Mammographic screening: international perspective.

The twentieth century saw the introduction of mammography as a diagnostic tool and its refinement as a screening method. It appears guaranteed that women who are well informed will seek mammography screening with high expectations of technical quality and accurate interpretation. More refined knowledge of breast anatomy and pathology will assist radiologists to interpret with high specificity. We will learn how to recognized more accurately normal structures and doubtful findings. We will gain experience in interpretation through faithful review of interval cancers and subtle screen-detected cancers, and will use educational tools that have the potential to improve the efficiency of education by directing attention to specific deficiencies. Mammographic screening has been advanced through the efforts of dedicated teams of physicians, scientists, and other professionals throughout the world. The international communication of ideas and discoveries will continue to challenge the boundaries of what can be accomplished in early detection as well as noninvasive therapy, and this body of knowledge will continue to be enriched by these diverse contributions.

Ten years of breast screening in the Screening Mammography Program of British Columbia, 1988-97.

OBJECTIVES: To evaluate 10 years outcomes of the Screening Mammography Program of British Columbia (SMPBC) and determine if breast screening targets were being achieved among women aged 40-80+ years. SETTING: Organised breast screening programme in British Columbia, Canada. METHODS: Rates of participation, abnormal referral, cancer detection, and interval cancer were calculated for asymptomatic women receiving an SMPBC mammography from 1988-97. RESULTS: 895,849 screening mammographies were provided to 335,433 women. 51.3% of women were age 50-69 years. Abnormalities were identified on 57,454 screens (6.4%) from which 3304 cancers were detected. Abnormal call rates were higher on first (9.8%), compared with subsequent screens (4.4%) and declined with age: 7.7% at age < 40 to 5.4% for age 70-79 years. Cancer detection rates were higher on first (5.0 per 1000) compared with subsequent screens (2.8 per 1000) and increased smoothly with age from 1.4 to 8.2 per 1000 from age < 40 to age 80 years and older. Twenty per cent of cancers were non-invasive. The median size of invasive cancers was 14 mm and 81% had no axillary lymph node metastases. The 12 month interval cancer rate was 0.6 per 1000 and did not vary significantly with age or screening history. The prevalence to expected incidence ratio was 3.1 for women age 50-79 years. CONCLUSION: Across a broad range of ages, surrogate indices of screening mammography success have been achieved in a population based, North American, organised breast cancer screening programme.

Potential contribution of computer-aided detection to the sensitivity of screening mammography.

PURPOSE: To determine the false-negative rate in screening mammography, the capability of computer-aided detection (CAD) to identify these missed lesions, and whether or not CAD increases the radiologists' recall rate. MATERIALS AND METHODS: All available screening mammograms that led to the detection of biopsy-proved cancer (n = 1,083) and the most recent corresponding prior mammograms (n = 427) were collected from 13 facilities. Panels of radiologists evaluated the retrospectively visible prior mammograms by means of blinded review. All mammograms were analyzed by a CAD system that marks features associated with cancer. The recall rates of 14 radiologists were prospectively measured before and after installation of the CAD system. RESULTS: At retrospective review, 67% (286 of 427) of screening mammography-detected breast cancers were visible on the prior mammograms. At independent, blinded review by panels of radiologists, 27% (115 of 427) were interpreted as warranting recall on the basis of a statistical evaluation index; and the CAD system correctly marked 77% (89 of 115) of these cases. The original attending radiologists' sensitivity was 79% (427 of [427 + 115]). There was no statistically significant increase in the radiologists' recall rate when comparing the values before (8.3%) with those after (7.6%) installation of the CAD system. CONCLUSION: The original attending radiologists had a false-negative rate of 21% (115 of [427 + 115]). CAD prompting could have potentially helped reduce this false-negative rate by 77% (89 of 115) without an increase in the recall rate.

Standardized abnormal interpretation and cancer detection ratios to assess reading volume and reader performance in a breast screening program.

PURPOSE: To determine the relationship between annual screening volume and radiologist performance in the Screening Mammography Program of British Columbia, Canada. MATERIALS AND METHODS: Standardized abnormal interpretation ratios and standardized cancer detection ratios were constructed for 35 readers with at least 3 years of experience with the Screening Mammography Program of British Columbia. The ratios were used to compare individual reader performance with the mean program performance after adjustment for the age and screening history (first versus subsequent screening examinations) of the women who underwent screening. RESULTS: The mean standardized abnormal interpretation ratio was better for readers of 2,000-2,999 (n = 8) and 3,000-3,999 (n = 9) screening mammograms per year than for those of less than 2,000 (n = 9) and 4, 000-5,199 (n = 9) screening mammograms per year. Differences in the mean standardized abnormal interpretation ratios were significant (P <.05) between the readers of less than 2,000 and of 2,000-2,999 screening mammograms per year, between readers of less than 2,000 and of 3,000-3,999 screening mammograms per year and between readers of 3,000-3,999 and of 4,000-5,199 screening mammograms per year. The mean standardized cancer detection ratio improved gradually with increasing annual volume, but the differences between groups were not statistically significant. Five of the eight readers of 2,000-2, 999 mammograms were reading 2,475 or more screening mammograms per year. CONCLUSION: Standardized abnormal interpretation ratios and standardized cancer detection ratios provide a method of comparing two important performance measures in a screening program. A minimum of 2,500 interpretations per year is associated with lower abnormal interpretation rates and average or better cancer detection rates.

Prognosis, treatment, and recurrence of breast cancer for women attending or not attending the Screening Mammography Program of British Columbia.

Breast cancer screening programs have been initiated in many countries in the past decade. To determine the impact of the Screening Mammography Program of British Columbia (SMPBC), disease and treatment outcomes for women with breast cancer diagnosed in BC between 1989 and 1996 were compared on the basis of attendance at the SMPBC. An SMPBC attender was a women diagnosed with breast cancer within three years of an SMPBC screen, regardless whether the cancer was detected as a result of that screen. Of the 13,636 women aged 40-89 years diagnosed with breast cancer in BC during the study period, 2,647 (19.4%) were SMPBC attenders. 73.5% of SMPBC attenders (N = 1,946) and 74.2% of non-attenders (N = 8,149) were referred to the BC Cancer Agency and had pathology, staging, treatment, and outcome information available. SMPBC attenders compared with non-attenders were more likely to have in situ disease alone, and those with invasive cancers had smaller tumors which were less likely to have grade III histology and less likely to have spread to axillary lymph nodes (all P < 0.001). SMPBC attenders were more likely to be treated with breast conservation and less likely to receive adjuvant chemotherapy or tamoxifen (P < 0.001). Log-rank tests showed local (P = 0.017), distant (P < 0.001), and overall (P < 0.001) disease-free survival were better for SMPBC attenders. These favorable surrogate endpoints suggest that the benefits of breast screening as demonstrated by randomized trials can be translated into community practice by an organized breast screening program.

Quality-oriented mass mammography screening.

PURPOSE: To demonstrate the ability of a mass mammography screening program to provide consistently high-quality mammography screening, while at the same time sustain a large volume of patients to keep the cost of mammography low. MATERIALS AND METHODS: A public-funded, mass mammography screening program, begun in 1988, is currently being conducted in five Canadian provinces. For the Screening Mammography Program of British Columbia, complete follow-up data are available for the first 57 months of operation. During that time, the program expanded from one center with five radiologist screeners to 14 centers with 30 radiologist screeners. There were 201,937 examinations performed on 128,325 women, 35% of whom were younger than 50 years. RESULTS: There were 802 cancers detected at an overall rate of 6.2 per 1,000 women (2.8 per 1,000 in women younger than 50 years and 8.1 per 1,000 in women older than 50 years). In the women younger than 50 years, 90 (72%) of the cancers were stage 0 or stage I, and the axillary lymph nodes were involved in 14 (11%). In the women 50 years or older, 496 (73%) of the cancers were stage 0 or stage 1, and the axillary lymph nodes were involved in 97 (14%). CONCLUSION: If quality is carefully controlled, the results of a mass screening program can be either maintained or improved. For both age groups, the prognostic characteristics are similar.

Screening mammography in British Columbia: 1988-1993.

Breast carcinoma continues to be the most common cause of death due to malignancy for women in Canada. The Screening Mammography Program of British Columbia, the first provincial screening program in Canada, was established in 1988 with funding from the Ministry of Health to diagnose the disease as early as possible. The program has grown rapidly, increasing from 7,100 examinations in a pilot project in 1988 to 89,390 examinations between April 1, 1992 and March 31, 1993 for a cumulative total of 201,937 examinations of 128,325 women, and it now offers free screening mammography throughout the province. The program has maintained quality control standards and low cost per mammogram while developing different operational models for the differing requirements of the various areas of the province. Similar proportions of women older or younger than age 50 have favourable characteristics such as small size of tumor (median: 15 to 16 mm) and negative lymph nodes (86% to 89%).

The Canadian National Breast Screening Study: a Canadian critique.

The Canadian National Breast Screening Study (CNBSS) was the first study designed to determine the efficacy of screening for breast carcinoma in women 40-49 years old. Women were randomized to undergo either annual mammography and physical examination or usual care after an initial physical examination [1]. Women 50-59 years old were randomized to undergo either annual mammography and physical examination or annual physical examination only [2]. This study, published by epidemiologists on the efficacy of a radiologic examination, therefore, invites evaluation by radiologists.

The British Columbia Mammography Screening Program: evaluation of the first 15 months.

We report our experiences in the first 15 months of a government-funded pilot project begun in 1988 to study the feasibility of rapid throughput, low-cost screening mammography in British Columbia. The primary goals of the project were (1) to determine the unit cost of screening mammography within the context of the program; (2) to design and put into operation a centralized system of data collection, analysis, and quality control to enable calculations of cancer detection rates, biopsy rates, biopsy yield ratios, staging, and other specific cancer characteristics; and (3) to study compliance in the community where the program was offered. A total of 11,824 women had mammography at a unit cost of U.S. $32.66. Computerized analysis revealed that (1) 11% of women had known primary risk factors; (2) findings on mammograms were interpreted as abnormal in 9% of screening examinations; (3) breast cancers were confirmed in 47 (22%) of 211 patients who had biopsies, and 87% of these were stage 0-1. The overall cancer detection rate was four per 1000, with five per 1000 for women who had not had mammography in the preceding 2 years and one per 1000 for women who had had mammography in the past 2 years. The results show that screening mammography can be conducted at low cost. Data collection and analysis and compliance were sufficiently convincing to initiate province-wide expansion.

The Screening Mammography Program of British Columbia: pilot study.

A government-funded pilot project of high volume screening mammography was conducted in Vancouver, British Columbia. 7,100 women were screened over a 9-month period, averaging 43 women per day at a cost of $33.81 per woman screened. 722 (10%) had abnormal mammograms; 144 received breast biopsies; and 29 were diagnosed with cancer. The overall cancer detection rate was 4.1 per 1,000 (0.8 and 4.8 for incident and prevalent cases, respectively). The staging distribution for the 29 cancer cases was 5, 15, 8 and 1 for in situ, stage I, II and III, respectively.

Ruptured breast implant: computed tomographic and mammographic findings.

We report the computed tomographic and mammographic findings in a patient with a ruptured breast implant. The diagnosis was made by recognition of alteration in prosthesis contour, collapse of the prosthesis envelope, and the presence of free silicone in the breast and axillary region.

Xeroradiography in the diagnosis of the Haglund syndrome.

Xeroradiography is the radiographic method of choice for assessment of soft tissues and calcaneal detail in patients suffering from a painful swelling localized in the heel. The radiographic triad of retrocalcaneal bursitis, superficial tendo Achillis bursitis, and Achilles tendon thickening, in the presence of an intact posterior superior calcaneal margin, are readily evaluated with xeroradiography. The Haglund syndrome is a painful inflammation involving the two bursae which surround the Achilles tendon. It is associated with a prominent posterior superior calcaneal margin. Of the two objective measurements devised to assess this prominence, neither the posterior calcaneal angle of Philip and Fowler of greater than 75 degrees nor the parallel pitch line (PPL) has proved to be a reliable index. In the present study, we evaluated four patients with heel pain and swelling as well as 100 control patients. The findings suggest that the prominence of the posterior calcaneal angle should be assessed relative to the known normal range rather than by comparison to a single fixed angulation which is arbitrarily designated as being abnormal.

Breast imaging.

Breast lumps are extremely common. The high prevalence of breast cancer in our society and increasing public awareness of screening methods make a review of breast imaging for family physicians topical. Mammography and xeromammography remain the basic tools, supplemented by sonography, guided biopsy and diaphanography, for investigating breast lumps. Galactography is the major additional investigation where nipple discharge is present. Screening programs are gaining acceptance and can significantly affect cancer mortality rates. This article discusses these issues from a primary physician's perspective.

Radiology of the Angelchik prosthesis for gastroesophageal reflux.

The placement of a ring prosthesis around the esophagus above the gastric cardia for treatment of gastroesophageal reflux has been shown to give acceptable clinical results and is technically easier than procedures such as gastropexy and fundoplication. Radiologists should be familiar with this surgical technique because postoperative follow-up and complications are best evaluated by radiologic imaging. The normal and abnormal radiologic features of the Angelchik antireflux device are described. Of 38 patients who underwent surgical implantation of the Angelchik prosthesis, four required postoperative removal of the device because of its dislodgment.