The comparative value of mammographic screening for women 40-49 years old versus women 50-64 years old.

OBJECTIVE: The purpose of our study was to compare the major prognostic factors (tumor size, axillary lymph node status, and tumor stage) of breast cancers detected at mammographic screening in women ages 40-49 years old with those in women ages 50-64 years old. MATERIALS AND METHODS: Study subjects were women ages 40-64 years old who participated in our mobile van mammographic screening program from April 1985 to June 1994. We retrospectively reviewed the clinical and pathology records of women in whom breast cancer was detected at mammographic screening. All examinations were performed with dedicated equipment using screen-film technique. RESULTS: A total of 44,301 screening examinations were done during the study period. Seventy-five cancers were detected in women ages 40-49 years old, and 128 cancers were detected in women ages 50-64 years old. The cancer detection rate was 3.0 per 1000 examinations in the younger age group compared with 5.5 per 1000 examinations in the older age group. The median size of breast cancers was 10 mm for women ages 40-49 versus 11 mm for women ages 50-64. Eighty-eight percent of the patients in both age groups had no evidence of metastasis to axillary lymph nodes. Nineteen percent of women in the younger age group had advanced breast cancer (stage II or higher) compared with 26% of women ages 50-64 (p = .25). No statistically significant differences were noted between the two age groups in the size, lymph node status, or stage of breast cancers detected at mammographic screening. However, the cancers found in younger women had slightly more favorable prognoses. CONCLUSION: The major prognostic factors of cancers detected with modern mammographic equipment appear to be at least as favorable for women ages 40-49 years old as for women ages 50-64 years old. As mammographic screening has already been shown to be beneficial for women ages 50-64 years old, screening should also be beneficial for women ages 40-49 years old.

Initial versus subsequent screening mammography: comparison of findings and their prognostic significance.

OBJECTIVE: The goal of this study was to compare findings on initial and subsequent screening mammograms to determine the prognostic significance of screening-detected abnormalities. MATERIALS AND METHODS: All 3386 abnormal examinations from a 9-year mammographic screening program were studied. An initial examination was defined as one for which there were no prior films available for comparison (even if one or more prior examinations had been performed); the remainder were called subsequent examinations. The principal mammographic feature of each abnormality was recorded, as well as whether a biopsy was performed. For all screening-detected cancers, we also determined several surrogate markers of prognosis (tumor size, presence of axillary lymph node metastasis, and tumor stage). These various parameters were analyzed as a function of initial versus subsequent screening. RESULTS: The frequency of abnormal examinations was more than 2 times greater for initial examinations (7%) than for subsequent examinations (3%). Only minor differences were noted between initial and subsequent screenings when comparing the principal mammographic features of the abnormalities. However, the number of cancers found per number of biopsies performed was significantly greater (p = .02) for subsequent screenings (41%) than for initial screenings (32%). Among the 333 cancers detected, tumor size was significantly smaller for subsequent screenings (p = .0076). Node-negative status and early tumor stage (stage 0 or 1) also were found more frequently for subsequently screened cancers, but these differences were not statistically significant. CONCLUSION: Substantially fewer abnormal screening interpretations are made when mammography has been performed previously and when the prior films are available for comparison. This results in cost savings and reduced morbidity at subsequent screening (no further work-up, less patient anxiety, fewer benign biopsies). Surrogate markers of prognosis also appear to be more favorable for cancers detected at subsequent screening.

Clinical efficacy of mammographic screening in the elderly.

PURPOSE: To compare mammographic screening results for women aged 65 years and older (elderly group) with those for women aged 50-64 years (younger group). MATERIALS AND METHODS: Mammography was performed in 32,140 women aged 50 years and older (10,914 elderly, 21,226 younger). Parameters studied included demographic data, screening interpretations, disposition of abnormal interpretations, results of biopsies, and characteristics of breast cancers. RESULTS: The cancer detection rate is substantially higher in elderly women (9.2 per 1,000 women) than in younger women (5.7 per 1,000 women). The median size of cancers in elderly women is 11 mm (vs 12 mm in younger women). Axillary nodal status is 93% node negative in elderly women (vs 88% node negative in younger women). Cancer stage is earlier in elderly women than it is in younger women (84% stage 0 or 1 vs 75% stage 0 or 1). CONCLUSION: Mammographic screening is at least as effective in detecting cancers for which there is a favorable prognosis in women aged 65 years and older as it is in women aged 50-64 years. Because the efficacy of screening in younger-group women has already been proved, it may be inferred that screening also benefits elderly-group women.

Medical audit of a rapid-throughput mammography screening practice: methodology and results of 27,114 examinations.

Medical audit results from the entire experience of a rapid-throughput mammography screening practice are presented, comprising 27,114 examinations conducted from April 1985 to September 1989. The authors screened a self-selected physician-referred population, almost 94% of whom were asymptomatic. Estimated sensitivity of initial mammography interpretation was 93.1% with a specificity of 94.2% and a positive predictive value of 10.0%. Biopsies prompted by screening yielded a diagnosis of malignancy in 32.1% of cases; 170 breast cancers were identified, 67.1% requiring mammographic needle localization. Median cancer size was 12 mm, the rate of axillary nodal metastasis was 11.0%, and the systemic metastasis rate was 1.2%. Of the cancers found, 76.5% were stage 0 or stage 1. Conducting a medical audit is the most convincing way to demonstrate the success of a mammography screening practice, thereby providing this important information for the benefit of screenees, referring physicians, third-party payers, and the personnel who perform the screening.

Baseline screening mammography: one vs two views per breast.

To compare the advantages of one-view vs two-view mammography screening, films were reviewed for 2500 consecutive asymptomatic women undergoing baseline mammography. To provide screening at low cost, examinations were limited to two radiographs per breast, one each in the craniocaudal and mediolateral oblique projections, with the understanding that those few patients with detected abnormalities would require additional mammograms, taken with an individually directed, problem-solving approach, at considerably higher cost. Two separate interpretations were made of each case, one using only the oblique projection images, the other using both oblique and craniocaudal views. Two-view interpretations not only identified more cancers than one-view readings (27 vs 25), they also required fewer additional mammograms to evaluate potential abnormalities (179 vs 642, 7% vs 26%). These advantages outweigh the additional radiation risk and added cost. Baseline screening mammography should be done with two views per breast.

Mammographic screening: how to operate successfully at low cost.

To offer mammographic screening to asymptomatic women at low cost requires a different approach than is appropriate for solving the more complex problems presented by symptomatic patients. Since the goal of screening is to detect unsuspected abnormalities, not to characterize them fully, operational procedures can be streamlined to maximize patient throughput and achieve substantial cost savings. Such procedures will be successful only if applied to large numbers of patients, thereby permitting cost reduction by economies of large-scale operation. Computerization of record-keeping and of image interpretation is ideally suited for screening examinations and permits further cost savings. Experience with a prototype low-cost screening program has shown that with only 15 patients per day, operation is feasible at a charge of $50 per patient. The income lost from asymptomatic patients, who will pay lower fees compared with the traditional mammography fees they now pay, is more than offset by the income generated by additional problem-solving mammograms needed to fully characterize screening-detected abnormalities and by the increased use of needle localization procedures to guide biopsy.

Breast arterial calcification in association with diabetes mellitus: too weak a correlation to have clinical utility.

A large-scale prospective study was designed to characterize the association between breast arterial calcification and diabetes mellitus. Arterial calcification was seen on the mammograms of 481 of 5,000 consecutive patients. The prevalence of arterial calcification was substantially higher among diabetics (45/106 = 42.5%) than among nondiabetics (436/4,894 = 8.9%). An even more significant association was found between arterial calcification and advancing age for both diabetics and nondiabetics. None of the 31 patients younger than 50 years with arterial calcification were diabetic, and none of the nine diabetics younger than 50 years had arterial calcification. Most important, less than 10% (45/481) of the patients who demonstrated arterial calcification were found to be diabetic. The presence of arterial calcification on mammograms is a more reliable indicator of advancing age than of diabetes, and the association of breast arterial calcification with diabetes is too weak to be clinically useful.