Effect of previous benign breast biopsy on the interpretive performance of subsequent screening mammography.

BACKGROUND: Most breast biopsies will be negative for cancer. Benign breast biopsy can cause changes in the breast tissue, but whether such changes affect the interpretive performance of future screening mammography is not known. METHODS: We prospectively evaluated whether self-reported benign breast biopsy was associated with reduced subsequent screening mammography performance using examination data from the mammography registries of the Breast Cancer Surveillance Consortium from January 2, 1996, through December 31, 2005. A positive interpretation was defined as a recommendation for any additional evaluation. Cancer was defined as any invasive breast cancer or ductal carcinoma in situ diagnosed within 1 year of mammography screening. Measures of mammography performance (sensitivity, specificity, and positive predictive value 1 [PPV1]) were compared both at woman level and breast level in the presence and absence of self-reported benign biopsy history. Referral to biopsy was considered a positive interpretation to calculate positive predictive value 2 (PPV2). Multivariable analysis of a correct interpretation on each performance measure was conducted after adjusting for registry, year of examination, patient characteristics, months since last mammogram, and availability of comparison film. Accuracy of the mammogram interpretation was measured using area under the receiver operating characteristic curve (AUC). All statistical tests were two-sided. RESULTS: A total of 2,007,381 screening mammograms were identified among 799,613 women, of which 14.6% mammograms were associated with self-reported previous breast biopsy. Multivariable adjusted models for mammography performance showed reduced specificity (odds ratio [OR] = 0.74, 95% confidence interval [CI] = 0.73 to 0.75, P < .001), PPV2 (OR = 0.85, 95% CI = 0.79 to 0.92, P < .001), and AUC (AUC 0.892 vs 0.925, P < .001) among women with self-reported benign biopsy. There was no difference in sensitivity or PPV1 in the same adjusted models, although unadjusted differences in both were found. Specificity was lowest among women with documented fine needle aspiration-the least invasive biopsy technique (OR = 0.58, 95% CI = 0.55 to 0.61, P < .001). Repeating the analysis among women with documented biopsy history, unilateral biopsy history, or restricted to invasive cancers did not change the results. CONCLUSIONS: Self-reported benign breast biopsy history was associated with statistically significantly reduced mammography performance. The difference in performance was likely because of tissue characteristics rather than the biopsy itself.

International comparison of performance measures for screening mammography: can it be done?

OBJECTIVE: Published screening mammography performance measures vary across countries. An inter-national study was undertaken to assess the comparability of two performance measures: the recall rate and positive predictive value (PPV). These measures were selected because they do not require identification of all cancers in the screening population, which is not always possible. SETTING: The screening mammography programs or data registries in 25 member countries of the International Breast Cancer Screening Network (IBSN). METHODS: In 1999 an assessment form was distributed to IBSN country representatives in order to obtain information on how screening mammography was performed and what specific data related to recall rates and PPV were collected. Participating countries were then asked to provide data to allow calculation of recall rates, PPV and cancer detection rates for screening mammography by age group for women screened in the period 1997-1999. RESULTS: Twenty-two countries completed the assessment form and 14 countries provided performance data. Differences in screening mammography delivery and data collection were evident. For most countries, recall rates were higher for initial than for subsequent mammograms. There was no consistent relationship of initial to subsequent PPV, although PPV generally decreased as the recall rate increased. Recall rates decreased with increasing age, while PPV increased as age increased. CONCLUSION: Similar patterns for mammography performance measures were evident across countries.However, the development of a more standardized approach to defining and collecting data would allow more valid international comparisons, with the potential to optimize mammography performance. At present, international comparisons of performance should be made with caution due to differences in defining and collecting mammography data.

Reassessment of breast cancers missed during routine screening mammography: a community-based study.

OBJECTIVE: The purpose of this study was to have a series of screening mammograms from routine practice, including false-negative results, reviewed by peer community-based experienced radiologists to determine the percentage of these false-negative findings that might be considered detectable. MATERIALS AND METHODS: All screening cases for 1997 and 1998 were identified from the Carolina Mammography Registry. Mammographic assessments from community mammography practices were linked with population-based cancer outcomes. The findings of four community-based radiologists who reviewed the mammograms of 339 asymptomatic women were 93 false-negatives, 180 true-negatives, and 66 false-positives. The percentage of false-negative, true-negative and false-positive findings on breast films that reviewers evaluated was determined. The findings of the reviewers were compared with the original interpreting radiologists' assessments. RESULTS: The overall breast-specific workup rate by the reviewing radiologists was 21%. The average workup rate for the false-negative findings was 42% (range, 35-51%). Adjusting for the 13% workup rate in the cancer-free breasts, the percentage of false-negative findings that were detectable was estimated to be 29%. CONCLUSION: This peer review of screening mammograms from a population-based screening registry estimated a missed detectable cancer rate of 29%. Thus, 71% of cancers missed at screening would not have been worked up by peers in the same community.

Association of recall rates with sensitivity and positive predictive values of screening mammography.

OBJECTIVE: The performance of screening mammography is measured mainly by its sensitivity, positive predictive value, and cancer detection rate. Recall rates are also suggested as a surrogate measure. The main objective of this study was to measure the effect on sensitivity and positive predictive value as recall rates increase in the community practice of mammography. MATERIALS AND METHODS: Mammography and pathology data are linked in the Carolina Mammography Registry, a population-based registry of screening mammography. Our mammography database is created from prospectively collected data from mammography facilities; the data include information on the woman and the imaging studies. Our pathology database is created from prospectively collected breast pathology data received from pathology sites and the Central Cancer Registry. Women in the registry who were 40 years old and older and who underwent screening mammography between January 1994 and June 1998 were included. "Recall rate" was defined as the percentage of screening studies for which further workup was recommended by the radiologist. RESULTS: The study included 215,665 screening mammograms. The mean age of the women was 56 years. The recall rates of the average practice ranged from 1.9% to 13.4%. Sensitivity rose from a mean of 65% in the lowest recall rates to 80.2% at the highest level of recall rates. The positive predictive value of screening decreased from 7.2% in the lowest level of recall to 3.3% in the highest. As recall rates increased, sensitivity increased very little beyond a recall rate of 4.8%, and positive predictive value began decreasing significantly at a recall rate of 5.9%. CONCLUSION: Practices with recall rates between 4.9% and 5.5% achieve the best trade-off of sensitivity and positive predictive value.

The use of census data for determining race and education as SES indicators: a validation study.

PURPOSE: Little research has examined the validity of using census data to determine an individual's socio-economic status (SES), as measured by race and educational level. This study assessed the accuracy of using aggregate level data from United States Census Block Groups in determining race and education SES indicators in a cohort of women from North Carolina. METHODS: The study analyzed patient data from the Carolina Mammography Registry and 1990 United States Census in 21 North Carolina counties. Women (n = 39,546) were geocoded to their census block group and their block group characteristics (surrogate measures) were validated with their self-reported values on race and education. An analysis was performed to explore whether using these surrogate measures would affect measured associations with the self-reported values. RESULTS: Whites were accurately identified (84.8%) more consistently than Blacks (14.1%) regardless of their urban/rural status. Women without a high school diploma or equivalent were accurately identified (56.2%) more often than those with higher education levels (45.9%). Analyses using the surrogate measures were significantly different than the true values according to chi-square statistics. CONCLUSIONS: Use of census data to derive SES indicators tends to be more accurate for the majority than the minority population. Researchers must be sensitive to the ecologic fallacy when using aggregate level data such as the census to determine individual level characteristics.

Effect of variations in operational definitions on performance estimates for screening mammography.

RATIONALE AND OBJECTIVES: The Mammography Quality Standards Act requires practices to measure limited aspects of their performance. The authors conducted this study to calculate the differences in measurements of sensitivity and specificity due only to differences in the definitions used in the analysis. This included definitions for case inclusion. MATERIALS AND METHODS: Data from the New Mexico Mammography Project for January 1991 to December 1995 on 136,540 women who underwent screening mammography were analyzed. A starting definition was created for each performance measure. The components of the definition were varied, and estimates of sensitivity and specificity for the different definitions were calculated. RESULTS: Sensitivity was lower and specificity was higher when assessed on the basis of the results of all imaging performed in the screening work-up rather than on the initial screening examination alone. Sensitivity was higher and specificity was lower in women who did not undergo rather than in women who did recently undergo a previous examination. When the definition of a positive examination included cases that were recommended for short-term follow-up, the work-up sensitivity was slightly higher and the work-up specificity was considerably lower. Longer follow-up times for determining the diagnosis of cancer were associated with decreasing sensitivity, particularly when the follow-up period extended beyond 12 months. CONCLUSION: Variations in the operational definitions for measures of mammographic performance affect these estimates. To facilitate valid comparisons, reports need to be explicit regarding the definitions and methods used.

Current medicolegal and confidentiality issues in large, multicenter research programs.

The convenience of fast computers and the Internet have encouraged large collaborative research efforts by allowing transfers of data from multiple sites to a single data repository; however, standards for managing data security are needed to protect the confidentiality of participants. Through Dartmouth Medical School, in 1996-1998, the authors conducted a medicolegal analysis of federal laws, state statutes, and institutional policies in eight states and three different types of health care settings, which are part of a breast cancer surveillance consortium contributing data electronically to a centralized data repository. They learned that a variety of state and federal laws are available to protect confidentiality of professional and lay research participants. The strongest protection available is the Federal Certificate of Confidentiality, which supersedes state statutory protection, has been tested in court, and extends protection from forced disclosure (in litigation) to health care providers as well as patients. This paper describes the careful planning necessary to ensure adequate legal protection and data security, which must include a comprehensive understanding of state and federal protections applicable to medical research. Researchers must also develop rules or guidelines to ensure appropriate collection, use, and sharing of data. Finally, systems for the storage of both paper and electronic records must be as secure as possible.

Comparison of woman-specific versus breast-specific data for reporting screening mammography performance.

RATIONALE AND OBJECTIVES: Screening mammography data can be reported on a breast-specific or woman-specific level, and much mammography data available for research is woman-specific. The purpose of this study was to determine if woman-specific screening mammography data are sufficient for research and reporting by measuring and comparing the accuracy of screening mammography on a breast-specific and on a woman-specific level. MATERIALS AND METHODS: Definitions for true-positive and false-positive mammography results were developed to distinguish between breast-specific and woman-specific calculations. The sensitivity, specificity, and positive predictive values of screening mammography were calculated on a breast-specific and on a woman-specific basis for the entire population of the Carolina Mammography Registry and for a randomly selected subset of the population. RESULTS: Only small differences were found in breast-specific versus woman-specific calculations of sensitivity, specificity, and positive predictive values for both the entire population and the smaller subset population. For both populations, woman-specific sensitivity and positive predictive values were slightly higher than the same breast-specific values, and woman-specific specificity was slightly lower. CONCLUSION: For research and reporting, woman-specific data are sufficient.

Squamous cell carcinomas that arise in the oral cavity and tongue base: can CT help predict perineural or vascular invasion?

PURPOSE: To determine the ability to use computed tomography (CT) to predict invasion of adjacent nerves or vessels by oral cavity tumors. MATERIALS AND METHODS: Contrast material-enhanced CT scans and histopathologic reports were retrospectively reviewed in 48 patients (36 men, 12 women) aged 38-75 years who underwent gross total resection of squamous cell carcinomas arising in the tongue, the base of the tongue, and the floor of the mouth. CT criteria for diagnosis of perineural or vascular invasion were aggressive tumor margins, invasion of the sublingual space, and direct adjacency of the tumor to the enhanced lingual vasculature in the sublingual space. CT and histopathologic findings of perineural and/or vascular invasion by tumor were correlated in all patients. RESULTS: With the above criteria, CT findings predictive of perineural or vascular invasion had a sensitivity of 88%; specificity, 83%; positive predictive value, 85%; and negative predictive value, 84%. CONCLUSION: CT findings can be used to predict perineural or vascular invasion by oral cavity tumors.

Patient compliance in mobile screening mammography.

RATIONALE AND OBJECTIVES: We assessed the follow-up behavior of women who had abnormal results of screening mammograms taken on a mobile van. METHODS: A retrospective cohort study was conducted between 1988 and 1991 of all women served by a mobile mammography van in rural North Carolina. Compliance with radiologist recommendations for follow-up was assessed through review of patient records and mail surveys of patients with incomplete records. RESULTS: Compliance was 44% for negative or benign mammograms, 57% for indeterminate mammograms, and 62% for probably malignant or malignant mammograms. Women who had a previous mammogram or had a malignant finding were more likely to comply with follow-up recommendations (p < .0001) than women with normal or benign results and no history of mammography. Compliers and noncompliers did not differ with respect to family history of breast cancer or personal history of breast discomfort. CONCLUSION: Compliance with recommendations in this setting was lower than expected. This may be because rural women using mobile van mammography have limited access to the resources needed for appropriate follow-up. Further research is needed to examine explanations for poor compliance in this setting.

Abdominal CT findings in sarcoidosis: radiologic and clinical correlation.

PURPOSE: To estimate the prevalence of abdominal computed tomographic (CT) findings in sarcoidosis and to correlate these findings with those at chest radiography, clinical status, and level of angiotensin converting enzyme (ACE). MATERIALS AND METHODS: Abdominal CT examinations in 59 patients with sarcoidosis were evaluated for adenopathy, liver and spleen size, and discrete lesions within the liver or spleen. RESULTS: Extensive adenopathy was seen in 10% of patients. Marked hepatic and splenic enlargement was seen in 8% and 6%, respectively. Nodules were seen in the spleen in eight (15%) patients and in the liver in three (5%). Although liver size, spleen size, and adenopathy were directly related (P < .0001), the presence of nodules was not strongly related to organ size. Abdominal CT findings were related to clinical status and elevated ACE levels but not to chest radiographic stage. CONCLUSION: Marked abdominal CT findings are uncommon in sarcoidosis and correlate with disease activity but not chest radiographic stage.

Diagnosis of prostatic carcinoma: value of random transrectal sonographically guided biopsies.

OBJECTIVE: We studied the efficacy of random, transrectal sonographically guided biopsies in the diagnosis of prostatic carcinoma in a high-risk population. SUBJECTS AND METHODS: During a 2-year period, 570 transrectal sonographically guided prostatic biopsies were done because of clinical findings suggestive of prostatic carcinoma. Biopsies of hypoechoic lesions that were suggestive of carcinoma and segmental random biopsies of normal-appearing lobes of the prostate were performed. Transrectal sonographic findings were correlated with results of pathologic examination of the biopsy specimen and with surgical results, when available. RESULTS: Of the 202 patients found to have carcinoma, the carcinoma was detected with directed biopsy in 145 patients (72%). One hundred twenty (71%) of 169 carcinomas were detected with random biopsy when that procedure was performed. Random biopsies were the only method of diagnosing 57 (28%) of the 202 carcinomas, increasing the yield by 39%. CONCLUSION: Yield of carcinoma on transrectal sonographically guided biopsies increases significantly when segmental random biopsies are performed. Transrectal sonographically guided biopsies should include cores through hypoechoic lesions that are suggestive of carcinoma and bilateral segmental random biopsies.

Analysis of cancers missed at screening mammography.

Analysis of 320 cancers found in a screened population between August 1985 and May 1990 revealed 77 cancers that were "missed" at screening mammography. The missed lesions consisted of cancers incorrectly diagnosed after mammography (false-negative results) but visible in retrospect (n = 19); cancers correctly diagnosed after mammography but visible in retrospect on an earlier mammogram (n = 47); and cancers that went undetected by the first of two readers (n = 11). Missed lesions were categorized according to type of miss, reason for the miss, breast density, lesion features, and lesion location. The missed lesion were compared with 121 cancers that were correctly diagnosed at screening mammography. The missed cancers occurred in women with denser breasts (P = .046), were less likely to demonstrate malignant microcalcifications, and were more likely to demonstrate a developing opacity as an indication of cancer (P = .005). An understanding of the characteristics of missed lesions may be a valuable aid in increasing the sensitivity of screening mammography.

Efficacy of prostate-specific antigen and magnetic resonance imaging in staging stage C adenocarcinoma of the prostate.

OBJECTIVES: The authors compared the two most common presurgical tests now used for the preoperative staging of adenocarcinoma of the prostate, prostate-specific antigen (PSA) and magnetic resonance imaging (MRI). METHODS: One hundred consecutive radical retropubic prostatectomy patients were imaged at 1.5 Tesla before surgery with routine T1-weighted and T2-weighted transaxial images. The images were analyzed by two experienced radiologists for evidence of extracapsular disease. Radiologists rated each gland on a scale of 0 to 100 for the percentage likelihood of extracapsular disease based on its MRI appearance. Receiver operator characteristic (ROC) curves were plotted, and areas were calculated for the two radiologists and the preoperative PSA values. RESULTS: Comparison of the areas of the ROC curves generated from the two radiologists and those from the preoperative PSA values showed no statistical difference. CONCLUSIONS: In this series, radiologic interpretation of body coil MRI studies in those patients chosen for a radical retropubic prostatectomy was no better in staging adenocarcinoma of the prostate than simply using the preoperative PSA values.

Post-ligation dilatation of the fallopian tube.

RATIONALE AND OBJECTIVES: Dilatation of fallopian tube remnants after ligation has been described but never systematically studied in post-ligation hysterosalpingograms (HSGs). This study describes the frequency and appearance of proximal tubal remnant dilatation as seen on HSGs in women with a history of bilateral tubal ligation (BTL). METHODS: A retrospective review of medical records and a subjective and objective evaluation of dilatation seen on HSGs included 68 consecutive women seen for pre-reanastomosis HSG. RESULTS: Among the 68 women, 44 (67%) had objectively measured dilatation on one or both tubes. Dilatation was present in both short and long tubal remnants. There were no measurable differences between women with and without presence of dilatation. Neither length nor dilatation of tubal remnant was associated with pregnancy outcome. CONCLUSIONS: Dilatation of the tubal remnant after bilateral tubal ligation is a common finding on HSG and can be accurately identified from the HSG by radiologists. Dilatation is not strictly related to length, and in our small sample with follow-up, was not associated with pregnancy outcome.

MR imaging in adenocarcinoma of the prostate: interobserver variation and efficacy for determining stage C disease.

Patients with adenocarcinoma of the prostate confined to the gland (stage B) are candidates for a potentially curative surgical procedure (radical retropubic prostatectomy). However, patients with adenocarcinoma that penetrates the capsule or invades the seminal vesicles (stage C) are no longer considered good candidates for surgical cure of their disease. The purpose of this study was to compare the ability of four radiologists to detect stage C disease on MR images and to evaluate interobserver variability. One hundred consecutive MR studies of the prostate were reviewed independently by four radiologists to determine whether the cancer was stage C (capsule penetration or seminal vesicle invasion by tumor). A radical prostatectomy was performed in each case, and careful histologic assessment was made of the prostatic capsule and seminal vesicles for any evidence of stage C disease. The sensitivity, specificity, and accuracy (true-positive + true-negative/100 patients) in detecting stage C disease were calculated for each of the four readers. Four receiver-operating-characteristic curves were generated and compared by means of the univariate z score. Percentage agreement was calculated for five specific areas of the prostate on MR images, and observations made by the best reader were compared with the other three to help determine interreader variability. The results showed that the sensitivity and specificity of MR imaging in detecting stage C disease ranged from .24 to .61 (mean, .48) and .49 to .79 (mean, .66), respectively. The accuracy of MR imaging ranged from .47 to .61 (mean, .55). The univariate z score test showed that one of the readers significantly differed from the other three. The average percentage agreement between that reader and the other three was 70% for the five separate anatomic regions. This study shows that considerable interobserver variation exists in the interpretation of MR images for staging cancer of the prostate. The average accuracy among four radiologists in determining the presence of stage C adenocarcinoma of the prostate from MR images was only slightly above a chance guess at .55.

Acyclovir in pregnancy registry: six years' experience. The Acyclovir in Pregnancy Registry Advisory Committee.

The Acyclovir in Pregnancy Registry was established to gather data on prenatal exposure to acyclovir. Exposed pregnancies are tracked prospectively to ascertain exposure, risk factors, and pregnancy outcome. Through June 30, 1990, 312 acyclovir-exposed pregnancies had been reported and followed. Of these, 239 were exposed during the first trimester; outcomes included 24 spontaneous fetal losses, 47 induced abortions, 159 live births of infants without congenital abnormalities, and nine outcomes with congenital abnormalities. Among the 73 second- and third-trimester exposures, one infant was born with an abnormality. Exposures are also reported to the registry retrospectively, ie, after the outcome of pregnancy is known. Registry findings to date do not show an increase in the number of birth defects among the prospective reports when compared with that expected in the general population, and there is no consistent pattern of abnormalities among retrospective or prospective reports. These findings should provide some reassurance in counseling women following inadvertent prenatal exposure. The cases accumulated to date represent a sample of insufficient size for reaching reliable and definitive conclusions about the safety of acyclovir for pregnant women and their developing fetuses. Therefore, until further information is available, the Acyclovir in Pregnancy Registry Advisory Committee recommends following the 1989 Centers for Disease Control Sexually Transmitted Diseases Treatment Guidelines for the use of acyclovir in pregnancy, and encourages reporting of all prenatal exposures to the registry (1-800-722-9292, ext. 8465).

Sensitivity and specificity of computed tomography for the detection of adrenal metastatic lesions among 91 autopsied lung cancer patients.

The ability of computed tomography (CT) to detect metastatic lesions in adrenal glands was evaluated on 91 autopsied lung cancer patients who died in 11 hospitals in the eastern United States and Canada from January 1983 to February 1988. Abdominal CT scans within 90 days of death were reviewed twice by two radiologists blinded to the autopsy diagnosis. The likelihood of metastatic spread in each adrenal gland was scored on a five-level scale. Histopathologic findings at autopsy were used to establish the presence or absence of metastases. The sensitivity of CT was low. Among 53 adrenal glands with proven metastatic lesions, the proportion with positive CT scans varied from 20.0% to 41.1%, according to the positivity threshold. In contrast, the specificity of CT was high, even at relaxed positivity thresholds, from 84.5% to 99.4%. The relatively low sensitivity of CT to detect adrenal metastatic lesions is explained to a large extent by the lack of substantial structural changes in many adrenal glands found to have metastases at autopsy. With a strongly positive CT scan, the probability of an adrenal metastatic lesion is high, and confirmatory adrenal biopsy may not be needed in patients with adenocarcinoma and large cell carcinoma.

Computed tomography in the evaluation of clinical stage IB carcinoma of the cervix.

A retrospective analysis of 47 cases of clinical stage IB cervical carcinoma radiologically staged with computed tomography (CT) was undertaken. There were no cases where CT provided information which altered staging. In 5 cases, CT suggested extension of disease beyond the cervix which was not confirmed surgically or with other staging procedures. In 3 cases, one or more normal-sized obturator or internal iliac nodes with metastatic disease were discovered at surgery, but the high common iliac and periaortic nodes were disease free. We conclude that routine use of CT in patients with clinical stage IB cervical carcinoma is not warranted unless the patient's body habitus precludes accurate physical examination.