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A Monte Carlo model simulating actual populations was employed to evaluate the precision in estimation of a standardized sampling method proposed by the Global Programme on AIDS of the World Health Organization, for general use in collecting population-based data on HIV seroprevalence. It appears that in real populations, where there is likely to be 'pocketing' of infection, the proposed methodology will generally fail to provide estimates accurate to within 1% of the true population value. However, if the primary objective of a particular survey is to construct confidence intervals that include the true population HIV seroprevalence rate, then this survey method appears to be a reasonable choice. This study also suggests that selection of only one adult per household improves the precision of resulting estimates. However, since selection of only one adult per household would require that more households be visited, any gain in precision would need to be weighed against the likely increase in cost of household visits.

Clinical and mammographic data of 1009 consecutive patients were correlated with histopathologic data of 1144 biopsy specimens of nonpalpable breast lesions to better define the presentation and biologic behavior of early breast cancer. Patients with malignant neoplasms (269 [24%] of 1144 specimens) were older (mean age, 62.1 years) than patients with benign lesions (mean age, 54.9 years). Furthermore, patients with invasive disease were older (mean age, 63.3 years) than patients with noninvasive disease (mean age, 58.5 years) with an overall increased risk of invasive cancer per year of 1.035. A 58% incidence of invasive cancer was detected for lesions characterized by calcifications, while the incidence of invasive cancer was 84% for isolated mass lesions (relative risk, 4.31 for masses). Isolated mammographic calcifications associated with cancer appeared in a younger population and were significantly associated with noninvasive ductal cancer. Breast cancer presenting as a mammographic mass appeared in an older group and was highly associated with the presence of invasive disease.

We prospectively studied 718 women who underwent biopsy of the breast for suspicious, mammographically detected mammary lesions in an attempt to identify key clinical risk factors, as well as roentgenographic characteristics associated with the appearance of early carcinoma of the breast. Patients with a benign outcome had an average age of 55 years versus 63 years for patients with carcinoma of the breast. Seventy-six per cent of these patients had no previous history of mammary problems, 20 per cent had a positive family history for carcinoma of the breast, 58 per cent were premenopausal and 21 per cent had used birth control pills. Except for age (p less than 0.001), the distribution of clinical risk factors was equal among patients with benign or malignant outcomes. Suspicious mammographic findings included mass lesions (53 per cent), calcifications (36 per cent) and the association of both (11 per cent). The predominant Wolfe pattern on mammography was P1 (36 per cent). No relationship was observed between Wolfe pattern and malignant conditions. In this group of patients, mammography was poorly specific; however, the positive predictive value increased with age and is related to the age-specific prevalence of carcinoma of the breast. Eight hundred and twenty-five lesions were removed. Twenty-five per cent (n = 203) of the specimens taken at biopsy contained carcinoma. Stellate mass lesions were highly suggestive of a malignant growth (p less than 0.0001). No relationship between the size of the suspicious mammographic mass and the malignant lesion was observed. A marked correlation (chi-square test with Yate's correction) was observed between malignant tumor and lesions with a linear or branching pattern, more than 15 calcifications, or small sized calcifications. The presence of a mass with calcifications was associated with carcinoma in 34 per cent. The incidence of invasive carcinoma was much higher for mass lesions (81 per cent) than for suspicious calcifications (56 per cent) (p less than 0.0001).

We prospectively studied 239 consecutive patients who underwent breast biopsy for 277 nonpalpable lesions characterized by mammographic microcalcifications. Clinical and mammographic characteristics were correlated with histologic findings in an attempt to identify patients more likely to have early breast cancer. The distribution of clinical risk factors was equal between patients with benign or malignant outcomes. The predominant Wolfe pattern on mammography was P2 (38%); however, no relationship was observed between the Wolfe pattern and malignancy. A marked correlation was observed between malignancy and small lesions, more than 15 calcifications, and calcifications in a linear or branching pattern. Twenty-four percent (n = 67) of the biopsy specimens contained either ductal or lobular breast cancer. This study highlights the necessity of an aggressive approach toward suspicious calcifications found by mammography.

Thirty patients with suspected abnormality of the breasts on mammography were evaluated with magnetic resonance imaging (MRI) in a blind fashion. Spin-echo (SE) 250/30 msec scans were used to screen the examined breast. At the location of the suspected abnormality, inversion recovery (IR) 1000/30/300, SE 1000/30, and SE 1000/120 scans were performed. On the basis of these magnetic resonance images and experience with 70 previously studied patients, abnormalities of the breasts were grouped into five patterns. Ten malignant lesions exceeded 1 cm in diameter and were all correctly diagnosed by mammography and MRI. Of the remaining 20 benign conditions, four were suspicious for malignancy on MRI compared to eight with mammography. The shape of the lesion and the change in its signal intensity with different MR radiofrequency pulse sequences allows differentiation between a benign and a malignant process. On the basis of this preliminary experience, it seems MRI may have an adjunctive role to screening mammography. SE 1000/120 scans show higher signal intensity from carcinoma than from normal duct tissue, fibrocystic disease, and fibroadenoma. In this respect, it may allow some tissue specification in the breast.

Two patients with breast abnormalities, one malignant and one benign, were studied with nuclear magnetic resonance (NMR) imaging utilizing a cryogenic superconducting magnet. Three-dimensional NMR images were obtained in one case and single slice planar images were obtained in the other. The NMR images correlated well with the corresponding mammograms. Although both conditions exhibited a different signal intensity for the area of abnormality compared to adjacent ductal and fatty tissue, the configuration of the abnormal areas allowed distinction between benign and malignant process.

A preliminary comparative evaluation of mammography and magnetic resonance imaging (MRI) of the human breast in a variety of benign and malignant conditions is presented. Although the accuracy of MRI in the evaluation of the human breast is not yet established, it appears to be as sensitive as mammography in the detection of breast abnormalities.