Unifocal Invasive Lobular Carcinoma: Tumor Size Concordance Between Preoperative Ultrasound Imaging and Postoperative Pathology

ACR Appropriateness Criteria® Imaging of Invasive Breast Cancer

As the proportion of women diagnosed with invasive breast cancer increases, the role of imaging for staging and surveillance purposes should be determined based on evidence-based guidelines. It is important to understand the indications for extent of disease evaluation and staging, as unnecessary imaging can delay care and even result in adverse outcomes. In asymptomatic patients that received treatment for curative intent, there is no role for imaging to screen for distant recurrence. Routine surveillance with an annual 2-D mammogram and/or tomosynthesis is recommended to detect an in-breast recurrence or a new primary breast cancer in women with a history of breast cancer, and MRI is increasingly used as an additional screening tool in this population, especially in women with dense breasts. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision process support the systematic analysis of the medical literature from peer reviewed journals. Established methodology principles such as Grading of Recommendations Assessment, Development, and Evaluation or GRADE are adapted to evaluate the evidence. The RAND/UCLA Appropriateness Method User Manual provides the methodology to determine the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where peer reviewed literature is lacking or equivocal, experts may be the primary evidentiary source available to formulate a recommendation.

Invasive Lobular Carcinoma: A Review of Imaging Modalities with Special Focus on Pathology Concordance

Invasive lobular cancer (ILC) is the second most common type of breast cancer. It is characterized by a unique growth pattern making it difficult to detect on conventional breast imaging. ILC can be multicentric, multifocal, and bilateral, with a high likelihood of incomplete excision after breast-conserving surgery. We reviewed the conventional as well as newly emerging imaging modalities for detecting and determining the extent of ILC- and compared the main advantages of MRI vs. contrast-enhanced mammogram (CEM). Our review of the literature finds that MRI and CEM clearly surpass conventional breast imaging in terms of sensitivity, specificity, ipsilateral and contralateral cancer detection, concordance, and estimation of tumor size for ILC. Both MRI and CEM have each been shown to enhance surgical outcomes in patients with newly diagnosed ILC that had one of these imaging modalities added to their preoperative workup.

Image processing improvements afford second-generation handheld optoacoustic imaging of breast cancer patients

BACKGROUND

Since the initial breast transillumination almost a century ago, breast cancer imaging using light has been considered in different implementations aiming to improve diagnostics, minimize the number of available biopsies, or monitor treatment. However, due to strong photon scattering, conventional optical imaging yields low resolution images, challenging quantification and interpretation. Optoacoustic imaging addresses the scattering limitation and yields high-resolution visualization of optical contrast, offering great potential value for breast cancer imaging. Nevertheless, the image quality of experimental systems remains limited due to a number of factors, including signal attenuation with depth and partial view angle and motion effects, particularly in multi-wavelength measurements.

METHODS

We developed data analytics methods to improve the accuracy of handheld optoacoustic breast cancer imaging, yielding second-generation optoacoustic imaging performance operating in tandem with ultrasonography.

RESULTS

We produced the most advanced images yet with handheld optoacoustic examinations of the human breast and breast cancer, in terms of resolution and contrast. Using these advances, we examined optoacoustic markers of malignancy, including vasculature abnormalities, hypoxia, and inflammation, on images obtained from breast cancer patients.

CONCLUSIONS

We achieved a new level of quality for optoacoustic images from a handheld examination of the human breast, advancing the diagnostic and theranostic potential of the hybrid optoacoustic-ultrasound (OPUS) examination over routine ultrasonography.

Ultrasound Imaging Morphology is Associated with Biological Behavior in Invasive Ductal Carcinoma of the Breast

Objectives:

Ultrasound (US) is commonly used for diagnostic evaluation of breast lesions. The objective of this study was to investigate the association between US imaging morphology from routine radiologists’ interpretation and biological behavior such as receptor status and tumor grade determined from histopathology in invasive ductal carcinoma (IDC).

Material and Methods:

This retrospective study included 453 patients with pathology-verified diagnosis of IDC who had undergone US imaging and had surgery over a 5-year period. US and surgical pathology reports were reviewed and compiled. Correlation analyses and age-adjusted multivariable models were used to determine the association between US imaging morphology and receptor status, tumor grade, and germ line mutation of the breast cancer genes (BRCA1 and BRCA2). The odds ratio (OR), area under receiver operating characteristic curve (AUC), and 95% confidence intervals (CI) were obtained.

Results:

The likelihood for high-grade cancer increased with size (OR: 1.066; CI: 1.042–1.091) and hypo-echogenicity (OR: 2.044; CI: 1.337–3.126), and decreased with angular or spiculated margins (OR: 0.605; CI: 0.393–0.931) and posterior acoustic shadowing (OR: 0.352; CI: 0.238–0.523). These features achieved an AUC of 0.799 (CI: 0.752–0.845) for predicting high-grade tumors. The likelihood for Estrogen Receptor-positive tumors increased with posterior acoustic shadowing (OR: 3.818; CI: 2.206–6.607), angulated or spiculated margins (OR: 2.596; CI: 1.159–5.815) and decreased with US measured tumor size (OR: 0.959; CI: 0.933–0.986) and hypoechoic features (OR: 0.399; CI: 0.198– 0.801), and achieved an AUC of 0.787 (CI: 0.733–0.841). The likelihood for Progesterone Receptor-positive tumors increased with posterior acoustic shadowing (OR: 2.732; CI: 1.744–4.28) and angulated or spiculated margins (OR: 2.618; CI: 1.412–4.852), and decreased with US measured tumor size (OR: 0.961; CI: 0.937–0.985) and hypoechoic features (OR: 0.571; CI: 0.335–0.975), and achieved an AUC of 0.739 (CI: 0.689–0.790). The likelihood for Human epidermal growth factor receptor 2-positive tumors increased with heterogeneous echo texture (OR: 2.141; CI: 1.17– 3.919) and decreased with angulated or spiculated margins (OR: 0.408; CI: 0.177–0.944), and was marginally associated with hypoechoic features (OR: 2.101; CI: 0.98–4.505) and circumscribed margins (OR: 4.225; CI: 0.919–19.4). The model with the aforementioned four US morphological features and achieved an AUC of 0.686 (CI: 0.614–0.758). The likelihood for triple-negative breast cancers increased with hypo-echogenicity (OR: 2.671; CI: 1.249–5.712) and decreased with posterior acoustic shadowing (OR: 0.287; CI: 0.161–0.513), and achieved an AUC of 0.739 (CI: 0.671– 0.806). No statistical association was observed between US imaging morphology and BRCA mutation.

Conclusion:

In this study of over 450 IDCs, significant statistical associations between tumor grade and receptor status with US imaging morphology were observed and could serve as a surrogate imaging marker for the biological behavior of the tumor.

Accuracy of Preoperative Breast MRI Versus Conventional Imaging in Measuring Pathologic Extent of Invasive Lobular Carcinoma

OBJECTIVE

To determine whether invasive lobular carcinoma (ILC) extent is more accurately depicted with preoperative MRI (pMRI) than conventional imaging (mammography and/or ultrasound).

METHODS

After IRB approval, we retrospectively identified women with pMRIs (February 2005 to January 2014) to evaluate pure ILC excluding those with ipsilateral pMRI BI-RADS 4 or 5 findings or who had neoadjuvant chemotherapy. Agreement between imaging and pathology sizes was summarized using Bland-Altman plots, absolute and percent differences, and the intraclass correlation coefficient (ICC). Rates of underestimation and overestimation were evaluated and their associations with clinical features were explored.

RESULTS

Among the 56 women included, pMRI demonstrated better agreement with pathology than conventional imaging by mean absolute difference (1.6 mm versus -7.8 mm, P < 0.001), percent difference (10.3% versus -16.4%, P < 0.001), and ICC (0.88 versus 0.61, P = 0.019). Conventional imaging more frequently underestimated ILC span than pMRI using a 5 mm difference threshold (24/56 (43%) versus 10/56 (18%), P < 0.001), a 25% threshold (19/53 (36%) versus 10/53 (19%), P = 0.035), and T category change (17/56 (30%) versus 7/56 (13%), P = 0.006). Imaging-pathology size concordance was greater for MRI-described solitary masses than other lesions for both MRI and conventional imaging (P < 0.05). Variability of conventional imaging was lower for patients ≥ the median age of 62 years than for younger patients (SD: 12 mm versus 22 mm, P = 0.012).

CONCLUSION

MRI depicts pure ILC more accurately than conventional imaging and may have particular value for younger women.

Tumor size estimation of the breast cancer molecular subtypes using imaging techniques

Background and aim

In medical practice the classification of breast cancer is most commonly based on the molecular subtypes, in order to predict the disease prognosis, avoid over-treatment, and provide individualized cancer management. Tumor size is a major determiner of treatment planning, acting on the decision-making process, whether to perform breast surgery or administer neoadjuvant chemotherapy. Imaging methods play a key role in determining the tumor size in breast cancers at the time of the diagnosis.

We aimed to compare the radiologically determined tumor sizes with the corresponding pathologically determined tumor sizes of breast cancer at the time of the diagnosis, in correlation with the molecular subtypes.

Methods

Ninety-one patients with primary invasive breast cancer were evaluated. The main molecular subtypes were luminal A, luminal B, HER-2 positive, and triple-negative. The Bland-Altman plot was used for presenting the limits of agreement between the radiologically and the pathologically determined tumor sizes by the molecular subtypes.

Results

A significantly proportional underestimation was found for the luminal A subtype, especially for large tumors. The p-values for the magnetic resonance imaging, mammography, and ultrasonography were 0.020, 0.030, and <0.001, respectively. No statistically significant differences were observed among the radiologic modalities in determining the tumor size in the remaining molecular subtypes (p>0.05).

Conclusion

The radiologically determined tumor size was significantly smaller than the pathologically determined tumor size in the luminal A subtype of breast cancers when measured with all three imaging modalities. The differences were more prominent with ultrasonography and mammography. The underestimation rate increases as the tumor gets larger.