Human papillomavirus triage of women with persistent borderline or mildly dyskaryotic smears: Comparison of costs and side effects of three alternative strategies

High lifetime probability of screen-detected cervical abnormalities

Objective

Regular screening and follow-up is an important key to cervical cancer prevention; however, screening inevitably detects mild or borderline abnormalities that would never progress to a more severe stage. We analysed the cumulative probability and recurrence of cervical abnormalities in the Finnish organized screening programme during a 22-year follow-up.

Methods

Screening histories were collected for 364,487 women born between 1950 and 1965. Data consisted of 1 207,017 routine screens and 88,143 follow-up screens between 1991 and 2012. Probabilities of cervical abnormalities by age were estimated using logistic regression and generalized estimating equations methodology.

Results

The probability of experiencing any abnormality at least once at ages 30–64 was 34.0% (95% confidence interval [CI]: 33.3–34.6%). Probability was 5.4% (95% CI: 5.0–5.8%) for results warranting referral and 2.2% (95% CI: 2.0–2.4%) for results with histologically confirmed findings. Previous occurrences were associated with an increased risk of detecting new ones, specifically in older women.

Conclusion

A considerable proportion of women experience at least one abnormal screening result during their lifetime, and yet very few eventually develop an actual precancerous lesion. Re-evaluation of diagnostic criteria concerning mild abnormalities might improve the balance of harms and benefits of screening. Special monitoring of women with recurrent abnormalities especially at older ages may also be needed.

Risk of cervical cancer after completed post-treatment follow-up of cervical intraepithelial neoplasia: population based cohort study

OBJECTIVE

To compare the risk of cervical cancer in women with histologically confirmed cervical intraepithelial neoplasia who returned to routine screening after having completed post-treatment follow-up with consecutive normal smear test results with women with a normal primary smear test result.

DESIGN

Population based cohort study using data from a nationwide pathology register.

SETTING

The Netherlands, 1994 to 2006.

POPULATION

38,956 women with histologically confirmed intraepithelial neoplasia grades 1 to 3 with completed follow-up after treatment.

INTERVENTION

Routine post-treatment follow-up of cervical intraepithelial neoplasia, recommending smear tests at six, 12, and 24 months.

MAIN OUTCOME MEASURE

Incidence of cervical cancer in the period from completed follow-up with negative test results after cervical intraepithelial neoplasia to the next primary test. 10-year hazard ratios were compared with periods after normal results for the primary smear test, adjusted for year in follow-up.

RESULTS

20 cervical cancers were diagnosed during 56,956 woman years after completed follow-up of cervical intraepithelial neoplasia, whereas 1613 cervical cancers were diagnosed during 25,020,697 woman years after a normal primary smear test result. The incidence of 35.1 (95% confidence interval 21.4 to 54.2) per 100,000 woman years and 6.4 (6.1 to 6.8) per 100,000 woman years, respectively, led to an adjusted hazard ratio of 4.2 (95% confidence interval 2.7 to 6.5) for periods after completed follow-up compared with periods after normal primary smear test results. This hazard ratio was increased for all ages. No significant difference in risk of cervical cancer was observed by grade of cervical intraepithelial neoplasia.

CONCLUSIONS

An excess risk of cervical cancer previously observed for women treated for cervical intraepithelial neoplasia was also observed in the subgroup of women who completed their post-treatment follow-up with three consecutive normal smear test results. The overall corrected risk of cervical cancer in these women was increased fourfold 35 cases per 100,000 woman years) compared with women with normal primary smear test results (6 per 100,000 woman years).

Liquid-based cervical cytology using ThinPrep technology: weighing the pros and cons in a cost-effectiveness analysis

PURPOSE

Cervical cancer screening with liquid-based cytology (LBC) has been developed as an alternative to the conventional Papanicolaou (CP) smear. Cost-effectiveness is one of the issues when evaluating LBC. Based on the results of a Dutch randomised controlled trial, we conducted cost-effectiveness threshold analyses to investigate under what circumstances manually screened ThinPrep LBC is cost-effective for screening.

METHODS

The MISCAN-Cervix microsimulation model and data from the Dutch NETHCON trial (including 89,784 women) were used to estimate the costs and (quality-adjusted) life years ((QA)LYs) gained for EU screening schedules, varying cost-effectiveness threshold values. Screening strategies were primary cytological screening with LBC or CP, and triage with human papillomavirus (HPV) testing.

RESULTS

Threshold analyses showed that screening with LBC as a primary test can be cost-effective if LBC is less than <euro>3.2 more costly per test than CP, if the sensitivity of LBC is at least 3-5 % points higher than CP, if the quality of life for women in triage follow-up is only 0.39, or if the rate of inadequate CP smears is at least 16.2 %.

CONCLUSIONS

Regarding test characteristics and costs of LBC and CP, only under certain conditions will a change from CP to manually screened ThinPrep LBC be cost-effective. If none of these conditions are met, implementation of manually screened ThinPrep LBC seems warranted only if there are advantages other than cost-effectiveness. Further research is needed to establish whether other LBC systems will be more favorable with regard to cost-effectiveness.

Cost-effectiveness of cervical cancer screening: cytology versus human papillomavirus DNA testing

OBJECTIVE

To determine the most cost-effective screening programme for cervical cancer.

DESIGN

Cost-effectiveness analysis from a societal perspective.

SETTING

The Netherlands.

POPULATION

Dutch women who have not been invited for human papillomavirus (HPV) vaccination.

METHODS

We calibrated the microsimulation screening analysis (MISCAN) model to Dutch epidemiological data. We used this model to consider nine screening strategies that use: (i) cytological testing with cytology triage for borderline/mildly abnormal smears; (ii) HPV testing with cytology triage for HPV-positive smears; or (iii) cytological testing with HPV triage for borderline/mildly abnormal smears. For each strategy, we varied the number of screening rounds, the time interval, the age of the first screening, and the type of cytological testing (conventional or liquid-based cytology).

MAIN OUTCOME MEASURES

Quality-adjusted life years (QALYs) gained and costs from a societal perspective.

RESULTS

Under the base-case assumptions, primary HPV testing with cytology triage is the most cost-effective strategy. Using cost-effectiveness thresholds of € 20,000 and € 50,000 per QALY gained yields optimal screening programmes with three and seven screening rounds, respectively. The results are sensitive to several uncertain model inputs, most importantly the costs of the HPV test. For women aged 32 years or younger, primary cytology screening is more cost-effective than primary HPV testing.

CONCLUSIONS

Increasing the interval between screening rounds and changing the primary test from cytology to HPV testing can improve the effectiveness and decrease the costs of cervical cancer screening in the Netherlands.

Primary screening for human papillomavirus compared with cytology screening for cervical cancer in European settings: cost effectiveness analysis based on a Dutch microsimulation model

OBJECTIVES

To investigate, using a Dutch model, whether and under what variables framed for other European countries screening for human papillomavirus (HPV) is preferred over cytology screening for cervical cancer, and to calculate the preferred number of examinations over a woman's lifetime.

DESIGN

Cost effectiveness analysis based on a Dutch simulation model. Base case analyses investigated the cost effectiveness of more than 1500 different screening policies using the microsimulation model. Subsequently, the policies were compared for five different scenarios that represent different possible scenarios (risk of cervical cancer, previous screening, quality associated test characteristics, costs of testing, and prevalence of HPV).

SETTING

Various European countries.

POPULATION

Unvaccinated women born between 1939 and 1992.

MAIN OUTCOME MEASURES

Optimal screening strategy in terms of incremental cost effectiveness ratios (costs per quality adjusted life years gained) compared with different cost effectiveness thresholds, for two levels of sensitivity and costs of the HPV test.

RESULTS

Primary HPV screening was the preferred primary test over the age of 30 in many considered scenarios. Primary cytology screening was preferred only in scenarios with low costs of cytology and in scenarios with a high prevalence of HPV in combination with high costs of HPV testing.

CONCLUSIONS

Most European countries should consider switching from primary cytology to HPV screening for cervical cancer. HPV screening must, however, only be implemented in situations where screening is well controlled.

Anxiety and borderline PAP smear results

PURPOSE

Low-grade abnormalities after cervical cancer screening, i.e. borderline (Pap 2) or mildly (Pap 3a1) dyskaryotic (BMD) smear results, are found in considerable numbers of women annually. We compared quality of life and anxiety in women with BMD and a reference group of screening participants who were awaiting smear taking.

METHODS

Five hundred and fifty women with BMD in the preceding 6-24 months, identified through a regional screening organisation, were sent a questionnaire addressing generic quality of life (12-item Short-Form Health Survey [SF-12], EuroQol classification [EQ-5D]), generic anxiety (STAI-6) and screen-specific anxiety (Psychological Consequences Questionnaire [PCQ]).

RESULTS

After adjustment for differences in background characteristics, women with BMD (n=270) reported more generic anxiety (44.4 versus 32.6) and screen-specific anxiety (5.0 versus 1.4) than the reference group (n=352). The differences indicated statistical (p<0.001) and clinical significance. High anxiety (STAI-6>44) was reported by 49% of the BMD group. Mental quality of life was worse in the BMD than in the reference group (44.2 versus 52.0, p<0.001). The BMD group considered screening more often frightening (27% versus 10%) and reported 'fear for cervical cancer' more frequently as their reason for having a (repeat) smear taken (62/270, 23% versus 12/346, 4%).

CONCLUSION/DISCUSSION

BMD smears were consistently associated with considerable excess anxiety in the period of 6-24 months after the original BMD Pap smears had been taken.

Comparison of HPV and cytology triage algorithms for women with borderline or mild dyskaryosis in population-based cervical screening (VUSA-screen study)

We studied the effectiveness of high-risk human papillomavirus (hrHPV) triage for immediate colposcopy in women with borderline or mild dyskaryosis (BMD). In the Utrecht province of the Netherlands, women aged 30-60 years who participated in the regular cervical screening programme were offered hrHPV testing and cytology (intervention group) or cytology only (control group). In the intervention group (n = 337), women with BMD were immediately referred for colposcopy only if the sample was hrHPV positive. Women with a hrHPV negative test were advised to repeat cytology at 6 and 18 months and were referred for colposcopy if and when the repeat test result was positive (BMD or worse). In the control group (n = 329), referral of women with BMD was delayed until cytology was repeatedly positive at 6 or 18 months. The CIN3 detection rates were 10.7% (36/337) in the intervention group and 6.4% (21/329) in the control group (p = 0.047). Moreover, hrHPV triaging resulted in shorter time to diagnosis (154 vs. 381 days). Although the number of colposcopy referrals was 51.5% higher in the intervention group than in the control group, the medical costs per detected CIN3 were slightly lower ([euro] 4781 vs. [euro] 6235). If, in addition, hrHPV negative women had been referred back to routine screening at baseline, the CIN3 rate would have been 10.1% (34/337) and colposcopy rate would only have been 30.4% higher than in the control group. This study shows that hrHPV triaging of women with BMD is at least as effective for detecting CIN3 as repeat cytology, also when hrHPV negative women are referred back to routine screening.