Diffuse invasive breast carcinoma of no special type

Imaging biomarkers are underutilised but highly predictive prognostic factors for the more fatal breast cancer subtypes

PURPOSE

The development and refinement of breast imaging modalities offer a wealth of diagnostic information such as imaging biomarkers, which are primarily the mammographic appearance of the various breast cancer subtypes. These are readily available preoperatively at the time of diagnosis and can enhance the prognostic value of currently used molecular biomarkers. In this study, we investigated the relative utility of the molecular and imaging biomarkers, both jointly and independently, when predicting long-term patient outcome according to the site of tumour origin.

METHODS

We evaluated the association of imaging biomarkers and conventional molecular biomarkers, (ER, PR, HER-2, Ki67), separately and combined, with long-term patient outcome in all breast cancer cases having complete data on both imaging and molecular biomarkers (n = 2236) diagnosed in our Institute during the period 2008-2019. Large format histopathology technique was used to document intra- and intertumoural heterogeneity and select the appropriate foci for evaluating molecular biomarkers.

RESULTS

The breast cancer imaging biomarkers were strongly predictive of long-term patient outcome. The molecular biomarkers were predictive of outcome only for unifocal acinar adenocarcinoma of the breast (AAB), but less reliable in the multifocal AAB cases due to variability of molecular biomarkers in the individual tumour foci. In breast cancer of mesenchymal origin (BCMO), conventionally termed classic invasive lobular carcinoma, and in cancers originating from the major lactiferous ducts (ductal adenocarcinoma of the breast, DAB), the molecular biomarkers misleadingly indicated favourable prognosis, whereas the imaging biomarkers in BCMO and DAB reliably indicated the high risk of breast cancer death. Among the 2236 breast cancer cases, BCMO and DAB comprised 21% of the breast cancer cases, but accounted for 45% of the breast cancer deaths.

CONCLUSIONS

Integration of imaging biomarkers into the diagnostic workup of breast cancer yields a more precise, comprehensive and prognostically accurate diagnostic report. This is particularly necessary in multifocal AAB cases having intertumoural heterogeneity, in diffuse carcinomas (DAB and BCMO), and in cases with combined DAB and AAB. In such cases, the imaging biomarkers should be prioritised over molecular biomarkers in planning treatment because the latter fail to predict the severity of the disease. In combination with the use of the large section histopathology technique, imaging biomarkers help alleviate some of the current problems in breast cancer management, such as over- and under-assessment of disease extent, which carry the risk of overtreatment and undertreatment.

Delayed presentation of inflammatory breast carcinoma during the COVID-19 pandemic

Background

Breast cancer may present with distinct cutaneous manifestations that may be paraneoplastic or secondary to direct skin infiltration, distant skin metastases, or dermal lymphatic tumor embolization (inflammatory breast carcinoma).

Case report

A 51-year-old Asian woman visited the emergency care department during the outbreak of COVID-19 in Northern Italy. About 6 months before, she had noted the onset of right breast swelling accompanied by skin redness and itching. She never consulted a physician, and, over time, the local skin condition progressed to a large scaly plaque covering the entire breast surface including the nipple. At presentation, abduction of the right upper limb was impaired due to severe shoulder pain. CT scan showed the presence of bilateral breast masses with necrotic and colliquative features, and multiple skeletal, nodal, pulmonary, and brain images suggestive of metastases. An ultrasound-guided core biopsy of the contralateral breast showed grade 2 non-special type infiltrating carcinoma. The patient was referred to the breast oncology unit and is currently being treated with aromatase inhibitors and chemotherapy.

Conclusion

The COVID-19 pandemic has disrupted the entire spectrum of oncological care including breast cancer. Hopefully, telemedicine will contribute to increase patients' confidence and will provide earlier diagnosis and treatment while minimizing the risk of contagion.

The clinical value of detecting microcalcifications on a mammogram

Many breast lesions are associated with microcalcifications that are detectable by mammography. In most cases, radiologists are able to distinguish calcifications usually associated with benign diseases from those associated with malignancy. In addition to their value in the early detection of breast carcinoma and accurate radiological diagnosis, the presence of microcalcifications often affects the extent of surgical intervention. Certain types of microcalcifications are associated with negative genetic and molecular characteristics of the tumor and unfavorable prognosis. Microcalcifications localized in the larger ducts (duct-centric, casting-type microcalcifications) represent an independent negative prognostic marker compared to lesions containing other types of microcalcifications and to non-calcified lesions. In this review, we summarize the theoretical and methodological background for understanding the clinical impact and discuss the diagnostic and prognostic value of microcalcifications detected in the breast by mammography.

The subgross morphology of breast carcinomas: a single-institution series of 2033 consecutive cases documented in large-format histology slides

A large-format histology technique represents the most convenient method for documenting and assessing the subgross morphological prognostic parameters of breast cancer (i.e., the distribution of the tumor's invasive and in situ components, disease extent, and tumor size), especially when used in conjunction with systematic radiological-pathological correlation. Here we report a consecutive series of 2033 breast carcinomas operated on in Dalarna, Sweden, with a particular focus on these subgross parameters. We separately analyzed the distributions of the in situ and invasive components of the tumors and then combined these into an aggregate pattern when both components were present. We found that 40% of breast carcinomas had a simple (unifocal) subgross morphology, while 60% had a complex morphology presenting with multifocal or diffuse components. Extensive tumors (occupying a total volume of breast tissue with the greatest dimension being ≥ 40 mm) were more common in complex cases, occurring in 66% of multifocal cases and 88% of diffuse cases, compared with only 5% of unifocal cases. Compared with luminal A-like tumors, HER2-expressing tumors exhibited a significantly larger extent. Triple-negative and basal-like carcinomas tended to have a larger tumor size (based on the largest dimension of the largest invasive focus). In this report, we discuss the prognostic impact of these parameters and the necessity of their correct assessment in the diagnostic routine.

Three-dimensional tumor visualization of invasive breast carcinomas using whole-mount serial section histopathology: implications for tumor size assessment

PURPOSE

Linear tumor size (T-size) estimated with conventional histology informs breast cancer management. Previously we demonstrated significant differences in margin and focality estimates using conventional histology versus digital whole-mount serial sections (WMSS). Using WMSS we can measure T-size or volume. Here, we compare WMSS T-size with volume, and with T-size measured conventionally. We also compare the ellipsoid model for calculating tumor volume to direct, WMSS measurement.

METHODS

Two pathologists contoured regions of invasive carcinoma and measured T-size from both WMSS and (simulated) conventional sections in 55 consecutive lumpectomy specimens. Volume was measured directly from the contours. Measurements were compared using the paired t-test or Spearman's rank-order correlation. A five-point 'border index' was devised and assigned to each case to parametrize tumor shape considering 'compactness' or cellularity. Tumor volumes calculated assuming ellipsoid geometry were compared with direct, WMSS measurements.

RESULTS

WMSS reported significantly larger T-size than conventional histology in the majority of cases [61.8%, 34/55; means = (2.34 cm; 1.99 cm), p < 0.001], with a 16.4% (9/55) rate of 'upstaging'. The majority of discordances were due to undersampling. T-size and volume were strongly correlated (r = 0.838, p < 0.001). Significantly lower volume was obtained with WMSS versus ellipsoid modeling [means = (1.18 cm³; 1.45 cm³), p < 0.001].

CONCLUSIONS

Significantly larger T-size is measured with WMSS than conventionally, due primarily to undersampling in the latter. Volume and linear size are highly correlated. Diffuse tumors interspersed with normal or non-invasive elements may be sampled less extensively than more localized masses. The ellipsoid model overestimates tumor volume.

The new TNM-based staging of breast cancer

This review describes the changes that have been implemented in the Tumor-Node-Metastasis (TNM)-based staging of breast cancers by the new, 8th editions of the relevant Union for International Cancer Control (UICC) and American Joint Committee on Cancer (AJCC) publications. After giving a background for TNM being the common language of cancer staging and related activities like cancer treatment and registration, it summarizes not only the changes but reviews some highlights important for pathologists, and lists and comments on the differences between the publications and diagnostic practices based on them. A section is dedicated to the prognostic stages of breast carcinomas introduced in the AJCC Cancer Staging Manual, but not mentioned in the UICC TNM classification of malignant tumors. A few issues that are not appropriately covered by TNM according to the authors' view (e.g., multifocal tumors, larger lymph node metastases identified by molecular methods, the heterogeneous prognosis of M1-defined stage IV disease) close the review with the final thoughts raising the vision of a potential loss of the common staging language.