A case-control study to estimate the impact of the Icelandic population-based mammography screening program on breast cancer death

Background: The Icelandic breast cancer screening program, initiated November 1987 in Reykjavik and covering the whole country from December 1989, comprises biennial invitation to mammography for women aged 40-69 years old.

Purpose: To estimate the impact of mammography service screening in Iceland on deaths from breast cancer.

Material and Methods: Cases were deaths from breast cancer from 1990 onwards in women aged 40 and over at diagnosis, during the period November 1987 to December 31, 2002. Age- and screening-area-matched, population-based controls were women who had also been invited to screening but were alive at the time their case died.

Results: Using conditional logistic regression on the data from 226 cases and 902 controls, the odds ratio for the risk of death from breast cancer in those attending at least one screen compared to those never screened was 0.59 (95% CI 0.41-0.84). After adjustment for healthy-volunteer bias and screening-opportunity bias, the odds ratio was 0.65 (95% CI 0.39-1.09).

Conclusion: These results indicate a 35-40% reduction in breast cancer deaths by attending the Icelandic breast cancer screening program. These results are consistent with the overall evidence from other observational evaluations of mammography-based programs.     

Medical radiologic technologist review: effects on a population-based breast cancer screening program

PURPOSE: To evaluate the effects of medical radiologic technologist review of mammograms in a population-based breast cancer screening program. MATERIALS AND METHODS: A technologist review pilot project was incorporated into the Regina, Saskatchewan, Canada, reading center. Technologists received special training in mammographic interpretation. They reviewed all 27,863 mammograms obtained at the center from July 1995 to September 1996 that were reviewed by a radiologist and selected cases for second blind reading by another radiologist. When the two radiologists' readings were in agreement, the report was sent. When the readings differed, a third opinion was obtained from the program's consulting radiologist. Changes in the number of mammograms interpreted as abnormal and the number of cancers detected were assessed. RESULTS: The technologist review was responsible for the detection of nine cancers missed at the first radiologist's interpretation. Technologists were very discriminating; only 391 cases (1.4%) were sent for double reading. The positive predictive value of screening did not change significantly (7.5% without review, 8.1% with review; P > .20). CONCLUSION: A substantial number of cancers were found with the technologist review. The number of mammograms interpreted as abnormal was reduced slightly. The technologist review proved to be a cost-effective alternative to double reading by two radiologists.     

荷兰两年期乳腺钼靶筛查检出双侧乳腺癌的流行病学研究

目的研究和探讨在两年期的乳腺钼靶筛查中能够检出双侧乳腺癌的发生率,并评估乳腺钼靶筛查对双侧乳腺癌检出的敏感度。材料与方法所有参加筛查的妇女均知     

Clinical breast examination in a comprehensive breast cancer screening program: contribution and cost

PURPOSE: To retrospectively evaluate the cost of clinical breast examination (CBE) and its contribution to screening mammography in the detection of breast cancer. MATERIALS AND METHODS: The study received a waiver of authorization from the institutional review board, informed patient consent was not required, and the study was compliant with HIPAA regulations. The records of 60 027 consecutive asymptomatic patients who underwent screening mammography were retrospectively reviewed. CBE was performed on all patients by a nurse practitioner. Patients with positive CBE findings were required to convert from screening to diagnostic evaluation; the number of cancer diagnoses that resulted was determined. The reports, four-view mammograms, or both of patients requiring conversion to diagnostic evaluation were reviewed to determine those patients likely to undergo diagnostic imaging on the basis of screening mammographic findings alone. The cost of CBE was calculated and divided by the number of cancers detected solely with CBE to determine the cost of CBE per additional cancer detected. RESULTS: Four hundred seventy-four (age range, 32-95) of 60 027 asymptomatic patients had positive CBE findings which required conversion to diagnostic evaluation. Forty-six cancers in 44 patients were subsequently diagnosed; 32 would have been detected with mammography alone, whereas 14 were imperceptible at screening mammography. The cost of CBE was $122 598 per cancer detected solely with positive CBE findings. CONCLUSION: CBE performed by nurse practitioners led to the diagnosis of 14 cancers in 13 patients with mammographically occult tumors (0.02% of the screening population and approximately 3% of all cancers diagnosed at the facility during this study). The cost of detecting these additional cancers is estimated to be $122 598 per cancer.     

Corporate-sponsored breast cancer screening at the work site: results of a statewide program

Mobile screening mammography was offered to 3,627 employees of a large corporation in Pennsylvania and Delaware. The examination was available to women employees or employee spouses aged 35 years and older. Women were charged $30 for a standard two-view examination. They also received health education materials on mammography and breast self-examination. The remaining costs of the program were underwritten by the corporation. During this program, 3,627 mammographic studies were performed; 63 biopsies were recommended. Fifty-seven biopsies were performed, and nine cancers were diagnosed. Costs of this program are presented in detail. The authors conclude that mobile screening programs at the work site provide an inexpensive, convenient alternative to more traditional screening programs. The inherent advantages of this program are the low cost, the relative ease with which the examination can be performed, and the positive role that corporate medical personnel assume in encouraging individual and group participation.     

Radiologic aspects of breast cancers detected through a breast cancer screening program.

Early detection of breast cancer and reduced mortality in women with this disease is today attributed to the widespread use of mammography. High-quality performance is essential in every step of breast cancer screening programs in order to avoid unnecessary anxiety and surgery in the women concerned. This report presents the radiologic aspects of screening cancers. A total of 8370 asymptomatic women aged between 50-69 years were screened with 2-view mammography, of which only 70 (0.84%) were selected for surgery after a thorough work-up. Cancers were verified histologically in 61 women and 9 showed non-malignant histology, giving a cancer detection rate of 7.3 cancers per thousand screened asymptomatic woman. The benign/malignant ratio in the operated cases is thus approximately 1:7. The cancers detected showed all existing types of mammographic features where 77% (47 cases) showed rather typical findings, such as spiculated densities both with and without microcalcifications and with microcalcifications only. The remaining 23% (14 cases) showed parenchymal distortions, asymmetric and well-defined densities, both with and without calcifications. Our results indicate that surgery can be minimized without impairing the breast cancer detection rate. Radiologists in screening programs should be aware that a large proportion of non-palpable breast cancers present in rather unconventional forms. This point is important in order to maintain a high cancer detection rate and thereby justify the widespread use of mammography as a screening tool for breast cancer in asymptomatic women.     

Influence of review design on percentages of missed interval breast cancers: retrospective study of interval cancers in a population-based screening program

PURPOSE: To retrospectively investigate whether different review designs have an influence on the estimate of missed interval cancer in a population-based breast cancer screening program. MATERIALS AND METHODS: The Norwegian Breast Cancer Screening Program invites women aged 50-69 years to undergo biennial screening mammography. The current study was part of the evaluation and scientific aspects of the screening program and thus was covered by the general ethical approval of the screening program as a part of the Cancer Registry of Norway. All participants signed an informed consent that specified that data related to their screening visit could be used for evaluation and scientific purposes. Six radiologists (9-34 years of experience in mammography) reviewed previously obtained bilateral two-view screening and diagnostic mammograms of 231 interval cancers, 117 screening-detected cancers, and 373 normal cases. Four review designs were used: individual and paired blinded review and individual and consensus informed review. A five-point interpretation scale was used to reclassify the cancers into missed cancers, minimal signs, and true cancers. The number and proportion of subgroups were estimated with 95% confidence intervals. RESULTS: Of 231 interval cancers, 46 (19.9%) were reclassified as missed cancers with the mixed blinded individual review and 54 (23.4%) were classified as missed cancers with the mixed blinded paired review. Eighty-three cancers (35.9%) were classified as missed cancers with individual informed review, and 78 (33.8%) were classified as missed cancers with consensus informed review. Thirty-nine cancers (16.8%) were reclassified as missed when four or more radiologists assigned a score of 2 or more (probably benign or more suspicious); three cancers (1.3%) were reclassified as missed when a score of 4 or more (probably malignant or more suspicious) was assigned. CONCLUSION: The percentage of interval cancers classified as missed ranged from 1.3% to 35.9% according to review design. To encourage learning, a review protocol should include both blinded and informed designs.     

Mammographic parenchymal patterns and breast cancer risk. A case control study of a population-based screening experience

The authors investigated the association between mammographic parenchymal patterns and breast cancer risk by a case control study. Three-hundred and thirty-four cancers, either screen or interval detected in the course of a screening program, were assumed as cases and compared to 668 non-cancer controls matched by age, residence and date of screening examination. Parenchymal patterns were classified by retrospective blind review of randomly mixed films by two independent readers. A high agreement was achieved on a two-group scale (N1-P1 vs P2-DY) inter and intraobserver consistency being 0.94 and 0.95, respectively. The relative risk of breast cancer exposure (RR) with respect to N1 pattern was 1.99 for P1, 3.59 for P2 and 4.18 for DY patterns. The RR of P2-DY with respect to N1-P1 patterns was 2.62. The results did not change after stratification by age group. Parenchymal patterns do not seem to be a reliable criterion for selecting high risk women for screening as in this series only 57% of all cancers occurred in high risk (P2-DY) subjects.     

农村居民糖尿病患者痴呆患病率调查

目的:调查了解我国农村居民糖尿病患者痴呆的患病率。方法:选择湖南省慈利县50岁及以上农村居民中的糖尿病患者641例作为观察组,另外选择与其性别、年龄相匹配的非糖尿病患者641例作为对照组。采用入户调查问卷及简易精神状态检查量表(MMSE)进行认知功能的筛查,对MMSE低于划界分者由神经内科医师组成的专家组做进一步检查,并按照美国精神病学会精神障碍诊断与统计手册第4版(DSM-Ⅳ)标准进行痴呆的诊断。结果:(1)观察组完成调查624例,罹患痴呆33例,患病率5.28%(95%CI3.33%～7.82%);对照组完成调查619例,罹患痴呆14例,患病率2.26%(95%CI1.14%～4.01%。观察组痴呆患病率非常显著高于对照组(P<0.01)。(2)观察组50～59岁、60～69岁、70～79岁及80岁以上4个年龄段中痴呆的患病率分别为2.23%(5/224)、4.74%(11/232)、7.33%(8/109)、13.15%(10/76,趋势χ2=16.27,P<0.01);对照组相应年龄段痴呆患病率分别为1.35%(3/222)、1.70%(4/234)、3.57%(4/112)及4.10%(3/73,趋势χ2=8.37,P<0.05)。(3)观察组中男性和女性痴呆患病率分别为3.72%(9/242)和6.01%(24/399),男性和女性痴呆患病率比较,差异显著(P<0.05);对照组中男性和女性痴呆患病率分别为1.68%(5/238)和1.98(8/403),虽然女性痴呆患病率高于男性,但差异不显著(P>0.05)。结论:糖尿病患者痴呆的患病率非常显著高于非糖尿病患者,而且女性糖尿病患者痴呆的患病率显著高于男性糖尿病患者,且两组人群痴呆的患病率均随着年龄增大而升高。     

146例女性乳腺癌危险因素的病例对照研究

应用1:1配比的病例对照研究方法对146例女性乳腺癌患者及其对照的危险因素进行了研究.分析结果表明:结婚年龄迟、初产年龄晚、有乳腺良性疾病史、有乳腺癌及其他恶性肿瘤家族史、月经周期不规律、腊肉香肠摄入量多、被动吸烟等因素可能为乳腺癌主要危险因素.而高产次、哺乳时间长、蔬菜摄入量多、服用维生素类药物等则可能是乳腺癌的保护因素.     

Digital versus screen-film mammography: a retrospective comparison in a population-based screening program

Background

Digital radiography has several advantages over screen-film radiography in data storage and retrieval, making it an attractive alternative to screen-film radiography in screening mammography programs, if it performs as well.

Methods

We retrospectively compared screen-film mammography, photon-counting direct radiography, and computed radiography with population-based screening data from the Breast Unit at Helsingborg Hospital, Sweden, collected between January 2000 and February 2005. Outcomes were cancer detection rates, recall rates, and positive predictive values for breast cancer detection in women reappearing for screening.

Results

Data were available for 52,172 two-view mammography examinations of 24,875 women. No initial screening (prevalence) examinations were included. Cancer detection rates based on mammographic findings were 0.31% (81/25,901) for film, 0.49% (48/9841) for photon-counting, and 0.38% (63/16,430) for computed radiography. The recall rate for film was 1.4%, which was significantly higher than that for PC-DR (1.0%; P < 0.001) and computed radiography (1.0%; P < 0.001). The positive predictive value was lower for film (22%) than for photon-counting (47%; P < 0.001) and computed radiography (39%; P < 0.001). In addition, the average glandular dose was 1.1 mGy for film, 0.28 mGy for photon-counting and 0.92 mGy for computed radiography. Thus, photon-counting provided a 75% dose reduction, and computed radiography a 16% dose reduction, over film.

Conclusions

Digital radiography, especially photon-counting, performs as well as or better than screen-film radiography. Given the advantages related to improved data storage and communication, digital radiography seems to be a valid alternative to screen-film radiography.     

A decentralized breast cancer screening program in the French department of Bas-Rhin

Since 1989, in the French department of Bas-Rhin, a breast cancer screening program in going on and its results are presented here. This program, concerning women of 50 to 65 years-old, is decentralized, based on private or public radiologists and the motivation of women because there is no invitation. The interval between screening test is 2 years. After 8 years, the results are rather satisfactory: participation rate of the initial cohort is 77% in December 31st 1997, participation at incident screenings is above than 85%, early indicators (recall rate, detection rate, PPV of screening, PPV of biopsy) are improving with time to attain numbers like international studies. The ADEMAS program shows that a decentralized screening program, based on existing medical structures is possible in France. Anyway, it must be organized, evaluated at any time, with a quality assurance system to guarantee the women the best taking charge.     

Contrast-enhanced spectral mammography in recalls from the Dutch breast cancer screening program: validation of results in a large multireader,multicase study

Objectives

Contrast-enhanced spectral mammography (CESM) is a promising problem-solving tool in women referred from a breast cancer screening program. We aimed to study the validity of preliminary results of CESM using a larger panel of radiologists with different levels of CESM experience.

Methods

All women referred from the Dutch breast cancer screening program were eligible for CESM. 199 consecutive cases were viewed by ten radiologists. Four had extensive CESM experience, three had no CESM experience but were experienced breast radiologists, and three were residents. All readers provided a BI-RADS score for the low-energy CESM images first, after which the score could be adjusted when viewing the entire CESM exam. BI-RADS 1-3 were considered benign and BI-RADS 4-5 malignant. With this cutoff, we calculated sensitivity, specificity and area under the ROC curve.

Results

CESM increased diagnostic accuracy in all readers. The performance for all readers using CESM was: sensitivity 96.9 % (+3.9 %), specificity 69.7 % (+33.8 %) and area under the ROC curve 0.833 (+0.188).

Conclusion

CESM is superior to conventional mammography, with excellent problem-solving capabilities in women referred from the breast cancer screening program. Previous results were confirmed even in a larger panel of readers with varying CESM experience.

Key Points

? CESM is consistently superior to conventional mammography ? CESM increases diagnostic accuracy regardless of a reader’s experience ? CESM is an excellent problem-solving tool in recalls from screening programs

     

Update of the Swedish two-county program of mammographic screening for breast cancer.

The results of the Swedish two-county trial of mammographic screening for breast cancer are presented, updated to December 31, 1990, which is an average of 10.8 years follow-up per person. The main result of the trial in terms of breast cancer mortality remained the same: compared with the control group, the group invited to screening had a relative breast cancer mortality of 0.70 (P = 0.0002) with 95% confidence interval (0.58, 0.85). Analysis of survival showed that relative to the control group, the cancers detected at prevalence screen, incidence screens, and in the interval between screens had a good prognosis, whereas cancers detected in those who had refused screening had a very poor prognosis. When adjusted for tumor size, lymph node status, and tumor grade (differentiation), the better survival associated with incidence screen and interval detection was largely accounted for, indicating that the benefit of incidence screening is largely achieved through the effect of screening on the three prognostic variables, notably size of the tumor. Results indicate that to achieve a substantial mortality reduction, 50% of screen-detected invasive cancers should be less than 15 mm in diameter, at least 30% of screen-detected grade 3 tumors should be less than 15 mm, and at least 70% of screen-detected tumors should not have lymph node metastases. The percentage of grade 3 tumors of a given size should be the same in screen-detected cancers as in clinically detected, and breast cancer prevalence at first screen should be at least three times the expected incidence rate in the absence of screening. This should be achieved without the recall rate for further examination exceeding 9%, and procedures including further imaging techniques and fine needle aspiration or core biopsy should be used before resorting to surgical biopsy. These aims can be achieved in specialist screening centers if particular attention is paid to resources for screening and diagnostic evaluation, specialist training of clinical and technologic screening staff, and ongoing monitoring of mammographic quality, recall rates, and the attributes of the tumors detected.     

Bioavailable serum estradiol may alter radiation risk of postmenopausal breast cancer: a nested case-control study

Purpose: Ionizing radiation and high levels of circulating estradiol are known breast cancer carcinogens. We investigated the risk of first primary postmenopausal breast cancer in relation to the combined effects of whole-body ionizing radiation exposure and prediagnostic levels of postmenopausal sex hormones, particularly bioavailable estradiol (bE₂).

Materials and methods: A nested case-control study of 57 incident breast cancer cases matched with 110 controls among atomic bomb survivors. Joint effects of breast radiation dose and circulating levels of sex hormones were assessed using binary regression and path analysis.

Results and conclusion: Radiation exposure, higher levels of bE₂, testosterone and progesterone, and established reproductive risk factors were positively associated with postmenopausal breast cancer risk. A test for mediation of the effect of radiation via bE₂ level suggested a small (14%) but significant mediation (p?=?0.004). The estimated interaction between radiation and bE₂ was large but not significant (interaction?=?3.86; p?=?0.32). There is accumulating evidence that ionizing radiation not only damages DNA but also alters other organ systems. While caution is needed, some portion of the radiation risk of postmenopausal breast cancer appeared to be mediated through bE₂ levels, which may be evidence for cancer risks due to both direct and indirect effects of radiation.