer (CxCa) and precancer diagnoses in a national, heterogeneous population.

Methods

We assessed the results of cotesting, performed by Quest Diagnostics, in 13,633,071 women 30 years and older, tested 2010 to 2018. Cotest results preceding CxCa or precancer diagnoses were analyzed and stratified by histopathology.

Results

Among all screening results, 1,615 cotests preceded 1,259 CxCa diagnoses, and 11,164 cotests preceded 8,048 cervical precancer diagnoses. More women who were subsequently diagnosed with CxCa within 1 year were identified by the LBC result than by the HPV result (85.1%, 1,015/1,193 vs 77.5%, 925/1,193). Among all women with CxCa, the overall rate of nondetection was 13.1% (212/1,615) for cotesting results (LBC negative/HPV negative) and this rate increased substantially when testing exceeded 12 months compared to within 1 year prediagnosis of either CxCa or precancer.

Conclusions

Analysis of 9-year cotest results from a national reference laboratory confirms the value of LBC element in cotesting. This supports that LBC/HPV cotesting enhances screening for the identification of CxCa in women 30 years and older, more so than LBC or HPV alone within cotesting.

Personalized Medicine and Cervical Screening: Development of Individualized Quantitative Risk Assessments for Cervical Adenocarcinoma and Adenocarcinoma in situ

INTRODUCTION

Cervical screening has decreased the incidence of cervical carcinoma around the world primarily by preventing cervical squamous carcinoma, with significantly less measurable protective benefits in prevention of cervical adenocarcinoma. In this study, we apply Bayesian modeling of cervical clinical, screening, and biopsy data from a large integrated health system to explore the feasibility of calculating personalized risk assessments on screened system patients for subsequent histopathologic diagnoses of invasive cervical adenocarcinoma (AdCa) or cervical adenocarcinoma in situ (AIS).

MATERIALS AND METHODS

Diagnoses of cervical AIS or AdCa rendered between 2005 and 2018 were identified in our large health system database with 1,053,713 cytology results, 354,843 high-risk (hr) human papillomavirus (HPV) test results, and 99,012 cervical histopathologic results. Using our continuously updated Bayesian cervical cancer screening model which includes clinical data, cervical screening results, and cervical biopsy results, we projected quantitative estimates of patients' 5-year cumulative risk for cervical AIS or AdCa.

RESULTS

161 patients were identified with AIS (ages 17-75, mean 37 years), and 99 patients had diagnoses of cervical AdCa (ages 26-91, mean 48 years). Quantitative Bayesian 5-year cumulative risk projections for diagnoses of cervical AdCa or AIS in patients with different cervical screening test and biopsy histories were determined. The highest patient risk projections for subsequent cervical AdCa and/or AIS histopathologic diagnoses were associated with prior cervical screening test results of HPV-positive atypical glandular cells. Prior squamous cytologic abnormalities were associated with lower risk estimates. Prior histopathologic diagnoses of squamous abnormalities also influenced quantitative risk. A prior histopathologic diagnosis of AIS was associated with a very low risk of subsequent AdCa, consistent with effective excisional treatment. AdCa risk was greatest in women aged 30-65 years with prior CIN3 biopsy results, whereas AIS risk was greatest in women <30.

CONCLUSION

Prevention of cervical AdCa in screened patients remains a major challenge for cervical screening. Individualized risk projections for cervical glandular neoplasia reflecting patient age, prior cervical screening test results, and prior cervical biopsy history are feasible using Bayesian modeling of health system data.

Are CIN3 risk or CIN3+ risk measures reliable surrogates for invasive cervical cancer risk?

•Discuss ASCCP guideline. •CIN3 reliable surrogates for cervical cancer? •The Pittsburgh Cervical Cancer Screening Model.

HPV detection rates and histopathologic follow-up of patients with HSIL cytology in a large academic women's hospital laboratory

INTRODUCTION

High risk (hr) human papillomavirus (HPV) testing has been proposed as a possible replacement for Papanicolaou (Pap) cytology for cervical screening. The aim of the present study was to assess the hrHPV detection rates using 3 available Food and Drug Administration-approved HPV assays in patients with high-grade squamous intraepithelial lesion (HSIL) cytology results and to correlate the cervical screening test results with the immediate histopathologic findings.

MATERIALS AND METHODS

Cases with positive HSIL ThinPrep cytology findings, concurrent hrHPV testing results, and histopathologic follow-up results obtained within 6 months of the Pap/HPV co-testing were identified from July 2010 to April 2018.

RESULTS

A total of 943 HSIL Pap tests were identified with adjunctive hrHPV co-testing, and hrHPV was detected in 883 (93.6%) of these 943 cases. Cervical intraepithelial neoplasia ≥2 (CIN2+) lesions were diagnosed in 71.5% of patients, including 3.2% with invasive squamous cell carcinoma (SCC). In all hrHPV testing platforms, the detection rate for CIN2+ was significantly greater for the patients with positive HPV testing (72.7%) than for those with negative HPV testing (53.4%). However, CIN2+ lesions, including 3 cases of SCC, were found in 24 of 45 women (53.4%) with HSIL Pap and negative HPV testing results.

CONCLUSIONS

The risk of CIN2+ histopathologic findings was significantly greater for patients with hrHPV-positive HSIL results. However, a subset of patients with HPV-negative HSIL results were found to have CIN2+ lesions, including SCC. The long-term effects of primary HPV screening on cervical cancer incidence, stage, and prognosis remain uncertain.

Individualized Bayesian Risk Assessment for Cervical Squamous Neoplasia

Background:

Cervical screening could potentially be improved by better stratifying individual risk for the development of cervical cancer or precancer, possibly even allowing follow-up of individual patients differently than proposed under current guidelines that focus primarily on recent screening test results. We explore the use of a Bayesian decision science model to quantitatively stratify individual risk for the development of cervical squamous neoplasia.

Materials and Methods:

We previously developed a dynamic multivariate Bayesian network model that uses cervical screening and histopathologic data collected over 13 years in our system to quantitatively estimate the risk of individuals for the development of cervical precancer or invasive cervical cancer. The database includes 1,126,048 liquid-based cytology test results belonging to 389,929 women. From-the-vial, high risk human papilloma virus (HPV) test results and follow-up gynecological surgical procedures were available on 33.6% and 12% of these results (378,896 and 134,727), respectively.

Results:

Historical data impacted 5-year cumulative risk for both histopathologic cervical intraepithelial neoplasia 3 (CIN3) and squamous cell carcinoma (SCC) diagnoses. The risk was highest in patients with prior high grade squamous intraepithelial lesion cytology results. Persistent abnormal cervical screening test results, either cytologic or HPV results, were associated with variable increasing risk for squamous neoplasia. Risk also increased with prior histopathologic diagnoses of precancer, including CIN2, CIN3, and adenocarcinoma in situ.

Conclusions:

Bayesian modeling allows for individualized quantitative risk assessments of system patients for histopathologic diagnoses of significant cervical squamous neoplasia, including very rare outcomes such as SCC.

The impact of primary HPV screening on the incidence of cervical cancer in New Zealand

INTRODUCTION

Our objective was to evaluate the impact on the incidence of cervical cancer in New Zealand of 5-yearly human papillomavirus (HPV) primary screening compared with 3-yearly cytology.

MATERIALS AND METHODS

Unbiased estimates of the screening test sensitivity of HPV and cytology screening, and screening coverage, were used to calculate the reduction in cervical cancer incidence obtained by current cytology screening and the new HPV screening policy.

RESULTS

HPV screening in New Zealand is predicted to increase the incidence of cervical cancer in women being screened by 81.7% (95% CI: 38.9%-124.7%). The overall increase in the population incidence of cervical cancer in New Zealand was estimated to be 46.7% (95% CI 42.6%-50.8%), leading to about 57 more women developing cervical cancer each year.

CONCLUSIONS

The results indicate that lengthening the screening interval concurrently with changing to HPV testing may reduce the protection from invasive cervical cancer for women. Women in New Zealand should continue to be screened by cytology every 3 years. Changes to screening policy should be carefully designed so that changes in screening effectiveness can be accurately measured.

Estimation of overdiagnosis by detection to incidence ratio in cancer screening

Objective

We aimed to introduce a concept of overdiagnosis with actual formulae. In screening for invasive cancer, the detection proportion to incidence rate (D/I) ratio is used as an intermediate indicator of effect. D is the detection rate (proportion) at screen and I is the background risk (i.e. the expected incidence rate if there were no screening). We sought to determine a proper use of the D/I ratio in the estimation of overdiagnosis in screening.

Methods

We propose the difference between the D/I ratio per year and incidence-based sensitivity as an estimate of overdiagnosis. As an example to evaluate this, we used screening for colorectal cancer, run as a randomized public health policy in Finland.

Conclusion

The use of the D/I ratio is inappropriate in predicting effect, and we recommend that the D/I ratio be used as a component in the estimation of overdiagnosis in screening for invasive cancer.

Association of symptoms and interval breast cancers in the mammography-screening programme: population-based matched cohort study

Background

We assessed the association between symptoms reported at breast cancer screening visits and interval cancers (ICs) in a prospective manner.

Methods

This population-based matched cohort study uses data of the Finnish National Breast Cancer Screening Programme that invites women aged 50–69 years old during 1992–2012. Subjects who attended screening with symptoms were matched with asymptomatic reference cohorts based on age at screening visit, year of invitation, number of invited visits and municipality of invitation. The primary outcome was ICs.

Results

Women with a lump had a threefold (hazard ratio 3.7, 95% confidence interval (CI) 3.0–4.6) risk of ICs and a higher risk (hazard ratio 1.7, 95% CI 1.4 to 2.0) at the subsequent visit compared with those without a lump. The fatal interval cancer risk increased by 0.39 per 1000 screens with a lump. The cumulative incidences of interval cancer increased within a month of a mammography-negative visit with a lump and after about 6 months of the visit with retraction or nipple discharge.

Conclusion

Women with breast symptoms have a clearly increased risk of interval breast cancer after the screening visit. Our findings indicate the need for different screening strategies in symptomatic women.

HPV screening, invasive cervical cancer and screening policy in Australia

INTRODUCTION

The new cervical screening policy in Australia replaces 2-yearly cytology with 5-yearly human papillomavirus (HPV) screening. However, 2 of 5 randomized trials that have reported the number of women with cervical cancer found the incidence rate of invasive cervical cancer during follow-up to be higher for HPV compared with cytology screening. Therefore, we have estimated the possible impact of the new policy on cervical cancer incidence in Australia.

MATERIALS AND METHODS

Available estimates of the relative protection from cytology screening, estimates of the coverage of the 2-yearly cytology screening policy of the Australian national cervical screening program, and estimates of screening test sensitivity were used to estimate the change in the incidence of cervical cancer from the introduction of the new policy.

RESULTS

HPV screening 5-yearly was predicted to increase the annual incidence of cervical cancer in women screened to 121% (95% CI: 73%-169%) of current incidence after 10 years. The overall incidence of cervical cancer in Australia was predicted to increase by 39.2% (95% CI: 34.0%-44.4%) with an additional 222 women developing cervical cancer each year after 10 years.

CONCLUSIONS

Measures of the screening sensitivity of HPV testing and cervical cytology suggest the introduction of 5-yearly HPV primary screening may increase the incidence cervical cancer in Australia.

Predicting the effectiveness of the Finnish population-based colorectal cancer screening programme

Objective

Because colorectal cancer (CRC) has a long natural history, estimating the effectiveness of CRC screening programmes requires long-term follow-up. As an alternative, we here demonstrate the use of a temporal multi-state natural history model to predict the effectiveness of CRC screening.

Methods

In the Finnish population-based biennial CRC screening programme using faecal occult blood tests (FOBT), which was conducted in a randomised health services study, we estimated the pre-clinical incidence, the mean sojourn time (MST), and the sensitivity of FOBT using a Markov model to analyse data from 2004 to 2007. These estimates were applied to predict, through simulation, the effects of five rounds of screening on the relative rate of reducing advanced CRC with 6 years of follow-up, and on the reduction in mortality with 10 years of follow-up, in a cohort of 500,000 subjects aged 60 to 69.

Results

For localised and non-localised CRC, respectively, the MST was 2.06 and 1.36 years and the sensitivity estimates were 65.12% and 73.70%. The predicted relative risk of non-localised CRC and death from CRC in the screened compared with the control population was 0.86 (95% CI: 0.79–0.98) and 0.91 (95% CI: 0.85–1.02), respectively.

Conclusion

Based on the preliminary results of the Finnish CRC screening programme, our model predicted a 9% reduction in CRC mortality and a 14% reduction in advanced CRC.

Artificial Neural Networks as Decision Support Tools in Cytopathology: Past, Present, and Future

OBJECTIVE

This study aims to analyze the role of artificial neural networks (ANNs) in cytopathology. More specifically, it aims to highlight the importance of employing ANNs in existing and future applications and in identifying unexplored or poorly explored research topics.

STUDY DESIGN

A systematic search was conducted in scientific databases for articles related to cytopathology and ANNs with respect to anatomical places of the human body where cytopathology is performed. For each anatomic system/organ, the major outcomes described in the scientific literature are presented and the most important aspects are highlighted.

RESULTS

The vast majority of ANN applications are related to cervical cytopathology, specifically for the ANN-based, semiautomated commercial diagnostic system PAPNET. For cervical cytopathology, there is a plethora of studies relevant to the diagnostic accuracy; in addition, there are also efforts evaluating cost-effectiveness and applications on primary, secondary, or hybrid screening. For the rest of the anatomical sites, such as the gastrointestinal system, thyroid gland, urinary tract, and breast, there are significantly less efforts relevant to the application of ANNs. Additionally, there are still anatomical systems for which ANNs have never been applied on their cytological material.

CONCLUSIONS

Cytopathology is an ideal discipline to apply ANNs. In general, diagnosis is performed by experts via the light microscope. However, this approach introduces subjectivity, because this is not a universal and objective measurement process. This has resulted in the existence of a gray zone between normal and pathological cases. From the analysis of related articles, it is obvious that there is a need to perform more thorough analyses, using extensive number of cases and particularly for the nonexplored organs. Efforts to apply such systems within the laboratory test environment are required for their future uptake.

Lung cancer screening overdiagnosis: reports of overdiagnosis in screening for lung cancer are grossly exaggerated

The National Lung Cancer Screening Trial (NLST) demonstrated a mortality reduction benefit associated with low-dose computed tomography (LDCT) screening for lung cancer. There has been considerable debate regarding the benefits and harms of LDCT lung cancer screening, including the challenges related to its practical implementation. One of the controversies regards overdiagnosis, which conceptually denotes diagnosing a cancer that, either because of its indolent, low-aggressiveness biologic behavior or because of limited life expectancy, is unlikely to result in significant morbidity during the patient's remainder lifetime. In theory, diagnosing and treating these cancers offer no measurable benefit while incurring costs and risks. Therefore, if a screening test detects a substantial number of overdiagnosed cancers, it is less likely to be effective. It has been argued that LDCT screening for lung cancer results in an unacceptably high rate of overdiagnosis. This article aims to defend the opposite stance. Overdiagnosis does exist and to a certain extent is inherent to any cancer-screening test. Nonetheless, the concept is less dualistic and more nuanced than it has been suggested. Furthermore, the average estimates of overdiagnosis in LDCT lung cancer screening based on the totality of published data are likely much lower than the highest published estimates, if a careful definition of a positive screening test reflecting our current understanding of lung cancer biology is utilized. This article presents evidence on why reports of overdiagnosis in lung cancer screening have been exaggerated.

Addressing overuse and overdiagnosis in colorectal cancer screening for average-risk individuals

SUMMARY 

Inappropriate screening harms healthy individuals and squanders precious resources. The purpose of this review is to address harms of colorectal cancer screening derived from overuse and overdiagnosis in average-risk individuals. Overuse is associated with shorter than recommended repeat screening and surveillance intervals, and screening in individuals who would not derive benefit because of advanced age or significant comorbidity. Overuse can unnecessarily increase patient harm from overdiagnosis or colonoscopy complications as well as gastroenterologist workload and healthcare costs. There is no evidence to suggest that overdiagnosis is an issue for colorectal cancer screening. However, targeting on cancer prevention (detection of adenomatous polyps) rather than early detection will lead to overdiagnosis as only a small minority of polyps develop into cancer.