Mammographically negative breast cancer at the Strathfield Breast Centre

Impact of the Addition of Digital Breast Tomosynthesis (DBT) to Standard 2D Digital Screening Mammography on the Rates of Patient Recall, Cancer Detection, and Recommendations for Short-term Follow-up

RATIONALE AND OBJECTIVES

The addition of digital breast tomosynthesis (DBT) to digital screening mammography (DM) has been shown to decrease recall rates and improve cancer detection rates, but there is a lack of data regarding the impact of DBT on rates of short-term follow-up. We assessed possible changes in performance measures with the introduction of DBT at our facility.

MATERIALS AND METHODS

In our observational study, databases were used to compare rates of recall, short-term follow-up, biopsy, and cancer detection between women undergoing DM without (n = 10,477) and women undergoing DM with (n = 2304) the addition of DBT. Regression analysis was performed to determine associations with patient age, breast density, and availability of comparison examinations.

RESULTS

The addition of DBT resulted in significantly lower recall rates (16%-14%, P = .017), higher rates of biopsy (12.7%-19.1%, P < .01), and increased detection of ductal carcinoma in situ, with a difference of 2.3 cases per 1000 screens (P = .044). A 33% increase in cancer detection rates was observed with DBT, which did not reach statistical significance. Short-term follow-up of probably benign findings was 80% higher in the DBT group (odds ratio = 1.80, 95% confidence interval = 1.38-2.36, P < .001).

CONCLUSIONS

To our knowledge, we are the first to study the impact of DBT on rates of short-term follow-up, and observed an 80% increase over the DM group. Further research is needed to determine the malignancy rate of Breast Imaging Reporting and Data System 3 lesions detected with DBT, and establish appropriate follow-up to maximize cancer detection while minimizing expense and patient anxiety.

Value of one-view breast tomosynthesis versus two-view mammography in diagnostic workup of women with clinical signs and symptoms and in women recalled from screening

OBJECTIVE

The purpose of this study is to compare the diagnostic value of one-view digital breast tomosynthesis versus two-view full-field digital mammography (FFDM) alone, and versus a combined reading of both modalities.

MATERIALS AND METHODS

The datasets of one-view digital breast tomosynthesis and two-view FFDM of abnormal mammograms in 144 consecutive women admitted for diagnostic workup with clinical signs and symptoms (n = 78) or recalled from screening (n = 66) were read alone and in a combined setting. The malignant or benign nature of the lesions was established by histologic analysis of biopsied lesions or by 12-16-month follow-up.

RESULTS

Eighty-six of the 144 patients were found to have breast cancer. The BI-RADS categories for one-view digital breast tomosynthesis were significantly better than those for two-view FFDM (p < 0.001) and were equal to those of the combined reading in both women admitted for diagnostic workup and women recalled from screening. The sensitivity and negative predictive values of digital breast tomosynthesis were superior to those of FFDM in fatty and dense breasts overall and in women admitted for diagnostic workup and in women recalled from screening. Only 11% of digital breast tomosynthesis examinations required additional imaging, compared with 23% of FFDMs.

CONCLUSION

In patients with abnormal mammograms, one-view digital breast tomosynthesis had better sensitivity and negative predictive value than did FFDM in patients with fatty and dense breasts. They also suggest that digital breast tomosynthesis would likely increase the predictive values if incorporated in routine screening.

Breast tomosynthesis in clinical practice: initial results

PURPOSE

The purpose of this study was to assess the potential value of tomosynthesis in women with an abnormal screening mammogram or with clinical symptoms. Mammography and tomosynthesis investigations of 513 woman with an abnormal screening mammogram or with clinical symptoms were prospectively classified according to the ACR BI-RADS criteria. Sensitivity and specificity of both techniques for the detection of cancer were calculated. In 112 newly detected cancers, tomosynthesis and mammography were each false-negative in 8 cases (7%). In the false-negative mammography cases, the tumor was detected with ultrasound (n = 4), MRI (n = 2), by recall after breast tomosynthesis interpretation (n = 1), and after prophylactic mastectomy (n = 1). Combining the results of mammography and tomosynthesis detected 109 cancers. Therefore in three patients, both mammography and tomosynthesis missed the carcinoma. The sensitivity of both techniques for the detection of breast cancer was 92.9%, and the specificity of mammography and tomosynthesis was 86.1 and 84.4%, respectively. Tomosynthesis can be used as an additional technique to mammography in patients referred with an abnormal screening mammogram or with clinical symptoms. Additional lesions detected by tomosynthesis, however, are also likely to be detected by other techniques used in the clinical work-up of these patients.

The role of ultrasonography as an adjunct to mammography in the detection of breast cancer. a systematic review

The aim of this review was to summarise the diagnostic performance of ultrasonography as an adjunct to mammography in the detection of breast cancer and to identify clinical indications. A systematic review was performed of all publications in MEDLINE and EMBASE between 1990 and 2000 on the role of ultrasonography as an adjunct to mammography. 22 studies were included, showing a large variety of indications for ultrasonography and variations in the diagnostic performance of mammography and ultrasonography. There were six studies comparing a combined diagnosis of mammography and ultrasonography together with mammography alone, of which three studies had an increased sensitivity at the cost of a lower specificity. The methods of selecting the study population and interpretation of ultrasonography significantly influenced the diagnostic performance of mammography and ultrasonography relative to each other (P=0.003, P=0.03, respectively). Based on the studies reviewed, little evidence-based support was found to confirm the well recognised value of ultrasonography as an adjunct to mammography in the detection of breast cancer in clinical practice. Furthermore, no clinical indications for additional ultrasonography could be defined. The heterogeneity in the diagnostic performance in these studies may be explained by the methods of patient selection and ultrasonography interpretation, as well as by their poor quality.

Mammographically Occult Breast Cancers

A small percentage of breast cancers are not visible on mammography. Since mammographically occult malignancies may be more difficult to diagnose, we hypothesized that the lack of visualization would cause a delay in detection, more aggressive surgical and adjuvant therapy, and poorer outcome. Patients with mammographically occult malignancies were compared to patients with cancers visible on mammogram. The significance of mammographic visibility for treatment and local and distant recurrence rates were evaluated. Ninety-one of the 813 (11%) cancers were mammographically occult. Patients with mammographically occult malignancies were significantly younger, of lower body weight, and had fewer pregnancies than patients with cancers visible on mammography: age, body weight, and parity were statistically significant (p < 0.001) in stepwise logistic regression. Ductal carcinoma in situ was significantly more frequently diagnosed in patients with mammographically visible malignancies (14% versus 4%, p = 0.0163) and nodal involvement was significantly more frequent in patients with mammographically occult malignancies (35% versus 24%, p = 0.0391). Diagnostic delays exceeding 3 months were experienced by 24% of patients with mammographically occult malignancies compared to 13% of patients with tumor visible on mammography (p < 0.0001). Adjuvant chemotherapy was given to 63% of patients with occult malignancies compared to 41% of patients with mammographically visible cancers (p = 0.0027). The use of breast-conserving therapy and adjuvant radiation and tamoxifen were comparable. Survival free of local recurrence and distant metastases for the 403 patients followed for 5 years or more was not related to mammographic visibility.

Breast cancers invisible on mammography

BACKGROUND

A proportion of the cancers 'missed' at mammography are invisible even with the benefit of hindsight. The aim of the present study was to identify a group of women with proven breast cancer whose mammograms did not show a suspicious lesion even in retrospect (i.e. the truly mammographically occult cancers), and to compare them with mammogram-positive cancers.

METHODS

A total of 1757 breast cancers was diagnosed at the Wesley Breast Clinic's Screening or Diagnostic Services between July 1987 and August 1997. One hundred and twenty cases were identified where, after independent review by two of the authors, no mammographic abnormality could be found in the region where the cancer was subsequently found. These 120 cases were compared with 1548 cancers considered to have a lesion visible on mammography, whether benign, indeterminate, suspicious or malignant in appearance.

RESULTS

In 90% of the mammogram-negative cancers, a clinical abnormality led to further investigation, while the remainder were found incidentally on ultrasound. There were a higher proportion of dense breasts, and of women aged 40-49, in the mammogram-negative cancers than in the mammogram-positive cancers. The mammogram-negative cancers were of smaller size overall, but three of them were surprisingly large (7-11 cm). In both the mammogram-positive and -negative cancers approximately 60% were ductal invasive cancers.

CONCLUSIONS

Where factors are present that make mammographically occult malignancy more likely (e.g. age 40-49 and dense breasts), women may be targeted for further investigation by other modalities. This is essential in the presence of a clinical abnormality.

Breast cancer in young women

BACKGROUND

It is believed that cancer of the breast is more difficult to diagnose in young women and it has long been disputed whether breast cancer occurring in women aged < or = 40 years is more aggressive than that occurring later in life. A number of reports in the literature suggest that the disease is of similar aggressiveness in the young patients and older age groups, while other reports suggest that it is more aggressive and carries a higher mortality in young women.

METHODS

To address these aspects of breast cancer we have undertaken a review of the cases treated at The Strathfield Breast Centre between 1989 and 1996 and compared the disease in the young and old groups with particular reference to the modes of diagnosis, the pathological staging and types of tumour and the outcomes of treatment.

RESULTS

The accuracy of ultrasound and fine needle aspiration biopsy were similar in both groups, but the false negative rate of mammography in the young patients was 15% or 50% greater than that which was observed in the older patients. The incidence of histopathological type, bilaterality, size of lesion and receptor positivity were the same in both groups. In the young group, 40% had Grade 3 tumours compared with 27% in the older group. Nineteen per cent of young patients had 4 or more lymph nodes involved while only 10% of the older patients had similar lymph node involvement. Overall 5-year survival was 79% in the older patients compared with 90% in the young patients.

CONCLUSIONS

The spectrum of disease is similar in both the young and older patient and the prognosis is no worse for the young group but mammography is less effective in the diagnosis of the young patient.