Interval Cancer Rate Research Articles

Abstract P6-02-05: Digital versus screen-film mammography in population-based breast cancer screening: Performance indicators and tumor characteristics of screen-detected and interval cancers

Abstract Purpose: To evaluate whether the introduction of full-field digital mammography (FFDM) in screening has resulted in any changes in performance indicators compared to screen-film mammography (SFM), including tumor characteristics and incidence rates of interval cancers. Materials and Methods Data of the Dutch National Cancer Screening Programme, region North (2004-2010) were linked to the Netherlands Cancer Registry (N=902,868). Screening performance indicators (recall rate, detection rate, positive predictive value, sensitivity and specificity) and tumor characteristics of screen-detected cancers were compared between FFDM and SFM, as were incidence rates and tumor characteristics of interval cancers. Analyses were stratified by initial and subsequent examinations. Differences were compared using chi-square. Results Initial examinations: After initial examinations recall rates were 2.1% for SFM and 3.0% for FFDM (p<0.001). The positive predictive value was 25.6% for SFM and 19.9% for FFDM (p=0.002) and detection rates were similar. The detection rate for DCIS was 0.86 per 1000 women for SFM compared to 1.18 per 1000 women for FFDM (p=0.137). Similar percentages of low grade DCIS were found for SFM and FFDM (18% vs. 14%;p=0.860). No difference were found in tumor size, morphology, grade and nodal status of invasive screen-detected cancers. Subsequent examinations: After subsequent examinations performance indicators were similar. Detection rates for DCIS were 0.74 per 1000 women for SFM versus 0.81 per 1000 women for FFDM (p=0.298). For invasive cancers, detection rates were 4.54 per 1000 women for SFM versus 4.33 per 1000 women for FFDM (p=0.210). The percentages of low grade DCIS were similar for SFM and FFDM (12% vs.9%; p=0.524). Invasive cancers diagnosed with FFDM were more often of high grade (p=0.024) and ductal type (p=0.030). No difference was found in the incidence rates of interval cancers for SFM and FFDM after initial examinations (2.69/1000 vs.2.51/1000; p=0.787). The sensitivity after initial examinations was 66.1% for SFM and 69.1% for FFDM (p=0.657), specificity was 98.5% and 96.9% for SFM and FFDM, respectively (p<0.001). After subsequent examinations the incidence rates of interval cancer were 2.30/1000 for SFM and 2.41/1000 for FFDM (p=0.652), sensitivity was 69.7% for SFM and 66.7% for FFDM (p=0.232). Specificity was 99.4% SFM and 99.2% for FFDM (p<0.001). No differences were found in tumor size, morphology, grade or nodal status of interval cancers diagnosed after FFDM compared to SFM after initial or after subsequent examinations. Conclusions Compared to SFM, FFDM resulted in similar rates of screen-detected and interval cancers, indicating that FFDM performs as well as SFM in a breast cancer screening program, with more invasive cancers of high grade and ductal type found after subsequent screens. FFDM resulted in a higher recall rate and lower PPV. No signs of an increase in low-grade DCIS (which might connote possible overdiagnosis) were seen. Tumor characteristics of interval cancers were similar. Citation Format: De Munck L, De Bock GH, Otter R, Reiding D, Broeders MJM, Willemse PHB, Siesling S. Digital versus screen-film mammography in population-based breast cancer screening: Performance indicators and tumor characteristics of screen-detected and interval cancers. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P6-02-05.

Abstract P6-02-02: Increased interval cancers after the 2009 U.S. preventive services task force guidelines: A single-center, retrospective analysis

Abstract Background: In late 2009, the U.S. Preventive Services Task Force (USPSTF) increased the recommended time between screening mammography from one year to two years. We examined the effect of USPSTF recommendations in an integrated safety-net system whose patients often have intermittent access to care. The purpose of this study was to determine if changes in screening guidelines were associated with stage migration or changes in rate of interval cancers. Methods: We conducted a retrospective cohort analysis of breast cancer patients diagnosed between 2005-2013 at one safety-net hospital. We abstracted stage at diagnosis, time intervals between screening and diagnostic imaging, as well as BIRADS classification from clinical and administrative billing data. We divided patients into two cohorts: Those diagnosed with breast cancer "pre-2010" (2005 – 2010) and "post-2010" (2011-2013). We compared stage of diagnosis between cohorts using Chi-Square tests. In a subset of patients for whom we had prior screening imaging information, we determined the rate of interval cancers. Interval cancers were defined as patients whose diagnosis occurred within 14 months (pre-2010) or within 26 months (post-2010) of normal screening mammography. Logistic regression was used to determine the unadjusted odds of interval cancer as a function of being post-2010 versus pre-2010. Results: There were 521 unique, breast cancer patients between 2005-2013, Distribution of Breast Cancer by Stage Stage 0Stage IStage IIStage IIIStage IVTotal2005-200941816142242492010-20134679824421272 249 in the 'pre-2010' cohort, and 272 in the 'post-2010' cohort. In the 2005-2009 cohort, 32.5% and 24.5% of patients were stage I and Stage II respectively. In 2010-2013, 29.0% and 30% were stage I and stage II, respectively. The difference in stage at diagnosis was not statistically significant (p=0.62). In a subset of 178 patients with available screening imaging data, we determined the rate of interval cancers. Pre-2010, 7.4% (8/108) of patients had an interval cancer. Post-2010, 20% (14/70) patients had an interval cancer. Patients diagnosed post-2010 had three times the odds of having an interval cancer compared to pre-2010 patients (OR = 3.13, 95% CI 1.24-7.91, p=0.01). Discussion: The USPSTF 2009 recommendation is associated with a statistically significant increase in interval cancers in a safety-net population, but we cannot conclude that this contributes to stage migration in this limited population. Investigation of larger groups is needed to further assess how USPSTF guidelines affect outcomes in underserved populations. Citation Format: Townsend NT, Everhart RM, Bayliss EA, Jaiswal K. Increased interval cancers after the 2009 U.S. preventive services task force guidelines: A single-center, retrospective analysis. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P6-02-02.

Abstract P6-02-04: Screen detected and interval cancers; genomic analysis points to different molecular etiology?

Abstract Breast cancers diagnosed after a negative mammogram but prior to the next screening episode are termed "interval cancers" and comprise as many as 25% of all cancers detected in women attending population-based screening programs. The high interval cancer rate is a major problem affecting the effectiveness of mammographic screening. It is unclear whether interval cancers represent a distinct biological entity compared to screen-detected cancers or whether their designation is simply an arbitrary outcome of screening timing. Using an Australian prospective population-based cohort of over 53,000 women (lifepool), 537 cases of breast carcinoma (in situ and invasive breast cancer) were identified, of which 293 had known screening status at time of diagnosis. Pathology reports, mammographic density data, germline DNA and tumor tissue were available for analysis. Screen and interval cases showed no significant differences in mammographic density or PR status but there were trends towards higher proportions of ER negative and HER2 positive cases in interval cancers (p<0.1). Interval cancers also had a younger age at diagnosis (p<0.01), increased tumor size (p<0.01) and higher grade (p<0.01). Copy number analysis was performed on a subset of invasive breast cancer cases using OncoScan MIP arrays. No difference in the overall number of copy number aberrations or fraction of the genome altered were observed, however specific differences were noted between interval and screen detected cases. These included copy number changes on chromosomes 8 and 11. Analysis of germline DNA was performed using a panel sequencing approach of known breast cancer genes as well as lower-penetrance SNPs. Pathogenic mutations in BRCA1, BRCA2, TP53 and PALB2 were identified in 1/13 interval cases (in BRCA2), 1/66 screen-detected cases and 8/74 cases with currently unknown screen/interval status. Screen detected cancers may thus have a reduced contribution from high-penetrance predisposing variants. Citation Format: Gorringe KL, Hunter SM, Byrne D, Devereux L, Rowley SM, Elder K, Huynh R, Pridmore V, Hopper J, Kavanagh A, Mitchell G, Mann BG, Fox SB, Campbell IG. Screen detected and interval cancers; genomic analysis points to different molecular etiology?. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P6-02-04.

Performance of Screening Mammography: A Report of the Alliance for Breast Cancer Screening in Korea.

ObjectiveTo analyze the diagnostic accuracy and trend in screening mammography in Korea.Materials and MethodsWe retrospectively linked the information from hospitals participating in the Alliance of Breast Cancer Screening in Korea (ABCS-K) and the database of the National Cancer Screening Program. We calculated performance indicators, including the recall rate, cancer detection rate (CDR), positive predictive value (PPV), sensitivity, specificity, false-positive rate (FPR), and interval cancer rate (ICR). Changes in the performance indicators were calculated as the annual percent change with 95% confidence interval (CI).ResultsWe enrolled 128756 cases from 10 hospitals from 2005 to 2010. The recall rate was 19.1% with a downward trend over time (-12.1% per year; 95% CI, -15.9 to -8.2). The CDR was 2.69 per 1000 examinations, without a significant trend. The PPV was 1.4% with an upward trend (20.8% per year; 95% CI, 15.2 to 26.7). The sensitivity was 86.5% without a significant trend, whereas the specificity was 81.1% with an upward trend (3.3% per year; 95% CI, 2.1 to 4.5). The FPR was 18.9% with a downward trend (-12.4% per year; 95% CI, -16.2 to -8.4). The ICR was 0.5 per 1000 negative examinations without a significant trend. There were institutional variations in the diagnostic accuracy and trend except for the CDR, sensitivity, and ICR.ConclusionThe sensitivity and CDR of screening mammography in the ABCS-K from 2005 to 2010 were compatible with those for Western women. The recall rate, PPV and specificity, however, were suboptimal, although they showed significant improvements over this period. A further analysis is required to explain institutional variations.

Screen detection of ductal carcinoma in situ and subsequent incidence of invasive interval breast cancers: a retrospective population-based study

SummaryBackgroundThe value of screen detection and treatment of ductal carcinoma in situ (DCIS) is a matter of controversy. At present, the extent to which the diagnosis and treatment of DCIS could prevent the occurrence of invasive breast cancer in the future is not clear. We sought to estimate the association between detection of DCIS at screening and invasive interval cancers subsequent to the relevant screen.MethodsWe obtained aggregate data for screen-detected cancers from 84 local screening units within 11 regional Quality Assurance Reference Centres in England, Wales, and Northern Ireland from the National Health Service Breast Screening Programme. Data for DCIS diagnoses were obtained for women aged 50–64 years who were invited to and attended mammographic breast screening from April 1, 2003, to March 31, 2007 (4 screening years). Patient-level data for interval cancer arising in the 36 months after each of these were analysed by Poisson regression with invasive interval cancer screen detection rate as the outcome variable; DCIS detection frequencies were fitted first as a continuous and then as a categorical variable. We repeated this analysis after adjustment with both small size and high-grade invasive screen-detected cancers.FindingsWe analysed data for 5 243 658 women and on interval cancers occurring in the 36 months after the relevant screen. The average frequency of DCIS detected at screening was 1·60 per 1000 women screened (median 1·50 [unit range 1·54–3·56] per 1000 women). There was a significant negative association of screen-detected DCIS cases with the rate of invasive interval cancers (Poisson regression coefficient −0·084 [95% CI −0·13 to −0·03]; p=0·002). 90% of units had a DCIS detection frequency within the range of 1·00 to 2·22 per 1000 women; in these units, for every three screen-detected cases of DCIS, there was one fewer invasive interval cancer in the next 3 years. This association remained after adjustment for numbers of small screen-detected invasive cancers and for numbers of grade 3 invasive screen-detected cancers.InterpretationThe association between screen-detected DCIS and subsequent invasive interval cancers suggests that detection and treatment of DCIS is worthwhile in prevention of future invasive disease.FundingUK Department of Health Policy Research Programme and NHS Cancer Screening Programmes.

Evaluation of a mammography screening program within the population-based Vorarlberg Health Monitoring & Prevention Program (VHM&PP)

ObjectivesTo describe the mammography screening program from 1989 to 2005 within a population-based prevention program in Austria and to appraise it according to recommended quality indicators. Material and methodFrom 01.01.1989 all women aged 40 years or older participating in the Vorarlberg Health Monitoring & Prevention Program (VHM&PP) was offered to undergo additionally a “screening mammography”. Passive follow-up has been performed by record linkages with the Vorarlberg cancer registry and mortality statistics for information on outcome variables. Interval cancer rates have been estimated and the survival after breast cancer has been calculated by life table technique by examination period and age groups (40–49 years, 50–69 years). ResultsBetween 1989 and 2005 50,100 women aged 40 to 69 years participated in the program, of which 123,652 mammogram results have been collected. In the target population the participation rate was 65.1%. During median follow-up time 13.5 years and 633,342 person-years overall 665 invasive cancer and 87 ductal carcinoma in situ (11.6%) cases have been identified. Between 1996 and 2004 the detection rates were 239.9 per 100.000 among women aged 40–49 years and 543.2 per 100,000 among women aged 50–69 years. The rates for interval cancers were 160.4 and 277.4 per 100 000 negative screens, respectively. During median follow-up of 13.5 years 165 deaths occurred with no difference in survival between patients with interval and screen detected cancers. ConclusionA mammography screening program has been performed between 1989 and 2005 in Vorarlberg. Till 2005 most quality indicators improved and met the EU-recommendations suggesting that alternative approaches to organized mammography screening based on routine data should be explored.

EndocuffTM-Assisted Colonoscopy Improves Sessile Serrated Adenoma Detection Rate: A Single Academic Center Observational Study

Introduction: The detection of sessile serrated adenomas (SSAs) presents a particular challenge to the endoscopist, due to their flat morphology and indiscriminate borders. Missed or incompletely removed SSAs likely contribute to the unacceptably high rates of interval cancers (occurring within 3-5 years after colonoscopy). Endocuff (Arc Medical Design Ltd., Leeds, England) is a recently developed cap with soft projections designed to invert inward during insertion and, on withdrawal, serve to flatten colonic folds. Our goal was to determine if use of Endocuff affects detection rate of SSAs in a tertiary academic colonoscopy practice. Methods: Between August 2014 and May 2015 all colonoscopy procedures completed at the University of California at Irvine were prospectively enrolled into a colonoscopy quality database. SSA detection rate and number of SSAs detected per procedure were analyzed. Endocuff-assisted and standard colonoscopies were compared. Significance was determined by z-test for continuous variables and chi2 test for categorical variables. Results: 1,237 colonoscopies (inclusive of screening, surveillance and diagnostic indications) were completed over the study period (752 conventional colonoscopies and 485 Endocuff-assisted colonoscopies). SSA detection rate (% of cases with one or more SSAs), number of SSAs per procedure, and number of SSAs per SSA-positive procedure were all significantly higher in the Endocuff group (12.8 vs 6.6%, p = 0.005, 0.28 ±0.80 vs 0.15 ±0.48, p = 0.0014, 1.79 ±1.18 vs 1.40 ±0.63 p = 0.025, respectively). There was no significant difference in withdrawal time between the Endocuff group (19.7 ±12.2) and non-Endocuff group (19.3 ±14.3 p = 0.599). Conclusion: The use of Endocuff improved SSA detection rate and number of SSAs found per procedure. This benefit was appreciated without any significant difference in withdrawal time. Our experience demonstrates that Endocuff may play an important adjunctive role in efforts to reduce interval colorectal cancers. Randomized controlled or tandem colonoscopy studies will help verify these potentially important observations.

Demonstrating that colonoscopy is high quality.

Colonoscopy is the gold standard investigation for examining the lower GI tract [1]. It plays a fundamental role in investigation of symptomatic individuals and in screening for colorectal cancer (CRC) [2,3]. Colonoscopy must be high quality in order to maximize its benefit [4]. Poor-quality colonoscopy is associated with increased interval cancer rates [4]. High-quality colonoscopy involves a complete procedure that provides comprehensive inspection of colonic mucosa [5]. There are a number of markers of colonoscopy quality, [2,6,7] with cecal intubation rate (CIR) historically being the most widely reported [8]. Cecal intubation was previously confirmed by written documentation of the cecal landmarks; however, photo-documentation of the cecum is now the accepted method of confirming colonoscopy completion. The European Society of Gastrointestinal Endoscopy (ESGE) guidelines recommend that such photo-documentation includes images of both the ileocecal valve and the cecum with views of the appendiceal orifice [9]. CIR is variable and many measures have been used to improve it [10–12]. The United Kingdom has engaged in a comprehensive quality improvement program with significant improvements [10,13]. Other countries have demonstrated similar results [14]. Although CIR is an important marker of completion of a procedure, other markers of quality include adenoma detection rate (ADR), bowel preparation, rectal examination and rectal retroflexion, colonoscopy withdrawal time (CWT), polyp retrieval, and complication rates [15–21]. Furthermore, comfort scores, tattooing of suspected malignant lesions in the colon, and taking diagnostic biopsies for unexplained diarrhea are seen as quality markers in addition to the rate of postcolonoscopy colorectal cancer [22–25]. Clinician performance in each of these areas is variable, but those who perform well tend to do so across all measures [22]. Among all measures, the most important marker of colonoscopy quality is adenoma detection rate [15–17]. ADR has clearly been shown to correlate with interval cancers [4]. Patients scoped by colonoscopists with high ADRs have lower interval cancer rates [4]. Furthermore, patients scoped by colonoscopists with higher ADRs have lower CRC mortality rates [16]. Polyp detection rate (PDR) can be used as a surrogate marker of ADR [26]. The paper, “Meticulous cecal image documentation at colonoscopy is associated with improved polyp detection,” published in this edition of Endoscopy International Open, explores the link between polyp detection rates and the quality of cecal photo-documentation. The paper reports a correlation between good-quality cecal photodocumentation and higher PDRs, including rightsided polyp detection (although some of these were hyperplastic polyps). Right-sided lesions are of particular interest and it may be that failure to detect them is one reason that screening programs are not adequately preventing right-sided colorectal cancer [27,28]. The reason for the correlation between PDR and image quality may be that colonoscopists who take time to capture convincing cecal images are generally more careful in their withdrawal examination. Another explanation may be that these “meticulous” colonoscopists have better control over the endoscope, which leads to better mucosal visualization. Longer mean CWTs are associated with increased adenoma detection, and are more relevant than total procedure times, as the majority of mucosal visualisation occurs on withdrawal of the colonoscope [19,29]. Although there was no statistically significant difference in procedure duration between “meticulous” and “non-meticulous” endoscopists in this study, the

National Breast Cancer Screening Programme, Singapore: evaluation of participation and performance indicators.

To evaluate participation rates and performance indicators in the National Breast Cancer Screening Programme, BreastScreen Singapore (BSS). Data on women aged 40-69 screened in the period 2002-2009 was obtained from BSS and from the Singapore Cancer Registry. Participation rates and performance indicators (including screen detection rates, small tumour detection rates, recall rates, accuracy and interval cancer rates) were examined. BSS participation rate has remained above 10% since 2005. Based on health surveys, national mammography rates have increased from 29.7% before BSS to 39.6% in 2010 after BSS. Performance indicators, with the exception of recall rates, specificity, and interval cancer rate (for first screen), generally improved from 2002-2006 to 2007-2009 and are comparable with organized breast screening programmes in other developed countries. BSS breast cancer screening coverage and rescreen rates in Singapore could be improved. Mechanisms to monitor recall rates are in place, and training opportunities are provided to aid the professional development of radiologists.

The role of dietary polyphenols in the moderation of the inflammatory response in early stage colorectal cancer

ABSTRACTCurrent focus in colorectal cancer (CRC) management is on reducing overall mortality by increasing the number of early-stage cancers diagnosed and treated with curative intent. Despite the success of screening programs in down-staging CRC, interval cancer rates are substantial and other strategies are desirable. Sporadic CRC is largely associated with lifestyle factors including diet. Polyphenols are phytochemicals ingested as part of a normal diet, which are abundant in plant foods including fruits/berries and vegetables. These may exert their anti-carcinogenic effects via the modulation of inflammatory pathways. Key signal transduction pathways are fundamental to the association of inflammation and disease progression including those mediated by NF-κB and STAT, PI3K and COX. Our aim was to examine the evidence for the effect of dietary polyphenols intake on tumor and host inflammatory responses to determine if polyphenols may be effective as part of a dietary intervention. There is good epidemiological evidence of a reduction in CRC risk from case-control and cohort studies assessing polyphenol intake. It would be premature to suggest a major public health intervention to promote their consumption; however, dietary change is safe and feasible, emphasizing the need for further investigation of polyphenols and CRC risk.

Identifying women with dense breasts at high risk for interval cancer: a cohort study.

Twenty-one states have laws requiring that women be notified if they have dense breasts and that they be advised to discuss supplemental imaging with their provider. To better direct discussions of supplemental imaging by determining which combinations of breast cancer risk and Breast Imaging Reporting and Data System (BI-RADS) breast density categories are associated with high interval cancer rates. Prospective cohort. Breast Cancer Surveillance Consortium (BCSC) breast imaging facilities. 365,426 women aged 40 to 74 years who had 831,455 digital screening mammography examinations. BI-RADS breast density, BCSC 5-year breast cancer risk, and interval cancer rate (invasive cancer ≤12 months after a normal mammography result) per 1000 mammography examinations. High interval cancer rate was defined as more than 1 case per 1000 examinations. High interval cancer rates were observed for women with 5-year risk of 1.67% or greater and extremely dense breasts or 5-year risk of 2.50% or greater and heterogeneously dense breasts (24% of all women with dense breasts). The interval rate of advanced-stage disease was highest (>0.4 case per 1000 examinations) among women with 5-year risk of 2.50% or greater and heterogeneously or extremely dense breasts (21% of all women with dense breasts). Five-year risk was low to average (0% to 1.66%) for 51.0% of women with heterogeneously dense breasts and 52.5% with extremely dense breasts, with interval cancer rates of 0.58 to 0.63 and 0.72 to 0.89 case per 1000 examinations, respectively. The benefit of supplemental imaging was not assessed. Breast density should not be the sole criterion for deciding whether supplemental imaging is justified because not all women with dense breasts have high interval cancer rates. BCSC 5-year risk combined with BI-RADS breast density can identify women at high risk for interval cancer to inform patient-provider discussions about alternative screening strategies. National Cancer Institute.

Interval cancer rates in the Irish national breast screening programme.

To compare interval cancer rates from the Irish breast screening programme, BreastCheck, for the period 2000-2007 with those from other European countries. Data from BreastCheck was linked to National Cancer Registry breast cancer registrations, to calculate numbers of women screened, screen-detected cancers, and interval cancers, by year of screening, in the first and second years after screening, and by initial or subsequent screen. Estimated underlying cancer incidence from the period 1996-1999 inclusive was used to calculate proportionate incidence. We calculated the interval cancer ratio as an alternative measure of the burden of interval cancers. There were 372,658 screening records for 178,147 women in the period 2000-2007. The overall interval rate was 9.6 per 10,000 screens. In the first year after screening, the interval cancer rate was 5.8 per 10,000 screens and this increased to 13.4 in the second year after screening. The screen detection rate for the period was 53.6 per 10,000 screened for all screens combined. Initial screens produced a higher detection rate at 66.9 per 10,000 screened compared with subsequent screens with a screen-detected rate of 41.4 per 10,000 screens. Interval breast cancer rates for the first years of the programme are within acceptable limits and are comparable with those in other European programmes. Nationwide roll-out together with the adoption of digital mammography may have an impact on interval cancer rates in future years.

Estimates of over-diagnosis of breast cancer due to population-based mammography screening in South Australia after adjustment for lead time effects

To estimate over-diagnosis due to population-based mammography screening using a lead time adjustment approach, with lead time measures based on symptomatic cancers only. Women aged 40-84 in 1989-2009 in South Australia eligible for mammography screening. Numbers of observed and expected breast cancer cases were compared, after adjustment for lead time. Lead time effects were modelled using age-specific estimates of lead time (derived from interval cancer rates and predicted background incidence, using maximum likelihood methods) and screening sensitivity, projected background breast cancer incidence rates (in the absence of screening), and proportions screened, by age and calendar year. Lead time estimates were 12, 26, 43 and 53 months, for women aged 40-49, 50-59, 60-69 and 70-79 respectively. Background incidence rates were estimated to have increased by 0.9% and 1.2% per year for invasive and all breast cancer. Over-diagnosis among women aged 40-84 was estimated at 7.9% (0.1-12.0%) for invasive cases and 12.0% (5.7-15.4%) when including ductal carcinoma in-situ (DCIS). We estimated 8% over-diagnosis for invasive breast cancer and 12% inclusive of DCIS cancers due to mammography screening among women aged 40-84. These estimates may overstate the extent of over-diagnosis if the increasing prevalence of breast cancer risk factors has led to higher background incidence than projected.

Colonoscopy in Colorectal Cancer Screening: Current Aspects.

Colonoscopy represents a very important diagnostic modality for screening for colorectal cancer, because it has the ability to both detect and effectively remove pro-malignant and malignant lesions. It is recommended by almost all international and national gastroenterology and cancer societies, as an initial screening modality or, following a positive fecal occult blood test, to be performed every 10years in individuals of average risk starting from the age of 50. However, a significant problem is the so-called post-screening (interval) polyps and cancers found some years after the index colonoscopy. In order to reduce the rate of interval cancers it is extremely necessary to optimize the quality and effectiveness of colonoscopy. Bowel preparation is of paramount importance for both accurate diagnosis and subsequent treatment of lesions found on colonoscopy. The quality of bowel preparation could be significantly improved by splitting the dose regimens, a strategy that has been shown to be superior to single-dose regimen. A good endoscopic technique and optimal withdrawal time offering adequate time for inspection, would further optimize the rate of cecal intubation and the number of lesions detected. During the last years, sophisticated devices have been introduced that would further facilitate cecal intubation. The percentage of total colonoscopies is now super-passing the level of 95% allowing the adenoma detection rate to be greater than the suggestive level of 25% in men and 15% in women. This review aims to provide the reader with the current knowledge concerning indications, usefulness, limitations and future perspectives of this probably most important screening technique for colorectal cancer available today.

819 Forty-Year Analysis of Colonoscopic Surveillance for Ulcerative Colitis Reveals Decreasing Risk of Interval and Advanced Cancer and Reducing Colectomy Rate for Dysplasia

Introduction While many aspects of colonoscopic surveillance program for colorectal cancer (CRC) in patients with ulcerative colitis (UC) have evolved, it is unknown how the risk of CRC changed over time. We report data from the largest and longest-running UC surveillance programs in the world, revealing a recent trend in CRC risk. Methods A retrospective chartreview of histologically confirmed extensive UC patients enrolled in long-term surveillance was performed. The primary end point was defined as death, colectomy, withdrawal from surveillance, or the census date (January 1, 2013). We compared per-decade CRC incidence rate (IR) over the last forty years i.e. first (1973-1982), second (1983-1992), third (19932002) and fourth decade (2003-2012). Cancer detected in symptom-driven investigations or surgery prior to the next scheduled surveillance was defined as interval CRC. Results A total of 1,375 patients underwent 8,650 colonoscopies (median, 5 per patient; interquartile range (IQR), 3 8) during 15,234 patient-years (PY) of follow-up (median, 11 years; IQR, 7 17). Cancer was detected in 72 patients (5.2% of study population), of which 15 were interval CRC (20.8%). While the overall CRC IR had decreased over the first three decades, there was a non-significant increase in the fourth decade (4.9 per 1,000 PY) compared with the third decade (3.7 per 1,000 PY; Chi-squared, P=0.30), which was attributable to a significant increase in IR of Dukes' A or B cancer in the fourth decade (3.2 per 1,000 PY) compared with the third decade (1.3 per 1,000 PY; P=0.045; figure 1). Likewise, there was an increase in IR of dysplasia (17.7 versus 11.7 per 1,000 PY; P=0.01). The chromoendoscopy, which was introduced in our center since 2002, was superior in detecting dysplasia compared with white-light endoscopy (lesion detection rate, 8.4% (92/1,098) versus 4.0% (175/4,373); Chi-squared, P<0.001). The IR of Dukes' C or disseminated cancer showed a linear decrease over the last four decade (2.5 to 1.4 per 1,000 PY in the first decade to last decade; Pearson's correlation, R= -0.99; P=0.01; figure 1). Furthermore, despite the decrease in colectomy rate for dysplasia (linear regression, R= -0.43; P=0.007), IR of interval CRC showed significant reduction over time (2.5 to 0.4 per 1,000 PY in the first decade to last decade; Pearson's correlation, R= -0.99; P=0.007; figure 2). Conclusion The colonoscopic surveillance is increasingly becoming effective in reducing advanced cancer and interval cancer risks, which maybe attributable to the improving lesion detection rate and subsequent decrease in the rate of false negative examinations. Although decreasing colectomy rate allowed more patients to retain their colon, it may have resulted in increased early cancer risk, highlighting the need for close monitoring of patients with dysplasia managed non-surgically.

A multicenter pragmatic study of an evidence-based intervention to improve adenoma detection: the Quality Improvement in Colonoscopy (QIC) study.

Low adenoma detection rates (ADRs) at colonoscopy are linked to significantly higher interval cancer rates, and vary between colonoscopists. Studies demonstrate that lesion detection is improved by: withdrawal time of ≥ 6 minutes; use of hyoscine butylbromide; position change; and rectal retroflexion. We evaluated the feasibility of implementing the above "bundle" of interventions into colonoscopy practice, and the effect on ADR. A longitudinal cohort design was used. Implementation combined central training, local promotion, and feedback. The uptake marker was change in hyoscine butylbromide use. Comparisons were between the 3 months before and the 9 months after the implementation phase, globally, by endoscopy unit and by quartile when colonoscopists were ranked according to baseline ADR. Chi-squared or Fisher's tests were used to evaluate significance. 12 units participated. Global and quartile analyses included data from 118 and 68 colonoscopists and 17 508 and 14 193 procedures respectively. A significant increase in hyoscine butylbromide use was observed globally (54.4 % vs. 15.8 %, P < 0.001), in all endoscopy units (P < 0.001) and quartiles (P < 0.001). A significant increase in ADR was observed globally (18.1 % vs. 16.0 %, P = 0.002) and in the lower two colonoscopist quartiles (P < 0.001), with a nonsignificant increase in the upper middle quartile and a significant fall to 21.5 %. in the upper quartile. The significant variations in ADR among the upper three quartiles disappeared. In routine clinical practice, introduction of a simple, inexpensive, evidence-based "bundle" of measures is feasible and is associated with higher global ADR, driven by improvements amongst the poorest performing colonoscopists.

How to treat diminutive polyps? Do we need more evidence?

How to treat diminutive polyps? Do we need more evidence?

OP019. Forty-Year Analysis of Colonoscopic Surveillance for Ulcerative Colitis Reveals Decreasing Risk of Interval and Advanced Cancer and Reducing Colectomy Rate for Dysplasia

OP019. Forty-Year Analysis of Colonoscopic Surveillance for Ulcerative Colitis Reveals Decreasing Risk of Interval and Advanced Cancer and Reducing Colectomy Rate for Dysplasia

Measuring the burden of interval cancers in long-standing screening mammography programmes.

Mammography screening programme sensitivity is evaluated by comparing the interval cancer rate (ICR) with the expected breast cancer incidence without screening, ie. the proportional interval cancer rate (PICR). The PICR is usually found by extrapolating pre-screening incidence rates, whereas ICR is calculated from data available in the screening programmes. As there is no consensus regarding estimation of background incidence, we seek to validate the ICR measure against the PICR. Screening data from the three mammography screening programmes of Stockholm, Copenhagen, and Funen in the period 1989-2011 provided data to calculate the ICR. The most commonly described methods of extrapolating pre-screening incidence rates to calculate the PICR were illustrated and PICRs were calculated by year and programme using these different methods and compared with the ICRs. PICRs varied greatly, reaching a difference of 32-34% in Stockholm, 79% in Copenhagen, and 100-106% in Funen between the highest and the lowest value, depending on which method was applied. PICRs exhibited large variations yearly and from programme to programme. ICRs did not vary to the same extent, ranging on average from 0.100 to 0.136 in the first 12-months and between 0.201 and 0.225 in the last 12-months of the two-year period after a negative screen across the three programmes. The value of the PICR is hugely influenced by which method is applied, whereas the ICR is calculated purely on data available within programmes. We find that the PICR, the establishing indicator for sensitivity, could preferably be replaced by the ICR.

Colorectal cancer screening.

Colorectal cancer is one of the most common malignancies in Australia, and screening to detect it an earlier stage is cost-effective. Furthermore, detection and removal of precursor polyps can reduce incidence. Currently, there are limited data to determine the screening rate in Australia, but it is certainly lower than the 80% screening rate considered desirable. Whether colonoscopy is used as the screening test or to follow up positive results of an initial non-invasive test, it plays a fundamental role. Despite high sensitivity and specificity, it is expensive and invasive with measurable risk and is not acceptable as an initial test to many participants. It does not provide complete protection, and interval cancers between planned colonoscopies are associated with proximal location, origin in sessile serrated adenomas and operator-dependent factors. An essential component of colorectal screening is the measurement of colonoscopy quality indicators, such as caecal intubation and adenoma detection rates, which are known to be associated with the rate of interval cancer. The non-invasive screening test currently recommended in Australia is biennial testing for faecal occult blood between the ages of 50 and 75 using a faecal immunochemical test, with positives evaluated by colonoscopy. This is provided through the National Bowel Cancer Screening Programme, currently for those at the ages of 50, 55, 60 and 65 years, with full implementation of biennial screening by 2020. To improve screening in Australia, the most fruitful approach may be to acknowledge that there is a choice of screening tests and to focus on the goal of improving overall participation rate and being able to measure this.