Breast cancers invisible on mammography

Mammographic sensitivity as a function of tumor size: A novel estimation based on population-based screening data

Background

Instead of a single value for mammographic sensitivity, a sensitivity function based on tumor size more realistically reflects mammography’s detection capability. Because previous models may have overestimated size-specific sensitivity, we aimed to provide a novel approach to improve sensitivity estimation as a function of tumor size.

Methods

Using aggregated data on interval and screen-detected cancers, observed tumor sizes were back-calculated to the time of screening using an exponential tumor growth model and a follow-up time of 4 years. From the observed number of detected cancers and an estimation of the number of false-negative cancers, a model for the sensitivity as a function of tumor size was determined. A univariate sensitivity analysis was conducted by varying follow-up time and tumor volume doubling time (TVDT). A systematic review was conducted for external validation of the sensitivity model.

Results

Aggregated data of 22,915 screen-detected and 10,670 interval breast cancers from the Dutch screening program were used. The model showed that sensitivity increased from 0 to 85% for tumor sizes from 2 to 20 mm. When TVDT was set at the upper and lower limits of the confidence interval, sensitivity for a 20-mm tumor was 74% and 93%, respectively. The estimated sensitivity gave comparable estimates to those from two of three studies identified by our systematic review.

Conclusion

Derived from aggregated breast screening outcomes data, our model’s estimation of sensitivity as a function of tumor size may provide a better representation of data observed in screening programs than other models.

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Mammographic sensitivity is a key indicator of screening effectiveness.

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Previous model using logistic function might overestimate size-specific sensitivity.

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Our model showed that sensitivity increased from 0 to 85% for tumor sizes from 2 to 20 mm.

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Our model may provide a better representation of data observed in screening programs.

Benefit of adding digital breast tomosynthesis to digital mammography for breast cancer screening focused on cancer characteristics: a meta-analysis

PURPOSE

We evaluated the benefit of adding digital breast tomosynthesis (DBT) to full-field digital mammography (FFDM) compared to FFDM alone for breast cancer detection, focusing on cancer characteristics.

METHODS

We searched electronic databases and relevant references for published studies comparing DBT plus FFDM to FFDM alone for breast cancer screening. Pooled risk ratios (RRs) for various pathologic findings were determined using random effects models.

RESULTS

Eleven eligible studies were included. Pooled RRs showed a greater cancer detection for DBT plus FFDM than for FFDM alone for invasive cancer (1.327; 95% CI, 1.168-1.508), stage T1 (1.388; 95% CI, 1.137-1.695), nodal-negative (1.451; 95% CI, 1.209-1.742), all histologic grades (grade I, 1.812; grade II/III, 1.403), and histologic types of invasive cancer (ductal, 1.437; lobular, 1.901). However, adding DBT did not increase for detection of carcinoma in situ (1.198; 95% CI, 0.942-1.524), stage ≥T2 (1.391; 95% CI, 0.895-2.163), or nodal-positive cancer (1.336; 95% CI, 0.921-1.938). Heterogeneity among studies was not significant in any subset analysis.

CONCLUSIONS

Adding DBT to FFDM enabled detection of early invasive breast cancer that might have been missed with FFDM alone. Knowing which cancer characteristic DBT detects may allow it to play a complementary role in predicting long-term patient outcomes and facilitate treatment planning.

-The advancement of biomarker-based diagnostic tools for ovarian, breast, and pancreatic cancer through the use of urine as an analytical biofluid

Despite considerable advancements, the development of effective cancer screening tools based on serum biomarker measurements has thus far failed to achieve a meaningful clinical impact. The incremental progress observed over the course of serum biomarker development suggests that further refinements based on novel approaches may yet result in a breakthrough. The use of urine as an analytical biofluid for biomarker development may represent such an approach. The unique characteristics of urine including a high level of stability, ease of sampling, and an inactive and low-complexity testing matrix offer several potential advantages over the use of serum. A number of recent reports have demonstrated the utility of urine in the identification of novel cancer biomarkers and also the improved performance of biomarkers previously evaluated in serum. In this review, advancements related to the use of urine biomarkers within the settings of ovarian, breast, and pancreatic cancer are presented and discussed. Findings regarding the identification of specific urine biomarkers for each disease are highlighted along with comparative analyses of urine and serum biomarkers as diagnostic tools.

Design study of a high-resolution breast-dedicated PET system built from cadmium zinc telluride detectors

We studied the performance of a dual-panel positron emission tomography (PET) camera dedicated to breast cancer imaging using Monte Carlo simulation. The proposed system consists of two 4 cm thick 12 x 15 cm(2) area cadmium zinc telluride (CZT) panels with adjustable separation, which can be put in close proximity to the breast and/or axillary nodes. Unique characteristics distinguishing the proposed system from previous efforts in breast-dedicated PET instrumentation are the deployment of CZT detectors with superior spatial and energy resolution, using a cross-strip electrode readout scheme to enable 3D positioning of individual photon interaction coordinates in the CZT, which includes directly measured photon depth-of-interaction (DOI), and arranging the detector slabs edge-on with respect to incoming 511 keV photons for high photon sensitivity. The simulation results show that the proposed CZT dual-panel PET system is able to achieve superior performance in terms of photon sensitivity, noise equivalent count rate, spatial resolution and lesion visualization. The proposed system is expected to achieve approximately 32% photon sensitivity for a point source at the center and a 4 cm panel separation. For a simplified breast phantom adjacent to heart and torso compartments, the peak noise equivalent count (NEC) rate is predicted to be approximately 94.2 kcts s(-1) (breast volume: 720 cm(3) and activity concentration: 3.7 kBq cm(-3)) for a approximately 10% energy window around 511 keV and approximately 8 ns coincidence time window. The system achieves 1 mm intrinsic spatial resolution anywhere between the two panels with a 4 cm panel separation if the detectors have DOI resolution less than 2 mm. For a 3 mm DOI resolution, the system exhibits excellent sphere resolution uniformity (sigma(rms)/mean) < or = 10%) across a 4 cm width FOV. Simulation results indicate that the system exhibits superior hot sphere visualization and is expected to visualize 2 mm diameter spheres with a 5:1 activity concentration ratio within roughly 7 min imaging time. Furthermore, we observe that the degree of spatial resolution degradation along the direction orthogonal to the two panels that is typical of a limited angle tomography configuration is mitigated by having high-resolution DOI capabilities that enable more accurate positioning of oblique response lines.

The effect of age, menopausal state, and breast density on (18)F-FDG uptake in normal glandular breast tissue

Theoretically, the degree of (18)F-FDG uptake in the glandular tissues of the normal breast can affect the detection of breast cancer. The aim of this prospective study was to investigate relationships among age, menopausal state, and breast density and determine whether they affect (18)F-FDG uptake in normal glandular breast tissue.

METHODS

Among 250 newly diagnosed breast cancer patients, 149 patients (mean age +/- SD, 50.9 +/- 9.70 y; range, 32-77 y) were analyzed because they had normal contralateral breasts confirmed by MRI, mammography, and (18)F-FDG PET examinations. PET images were acquired 60 +/- 2 min after the administration of (18)F-FDG (5.2 MBq/kg of body weight). The maximum and average standardized uptake value (SUVmax and SUVavg, respectively) of (18)F-FDG were calculated in the normal breast. Patients were divided into groups according to qualitative breast density and menopausal state. Descriptive statistics and 2-factorial analysis of covariance were used to assess the effects of qualitative breast density, menopausal state, and age on SUVmax and SUVavg. Pearson chi(2) was used to test the relationship between menopausal state and qualitative breast density.

RESULTS

The average age of patients with nondense breasts was significantly higher than that of patients with dense breasts (P < 0.01). Also, breast density related to menopausal state (P < 0.05). Dense breasts had an average SUVmax of 1.243 and mean SUVavg of 0.694, whereas nondense breasts had a mean SUVmax of 0.997 and mean SUVavg of 0.592. Analysis of covariance indicated that density and the linear effect of age were significant with regard to both SUVmax and SUVavg. After removing the linear effect of age, menopausal state had no effect on SUVmax and SUVavg.

CONCLUSION

(18)F-FDG uptake significantly decreases as age increases and breast density decreases. Age and qualitative breast density are independent factors and significantly affect (18)F-FDG uptake for both SUVmax and SUVavg. Menopausal state had no effect on SUVmax and SUVavg.

PET, PET/CT, and PET/MR Imaging Assessment of Breast Cancer

This review focuses mainly on clinical applications of PET/CT in patients with breast cancer. It discusses the role of 2-[18F]-fluoro-2-deoxy-D-glucose (FDG) PET/CT (and FDG PET) in the diagnosis and initial staging of breast cancer, in monitoring the response of disease to chemotherapy, and in identifying metastatic and recurrent disease. In addition, it discusses the role of MR imaging and potential future hybrid modalities such as PET/MR imaging.

Errors in cancer diagnosis: current understanding and future directions

PURPOSE

Errors in cancer diagnosis are likely the most harmful and expensive types of diagnostic errors. We reviewed the literature to understand the prevalence, origins, and prevention of errors in cancer diagnosis, focusing on common cancers for which early diagnosis offers clear benefit (melanoma and cancers of the breast, colon, and lung).

METHODS

We searched the Cochrane Library and PubMed from 1966 until April 2007 for publications that met our review criteria and manually searched references of key publications. Our search yielded 110 studies, of which nine were prospective studies and the remaining were retrospective studies.

RESULTS

Errors in cancer diagnosis were not uncommon in autopsy studies and were associated with significant harm and expense in malpractice claims. Literature on prevalence was scant. For each type of cancer, we classified preventable errors according to their origins in patient-physician encounters in the clinic setting, diagnostic test or procedure performance, pathologic confirmation of diagnosis, follow-up of patient or test result, or patient-related delays.

CONCLUSION

The literature reflects advanced knowledge of contributory factors and prevention for diagnostic errors related to the performance of procedures and imaging tests and emerging understanding of pathology errors. However, prospective studies are few, as are studies of diagnostic errors arising from the clinical encounter and patient follow-up. Future research should examine further the system and cognitive problems that lead to the many contributory factors we identified, and address interdisciplinary interventions to prevent errors in cancer diagnosis.

Breast image registration techniques: a survey

Breast cancer is the most common type of cancer in women worldwide. Image registration plays an important role in breast cancer detection. This paper gives an overview of the current state-of-the-art in the breast image registration techniques. For the intramodality registration techniques, X-ray, MRI, and ultrasound are the primary focuses of interest. Intermodality techniques will cover the combination of different modalities. Validation of breast registration methods is also discussed.

Mainstream breast cancer radiology perspective

Clinical breast-imaging tests must be fast, sensitive, specific, add information not otherwise available to clinicians at a reasonable cost, and be biopsy-capable. Mammography, breast ultrasound and imaging guided breast core biopsies and preoperative needle localizations are most often used in breast imaging facilities around the world. This article will describe mammography and breast ultrasound in current clinical practice for breast cancer detection, diagnosis, staging, image-guided biopsy, and for evaluation of response to neoadjuvant chemotherapy.

Breast magnetic resonance imaging: An essential role in malignant axillary lymphadenopathy of unknown origin

The aim of this retrospective case series was to assess the role of breast MRI in the investigation of "occult" malignancy, and the associated potential to influence patient management. Between January 2000 and March 2004, 18 patients, who presented with axillary lymphadenopathy, most likely due to "occult" breast cancer, were examined with MRI of the breast. The results showed 12 true positives, four true negatives, and two false positives. This gave an overall sensitivity of 85.7% and an overall accuracy of 86.7%. In those in whom malignancy was identified on MRI and subsequently proven histologically, 78% of these cancers were identified, and localized by preoperative MRI-guided sonography. In addition, 55% of these patients were eligible for conservative surgery. As such, MRI of the breast is highly sensitive for the detection of mammographically and clinically occult breast cancer. The use of MRI enables a preoperative diagnosis to be made in a high percentage of patients and may allow retrospective targeted ultrasound localization. Definitive surgical planning, including the option of breast conservation, is made possible with the result of the MRI examination.

Diagnostic assessment of nonpalpable breast cancer-the difference in diagnostic approach for the clinical treatment of breast cancer between the japanese guidelines and the national comprehensive cancer network (USA) guidelines

The detection of non-palpating breast cancer might improve the survival of patients with whole breast cancer because it can be diagnosed at an early stage. Therefore, to standardize the quality of patient care, a published assessment guideline is necessary in a clinical setting. For this purpose, Japan and USA have independent guidelines with different approaches. ''The evidence-based guideline for clinical treatment of breast cancer'' that was published in June 2005 by the Japanese breast cancer society, is the first set of integrated guidelines pertaining to breast cancer in Japan. These guidelines are presented in the research questions (RQ)format. This paper explains 7 RQs(out of 31 RQs)and also discusses the recommendations pertaining to the diagnosis of nonpalpable breast cancer. The National Comprehensive Cancer Network (NCCN; USA)guidelines, which are widely recognized as one of the most reliable guidelines based on published evidences, also contain the diagnostic assessment of asymptomatic patients with a negative physical examination. This paper discusses pros and cons of each of the above mentioned guidelines as well as their clinical application. It is necessary to use both the Japanese and NCCN guidelines while understanding the differences between the two.

Fluorodeoxyglucose-PET in the management of breast cancer

FDG-PET can be helpful in the diagnosis of primary breast cancer, especially in patients with dense breast tissue, significant fibrocystic changes, fibrosis after radiotherapy, and inconclusive results from MR imaging and other imaging modalities. PET has a limited role in patients with very small tumors and with well-differentiated and lobular types of breast cancer. In preoperative staging, FDG-PET has a low sensitivity for detection of regional lymph node involvement. Also, current PET imaging techniques can easily miss micrometastases. FDG-PET, however, has high positive predictive value for the axillary lymph node involvement, especially patient with advanced tumors. Compared with conventional imaging modalities, FDG-PET provides high diagnostic accuracy in detecting recurrent or metastatic breast carcinoma. FDG-PET seems to be highly useful for monitoring response to therapeutic interventions. This technique can identify response to therapy earlier than any other imaging method currently available. Obviously, identification of nonresponding patients could greatly improve patient management by allowing termination of ineffective and toxic therapies.

Des cancers du sein sans signe en mammographie : quand et pourquoi ?

Breast carcinomas with false negative mammogram correspond to carcinomas diagnosed with means other than mammogram when the mammogram, at the time of diagnosis, showed no significant abnormality. The rate of false mammogram is difficult to ascertain because few studies have been published on this subject. The absence of mammographic abnormality is related to histopathological characteristics of the tumor and mammographic features of the patient's breast tissue. The small size of the tumor, the lack of microcalcifications often due to tumor necrosis and the absence of any significant associated desmoplastic reaction are the main histopathological factors encountered, particularly for dense breasts.

[Breast cancers: abnormalities visible on a single view]

This article reviews abnormal mammographic findings that do not meet the BIRADS description of masses or clusters of microcalcifications: abnormalities visible on a single view, asymmetrical densities and unusual patterns (transparent appearances, ductal patterns and diffuse abnormalities). It is important for radiologists to become familiar with unusual mammographic manifestations of malignant lesions to avoid misdiagnosis. Correlation with clinical abnormalities, optimal mammographic technique and comparison with previous films are useful and important for accurate interpretation of these difficult and/or unusual cases. Ultrasound, MRI and percutaneous biopsy are also useful in selected cases.

Clinical applications of FDG-PET in oncology

Positron emission tomography together with F-18-deoxyglucose (FDG) has emerged as a valuable clinical tool in the field of oncology. FDG-PET diagnoses, stages and restages most cancers with a high diagnostic accuracy. The effects of chemotherapy on tumour metabolism can be monitored with this whole-body technique. Recent studies have established a high prognostic accuracy of PET for predicting the clinical outcome of cancer patients. The current review addresses the role of FDG-PET for diagnosing, staging and restaging of lung cancer, colorectal cancer, lymphoma, melanoma and breast cancer staging and provides a brief outlook for future applications of clinical PET imaging.

Ductal carcinoma in situ of the breast in Singapore: recent trends and clinical implications

BACKGROUND

Breast ductal carcinoma in-situ (DCIS) is increasingly being diagnosed as a result of screening mammography and better pathological recognition. With this and the rising breast cancer incidence in Singapore, DCIS is poised to become a bigger part of surgical practice. Principles of screening, diagnosis and management of DCIS have also been rapidly evolving. Against this background, a clinicopathological audit of recent cases of DCIS in our centre was performed.

METHODS

Thirty-eight cases of DCIS diagnosed in the period 1997-2000 were retrospectively analysed. Histological examination and immunohistochemical studies for oestrogen and progesterone receptor expression were performed.

RESULTS

In the present study, DCIS was most common in the group of patients who were <50 years (58%) as compared to an American series' where the corresponding group were > or =60 years (36%). Compared to a previous local study a decade ago, the present series showed that: (i) DCIS constituted a higher proportion of all breast cancers (6.4% vs 3.7%); (ii) a larger proportion of patients had disease detected by mammography (47% vs 10%); (iii) conservative breast excision was the only definitive surgery in 39% of cases (vs approximately 30%); and (iv) the mean size of lesions is smaller (13.5 mm vs 24.4 mm). Histologically, 26% of tumours were high grade, 71% had necrosis while 32% were oestrogen receptor (ER) and progesterone receptor (PR) negative. High grade tumours were associated with the presence of necrosis (P = 0.018), ER negativity (P = 0.015) and PR negativity (P = 0.001).

CONCLUSIONS

This study reveals interesting trends of DCIS in Singapore. The sizeable proportion of hormone receptor-negative tumours may have implications for the hormonal adjuvant therapy of DCIS.

Age as a predictive factor of mammographic breast density in Jamaican women

AIM

We sought to determine the relationship between age, and other clinical characteristics such as parity, oestrogen use, dietary factors and menstrual history on breast density in Jamaican women.

METHODS AND MATERIALS

A retrospective study was done of 891 patients who attended the breast imaging unit. The clinical characteristics were extracted from the patient records. Mammograms were assessed independently by two radiologists who were blinded to the patient clinical characteristics. Breast densities were assigned using the American College of Radiology (ACR) classification.

RESULTS

The concordance between the ACR classification of breast density between the two independent radiologists was 92% with k = 0.76 (SE = 0.02, P < 0.001). Women with low breast density were heavier (81.3 +/- 15.5 kg vs 68.4 +/- 14.3 kg, P < 0.0001, mean +/- standard deviation (SD)) and more obese (body mass index (BMI), 30.3 +/- 5.8 kg m(-2) vs 26.0 +/- 5.2 kg m(-2), P < 0.0001). Mammographic breast density decreased with age. The age adjusted odds ratios (ORs) for predictors significantly related to high breast density were parity, OR = 0.79 (95%CIratio0.71, 0.88), weight, OR = 0.92 (95% CIratio0.91, 0.95), BMI, OR = 0.83 (95% CIratio0.78, 0.89), menopause, OR = 0.51 (95% CIratio0.36, 0.74) and a history of previous breast surgery, OR 1.6 (95% CIratio1.1, 2.3).

CONCLUSION

The rate decline of breast density with age in our population was influenced by parity and body composition.

Mammographic tissue, breast cancer risk, serial image analysis, and digital mammography. Part 2. Serial breast tissue change and related temporal influences

The work presented herein is the second part of a review of breast tissue-related cancer-risk research. Briefly, in part 1, the tissue-risk research is discussed. In this part, factors that influence temporal breast tissue change are reviewed. Since breast composition is correlated with some of the known risk factors, understanding these influences may provide a mechanism for measuring the dynamics of breast cancer risk. The purpose of this work is to provide support for an automated serial mammography study under way at the authors' institution, where the digital mammographic images are acquired with a full-field digital mammography imaging system. At the initiation of the serial study, it was clear that the authors did not fully understand the nature of the problem: automatically comparing similar mammographic scenes acquired at different times. The evidence indicates that there are many factors that influence breast tissue at any given time and thus have the ability to alter the associated radiographic appearance over time. In general, the topics considered herein include aging; involution; breast development; exogenous and endogenous hormonal interactions such as hormone replacement therapy, oral contraceptive use, and menstrual timing; screening sensitivity issues and interval cancers; tumor growth rates; sojourn times; and lifestyle factors such as diet and exercise. Throughout this work, commentaries and suggestive strategies for automated serial image analysis are provided.

Role of breast magnetic resonance imaging in difficult diagnostic situations

In some patients with breast disease, mammography and ultrasonography can provide only limited diagnostic information. Magnetic resonance imaging of the breast has high sensitivity and specificity and can play a significant diagnostic role in problem situations. Patients who are most likely to benefit are those with (i) axillary adenopathy of unknown primary origin, (ii) possible tumour recurrence after surgery or radiotherapy, (iii) lesions overlying implants, or (iv) those requiring staging of lobular or multifocal carcinoma.