The impact of mammography screening programmes on incidence of advanced breast cancer in Europe: a literature review.

BACKGROUND: Observational studies have reported conflicting results on the impact of mammography service screening programmes on the advanced breast cancer rate (ABCR), a correlation that was firmly established in randomized controlled trials. We reviewed and summarized studies of the effect of service screening programmes in the European Union on ABCR and discussed their limitations. METHODS: The PubMed database was searched for English language studies published between 01-01-2000 and 01-06-2018. After inspection of titles and abstracts, 220 of the 8644 potentially eligible papers were considered relevant. Their abstracts were reviewed by groups of two authors using predefined criteria. Fifty studies were selected for full paper review, and 22 of these were eligible. A theoretical framework for their review was developed. Review was performed using a ten-point checklist of the methodological caveats in the analysis of studies of ABCR and a standardised assessment form designed to extract quantitative and qualitative information. RESULTS: Most of the evaluable studies support a reduction in ABCR following the introduction of screening. However, all studies were challenged by issues of design and analysis which could at least potentially cause bias, and showed considerable variation in the estimated effect. Problems were observed in duration of follow-up time, availability of reliable reference ABCR, definition of advanced stage, temporal variation in the proportion of unknown-stage cancers, and statistical approach. CONCLUSIONS: We conclude that much of the current controversy on the impact of service screening programmes on ABCR is due to observational data that were gathered and/or analysed with methodological approaches which could not capture stage effects in full. Future research on this important early indicator of screening effectiveness should focus on establishing consensus in the correct methodology.

FIT for the future: a case for risk-based colorectal cancer screening using the faecal immunochemical test.

Worldwide, the guaiac faecal occult blood test (gFOBT) is being replaced with the more accurate faecal immunochemical test (FIT) for colorectal cancer (CRC) screening. From January 2016, the National Screening Committee in the UK has recommended a change from the gFOBT to the FIT following a successful Bowel Cancer Screening Programme pilot study with over 40 000 participants. Although the test has shown improved uptake and the ability to detect significantly more colorectal cancers and advanced adenomas, the higher uptake and test positivity will challenge the capacity of colonoscopy services. One of the main advantages of the FIT is that it provides a quantitative haemoglobin concentration which has been shown to relate to the risk of CRC. Risk scoring systems which combine the FIT concentration with risk factor assessment have been shown to improve the sensitivity of the test. This individualized approach to screening could enable those at greatest risk to be referred for colonoscopy, optimizing resource use and ultimately patient outcomes.

Comparison of the performance of HPV tests in women with abnormal cytology: results of a study within the NHS cervical screening programme.

OBJECTIVE: The use of testing for human papillomavirus (HPV) is now recognized as an efficient means of triaging women with low-grade cytological abnormalities to either immediate referral to colposcopy or return to routine recall. We aimed to determine the sensitivity and specificity of each of four newer tests for HPV relative to the Qiagen Hybrid Capture 2 (HC2) assay in order to determine whether they could be approved for use in triage in the NHS cervical screening programme. METHODS: We compared the performance of each of four different HPV assays (Abbott M2000, Roche Cobas, Hologic Cervista and Gen-Probe APTIMA) with that of HC2 in order to determine the sensitivity and specificity of each test relative to HC2 for the detection of cervical intraepithelial neoplasia (CIN) grade 2 or worse, using routine cytology samples reported as borderline (atypical squamous cells) or mild dyskaryosis (low-grade squamous intraepithelial lesion) from six laboratories in England. All women who were found to be HPV positive on any test were referred to colposcopy. RESULTS: Between 2072 and 4217 tests were performed with each assay. All four assays were shown to have a relative sensitivity of no worse than 95% compared with HC2 when a cut-off of 2 relative light units (RLU) was used. All assays had higher relative specificity than HC2 for both borderline and mild cytology referrals (1.06-1.61). CONCLUSIONS: All assays tested met the criteria required. Consequently, all have now been approved for use in HPV triage in the NHS cervical screening programme.

Cost-effectiveness of prostate cancer screening: a simulation study based on ERSPC data.

BACKGROUND: The results of the European Randomized Study of Screening for Prostate Cancer (ERSPC) trial showed a statistically significant 29% prostate cancer mortality reduction for the men screened in the intervention arm and a 23% negative impact on the life-years gained because of quality of life. However, alternative prostate-specific antigen (PSA) screening strategies for the population may exist, optimizing the effects on mortality reduction, quality of life, overdiagnosis, and costs. METHODS: Based on data of the ERSPC trial, we predicted the numbers of prostate cancers diagnosed, prostate cancer deaths averted, life-years and quality-adjusted life-years (QALY) gained, and cost-effectiveness of 68 screening strategies starting at age 55 years, with a PSA threshold of 3, using microsimulation modeling. The screening strategies varied by age to stop screening and screening interval (one to 14 years or once in a lifetime screens), and therefore number of tests. RESULTS: Screening at short intervals of three years or less was more cost-effective than using longer intervals. Screening at ages 55 to 59 years with two-year intervals had an incremental cost-effectiveness ratio of $73000 per QALY gained and was considered optimal. With this strategy, lifetime prostate cancer mortality reduction was predicted as 13%, and 33% of the screen-detected cancers were overdiagnosed. When better quality of life for the post-treatment period could be achieved, an older age of 65 to 72 years for ending screening was obtained. CONCLUSION: Prostate cancer screening can be cost-effective when it is limited to two or three screens between ages 55 to 59 years. Screening above age 63 years is less cost-effective because of loss of QALYs because of overdiagnosis.

Estimating breast cancer mortality reduction and overdiagnosis due to screening for different strategies in the United Kingdom.

BACKGROUND: The benefits and harms of population-wide mammography screening have been long debated. This study evaluated the impact of screening frequency and age range on breast cancer mortality reduction and overdiagnosis. METHODS: We developed a Markov simulation model for the evaluation of mammography screening in a cohort of British women born in 1935-40. RESULTS: For triennial screening in women aged 47-73, breast cancer mortality reduction and overdiagnosis was 18.1% (95% confidence interval: 17.3%, 19.0%) and 5.6% (5.1%, 6.1%), of all breast cancer deaths and diagnoses, respectively, from age 40 to 85 years. For annual screening in the same age range, estimates for both outcomes increased considerably to 35.0% (34.2%, 35.7%) and 7.6% (7.1%, 8.1%), respectively. For the age extension of triennial screening from 50-70 to 47-73, we estimated 5 (3, 7) incremental breast cancer deaths avoided and 14 (9, 19) incremental cases overdiagnosed per 10 000 women invited for screening. CONCLUSIONS: Estimates of mortality reduction and overdiagnosis were highly dependent on screening frequency, age range, and uptake, which may explain differences between some previous estimates obtained from randomised trials and from service screening.

Longer mean colonoscopy withdrawal time is associated with increased adenoma detection: evidence from the Bowel Cancer Screening Programme in England.

BACKGROUND AND STUDY AIMS: Increasing colonoscopy withdrawal time (CWT) is thought to be associated with increasing adenoma detection rate (ADR). Current English guidelines recommend a minimum CWT of 6 minutes. It is known that in the Bowel Cancer Screening Programme (BCSP) in England there is wide variation in CWT. The aim of this observational study was to examine the relationship between CWT and ADR. PATIENTS AND METHODS: The study examined data from 31 088 colonoscopies by 147 screening program colonoscopists. Colonoscopists were grouped in four levels of mean CWT ( < 7, 7 - 8.9, 9 - 10.9, and ≥ 11 minutes). Univariable and multivariable analysis (binary logistic and negative binomial regression) were used to explore the relationship between CWT, ADR, mean number of adenomas and number of right-sided and advanced adenomas. RESULTS: In colonoscopists with a mean CWT < 7 minutes, the mean ADR was 42.5 % compared with 47.1 % in the ≥ 11-minute group (P < 0.001). The mean number of adenomas detected per procedure increased from 0.77 to 0.94, respectively (P < 0.001). The increase in adenoma detection was mainly of subcentimeter or proximal adenomas; there was no increase in the detection of advanced adenomas. Regression models showed an increase in ADR from 43 % to 46.5 % for mean CWT times ranging from 6 to 10 minutes. CONCLUSIONS: This study demonstrates that longer mean withdrawal times are associated with increasing adenoma detection, mainly of small or right-sided adenomas. However, beyond 10 minutes the increase in ADR is minimal. Mean withdrawal times longer than 6 minutes are not associated with increased detection of advanced adenomas. Withdrawal time remains an important quality metric of colonoscopy.

The impact of mammographic screening on breast cancer mortality in Europe: a review of trend studies.

OBJECTIVE: Analysing trends in population breast cancer mortality statistics appears a simple method of estimating the effectiveness of mammographic screening programmes. We reviewed such studies of population-based screening in Europe to assess their value. METHODS: A literature review identified 17 papers, of which 12 provided quantitative estimates of the impact of screening. Due to differences in comparisons and outcome measures, no pooled estimate of effectiveness was calculated. RESULTS: Comparisons included breast cancer mortality before and after the introduction of screening, trends in early and late starting areas and trends in age groups affected and unaffected by screening. Studies that calculated the percentage annual change after the start of screening found reductions of 1-9% per year (1%, 2.3-2.8% and 9% for those with adequate follow-up). Of studies that compared mortality in time periods before and after introduction of screening, three single country studies all had adequate follow-up and estimated mortality reductions ranging from 28% to 36%. Limitations of studies of population mortality rates include the inability to exclude deaths in women with breast cancer diagnosed before invitation to screening, diluting any observable impact of screening, and the gradual implementation of screening in a country or region. CONCLUSIONS: Although analysing population breast cancer mortality rates over time can be a first step in examining changes following the introduction of screening, this method is of limited value for assessment of screening impact. Other methods and individual data are necessary to properly quantify the effect.

An observational study to evaluate the performance of units using two radiographers to read screening mammograms.

AIM: To examine the performance of screening units in which a proportion of mammograms were double read using "non-discordant radiographer only (double) reading" (NDROR). MATERIALS AND METHODS: NDROR was used by seven pilot units between 2006 and 2009, and six further units in 2009 only. There were 51 comparison units. Screening performance outcome measures were calculated, and logistic regression was used to compare performance between the pilot and comparison units. RESULTS: Phase 1 pilot units read between on average 15 and 48% of mammograms per year using NDROR between 2006 and 2009 (median, 33%) and in 2009, phase 2 pilot units used NDROR to read between 4 and 77% of mammograms (median, 34%). The results showed an increase in recall rates in the phase 1 pilot units relative to the comparison units at both prevalent and incident screens (adjusted OR 1.09, 95% CI 1.05, 1.14; and adjusted OR 1.10, 95% CI 1.07, 1.14, respectively). There were also increases in the phase 2 pilot units relative to the comparison units; adjusted OR 1.08 (95% 1.00, 1.17) at prevalent screens, and adjusted OR 1.07 (95% CI 1.02, 1.14) at incident screens. There was no evidence to suggest a difference in cancer-detection rates between the pilot units and the comparison units. CONCLUSIONS: Evidence from the present study suggests that recall rates may increase as a result of units using radiographers to double read a proportion of their mammograms. However, there is little evidence to suggest that NDROR, as practiced by the pilot units in the present study, is likely to have major impacts on performance in the UK National Health Service Breast Screening Programme (NHSBSP), particularly if it is fully supported and closely monitored (particularly recall rates).

Nottingham trial of faecal occult blood testing for colorectal cancer: a 20-year follow-up.

BACKGROUND: Three large randomised trials have shown that screening for colorectal cancer (CRC) using the faecal occult blood test (FOBt) can reduce the mortality from this disease. The largest of these trials, conducted in Nottingham since 1981, randomised 152,850 individuals between the ages of 45 and 74 years to an intervention arm receiving biennial Haemoccult (FOB) test kit or to a control arm. In 2006, the National Bowel Cancer Screening Programme was launched in England using the FOBt, with the expectation that it will reduce CRC mortality. AIMS: To compare the CRC mortality and incidence in the intervention arm with the control arm after long-term follow-up. METHODS: The 152,850 randomised individuals were followed up through local health records and central flagging (Office for National Statistics). RESULTS: At a median follow-up of 19.5 years there was a 13% reduction in CRC mortality (95% CI 3% to 22%) in the intervention arm despite an uptake at first invitation of approximately 57%. The CRC mortality reduction in those accepting the first screening test, adjusted for the rate of non-compliers, was 18%. There was no significant difference in mortality from causes other than CRC between the intervention and control arms. Despite removing 615 adenomas >10 mm in size from the intervention arm, there was no significant difference in CRC incidence between the two arms. CONCLUSIONS: Although the reduction in CRC mortality was sustained, further follow-up of the screened population has not shown a significant reduction in the CRC incidence. Moreover, despite the removal of many large adenomas there was no reduction in the incidence of invasive cancer which was independent of sex and site of the tumour.

Incidence of cervical intraepithelial neoplasia grade 2 or worse in colposcopy-negative/human papillomavirus-positive women with low-grade cytological abnormalities.

OBJECTIVE: To determine the risk of incident high-grade cervical intraepithelial neoplasia (CIN) in human papillomavirus (HPV) -positive women with low-grade cytological abnormalities who had a satisfactory normal colposcopy. DESIGN: A retrospective follow-up study within the NHS HPV/LBC pilot studies. SETTING: The NHS Cervical Screening Programme in England. POPULATION: A total of 1063 HPV-positive women with borderline or mild dyskaryosis who were negative at colposcopy from three sites within the NHS HPV/liquid-based cytology (LBC) pilot studies. METHODS: HPV triage took place in 2001/02. In 2009 all information on additional management on HPV-positive/colposcopy-negative women was requested. The rate of disease following a negative colposcopy was calculated, and survival analysis was used to determine whether the grade of referral cytology impacted on risk of subsequent disease. Results were compared with those in women from the same population who had not been HPV triaged. MAIN OUTCOME MEASURES: Incident CIN2 or worse during follow up. RESULTS: Of 1063 eligible women 965 had documented follow up. The cumulative rate of CIN2+ at 3 years in these women was 4.4% (95% CI 4.0-7.0%); the median time from normal colposcopy to final result was 27 months. There was no significant increase in the risk of future disease associated with age or initial cytology result. CONCLUSIONS: The rate of subsequent high-grade CIN among colposcopically negative triaged women was sufficiently low to justify return to routine recall.

Performance measures in three rounds of the English bowel cancer screening pilot.

OBJECTIVES: To compare performance measures across all three rounds of the English bowel cancer screening faecal occult blood test pilot and their relation to social deprivation and ethnicity. METHODS: In each round in three primary care trusts, data for a restricted population of over 48,500 aged 60-69 years were analysed. Individual-based data included postcode linked to area-based data on the Index of Multiple Deprivation (IMD) 2004, and ethnicity. Outcomes were the rates of screening and colonoscopy uptake, positivity and detection of neoplasia (adenomas or bowel cancer) and bowel cancer, and the positive predictive values (PPVs) of a positive test for neoplasia and bowel cancer. Sensitivity was calculated by the proportional incidence method using data on interval cancers identified from cancer registrations. RESULTS: The overall uptake rate was 61.8%, 57.0% and 58.7% in the first, second and third rounds, respectively. Although the PPV for cancer decreased over the course of the three rounds (10.9% in the 1st round, 6.5% in 3rd round), the PPV for all neoplasia remained relatively constant (42.6% in 1st round, 36.9% in 3rd round). Deprivation and non-white ethnic background (principally Indian subcontinent in the pilot region) were associated with low screening and colonoscopy uptake rates, and this changed little over the three screening rounds. Uptake was lower in men, although differences in uptake between men and women decreased over time. Non-participation in previous rounds was a strong predictor of low uptake. CONCLUSIONS: Performance measures are commensurate with expectations in a screening programme reaching its third round of screening, but a substantial ongoing effort is needed, particularly to address the effects of deprivation and ethnicity in relation to uptake.

HPV testing as a triage for borderline or mild dyskaryosis on cervical cytology: results from the Sentinel Sites study.

BACKGROUND: Earlier pilot studies of human papillomavirus (HPV) triage concluded that HPV triage was feasible and cost-effective. The aim of the present study was to study the impact of wider rollout of HPV triage for women with low-grade cytology on colposcopy referral and outcomes. METHODS: Human papillomavirus testing of liquid-based cytology (LBC) samples showing low-grade abnormalities was used to select women for colposcopy referral at six sites in England. Samples from 10,051 women aged 25-64 years with routine call or recall cytology reported as borderline or mild dyskaryosis were included. RESULTS: Human papillomavirus-positive rates were 53.7% in women with borderline cytology and 83.9% in those with mild dyskaryosis. The range between sites was 34.8-73.3% for borderline cytology, and 73.4-91.6% for mild dyskaryosis. In the single site using both LBC technologies there was no difference in rates between the two technologies. The positive predictive value of an HPV test was 16.3% for CIN2 or worse and 6.1% for CIN3 or worse, although there was considerable variation between sites. CONCLUSION: Triaging women with borderline cytological abnormalities and mild dyskaryosis with HPV testing would allow approximately a third of these women to be returned immediately to routine recall, and for a substantial proportion to be referred for colposcopy without repeat cytology. Variation in HPV-positive rates results in differing colposcopy workload.

Screening outcomes in women over age 70 who self-refer in the NHSBSP in England.

SETTING: The NHS breast screening programme (NHSBSP) in England currently invites women aged 50-70 every three years. Whilst screening is acknowledged as efficacious for women aged 50-69, several countries routinely invite women up to the age of 74. The NHSBSP in England is beginning to invite women up to the age of 73. Although the incidence of breast cancer increases with age, the possible benefits of screening older women must be balanced against shorter life expectancies and possible overdiagnosis. In England women can self-refer after reaching the invitation upper age limit. OBJECTIVE: We examined the extent to which older women in England self-referred over a three-year period and studied the screening outcomes in these women. METHODS: Routinely collected data from screening units in England were used to calculate screening performance measures for women who self-referred between 1 April 2005 and 31 March 2008. The tumour characteristics of all screen-detected cancers were examined by previous screening history and age group (71-74 and ≥75 years). RESULTS: During the three-year period 139,910 women aged over 70 self-referred; equivalent to 4% of the female population aged over 70 having been screened. The majority of women who self-referred had been screened within the previous five years (76% of those aged 71-74 and 65% of those aged 75 or over). Approximately 4% of these women were recalled for assessment and cancer detection rates were similar in both age groups. CONCLUSION: Only a small proportion of all women aged over 70 utilize the self-referral policy of the NHSBSP, and most such women are aged below 80.

Pathological and mammographic prognostic factors for screen detected cancers in a multi-centre randomised, controlled trial of mammographic screening in women from age 40 to 48 years.

AIM: To assess pathological and radiological prognostic factors for cancers detected by screening within a multi-centre RCT trial of mammographic screening of younger women. METHOD: The survival of 232 women with screen detected invasive cancer was ascertained. Data on invasive cancer size, histological grade, nodal status, vascular invasion, mammographic spiculation, comedo calcification and mammographic background were assessed. Kaplan-Meier and Cox proportional hazards methods were used to examine survival. RESULTS: Univariate analysis indicated that women with cancers with the following features had poorer survival; ≥ 30 mm, histologically grade 3, heavily node positive (4 or more positive nodes), vascular invasion positive and displaying mammographic comedo calcification. In a multivariate model survival remained poorer in women with four or more nodes positive (HR 8.36, 95% CI 2.31, 30.17) and in those with comedo calcification (HR 3.00,95% CI 1.13, 7.99). CONCLUSION: Nodal status and the presence of mammographic comedo calcification have independent prognostic significance in young women with screen detected cancer.

Increasingly strong reduction in breast cancer mortality due to screening.

BACKGROUND: Favourable outcomes of breast cancer screening trials in the 1970s and 1980s resulted in the launch of population-based service screening programmes in many Western countries. We investigated whether improvements in mammography and treatment modalities have had an influence on the effectiveness of breast cancer screening from 1975 to 2008. METHODS: In Nijmegen, the Netherlands, 55,529 women received an invitation for screening between 1975 and 2008. We designed a case-referent study to evaluate the impact of mammographic screening on breast cancer mortality over time from 1975 to 2008. A total number of 282 breast cancer deaths were identified, and 1410 referents aged 50-69 were sampled from the population invited for screening. We estimated the effectiveness by calculating the odds ratio (OR) indicating the breast cancer death rate for screened vs unscreened women. RESULTS: The breast cancer death rate in the screened group over the complete period was 35% lower than in the unscreened group (OR=0.65; 95% CI=0.49-0.87). Analysis by calendar year showed an increasing effectiveness from a 28% reduction in breast cancer mortality in the period 1975-1991 (OR=0.72; 95% CI=0.47-1.09) to 65% in the period 1992-2008 (OR=0.35; 95% CI=0.19-0.64). CONCLUSION: Our results show an increasingly strong reduction in breast cancer mortality over time because of mammographic screening.

Interval cancers in the NHS breast cancer screening programme in England, Wales and Northern Ireland.

BACKGROUND: The United Kingdom NHS Breast Screening Programme was established in 1988, and women aged between 50 and 70 are routinely invited at three yearly intervals. Expected United Kingdom interval cancer rates have been calculated previously, but this is the first publication from an exercise to collate individual-based interval cancer data at a national level. METHODS: Interval cancer case ascertainment is achieved by the regular exchange of data between Regional Breast Screening Quality Assurance Reference Centres and Cancer Registries. The present analysis includes interval cancers identified in women screened between 1st April 1997 and 31st March 2003, who were aged between 50 and 64 at the time of their last routine screen. RESULTS: In the periods >0-<12 months, 12-<24 months and 24-<36 months after a negative screen, we found overall interval cancer rates and regional ranges of 0.55 (0.43-0.76), 1.13 (0.92-1.47) and 1.22 (0.93-1.57) per 1000 women screened, respectively. Rates in the period 33-<36 months showed a decline, possibly associated with early re-screening or delayed presentation. CONCLUSIONS: Interval cancer rates were higher than the expected rates in the 24-month period after a negative screen, but were similar to published results from other countries. Increases in background incidence may mean that the expected rates are underestimated. It is also possible that, as a result of incomplete case ascertainment, interval cancers rates were underestimated in some regions in which rates were less than the expected.

PSA levels and cancer detection rate by centre in the European Randomized Study of Screening for Prostate Cancer.

BACKGROUND: To describe the variation in PSA level by age group and screening round in the ERSPC centres and the variation in cancer detection rates in relation to the underlying prostate cancer incidence. METHODS: Individual data on men invited for the first and second screening rounds according to protocol (excluding early recalls and interval cancers) were obtained from the central database of the ERSPC (cut-off date 31st December 2006). Data were compared between and within centres for the core age group (55-69 at entry). The cancer detection rate (CDR) was compared with the expected background prostate cancer incidence rate in the absence of screening adjusted for the incidence rate in non-attenders and the control arm (IRS). RESULTS: Mean PSA values in the age groups 55-59 years and 65-69 years showed little variation by centre, except for the Dutch centre, where an increase from 1.6 to 1.8 ng/ml and a decline from 2.9 to 2.5ng/ml was observed, respectively. Most tumours were detected at the PSA range 4.0-9.9 ng/ml, with a shift to more cancer detection at 3.0-3.9 ng/ml in the second screening round. There was high variability in the CDR between the centres in both the first (16-46 per 1000) and the second screening rounds (14-50 per 1000). Although the ratio CDR/IRS was less variable, it is somewhat lower in Italy and Switzerland (12 and 14,respectively) and higher in the Netherlands (28), than in most other centres and in Belgium the ratio increased markedly, from 20 to 44 between the first and second rounds. CONCLUSION: There was no clear evidence of a relationship between the underlying incidence and mean PSA levels at screening or the cancer detection rate.

Randomized controlled trial of mammographic screening from age 40 ('Age' trial): patterns of screening attendance.

BACKGROUND: The Age trial was a randomized controlled trial to study the effect on breast cancer mortality of invitation to annual mammography from age 40 to 41. Uptake of invitation to screening mammography in UK women aged below 50 is of interest, particularly in the light of the recent announcement that the national breast screening programme will begin inviting women from age 47. METHODS: The trial took place in 23 National Health Service breast screening units in England, Wales and Scotland between 1991 and 2004. Data on invitation and attendance during 13 years of trial fieldwork were analysed. The participants were 53,884 women in the intervention arm of the Age trial who were randomized to receive annual invitation to mammography from age 40 or 41 up to age 48. The trial is registered as an International Standard Randomised Controlled Trial, number ISRCTN24647151. RESULTS: Uptake of invitation to routine screening was 68% at first round and 69% at subsequent rounds. A total of 43,709 women in the intervention arm (81%) attended at least one routine screen and 23,262 (43%) attended at least seven screens; 31,392 women attended 75% or more of all routine invitations they were offered. Previous trial attendance was a predictor of subsequent uptake; attendance was inversely related to Townsend deprivation score. CONCLUSION: Uptake in this trial was comparable with that in the UK screening programme for women aged over 50. There was an inverse relationship between deprivation level and the number of screens attended.

Evaluation of bowel cancer registration data in England, 1996-2004.

BACKGROUND: The National Health Service (NHS) bowel cancer screening programme (BCSP) was initiated across England in April 2006. To determine the feasibility of using national cancer registration data to assess the impact of the BCSP on stage-specific incidence, we studied trends in the incidence rates of colon (ICD10 C18) and rectosigmoid junction and rectum (ICD10 C19-C20) cancers and the completeness of data on Dukes stage in England. METHODS: Data were obtained from all nine cancer registries for the period 1996-2004, before the introduction of the BCSP, in men and women aged 50-79 years. RESULTS: Overall, incidence rates declined by 1% per year in the 9 years before the introduction of the BCSP (P<0.001). Dukes stage was recorded for 60% of all registrations but this varied between regions and over time. Only four registries had completeness of 74% or more. Registrations with unknown Dukes stage decreased from 1996 to 2000, and then increased during 2001-2004 affecting trends in stage-specific incidence. CONCLUSION: To study the impact of the BCSP on stage-specific incidence, regional variations in data completeness need to be addressed.

Risk of cervical abnormality after age 50 in women with previously negative smears.

There is discussion over the benefit of continuing cervical screening in women over the age of 50 with a history of negative cytology. We aimed to determine the risk of abnormal cytology in such women. Screening history data from 1985 to 2003 were obtained for a cohort of 2 million women from the NHS cervical screening programme from four Health Authorities in England. The 57,651 women in the cohort who reached age 40 between 1 January 1985 and 31 December 1990 and had at least one routine or opportunistic smear between ages 50 and 54 were included in the analysis. Exposure groups (negative cytology history, negative but including inadequate smears, and positive history) were defined on the basis of screening histories from ages 40 to 49. Sixty-four percent (134/206) (95% CI: 57-71%) of the moderate dyskaryosis or worse lesions at ages over 50 were detected from women in the negative smear history group. After allowance for time since last negative smear, the relative risk for the first primary smear over the age of 50 having moderate dyskaryosis or worse decreased from 0.60 (95% CI: 0.41-0.84) for two negative smear episodes to 0.25 (95% CI: 0.10-0.56) for four negative smear episodes, compared with the positive history group. If screening were discontinued for all women over 50 with a negative history, the majority of cytological abnormalities now being detected at these ages that lead directly to referral to colposcopy would be missed.