Earlier Breast Cancer Detection Using Automated Whole Breast Ultrasound With Mammography, Including Cost Comparisons
Earlier Breast Cancer Detection Using Automated Whole Breast Ultrasound With Mammography, Including Cost Comparisons
The purpose of this study is to determine whether addition of automated whole breast
 ultrasound to the usual screening mammography in a population of asymptomatic women with
 mammographically dense breasts will result in a significantly greater number of breast
 cancers discovered than would be found by mammography alone.
1. Study Design:

 A total of sixteen thousand women at 16 centers, will be evaluated with SonoCiné
 automated bilateral whole breast sonography and screening mammography. In this study a
 motor driven carrier will be used to have the transducer examine each breast completely
 [Appendix A]. In this way the images can be gathered in a contiguous manner and
 displayed in a ciné strip and as three-dimensional images of each scan row.

 These sonograms will be read by one of two designated investigator/radiologists at each
 site. The mammograms will be not read until after the sonogram is performed and read,
 and then will be read in the usual manner for that department without knowledge of the
 automated breast ultrasound. The mammograms will not necessarily be read by one of the
 investigators. The sonograms will initially be read and scored by one of the
 investigators at each site. These sonograms will be reviewed as ciné loops and as
 three-dimensional reconstructions of each scan row. The investigator will have no prior
 knowledge of the patient's mammogram or the reading.

 The data will be entered from each site into a central computer via internet. This
 computer will have no personal information about any subject other than her institution
 ID number and her birth date. Following entry of data from the separate readings of the
 mammogram and sonogram, one investigator will assess any abnormal mammogram or sonogram
 in light of the other imaging study for that patient to evaluate whether combined
 readings of both studies would have effected patient management.

 The investigators' call back, short-term follow-up and biopsy recommendation rates for
 the mammography, the sonography and the combined reading will be recorded. As with other
 breast imaging studies needle or open biopsies will be recommended for the mammograms
 and/or sonograms that are read as suspicious for carcinoma. Further diagnostic imaging
 studies will be ordered for any indeterminate finding.

 2. Procedures for Patient Entry on Study:

 Each patient is requested to obtain at her expense a screening mammogram on entry into
 the study. She must also agree to have a screening mammogram one year later. The patient
 must also give up the rights to the original films of the mammogram although copies will
 be made for the patient without charge if needed. No other studies are required. However
 the patient will also be required to fill out a demographic form.

 3. Criteria for Response Assessment:

 Each screening mammogram will be reviewed in the usual manner for that institution, not
 necessarily by one of the investigators. Each screening ultrasound will be reviewed in a
 timely manner by an investigator radiologist, and the patient will be informed of the
 results either directly or through her physician. If any study is considered abnormal
 the patient will be informed and called back for additional studies or other appropriate
 action.

 4. Definitions of Classification:

 True and false positive and negative rates will be calculated based on the results of
 the three initial imaging examinations, screening mammography (SM), screening automated
 ultrasound (SU) and both screening studies combined (SC)), performed on each subject in
 the PMA study. The above rates are calculated for each of the three initial imaging
 examinations independent of the results of the other initial imaging examinations.

 True Positive - A subject is TP for any of the three types of initial imaging
 examinations (SM, SU, or SC) that leads to a biopsy proven cancer (invasive or in situ
 breast cancer, or other intramammary malignancy).

 True Negative - A subject is TN for each initial imaging examination whose initial
 imaging examination is read as negative and who has a normal screening mammogram (or an
 indeterminate mammogram subsequently shown not to be cancer) one year later, and has not
 undergone a breast biopsy positive for cancer based on physical findings during the
 interim.

 False Positive - A subject is FP for a particular type of study, who has a benign breast
 biopsy based on that study, and who does not have a breast cancer elsewhere discovered
 by that study.

 False Negative - A subject is FN for a particular type of initial imaging examination,
 when the initial imaging examination is normal or benign, and a cancer is discovered on
 one of the other types of initial imaging examinations, or is discovered on the one-year
 mammogram, or is discovered by physical findings during the interim.

 Callback - A callback (CB) occurs when a subject is recalled for further evaluation
 because one of the initial imaging examinations is read as positive or indeterminate. A
 SU callback is the sonographic equivalent of a diagnostic evaluation ordered from a SM
 because of positive or indeterminate findings. Similarly, a SC callback occurs when
 evaluation of both the SM and the SU together are indeterminate or positive and requires
 further evaluation. CB rates will be calculated for each of the three initial imaging
 examinations by comparing the number of CB's with the total number subjects. % CB rate =
 Number of CB's / number of Study subjects.

 Callbacks can have three different outcomes: resolution, by showing the initial imaging
 examination was normal with further evaluation, short-term follow-up examination(s) at a
 later date to evaluate the findings of the initial imaging examination and the CB
 examination(s) further, or a biopsy because the initial imaging examination and/or the
 call back examination were sufficiently suspicious to warrant tissue evaluation.

 Follow-Up - Follow-up (FU) rates will be calculated for each of the three initial
 imaging examinations by comparing the number of short-term follow-up's with the total
 number of subjects. % FU rate = Number of FU's / number of Study subjects. The rate of
 positive follow-ups will be calculated. % +FU = Number of +FU's / Total number of
 follow-ups.

 Biopsy - Biopsy rates will be calculated for each of the three initial imaging
 examinations by comparing the number of biopsies with the total number of subjects. %
 Biopsy rate = Number of Biopsies / number of Study subjects. The rate of positive
 biopsies will be calculated. % + Biopsies = Number of + Biopsies / Total number of
 Biopsies. A subject may have more than one biopsy.

 5. "Off Study" Criteria:

 This study requires the performance of an initial mammogram, an initial automated
 screening ultrasound, and a final mammogram at one year. The patient also agrees to
 allow access to the results of any further diagnostic tests that occur because of
 positive findings in the original screening mammogram or ultrasound. The subject may
 withdraw at any time, in which case her data will not be utilized in the analysis. Any
 patient not completing the above tests will also be excluded from the analysis.

 6. Statistical Considerations:

 Since the 16,000 patients mostly will be covering the costs of their own tests, it is
 anticipated that they will be coming from a well-screened population. Such a population over
 the age of 40 years would be expected to generate interval cancers at a rate of about 0.25%
 annually. Consequently, about 40 carcinomas would present themselves for discovery during the
 study. Given the 20 to 25% expected false negative rate from screening mammography 8 to 10
 cancers will be available for discovery only by SonoCiné. If SonoCiné were to have an
 independent 20 to 25% false negative rate it would be expected to find 6 to 8 of the
 remaining cancers. If mammography is utilized alone with an estimated 75% accuracy, it is
 anticipated that 30 cancers would be identified based on mammography screening with a failure
 of 10 cancers not found. With the addition of Sonociné screening, it is predicted that
 additional 8 cancers would be found and the total failure rate (false negative findings)
 would be 2 cancers. This would increase the accuracy to 95%.

 If SonoCiné generally finds cancers at a smaller size than screening mammography, the actual
 number of cancers discovered by SonoCiné may be higher, since it will find some of the
 cancers that would be discovered by screening mammography the following year before they
 presented clinically. Also women with a known higher risk of breast cancer may
 disproportionately volunteer for this study and more cancers may be found both by mammography
 and automated whole breast ultrasound than expected. Since women are aware that
 mammographically dense breasts are more prone to be falsely negative by mammography, more
 women with this condition may join the study than expected. This may produce more
 mammographically occult cancers than expected. Breast density is one of the variables
 recorded in all subjects.

 Discriminant Function analysis will be the analysis of choice based on the fact that we wish
 to distinguish among several mutually exclusive groups, the best predictor that are important
 for distinguishing among the groups, and to develop a procedure for predicting group
 membership for new cases. The concept underlying discriminant analysis is that that linear
 combinations of independent variables are formed and serve as a basis for classifying cases
 into one of the groups. Assumptions include that each group must be a sample from a
 multivariate normal population and the population covariance matrices must be equal, although
 discriminant function analysis works fairly well in cases were there are exceptions.
 Dichotomous variables can also be included as predictor variables. Emphasis is on analyzing
 all the variables at one time and considering them together. By considering them
 simultaneously we are able to incorporate important information about their relationships
 with each other.

 Because the variables are interrelated, we will need to employ statistical techniques that
 incorporate these dependencies by analyzing the differences between groups by significance
 tests for the equality of group means for each variable utilizing F values, and their
 significance, and Wilks' Lambda to compare within group variability with total variability.
 Small values of lambda indicate that means associated with variables predicting group
 membership are different and may lead to model development.

 Since interdependencies among the variables affect most multivariate analyses, it is
 important to look at the correlation matrix of the predictor variables. Prior probability is
 an estimate of the likelihood that a case belongs to a particular group. Knowledge of prior
 probabilities can be calculated based on published statistics and is estimated to be .25% for
 cancer in the screening population. To take advantage of additional information available for
 developing a classification scheme for probability of group membership, classification of
 actual group membership can be compared with predicted group membership as well using
 discriminant function. Variables used to predict group memberships will be drawn from the
 Patient Form, the Imaging Form and the Biopsy Form. Variables will include initial risk
 factors, results of mammography findings, SonoCiné findings and the results of the biopsy.
 Although some variables are coded as categorical, most are ordinal and as interval and are
 appropriate for Discriminant Function analysis or the use of General Linear Model Procedure
 (GLM).Additional analysis looking at the distribution of time between events utilizing Life
 Tables and an extended Cox Regression model.

 Efficiency is defined as the use of resources that will produce the maximum benefit.
 Cost-benefit analysis can be performed at the end of the study by expressing both the
 benefits and costs of a program, not only in dollars but in quality of life and reduction of
 suffering. Benefits of the study, in addition to increased detection rate, may include over
 time an earlier detection of smaller cancers and an actual reduction in the need for biopsy.
 This will impact treatment and resource utilization also.
Inclusion Criteria:

 -  be at least 35 years old, unless she has a strong pre-menstrual family history of
 breast cancer

 -  have had no screening mammogram in the past 10 months

 -  agree to have a screening mammogram that will not be reviewed until after a SonoCiné
 is performed

 -  agree to have a screening mammogram in approximately one year

 -  agree to answer follow up question in approximately one year

 -  meet the usual criteria for breast screening (be asymptomatic of focal breast disease)

 -  have no history of breast cancer for at least one year

 -  agree to have both mammogram and SonoCiné if a physical finding or mammographic
 finding occurs within one year that requires biopsy

 Exclusion Criteria:

 -  greater than 7 cm compressed breast thickness at mammography