Diagnostic abilities of three CAD methods for assessing microcalcifications in mammograms and an aspect of equivocal cases decisions by radiologists.

Radiologists use an "Overall impression" rating to assess a suspicious region on a mammogram. The value ranges from 1 to 5. They will definitely send a patient for biopsy if the rating is 4 or 5. They will send the patient for core biopsy when a rating of 3 (indeterminate) is given. We have developed three methods to aid diagnosis of cases with microcalcifications. The first two methods, namely, Bayesian and multiple logistic regression (with a special "cutting score" technique), utilise six parameter ratings which minimise subjectivity in characterising the microcalcifications. The third method uses three parameters (age of patient, uniformity of size of microcalcification and their distribution) in a multiple stepwise regression. For both training set and test set, all three methods are as good as the two radiologists in terms of percentages of correct classification. Therefore, all three proposed methods potentially can be used as second readers.

Screen-detected breast cancer compared to symptomatic presentation: an analysis of surgical treatment and end-points of effective mammographic screening.

BACKGROUND: Mammographic screening has been shown to reduce mortality from breast cancer and to offer more opportunity for breast conservation surgery (BCS). The minimum standards (or surrogate end-points) that need to be achieved by a screening programme if it is to reduce mortality have been derived from the Two County Study. Three surrogate end-points that can be used to gauge the quality of the screening service are that 50% of the identified infiltrating cancers should be < 15 mm; at least 30% of grade 3 cancers should be < 15 mm; and 70% of screen-detected cancers should have a negative axillary dissection. The present study assesses these end-points of effective screening in an urban population referred to The Strathfield Breast Centre (TSBC). The screening end-points and surgical treatment of one group of women referred with a BreastScreen New South Wales (NSW)-detected breast cancer (screen group) were compared to all the other, mostly symptomatic, breast cancer referrals (symptom group). The problems with the current pattern of acceptance of mammographic screening in TSBC's referral area are discussed. METHODS: A prospective non-randomized study was done via analysis of the prospective database at The Strathfield Breast Centre (TSBC). RESULTS: There were 224 women in the screen group and 657 women in the symptom group. The mean tumour size was 18.1 mm in the screen group and 22.1 mm in the symptom group. There were significantly more small invasive cancers (< 15 mm) in the screen group (58%) compared with the symptom group (33%; P < 0.001). In the screen group there were more low-grade tumours but 30% of grade 3 tumours were < 15 mm compared with 16% in the symptom group (P = 0.009). In patients with invasive cancers who underwent axillary dissection, there was a significant difference in axillary node negativity, being 72% in the screen group and 59% in the symptom group (P = 0.003). In the screen group 64% of women had BCS compared with 51% in the symptom group (P = 0.002). CONCLUSIONS: These end-points of effective mammographic screening were met in the BreastScreen NSW group of women who were referred to TSBC despite the biases involved which could lessen the effectiveness of the screening programme. This crudely translated into a significant reduction in breast cancer mortality but selection and lead time bias has to be taken into account in evaluation of these data. There was a significantly greater chance of BCS in the screen group.

The operative management of screen-detected breast cancers.

BACKGROUND: Mammographic screening for breast cancer not only reduces the overall mortality from breast cancer but allows greater opportunities for breast-conserving operations. The predicted degree of breast conservation is not being realized, but is increasing in centres that have published their results. METHODS: The operative management of breast cancers diagnosed by BreastScreen Central and Eastern Sydney Screening and Assessment Service were compared between two time periods: January 1988-December 1992 (group 1) and January 1993-December 1995 (group 2). The rate of breast conservation, and other data were compared between the two periods. An attempt was made with multivariate analysis to identify some of the factors that made mastectomy rather than conservation more likely. RESULTS: There were 723 cancers detected that were suitable for analysis (group 1, n = 273; group 2, n = 450). In group 1 the breast conservation rate was 42.9%; this increased significantly to 60.4% in group 2 (P < 0.001). The data were examined to determine if there was any other factor that had changed over the time periods which might account for the increased rate of breast conservation. The use of pre-operative diagnostic techniques such as fine needle aspirate cytology and core biopsy increased significantly. Multivariate analysis comparing the differences in patient age, diagnostic technique, tumour type, grade, size, location and lymph node status, both independently and compositely did not account for the increase in breast conservation in group 2. CONCLUSION: The increase in breast conservation is due to other factors such as the surgeons' approach and patient attitude. The use of pre-operative, minimally invasive tissue sampling techniques is increasing.

Current issues in mammographic breast cancer screening.

Mammographic screening for the early detection of breast cancer is widely accepted as the most effective means currently available to reduce breast cancer deaths. However, evidence shows that to maximize benefits and minimize harm, mammographic screening must be of high quality.

Interval breast cancers in an Australian mammographic screening program.

OBJECTIVE: To determine the incidence of interval cancers which occurred in the first 12 months after mammographic screening at a mammographic screening service. DESIGN: Retrospective analysis of data obtained by crossmatching the screening Service and the New South Wales Central Cancer Registry databases. SETTING: The Central & Eastern Sydney Service of BreastScreen NSW. PARTICIPANTS: Women aged 40-69 years at first screen, who attended for their first or second screen between 1 March 1988 and 31 December 1992. MAIN OUTCOME MEASURES: Interval-cancer rates per 10000 screens and as a proportion of the underlying incidence of breast cancer (as estimated by the underlying rate in the total NSW population). RESULTS: The 12-month interval-cancer incidence per 10000 screens was 4.17 for the 40-49 years age group (95% confidence interval [CI], 1.35-9.73) and 4.64 for the 50-69 years age group (95% CI, 2.47-7.94). Proportional incidence rates were 30.1% for the 40-49 years age group (95% CI, 9.8-70.3) and 22% for the 50-69 years age group (95% CI, 11.7-37.7). There was no significant difference between the proportional incidence rate for the 50-69 years age group for the Central & Eastern Sydney Service and those of major successful overseas screening trials. CONCLUSION: Screening quality was acceptable and should result in a significant mortality reduction in the screened population. Given the small number of cancers involved, comparison of interval-cancer statistics of mammographic screening programs with trials requires age-specific or age-adjusted data, and consideration of confidence intervals of both program and trial data.

Ultrasound of malignant breast microcalcifications: role in evaluation and guided procedures.

Ultrasound examination will not always identify the malignant calcifications of ductal carcinoma in situ. However, the potential benefits of ultrasound examination of suspicious breast microcalcifications lie first in identifying a mass lesion associated with the calcifications and second in guiding fine needle cytology, core biopsy and hookwire localization. Because of these benefits it is recommended that ultrasound examination be performed as part of the evaluation of mammographic microcalcifications which are considered suspicious or diagnostic of malignancy.

Paget's disease of the breast: what the radiologist may expect to find.

Paget's disease of the nipple is characterized by the presence of Paget's cells in the epidermis of the nipple or areola. Two case reports of Paget's disease are described and used to highlight unusual features of the disease. The literature on the radiographic and pathologic findings of this disease is reviewed.

Phantom evaluation of the effect of film processing on mammographic screen-film combinations.

Mammographic image quality should be optimal for diagnosis, and the film contrast can be manipulated by altering development parameters. In this study phantom test objects were radiographed and processed for a given range of developer temperatures and times for four film-screen systems. Radiologists scored the phantom test objects on the resultant films to evaluate the effect on diagnosis of varying image contrast. While for three film-screen systems processing led to appreciable contrast differences, for only one film system did maximum contrast correspond with optimal phantom test object scoring. The inability to show an effect on diagnosis in all cases is possibly due to the variation in radiologist responses found in this study and in normal clinical circumstances. Other technical factors such as changes in film fog, grain and mottle may contribute to the study findings.

Surgical management of breast cancer. Experience of the Central Sydney Area Health Service Breast X-ray Programme, 1988-1991.

OBJECTIVE: To review the breast cancers detected in the first three years of the Central Sydney Area Health Service Breast X-ray Programme, their histopathology and their surgical management within the program. DESIGN: Between March 1988 and March 1991, women screened in the program who had a suspicious lesion were referred for surgical assessment at the program assessment centre at Rachel Forster Hospital. These women were seen by staff of the assessment centre, including program surgeons, and were then treated at either Rachel Forster Hospital or Royal Prince Alfred Hospital. Features examined include cancer detection, clinical findings, diagnostic techniques, histopathological diagnosis of the lesions and surgical management. RESULTS: One hundred and eight cancers were detected in 105 women, with 59% of the cancers impalpable. The benign to malignant ratio was 1.0:1.5. Twenty-four cancers (22%) were ductal carcinoma-in-situ with or without microinvasion, and 84 (78%) were frankly invasive. Of the 86 axillary dissections, 63 (73%) showed no node involvement on histological examination. At the time of diagnosis, 27% of the women had axillary node involvement proven by axillary dissection. The overall mastectomy rate was 58%. Radiotherapy, chemotherapy and tamoxifen were used in both stage I and stage II disease. CONCLUSION: The surgical management of cancers reflects similar findings reported in other screening programs. There is an increasing trend towards breast conservation surgery and up to 90% of the women in this study present with favourable prognostic factors for long term survival.

Case report: granular cell tumour of the breast.

We describe a granular cell tumour in the breast of a 62-year-old woman. This tumour is unusual in the breast, and though usually benign, may be misinterpreted as cancer.

Breast cancer diagnosis by screening mammography: early results of the Central Sydney Area Health Service Breast X-ray Programme.

The Central Sydney Area Health Service (CSAHS) Breast X-ray Programme is a pilot mammography screening project for breast cancer detection funded by the NSW Government. Screening by two-view mammography is carried out in a mobile van and is offered free to women aged over 45 years living in the CSAHS region, the inner western suburbs of Sydney. In the first 18 months of operation from March 1988, 7193 women were screened: 99 women underwent excision biopsy and 53 cancers were diagnosed. This is an overall detection rate of seven cancers per thousand women screened. Sixty per cent of the cancers were impalpable to the examining surgeon; 19% of all cancers were shown to have axillary node metastasis at the time of diagnosis. These results compare well with those of the major European screening studies.

The quality mammographic image. A review of its components.

Seven major factors resulting in a quality or high contrast and high resolution mammographic image have been discussed. The following is a summary of their key features: 1) Dedicated mammographic equipment. --Molybdenum target material --Molybdenum filter, beryllium window --Low kVp usage, in range of 24 to 30 --Routine contact mammography performed at 25 kVp --Slightly lower kVp for coned compression --Slightly higher kVp for microfocus magnification 2) Film density --Phototimer with adjustable position --Calibration of phototimer to optimal optical density of approx. 1.4 over full kVp range 3) Breast Compression --General and focal (coned compression). --Essential to achieve proper contrast, resolution and breast immobility. --Foot controls preferable. 4) Focal Spot. --Size recommendation for contact work 0.3 mm. --Minimum power output of 100 mA at 25 kVp desirable to avoid movement blurring in contact grid work. --Size recommendation for magnification work 0.1 mm. 5) Grid. --Usage recommended as routine in all but magnification work. 6) Film-screen Combination. --High contrast--high speed film. --High resolution screen. --Specifically designed cassette for close film-screen contact and low radiation absorption. --Use of faster screens for magnification techniques. 7) Dedicated processing. --Increased developing time--40 to 45 seconds. --Increased developer temperature--35 to 38 degrees. --Adjusted replenishment rate and dryer temperature. All seven factors contributing to image contrast and resolution affect radiation dosage to the breast. The risk of increased dosage associated with the use of various techniques needs to be balanced against the risks of incorrect diagnosis associated with their non-use.(ABSTRACT TRUNCATED AT 250 WORDS)