Rates of spectacle wear in early childhood in the Netherlands.

BACKGROUND: Refractive errors are relatively common all around the world. In particular, early onset myopia is associated with a significant burden in later life. Little is known about refractive errors in preschool children. The aim of this study was to assess the prevalence of spectacle wear, visual acuity and refractive errors in young Dutch children. METHODS: We analyzed data of three prospective population-based studies: 99,660 3- to 5-year-olds undergoing vision screening at preventive child healthcare organizations, 6934 6-year-olds from the Generation R study, and 2974 7-year-olds from the RAMSES study. Visual acuity was measured with Landolt-C or LEA charts, spectacle wear was assessed, and refractive errors at age 6 and 7 were measured with cycloplegic refraction. RESULTS: The prevalence of spectacle wear ranged from 1.5 to 11.8% between 3 to 7 years with no significant gender differences. Among children with spectacle wear at 6 years (N = 583) and 7 years (N = 350) 29.8 and 34.6% had myopia respectively, of which 21.1 and 21.6% combined with astigmatism; 19.6 and 6.8% had hyperopia, 37.2 and 11.1% hyperopia and astigmatism, and 12.5 and 32.7% astigmatism only. CONCLUSIONS: Spectacle wear in European children starts early in preschool and increases to a relatively frequent visual aid at school age. Advocating early detection and monitoring of refraction errors is warranted in order to prevent visual morbidities later in life.

Trends in incidence and detection of advanced breast cancer at biennial screening mammography in The Netherlands: a population based study.

INTRODUCTION: The aims of this study were to determine trends in the incidence of advanced breast cancer at screening mammography and the potential of screening to reduce it. METHODS: We included a consecutive series of 351,009 screening mammograms of 85,274 women aged 50-75 years, who underwent biennial screening at a Dutch breast screening region in the period 1997-2008. Two screening radiologists reviewed the screening mammograms of all advanced screen detected and advanced interval cancers and determined whether the advanced cancer (tumor > 20 mm and/or lymph node positive tumor) had been visible at a previous screen. Interval cancers were breast cancers diagnosed in women after a negative screening examination (defined as no recommendation for referral) and before any subsequent screen. Patient and tumor characteristics were compared between women with advanced cancer and women with non-advanced cancer, including ductal carcinoma in situ. RESULTS: A total of 1,771 screen detected cancers and 669 interval cancers were diagnosed in 2,440 women. Rates of advanced cancer remained stable over the 12-year period; the incidence of advanced screen-detected cancers fluctuated between 1.5 - 1.9 per 1,000 screened women (mean 1.6 per 1,000) and of advanced interval cancers between 0.8 - 1.6 per 1,000 screened women (mean 1.2 per 1,000). Of the 570 advanced screen-detected cancers, 106 (18.6%) were detected at initial screening; 265 (46.5%) cancers detected at subsequent screening had been radiologically occult at the previous screening mammogram, 88 (15.4%) had shown a minimal sign, and 111 (19.5%) had been missed. Corresponding figures for advanced interval cancers were 50.9% (216/424), 24.3% (103/424) and 25.1% (105/424), respectively. At multivariate analysis, women with a ≥ 30 months interval between the latest two screens had an increased risk of screen-detected advanced breast cancer (OR 1.63, 95%CI: 1.07-2.48) and hormone replacement therapy increased the risk of advanced disease among interval cancers (OR 3.04, 95%CI: 1.22-7.53). CONCLUSION: We observed no decline in the risk of advanced breast cancer during 12 years of biennial screening mammography. The majority of these cancers could not have been prevented through earlier detection at screening.

Lower sensitivity of screening mammography after previous benign breast surgery.

Few data are available on the effect of previous benign breast surgery on screening mammography accuracy. We determined whether sensitivity of screening mammography and tumor characteristics are different for women with and without previous benign breast surgery. We included a consecutive series of 317,398 screening mammograms of women screened between 1997 and 2008. During 2-year follow-up, clinical data, breast imaging, biopsy and surgery reports were collected from women with screen-detected or interval breast cancers. Screening sensitivity, tumor biology and tumor stages were compared between 168 women with breast cancer and prior ipsilateral benign breast surgery and 2,039 women with breast cancer but without previous ipsilateral, benign breast surgery. The sensitivity of screening mammography was significantly lower for women with prior surgery [64.3% (108/168) versus 73.4% (1,496/2,039), p = 0.01]. The concomitant increased interval cancer risk remained significant after logistic regression adjustment for age and breast density (OR = 1.5, 95% CI: 1.1-2.1). Comparing screen-detected cancers in women with and without prior breast surgery, no significant differences in estrogen receptor status (p = 0.56), mitotic activity (p = 0.17), proportions of large (T2+) tumors (p = 0.6) or lymph node positive tumors (p = 0.4) were found. Also for interval cancers, no differences were found in estrogen receptor status (p = 0.41), mitotic activity (p = 0.39), proportions of large tumors (p = 0.9) and lymph node positive tumors (p = 0.5) between women with and without prior breast surgery. We conclude that sensitivity of screening mammography is significantly lower in women with previous benign breast surgery than without, but tumor characteristics are comparable both for screen detected cancers and interval cancers.

Malpractice claims following screening mammography in The Netherlands.

Although malpractice lawsuits are frequently related to a delayed breast cancer diagnosis in symptomatic patients, information on claims at European screening mammography programs is lacking. We determined the type and frequency of malpractice claims at a Dutch breast cancer screening region. We included all 85,274 women (351,009 screens) who underwent biennial screening mammography at a southern breast screening region in The Netherlands between 1997 and 2009. Two screening radiologists reviewed the screening mammograms of all screen detected cancers and interval cancers and determined whether the cancer had been missed at the previous screen or at the latest screen, respectively. We analyzed all correspondence between the screening organization, clinicians and screened women, and collected complaints and claims until September 2011. At review, 20.9% (308/1,475) of screen detected cancers and 24.3% (163/670) of interval cancers were considered to be missed at a previous screen. A total of 19 women (of which 2, 6 and 11 women had been screened between 1997 and 2001 (102,439 screens), 2001 and 2005 (114,740 screens) and 2005 and 2009 (133,830 screens), respectively) had contacted the screening organization for additional information about their screen detected cancer or interval cancer, but filed no claim. Three other women directly initiated an insurance claim for financial compensation of their interval cancer without previously having contacted the screening organization. We conclude that screening-related claims were rarely encountered, although many screen detected cancers and interval cancers had been missed at a previous screen. A small but increasing proportion of women sought additional information about their breast cancer from the screening organization.

Do physical work factors and musculoskeletal complaints contribute to the intention to leave or actual dropout in student nurses? A prospective cohort study.

BACKGROUND: Little is known, whether physical workload and musculoskeletal complaints (MSCs) have an impact on the intended or actual dropout of nursing students in the later years of their degree program. PURPOSE: Studying the determinants of intention to leave and actual dropout from nursing education. We hypothesized that physical workload and MSCs are positively associated with these outcomes. METHODS: A prospective cohort study among 711 third-year students at a Dutch Bachelor of Nursing degree program. Multivariable backward binary logistic regression was used to examine the association between physical work factors and MSCs, and intention to leave or actual dropout. RESULTS: Intention to leave was 39.9% and actual dropout 3.4%. Of the nursing students, 79% had regular MSCs. The multivariable model for intention to leave showed a significant association with male sex, working at a screen, physical activity, decision latitude, co-worker support, distress and need for recovery. The multivariable model for dropout showed a significant association with living situation (not living with parents), male sex, sick leave during academic year and decision latitude. CONCLUSIONS: Our research shows that the prevalence of MSCs among nursing students is surprisingly high, but is not associated with intention to leave nor with actual dropout.

Patient and tumor characteristics of bilateral breast cancer at screening mammography in the Netherlands, a population-based study.

Few data are available on bilateral breast cancer in the screening population. The aim of this study was to determine patient and tumor characteristics of women with bilateral breast cancer at screening mammography. We included all 350,637 screening mammography examinations of women participating in a biennial screening program in a southern screening region of the Netherlands between May 1998 and January 2010. For referred women, all breast imaging reports, biopsy results, and surgery reports during one year after referral were collected. We compared patient and tumor characteristics of referred women with a diagnosis of bilateral breast cancer or unilateral breast cancer at workup. Bilateral or unilateral breast cancer had been diagnosed in respectively 40 (2.2%) and 1766 (97.8%) of 1806 referred women. Women with bilateral or unilateral breast cancer did not differ significantly in mean age, mammographic breast density, family history of breast cancer, or use of hormone replacement therapy. Compared with index cancers, contralateral cancers comprised significantly more lobular cancers (P = 0.02). Tumor size, mitotic activity, and estrogen receptor status were comparable for both groups, but contralateral cancers had a significantly lower risk of lymph node metastases (P = 0.03). Compared to unilateral breast cancer, contralateral malignancies in women with bilateral breast cancer comprised significantly more lobular cancers (P = 0.004) and lymph node negative cancers (P = 0.01). Contralateral breast cancers detected at screening comprise more lobular cancers and show less nodal involvement than index cancers or unilateral cancers. No differences are observed with respect to other patient and tumor characteristics.

Detection of bilateral breast cancer at biennial screening mammography in the Netherlands: a population-based study.

PURPOSE: To determine the incidence of bilateral breast cancer at biennial screening mammography and to assess the sensitivity of screening in the detection of bilateral breast cancer. MATERIALS AND METHODS: All women gave written informed consent, and the requirement to obtain review board approval was waived. The authors included all 302,196 screening mammograms obtained in 80,466 women aged 50-75 years in a southern breast screening region of the Netherlands between May 1998 and July 2008. During 2-year follow-up, the authors collected clinical data, breast imaging reports, biopsy results, and breast surgery reports from all patients with screening-detected and interval cancers. Two screening radiologists reviewed the screening and clinical mammograms of all bilateral screening-detected and interval cancers for mammographic abnormalities. The radiologists were initially blinded to each other's referral opinion, and discrepant assessments were followed by consensus reading. RESULTS: Of all women with screening-detected cancer (n = 1555) or interval cancer (n = 585), 52 (2.4%) had bilateral breast cancer. The sensitivity of screening mammography in the detection of bilateral breast cancer was 19% (10 of 52 women; 95% confidence interval: 8.5%, 29.9%). At blinded review, 18 of the 53 tumors not detected at screening (34%) were considered to be missed, 11 (21%) showed nonspecific minimal signs, and 24 (45%) had been mammographically occult at screening. Five women referred for further analysis experienced a 6-17-month delay in the diagnosis of the second breast cancer; in four of those women, the delay resulted from an incorrect Breast Imaging Reporting and Data System classification at clinical mammography. CONCLUSION: The sensitivity of screening mammography in the detection of bilateral breast cancer is disappointingly low. Both screening radiologists and clinical radiologists should pay vigorous attention to the contralateral breast to detect bilateral malignancies without diagnostic delay.

Introduction of additional double reading of mammograms by radiographers: effects on a biennial screening programme outcome.

PURPOSE: To determine the effect of introducing radiographer double reading, in addition to standard radiologist double reading, on screening mammography outcome. METHODS: In period A, 66,225 mammograms were read by two screening radiologists. In period B, 78,325 mammograms were read by two radiographers in addition and radiologists were blinded to the referral opinion of the radiographers. Mammograms, for which only radiographers had suggested referral, (i.e. cases that would only be referred by technologists) were re-evaluated by the screening radiologists. Women were referred if at least one radiologist considered this necessary, and diagnostic costs of these additional referrals were estimated. RESULTS: In period A, 322 cancers were diagnosed after referral of 678 women. During period B, radiologists initially referred 1122 patients and 411 cancers were detected. Radiologists' referral rate was higher in period B than in period A (1.43% versus 1.02%, p<0.001), as well as the cancer detection rate per 1000 women screened (CDR) (5.25 versus 4.86, p=0.3). The positive predictive value of referral (PPV) was 36.6% versus 47.5% (p<0.001). In period B, radiologist review of 544 additional positive radiographer readings led to 102 extra referrals, with 29 additional cancers detected, resulting in an overall referral rate of 1.56% (compared to period A, p<0.001), an overall CDR of 5.62 (p=0.048) and an overall PPV of 35.9% (p<0.001). Workup expenses of the 102 additional referrals were euro60,274. CONCLUSION: Additional radiographer double reading detected cancers that would have been missed by radiologists. Mean expenses for diagnostic confirmation of these extra cancers was euro2078 per cancer.

Utilization and cost of diagnostic imaging and biopsies following positive screening mammography in the southern breast cancer screening region of the Netherlands, 2000-2005.

We prospectively assessed trends in utilization and costs of diagnostic services of screen-positive women in a biennial breast cancer screening program for women aged 50-75 years. All 2,062 women with suspicious findings at screening mammography in the southern region of the Netherlands between 1 January 2000 and 1 July 2005 (158,997 screens) were included. Data were collected on any diagnostic examinations, interventional procedures, and surgical consultations with two-year follow-up. We used national reimbursement rates to estimate imaging costs and percutaneous biopsy costs. Cost prices, charged by hospitals, were used to estimate open surgical biopsy costs and surgical consultation costs. The largest increase in utilization of diagnostic procedures per 100 referrals was observed for axillary ultrasound (from 3.9 in 2000 to 33.5 in 2005) and for stereotactic core biopsy (from 2.1 in 2000 to 26.8 in 2005). Per 100 referrals, the open surgical biopsy rate decreased from 34.7 (2000) to 4.6 (2005) and the number of outpatient surgical consultations fluctuated between 269.8 (2000) and 309.7 (2004). Mean costs for the diagnosis of one cancer were Euro1,501 and ranged from Euro1,223 (2002) to Euro1,647 (2003). Surgical biopsies comprised 54.1% of total diagnostic costs for women screened in 2000, but decreased to 9.9% for women screened in 2005. Imaging costs increased from 23.7 to 43.8%, percutaneous biopsy costs from 9.9 to 27.2%, and consultation costs from 12.3 to 19.1%. We conclude that diagnostic costs per screen-detected cancer remained fairly stable through the years, although huge changes in the use of different diagnostic procedures were observed.

Psychiatric consultation with regard to requests for euthanasia or physician-assisted suicide.

The objective of this article is to describe the practice of psychiatric consultation with regard to explicit requests for euthanasia or physician-assisted suicide in the Netherlands. Written questionnaires were sent to an unselected sample of 673 Dutch psychiatrists, about half of all such specialists in the Netherlands. The response rate was 83%. Of the respondents, 36% (199 of 549) had at least once been consulted about a patient's request for physician-assisted death. The annual number of such psychiatric consultations is estimated to be 400 (about 4% of all requests for physician-assisted death). About one in four consultations is initiated by another psychiatrist. Consultants were mainly asked to assess whether the patient had a treatable mental disorder (68%) or whether the patient's request was well considered (66%). Assessment of the influence of transference and countertransference was less frequently sought (24%). Of the 221 consultation cases described, 67 (30%) ended in euthanasia or assisted suicide, whereas another 124 (56%) did not. In most, but not all, cases where the patient's request for physician-assisted death was refused, the respondent had judged that the request was not well considered or that the patient had a treatable mental disorder, or that the decision-making was influenced by transference and countertransference. We conclude that psychiatric consultation for patients requesting physician-assisted death in the Netherlands is rare, as in other countries. The issue of psychiatric consultation with regard to requests for physician-assisted death, especially in patients with a physical disease, needs to be further addressed.

Effectiveness of screening for amblyopia and other eye disorders in a prospective birth cohort study.

OBJECTIVE: To establish whether the current vision screening practice in the Netherlands is effective in preventing permanent visual loss and to estimate the sensitivity of the programme. SETTINGS: In the Netherlands, all children are invited for preverbal (1, 3, 6-9 and 14-24 months) and preschool (36, 45, and 60-72 months) vision screening. Screening attendance is high, but the effectiveness in reducing amblyopia is unknown. METHODS: In a 7-year cohort study, 4624 children born in the city of Rotterdam between 16 September 1996 and 15 May 1997 were followed through all routine vision screening examinations. At age seven, visual acuity (VA) of children still living in Rotterdam was assessed by study orthoptists. In case of VA > 0.1 logMAR in one or both eyes, two or more logMAR lines of interocular difference or eye disorders like strabismus, children underwent a more intensive eye examination. RESULTS: Attendance at the 9-month screening was 89%, decreasing to about 75% at later examinations. Of preverbal tests, 2.5% were positive, and of preschool tests, 10%. In total, 19% of children had a positive vision screening test at least once. Amblyopia prevalence was 3.4%. Sensitivity of the vision screening programme was 73% and specificity 83%. At age seven, 0.7-1.2% (confirmed vs final exam) of the children had a VA > 0.3 logMAR in the worse eye compared with 2-3.9% (in literature) reported prevalence in non-screening situations. Children who were less frequently screened had a higher chance of poor vision (>0.3 logMAR) at age seven. CONCLUSION: The Dutch child vision screening programme may reduce the risk of persistent amblyopia (VA > 0.3 logMAR) at age seven by more than half.

Two-view versus single-view mammography at subsequent screening in a region of the Dutch breast screening programme.

We retrospectively determined the effect of analogue two-view mammography versus single-view mammography at subsequent screens on breast cancer detection and determined financial consequences for a current digital mammography setting. Two screening radiologists reviewed the mammograms of 536 screen detected cancers (SDCs) and 171 interval cancers (ICs) with single-view mammography (medio-lateral-oblique view) at the last but one screen (SDCs) or latest screen (ICs). They determined whether two-view mammography at the last (but one) screen could have increased the cancer detection rate at that screening round. For subsequent screens, the radiologists also assessed the percentage of SDCs and ICs that had been missed at previous two-view screening mammography (SDC) or latest two-view screening (IC), respectively. Additional personnel and digital storage costs for standard two-view mammography at subsequent screening were calculated for digital screening. Two-view mammography could have facilitated earlier cancer detection in 40.9% (219/536) of SDCs and 39.8% (68/171) of ICs. For two-view screens, 24.4% of SDCs (213/871) were missed at previous two-view screening and 29.3% of ICs (110/375) were missed at the latest screen. Overall costs increase € 1.03/screen after implementation of digital two-view mammography. Standard two-view mammography at subsequent screening may modestly increase cancer detection at an earlier stage, whereas additional screening costs are limited.

Determinants and outcome of unsuccessful referral after positive screening in a large birth-cohort study of population-based vision screening.

PURPOSE: The efficacy of population-based vision screening is hampered by unsuccessful referral after a positive screening test. We studied the nature and causes of unsuccessful referral in a 7-year birth cohort study of vision screening in Rotterdam, the Netherlands. METHODS: All parents of children who had been unsuccessfully referred were asked whether they recalled the referral. Reasons for noncompliance, if any, were identified using semi-structured interviews. Screening records were checked for written evidence of the referral. The parents' fluency in Dutch and their socioeconomic status were also assessed. RESULTS: Of the 561 screen-positive children, 129 (23%) had not been referred successfully. For the current study, 97 parents were successfully contacted. Of these, 14 parents had been willingly noncompliant and 83 said they were unaware of the referral, with 47% having poor to moderate fluency in Dutch. In 53 cases, the screening charts contained no written evidence of any referral. Amblyopia was identified in 3 of the unsuccessful referrals. CONCLUSIONS: In this population-based screening program, 1 of 4 positively screened children was not successfully referred. Apart from parental noncompliance, the unsuccessful referrals can be explained by miscommunication, deficient documentation, and physician noncompliance with screening guidelines. An effective monitoring feedback system may improve the efficacy of child vision screening.

Rotterdam AMblyopia screening effectiveness study: detection and causes of amblyopia in a large birth cohort.

PURPOSE. The Dutch population-based child health monitoring program includes regular preverbal (age range, 1-24 months) and preschool (age range, 36-72 months) vision screening. This study is on the contribution of an organized vision screening program to the detection of amblyopia. METHODS. A 7-year birth cohort study of 4624 children was started in 1996/1997 in Rotterdam. Vision screening data were obtained from the child screening centers. Treating orthoptists working at the regional ophthalmology departments provided information about diagnosis and treatment. The diagnosis was reviewed by two experts. The parents provided additional information on their child's eye history through written questionnaires and telephone interviews. At age 7 years, the children underwent a final examination by the study orthoptists. RESULTS. Of the 3897 children still living in Rotterdam by 2004, 2964 (76.1%) underwent the final examination. Amblyopia was diagnosed in 100 (3.4%) of these (95% CI, 2.7-4.0). At age 7, 23% had visual acuity >0.3 logMAR. Amblyopia was caused by refractive error (n = 42), strabismus (n = 19), combined-mechanism (n = 30), deprivation (n = 7), or unknown (n = 2). Eighty-three amblyopia cases had been detected before age 7. Amblyopia detection followed positive results in vision screening in 56 children, either preverbal (n = 15) or preschool (n = 41). Twenty-six other amblyopes were self-referred (n = 12, before a first positive screening test), especially strabismic or combined-mechanism amblyopia; data were uncertain for one other positively screened amblyopic child. Amblyopia remained undetected until age 7 due to unsuccessful referral (n = 4, three with visual acuity >0.3 logMAR at age 7) or false-negative screening (n = 13). CONCLUSIONS. Most cases of amblyopia were detected by vision screening with visual acuity measurement. Preverbal screening contributed little to the detection of refractive amblyopia.

Delayed diagnosis of breast cancer in women recalled for suspicious screening mammography.

PURPOSE: To determine the frequency, pathology and causes of a delay in cancer diagnosis in women recalled for suspicious screening mammography. METHODS: We included all 290,943 screening mammograms of women aged 50-75 years, who underwent biennial screening mammography between 1st January 1995 and 1st January 2006. During a follow-up period of at least 2 years, clinical data, breast imaging reports, biopsy results and breast surgery reports were collected of all 3513 women with a positive screening result. Tumour stages of breast cancers with a diagnostic delay (defined as breast cancer confirmation more than 3 months following a positive mammography screen) were compared with those of cancers diagnosed within 3 months following referral and with interval cancers. RESULTS: A diagnostic delay occurred in 97 (6.5%) of 1503 screen-detected cancers. These 97 false-negative assessments comprised significantly more ductal cancers in situ (26.8%) than did cancers with an adequate assessment after recall (15.5%, p=0.004) or interval cancers (3.7%, p<0.001). Compared with interval cancers, cancers with a false-negative assessment had a more favourable tumour size (T1a-c, 87.3% versus T1a-c, 46.4%; p<0.001) and showed significantly fewer cases with axillary lymph node metastases (22.5% versus 48.2%; p<0.001). Between hospitals having performed the workup of at least 500 referred women each, the percentage of women with a false-negative assessment varied from 5.0% to 9.1% (p=0.03). In these hospitals, improper classification of lesions at diagnostic mammography comprised 64.4% of false-negative assessments. CONCLUSION: We found that 6.5% of recalled women experienced a delay in breast cancer diagnosis, with significant performance variations between hospitals.

Additional double reading of screening mammograms by radiologic technologists: impact on screening performance parameters.

BACKGROUND: Studies have shown that having mammography technologists review screening mammograms in addition to radiologist review may increase the number of breast cancers that are detected at screening mammography. We prospectively examined the effects on screening performance of adding independent double reading of screening mammograms by technologists to standard double reading by radiologists. METHODS: Twenty-one screening mammography technologists and eight certified screening radiologists participated in this study. From January 1, 2003, to January 1, 2005, all 61,251 screening mammograms obtained at two mammography screening units in The Netherlands were independently read (although the second reader was not blinded to the first reader's interpretation) by two technologists and, in turn, by two radiologists. Radiologists were blinded to the referral opinion of the technologists. During a 2-year follow-up period, we collected clinical data, breast imaging reports, biopsy results, and breast surgery reports of all women with a positive screening result (i.e., those that required additional imaging) from any reader. The distributions of categorical variables between subgroups were compared using chi-square or Fisher's exact tests. Differences in referral and detection by radiologists and technologists were assessed using McNemar's test. All statistical tests were two-sided. RESULTS: The radiologists referred 905 women (referral rate = 1.48%, 95% confidence interval [CI] = 1.38% to 1.57%), of whom 323 had breast cancer, corresponding to a positive predictive value of referral (PPV) of 35.7% (95% CI = 32.6% to 38.8%). Review of 446 additional technologist-positive readings led to another 80 referrals, resulting in the detection of 22 additional cancers. These extra referrals increased the initial referral rate from 1.48% to 1.61% (difference = 0.13%; 95% CI = 0.10% to 0.16%) and the cancer detection rate (CDR) from 5.27 to 5.63 cancers per 1000 women screened (difference = 0.36 cancers per 1000 women screened; 95% CI = 0.24 to 0.55). With technologist double reading only, 829 women would have been referred (referral rate = 1.35%, 95% CI = 1.26% to 1.45%); among these women, 286 cancers were diagnosed (PPV = 34.5%, 95% CI = 31.3% to 37.7%; CDR = 4.67 cancers per 1000 women screened, 95% CI = 4.13 to 5.21). Referral of all 1351 radiologist- and/or technologist-positive readings would have led to 362 cancers found at screening. The cancer detection rate for radiologist double reading would have increased from 5.27 to 5.91 cancers per 1000 women screened (relative increase = 12.1%, 95% CI = 8.8% to 16.5%; difference = 0.64 cancers per 1000 women screened, 95% CI = 0.47 to 0.87). CONCLUSION: A referral strategy that includes all technologist-positive readings, which would have increased the cancer detection rate while maintaining a low referral rate, should be considered.

A decade of breast cancer screening in The Netherlands: trends in the preoperative diagnosis of breast cancer.

PURPOSE: In a prospective, multi-institutional follow-up study we describe the trends in the preoperative pathologic confirmation of breast cancer of women who underwent breast cancer screening between 1995 and 2005. METHODS: We included all women aged 50-75 years who underwent biennial screening mammography in the southern breast cancer screening region of the Netherlands between February 13, 1995 and December 22, 2004. Clinical data, breast imaging reports, biopsy results and breast surgery reports were collected of all women with a positive screening result. Follow-up lasted through the next biennial screening examination and was approximately two years for all referred women. RESULTS: Of 258,900 mammographic screening examinations, 3,064 (1.2%) were positive screens. The majority of women (92%) were analyzed in four regional hospitals and workup yielded breast cancer in 1,332 women. From 1995 to 2005, the percentage of breast cancer cases that underwent percutaneous biopsy prior to surgery, increased from 42.4 to 100%. The proportion of cancers with a preoperative diagnosis of malignancy by percutaneous biopsy, increased from 27.1% in 1995 to 92.7% in 2004. Preoperative breast cancer confirmation by fine needle aspiration cytology (FNAC) gradually decreased from 91.3% to 14.5%, whereas preoperative confirmation by ultrasound guided core biopsy (USCB) or stereotactic core needle biopsy (SCNB) increased from 8.7% to 69.1% and from 0 to 17.4% respectively. CONCLUSIONS: A preoperative diagnosis of breast cancer is currently obtained in more than 90% of breast cancer patients. The increase in preoperative breast cancer diagnosis through 1995-2004 is correlated with the introduction of SNCB and increased use of USCB at the expense of FNAC.

Effect of recall rate on earlier screen detection of breast cancers based on the Dutch performance indicators.

BACKGROUND: The recall rate (i.e., the rate at which mammographically screened women are recalled for additional assessment) in the Dutch breast screening program (0.89% in 2000 for subsequent examinations) is the lowest worldwide, with possible consequences including higher rates of late-detected (i.e., "missed") interval and screen-detected cancers. To estimate the effect of changes in recall rate on earlier detection of cancers, we carried out a blinded review of interval and screen-detected cancers in the Dutch screening program. METHODS: A total of 495 sets of screen-negative mammograms (prediagnostic mammogram and the immediate previous mammogram) were collected from women participating in the biennial Dutch screening program. Of these, 250 were from control subjects, and 245 were from women who were subsequently diagnosed with breast cancer (123 interval and 122 screen-detected cancers). These mammograms were read by 15 radiologists who specialize in screening mammography and were blinded to outcome. Mean detection sensitivities for different false-positive rates were calculated using a linear mixed model. These results were used to calculate the effect of recall rate adjustment on earlier detection of cancers and numbers of false-positives. RESULTS: Increasing the recall rate to 2.0% would increase the detection rate from 4.20 per thousand to 4.52 per thousand due to the earlier detection of interval cancers. Moreover, 0.54 per thousand of the screen-detected cancers would be detected 2 years earlier (late screen-detected cancers). At recall rates of 3.0% and 4.0% the detection rate would increase to 4.58 per thousand and 4.63 per thousand, respectively, and 0.64 per thousand and 0.72 per thousand, respectively, of the screen-detected cancers would be detected 2 years earlier. For each 1.0% incremental increase in recall rate above 5.0%, the detection rate would increase by approximately 0.03 per thousand, with positive predictive values decreasing to below 10%. CONCLUSION: Breast cancer can be detected earlier by lowering the threshold for recall, especially for recall rates of 1%-4%. With further recall rate increases, cancer detection levels off with a disproportionate increase of false-positive rates.

Independent double reading of screening mammograms in The Netherlands: effect of arbitration following reader disagreements.

PURPOSE: To prospectively determine the value of arbitration by a panel of radiologists when two radiologists performing independent readings of screening mammograms do not reach a consensus about referral. MATERIALS AND METHODS: The study population consisted of women who participated in the Dutch Nationwide Breast Cancer Screening Program, in which biennial screening is offered to women aged 50-75 years. An arbitration panel of three radiologists assessed those screening mammograms for which two screening radiologists did not reach a consensus about referral necessity. Women were referred for further analysis if at least one arbitration panel radiologist considered referral to be necessary. RESULTS: The two screening radiologists agreed on the recommendation for referral of 498 (0.8%) of 65,779 screened women and on the recommendation for no referral of 64,949 (98.7%) women. They initially disagreed about the referral in 332 (0.5%) cases. After a mutual consultation, disagreement persisted regarding 183 (0.3%) mammograms. The arbitration panel referred 89 of these cases for further analysis, which revealed cancer in 20 (22%) cases. In three (3%) of the 94 cases that were not referred by the panel, breast cancer was detected at the site of previously discrepant mammographic findings seen at subsequent screening performed 2 years later. If all 183 discrepant cases had been referred, the referral rate would have increased from 0.8% to 0.9% at subsequent (incident) screenings and from 1.5% to 1.7% at initial screenings. In addition, at subsequent screenings, the number of cancers detected per 1,000 women screened would have increased from 4.4 to 4.5. CONCLUSION: Mammograms with discrepant findings constitute a very important subset of screening mammograms. All lesions that are subsequently proved to be malignant may not be detected with panel arbitration.

Computer-aided detection versus independent double reading of masses on mammograms.

PURPOSE: To evaluate the use of a computer-aided detection (CAD) system (designed for mammographic mass detection) to help improve mass interpretation and to compare CAD results with independent double-reading results. MATERIALS AND METHODS: Screening mammograms from 500 cases were collected; 125 of these cases were screening-detected cancers, and 125 were interval cancers. Previously obtained screening mammograms (ie, prior mammograms) were available in all cases. All mammograms were analyzed by a CAD system, which detected mass regions and assigned a level of (cancer) suspicion to each mass. Ten experienced screening radiologists read the prior mammograms. For independent interpretation with CAD, the suspicion rating assigned to each finding by the radiologist was weighted with the CAD output at the area of the finding. CAD markers on areas that were not reported by the radiologist were not used. Independent double reading was implemented by using a rule to combine the levels of suspicion assigned to findings by two radiologists. Results were evaluated by using localized-response receiver operating characteristic analysis. RESULTS: In a total of 141 cases, there was a visible abnormality at the location of the cancer on the prior mammogram, and 115 of these were classified as mass cases. For prior mammograms that depicted masses, the mean sensitivity of the radiologists, as averaged among the false-positive rates lower than 10%, was 39.4%; this increased by 7.0% with CAD and by 10.5% with double reading. Differences among single, double, and CAD readings were statistically significant (P <.001). CONCLUSION: Although independent double reading yields the best detection performance, the presence and probability of CAD mass markers can improve mammogram interpretation.