Clinical relevance of the distribution of the lesions in 500 consecutive breast cancer cases documented in large-format histologic sections

A conditional inference tree model for predicting cancer risk of non-mass lesions detected on breast ultrasound

OBJECTIVES

To generate and validate a prediction model based on imaging features for cancer risk of non-mass lesions (NMLs) detected on breast ultrasound (US).

METHODS

In this single-center study, consecutive women with 503 NMLs detected on breast US between 2012 and 2019 were retrospectively identified. The lesions were randomly assigned to the training or testing dataset with a 70/30 split. Age, symptoms, lesion size, and US features were collected. Multivariate analyses were employed to identify risk factors associated with malignancy. The predictive model was developed by using conditional inference trees (CTREE).

RESULTS

There were 498 patients (50.9 ± 13.29 years; range, 22-88 years) with 503 NMLs with histopathologic results or > 2-year follow-up, including 224 (44.5%) benign and 279 (55.5%) malignant lesions. At multivariate analysis, age (odds ratio (OR) = 1.08, 95% confidence interval (CI), 1.06-1.11, p < 0.001), NMLs with focal mass effect (OR = 3.03, 95% CI, 1.59-5.81, p = 0.001), indistinct glandular-fat interface (GFI) (OR = 4.23, 95% CI, 2.31-7.73, p < 0.001), geographic (OR = 3.47, 95% CI, 1.20-10.8, p = 0.022) and mottled (OR = 3.67, 95% CI, 1.32-10.21, p = 0.013) patterns, and calcifications (OR = 2.15, 95% CI, 1.16-4.01, p = 0.016) were associated with malignancy. The GFI status, architectural patterns, general morphology, and calcifications were consistently identified as the strongest US predictors of malignancy using CTREE analysis. Based on these factors, individuals were stratified into six risk groups. The predictive model showed an area under the curve of 0.797 in the testing dataset.

CONCLUSION

The CTREE model efficiently aids in interpreting and managing ultrasound-detected breast NMLs, overcoming BI-RADS limitations by refining cancer risk stratification.

CLINICAL RELEVANCE STATEMENT

The CTREE model allows for the reclassification of BI-RADS categories into subgroups with varying malignancy probabilities, thus providing a valuable enhancement to the BI-RADS assessment for the diagnosis of ultrasound-detected NMLs, with the potential to minimize unnecessary biopsies.

KEY POINTS

• The indistinct glandular-fat interface (GFI) status, NML with focal mass effect, geographic or mottled patterns, and calcifications are the strongest imaging predictors of malignant non-mass lesions (NMLs) detected on breast US. • A practical system has been created to categorize NMLs found in breast US; each classification is associated with a degree of diagnostic certainty. • The model may contribute to patient stratification by determining the relative likelihood of malignancy and thus support clinical decision-making and evidence-based management.

Histological Patterns and Mammographic Presentation of Invasive Lobular Carcinoma Show No Obvious Associations

Invasive lobular carcinoma of the breast has different mammographic appearances, including spiculated or lobulated masses, architectural distortion, increased breast density, and the possibility of also being occult. Histologically, the morphology is also variable, as several patterns have been described beside the classical one, including the solid, the alveolar, the trabecular, the one with tubular elements, and others. Of 146 ILC cases, 141 were reviewed for mammographic appearance and 136 for histological patterns by two radiologist and two pathologists, respectively; 132 common cases were analyzed for possible associations between mammographic presentation and the histological patterns. Interobserver agreement on the presence or absence of a given mammographic morphology ranged from 45% (increased density) to 95% (occult lesion); the most common radiomorphology was that of a spiculated mass. Interobserver agreement on the presence or absence of a given histological pattern ranged between 79% (solid) and 99% (classical) but was worse when semi-quantification was also included. The mammography-pathology correlation was less than optimal. Multifocality was more commonly detected by histology. The identification of a mammographic mass lesion often coincided with a mass-like lesion on the histological slides and vice versa, but nearly half of the mammographically occult lesions were felt to have masses on histological slides assessed grossly. Histological patterns showed no obvious associations with one or the other mammographic appearance.

A Comparison of In Vitro Studies between Cobalt(III) and Copper(II) Complexes with Thiosemicarbazone Ligands to Treat Triple Negative Breast Cancer

Metal complexes have gained significant attention as potential anti-cancer agents. The anti-cancer activity of [Co(phen)2(MeATSC)](NO3)3•1.5H2O•C2H5OH 1 (where phen = 1,10-phenanthroline and MeATSC = 9-anthraldehyde-N(4)-methylthiosemicarbazone) and [Cu(acetylethTSC)Cl]Cl•0.25C2H5OH 2 (where acetylethTSC = (E)-N-ethyl-2-[1-(thiazol-2-yl)ethylidene]hydrazinecarbothioamide) was investigated by analyzing DNA cleavage activity. The cytotoxic effect was analyzed using CCK-8 viability assay. The activities of caspase 3/7, 9, and 1, reactive oxygen species (ROS) production, cell cycle arrest, and mitochondrial function were further analyzed to study the cell death mechanisms. Complex 2 induced a significant increase in nicked DNA. The IC50 values of complex 1 were 17.59 μM and 61.26 μM in cancer and non-cancer cells, respectively. The IC50 values of complex 2 were 5.63 and 12.19 μM for cancer and non-cancer cells, respectively. Complex 1 induced an increase in ROS levels, mitochondrial dysfunction, and activated caspases 3/7, 9, and 1, which indicated the induction of intrinsic apoptotic pathway and pyroptosis. Complex 2 induced cell cycle arrest in the S phase, ROS generation, and caspase 3/7 activation. Thus, complex 1 induced cell death in the breast cancer cell line via activation of oxidative stress which induced apoptosis and pyroptosis while complex 2 induced cell cycle arrest through the induction of DNA cleavage.

Risk factors for breast cancer mortality after ductal carcinoma in situ diagnosis differ from those for invasive recurrence

BACKGROUND

Breast cancer mortality after ductal carcinoma in situ is rare, making it difficult to predict which patients are at risk and to identify whether risk factors for this outcome are the same as those for invasive recurrence. We aimed to identify whether risk factors for invasive recurrences are similar to those for breast cancer death after a diagnosis of pure ductal carcinoma in situ.

METHODS

The Surveillance, Epidemiology, and End Results Program was queried for female patients diagnosed with pure ductal carcinoma in situ. Cumulative incidence was estimated by treatment group using competing risks. Competing risks regression was then performed for the development of in-breast invasive recurrence with competing risks of breast and non-breast cancer death. Competing risks regression was then again performed for development of breast cancer mortality with the competing risk of non-breast cancer death.

RESULTS

A total of 29,515 patients were identified. Of them, 164 patients suffered breast cancer mortality without an intervening invasive recurrence, and 44 suffered breast cancer mortality after an invasive in-breast recurrence. On competing risks analysis for invasive in-breast recurrence, significant factors included lesion size >5 cm (hazard ratio = 1.59, 95% confidence interval 1.24-2.04, P < .001), diffuse disease (hazard ratio = 0.0005, 95% confidence interval 0.0003-0.0007, P < .001), other race (hazard ratio = 1.29, 95% confidence interval 1.10-1.52, P = .002), Black race (hazard ratio = 1.21, 95% confidence interval 1.01-1.46, P = .04), age at diagnosis (hazard ratio = 0.99, confidence interval 0.98-1.00, P = .02), low-grade disease (hazard ratio = 0.79, 95% confidence interval 0.64-0.96, P = .02), lumpectomy with radiation (hazard ratio = 0.67, 95% confidence interval 0.58-0.77, P < .001), and mastectomy (hazard ratio = 0.36, 95% confidence interval 0.30-0.44, P < .001). Significant factors for breast cancer mortality included age at diagnosis (hazard ratio = 1.04, 95% confidence interval 1.03-1.05, P < .001), Black race (hazard ratio = 2.88, 95% confidence interval 2.08-3.99, P < .001), diffuse disease (hazard ratio = 6.02, 95% confidence interval 1.39-26.07, P = .02), lumpectomy with radiation (hazard ratio = 0.51, 95% confidence interval 0.36-0.72, P < .001), and mastectomy (hazard ratio = 0.60, 95% confidence interval 0.50-0.92, P = .02).

CONCLUSION

Our results suggested that risk factors for in-breast invasive recurrence after a diagnosis of pure ductal carcinoma in situ differ from risk factors for breast cancer mortality and development of metastatic recurrence. In-breast invasive recurrence is not the only consideration for breast cancer specific mortality in ductal carcinoma in situ patients.

Pathological Diagnosis, Work-Up and Reporting of Breast Cancer 1st Central-Eastern European Professional Consensus Statement on Breast Cancer

This text is based on the recommendations accepted by the 4th Hungarian Consensus Conference on Breast Cancer, modified on the basis of the international consultation and conference within the frames of the Central-Eastern European Academy of Oncology. The recommendations cover non-operative, intraoperative and postoperative diagnostics, determination of prognostic and predictive markers and the content of cytology and histology reports. Furthermore, they address some specific issues such as the current status of multigene molecular markers, the role of pathologists in clinical trials and prerequisites for their involvement, and some remarks about the future.

Lobular Breast Cancer: Histomorphology and Different Concepts of a Special Spectrum of Tumors

Simple Summary

Invasive lobular breast cancer (ILC) is a special type of breast cancer (BC) that was first described in 1941. The diagnosis of ILC is made by microscopy of tumor specimens, which reveals a distinct morphology. This review recapitulates the developments in the microscopic assessment of ILC from 1941 until today. We discuss different concepts of ILC, provide an overview on ILC variants, and highlight advances which have contributed to a better understanding of ILC as a special histologic spectrum of tumors.

Abstract

Invasive lobular breast cancer (ILC) is the most common special histological type of breast cancer (BC). This review recapitulates developments in the histomorphologic assessment of ILC from its beginnings with the seminal work of Foote and Stewart, which was published in 1941, until today. We discuss different concepts of ILC and their implications. These concepts include (i) BC arising from mammary lobules, (ii) BC growing in dissociated cells and single files, and (iii) BC defined as a morpho-molecular spectrum of tumors with distinct histological and molecular characteristics related to impaired cell adhesion. This review also provides a comprehensive overview of ILC variants, their histomorphology, and differential diagnosis. Furthermore, this review highlights recent advances which have contributed to a better understanding of the histomorphology of ILC, such as the role of the basal lamina component laminin, the molecular specificities of triple-negative ILC, and E-cadherin to P-cadherin expression switching as the molecular determinant of tubular elements in CDH1-deficient ILC. Last but not least, we provide a detailed account of the tumor microenvironment in ILC, including tumor infiltrating lymphocyte (TIL) levels, which are comparatively low in ILC compared to other BCs, but correlate with clinical outcome. The distinct histomorphology of ILC clearly reflects a special tumor biology. In the clinic, special treatment strategies have been established for triple-negative, HER2-positive, and ER-positive BC. Treatment specialization for patients diagnosed with ILC is just in its beginnings. Accordingly, ILC deserves greater attention as a special tumor entity in BC diagnostics, patient care, and cancer research.

Mass and non-mass breast MRI patterns: a radiologic approach to sick lobe theory

BACKGROUND

According to sick lobe theory, one or more lobes of the breast are more prone to the development of carcinoma. However, the implications of this theory in breast magnetic resonance imaging (MRI) are unknown.

PURPOSE

To evaluate the MRI appearance of mass type (multifocal and multicentric diseases) and non-mass type (non-mass enhancements) sick lobe patterns, together with the histopathology results.

MATERIAL AND METHODS

MRI reports of 2015 patients in two tertiary breast imaging centers between June 2012 and June 2018 were retrospectively reviewed for multifocal-multicentric diseases and segmental, linear, and regional enhancements. A total of 113 patients were included. The specimens obtained by thick needle, vacuum, excisional biopsy/lumpectomy or mastectomy after breast MRI scans were pathologically assessed. The pathologic results were categorized as invasive carcinoma, precursor, and benign proliferative lesions according to the 2012 World Health Organization Classification of Tumors.

RESULTS

The percentage of underlying benign and precursor invasive lesions was significantly different in patients with mass and non-mass MRI patterns. While the pathology results of mass type patterns were premalignant and malignant in all cases, nearly half of the underlying histologies were benign proliferative subtypes in patients with non-mass type patterns.

CONCLUSION

In this study, the mass and non-mass patterns derived from sick lobe theory were related to different risks of malignancy in the pathological examinations.

Worm-Based Microfluidic Biosensor for Real-Time Assessment of the Metastatic Status

Simple Summary

We proposed a high-throughput screening and low-cost worm-based (WB) microfluidic biosensor to monitor biochemical cues related to metastasis. Caenorhabditis elegans placed in the WB biosensor chambers and exposed to samples conditioned with cancer cell clusters reflect differences in the chemotactic preference of worms. We observed a higher distribution of worms associated with samples of higher metastatic potential (p < 0.005). A chemotaxis index (CI) was defined to standardize the quantitative assessment from the WB biosensor, where increased metastatic potential was associated with higher CI levels (6.5 ± 1.37). We found that the secreted metabolite glutamate was a chemorepellent, and lower glutamate levels were associated with samples derived from more metastatic cancer cell clusters. In conclusion, WB biosensors could evaluate patient status in real time, thereby facilitating early detection of metastases and routine management.

Abstract

Background: Metastasis is a complex process that affects patient treatment and survival. To routinely monitor cancer plasticity and guide treatment strategies, it is highly desired to provide information about metastatic status in real-time. Here, we proposed a worm-based (WB) microfluidic biosensor to rapidly monitor biochemical cues related to metastasis in a well-defined environment. Compared to conventional biomarker-based methods, the WB biosensor allowed high throughput screening under low cost, requiring only visual quantification of outputs; Methods: Caenorhabditis elegans were placed in the WB biosensor and exposed to samples conditioned with cancer cell clusters. The chemotactic preference of these worms was observed under discontinuous imaging to minimize the impact on physiological activity; Results: A chemotaxis index (CI) was defined to standardize the quantitative assessment from the WB biosensor, where moderate (3.24–6.5) and high (>6.5) CI levels reflected increased metastasis risk and presence of metastasis, respectively. We demonstrated that the secreted metabolite glutamate was a chemorepellent, and larger clusters associated with increased metastatic potential also enhanced CI levels; Conclusions: Overall, this study provided a proof of concept for the WB biosensors in assessing metastasis status, with the potential to evaluate patient-derived cancer clusters for routine management.

Synthesis, characterization, DNA binding, topoisomerase inhibition, and apoptosis induction studies of a novel cobalt(III) complex with a thiosemicarbazone ligand

In this study, 9-anthraldehyde-N(4)-methylthiosemicarbazone (MeATSC) 1 and [Co(phen)2(O2CO)]Cl·6H2O 2 (where phen = 1,10-phenanthroline) were synthesized. [Co(phen)2(O2CO)]Cl·6H2O 2 was used to produce anhydrous [Co(phen)2(H2O)2](NO3)33. Subsequently, anhydrous [Co(phen)2(H2O)2](NO3)33 was reacted with MeATSC 1 to produce [Co(phen)2(MeATSC)](NO3)3·1.5H2O·C2H5OH 4. The ligand, MeATSC 1 and all complexes were characterized by elemental analysis, FT IR, UV-visible, and multinuclear NMR (1H, 13C, and 59Co) spectroscopy, along with HRMS, and conductivity measurements, where appropriate. Interactions of MeATSC 1 and complex 4 with calf thymus DNA (ctDNA) were investigated by carrying out UV-visible spectrophotometric studies. UV-visible spectrophotometric studies revealed weak interactions between ctDNA and the analytes, MeATSC 1 and complex 4 (Kb = 8.1 × 105 and 1.6 × 104 M-1, respectively). Topoisomerase inhibition assays and cleavage studies proved that complex 4 was an efficient catalytic inhibitor of human topoisomerases I and IIα. Based upon the results obtained from the 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium (MTS) assay on 4T1-luc metastatic mammary breast cancer cells (IC50 = 34.4 ± 5.2 μM when compared to IC50 = 13.75 ± 1.08 μM for the control, cisplatin), further investigations into the molecular events initiated by exposure to complex 4 were investigated. Studies have shown that complex 4 activated both the apoptotic and autophagic signaling pathways in addition to causing dissipation of the mitochondrial membrane potential (ΔΨm). Furthermore, activation of cysteine-aspartic proteases3 (caspase 3) in a time- and concentration-dependent manner coupled with the ΔΨm, studies implicated the intrinsic apoptotic pathway as the major regulator of cell death mechanism.

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.

Imaging Biomarkers as Predictors for Breast Cancer Death

Background

To differentiate the risk of breast cancer death in a longitudinal cohort using imaging biomarkers of tumor extent and biology, specifically, the mammographic appearance, basal phenotype, histologic tumor distribution, and conventional tumor attributes.

Methods

Using a prospective cohort study design, 498 invasive breast cancer patients diagnosed between 1996 and 1998 were used as the test cohort to assess the independent effects of the imaging biomarkers and other predictors on the risk of breast cancer death. External validation was performed with a cohort of 848 patients diagnosed between 2006 and 2010.

Results

Mammographic tumor appearance was an independent predictor of risk of breast cancer death (P=0.0003) when conventional tumor attributes and treatment modalities were controlled. The casting type calcifications and architectural distortion were associated with 3.13-fold and 3.19-fold risks of breast cancer death, respectively. The basal phenotype independently conferred a 2.68-fold risk compared with nonbasal phenotype. The observed deaths did not differ significantly from expected deaths in the validation cohort. The application of imaging biomarkers together with other predictors classified twelve categories of risk for breast cancer death.

Conclusion

Combining imaging biomarkers such as the mammographic appearance of the tumor with the histopathologic distribution and basal phenotype, accurately predicted long-term risk of breast cancer death. The information may be relevant for determining the need for molecular testing, planning treatment, and determining the most appropriate clinical surveillance schedule for breast cancer patients.

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.

Equivocal (HER2 IHC 2+) breast carcinomas: gene-protein assay testing reveals association between genetic heterogeneity, individual cell amplification status and potential treatment benefits

AIMS

Genetic heterogeneity can pose a challenge to identifying eligible cases for targeted therapy in the human epidermal growth factor receptor 2 (HER2) immunohistochemistry (IHC) 2+ breast carcinoma group. In this study, we characterised this subset of tumours according to clinicopathological parameters.

METHODS AND RESULTS

We assessed 1000 tumour cells per case and recorded the number of HER2 and chromosome enumeration probe 17 (CEP17) copies using gene-protein assay slides. HER2 status was determined based on ASCO/CAP 2013 guidelines. Tumours with 5-50% of cancer cells with amplification were considered to be heterogeneous, whereas those with >50% were considered to be non-heterogeneous. In a study cohort of 110 HER2 IHC 2+ carcinomas, 93 (84.5%) were non-amplified, 12 (10.9%) were amplified and five (4.5%) were ISH-equivocal. All the HER2-amplified and two of ISH-equivocal cases (12.7%) corresponded to non-heterogeneous tumours, with highly significant differences evident in the average HER2/CEP17 ratio (P = 0.0002) and the proportion of cells with HER2 >6 copies (P < 0.0001) compared with heterogeneous lesions. NST grade 3 and HER2-amplified carcinomas average HER2/CEP17 ratio correlated with an increased number of cells with HER2/CEP17 ≥2.0 (P < 0.014). Triple-negative CEP17 polysomic carcinomas showed increased metastatic capacity (P = 0.003) compared with other tumour types.

CONCLUSION

Non-heterogeneous HER2 IHC 2+ tumours tend to be HER2-amplified. Adding the percentage of cells with HER2 >6 copies to the average HER2/CEP17 ratio may facilitate assessment of amplification status in ISH-equivocal cases. The proportion of cells with HER2/CEP17 ≥2.0 contributes information concerning the actual average HER2/CEP17 ratio, depending on tumour type.

Clonality analysis of multifocal ipsilateral breast carcinomas using X-chromosome inactivation patterns

The definition of multifocal breast cancer is ambiguous, and its incidence varies depending on the definition and detection methods. Multifocal breast cancers either have the same clonal origin or arise from completely distinct progenitor cells. The current American Joint Committee on Cancer Staging system and College of American Pathologists breast tumor guidelines state that only the largest tumor needs to be staged and studied immunohistochemically, on the assumption that they are of the same origin. However, some multifocal tumors have been proved to have arisen from different clones. In the present study, 71 cases of surgically resected multifocal breast cancers were selected. To detect and characterize the tumors of each clonal origin, a human androgen receptor gene (HUMARA) assay to compare the X-chromosome inactivation patterns of multiple tumors was conducted. Twenty-nine of 71 (40.8%) patients were revealed to be heterozygous for HUMARA. Sixty-four (90.1%) patients had the same X chromosome inactivated in different tumors. Seven (9.9%) cases had different inactivated X chromosomes between multifocal tumors, indicating that those tumors were from separate progenitor cells. Five (7.0%) cases showed identical histologic features but had different inactivated HUMARA alleles. According to these results, 2 separate tumors might be synchronous primary tumors, although their histopathologic characteristics are similar. Furthermore, multifocal tumors can be of different origins despite being closely located to each other. These findings suggest that separate grouping of multiple breast tumors based on their clonal origin is needed for future studies.

Application of a novel prognostic invasive lesion index in ductal carcinoma in situ with minimal invasion of the breast

Multiple invasive foci has been shown to increase the risk of lymph node metastasis (LNM) in early breast cancer, but its prognostic implication remains unknown. We aimed to identify the prognostic value of the number of invasive foci in ductal carcinoma in situ with minimal invasion of the breast (DCIS‐MI), and further establish a prognostic invasive lesion index (ILI). A total of 193 patients with DCIS‐MI (the invasive component was up to 10 mm in diameter) were included. Univariate and multivariate analysis (logistic regression) were used to evaluate the predictive value of the number of invasive foci in LNM. The Kaplan–Meier curve was used for survival analysis. More than five invasive foci was an independent predictor for LNM (OR, 2.67, 95% CI, 1.12–6.33, P = 0.026), and associated with significantly shorter disease‐free survival (DFS) and overall survival (OS) compared with no more than five invasive foci (mean DFS 123.8 vs. 148.0 months, P = 0.002; and mean OS 133.5 vs. 151.4 months, P = 0.025). The ILI was established by the sum scores of the number of invasive foci and the invasive component size, having an optimal cut‐off point of 5.5 scores. The high‐ILI group (ILI >5 scores) had a higher incidence of LNM (23.6% vs. 6.9%) and worse prognosis than the low‐ILI group (ILI ≤5 scores). In conclusion, more than five invasive foci was an independent predictor for LNM and an unfavorable prognostic parameter. The ILI could potentially be used to predict survival prognosis in patients with DCIS‐MI.

Primary tumor location predicts the site of local relapse after nipple-areola complex (NAC) sparing mastectomy

PURPOSE

To assess the oncological safety of nipple-areola complex (NAC) sparing mastectomy in breast cancer patients.

METHODS

From 2010 to 2015, 518 breast cancer patients were submitted to NAC sparing mastectomy. Breast MRI and intraoperative assessment of the subareolar (SD) and proximal (ND) nipple ducts were performed to predict NAC involvement. Significant associations between pre- and postoperative variables with SD/ND involvement and with the risk of local recurrence were retrospectively investigated.

RESULTS

SD/ND were involved in 26.1% of the cases. Final pathology of SD/ND was predicted by tumor-NAC distance at MRI and intraoperative pathology with 75 and 93% accuracy, respectively. NAC involvement was more frequent in case of positive ND than positive SD (68.3 vs. 38.3%; p = 0.003). Fourteen (2.7%) local relapses developed over a mean follow-up of 33 months. Ki-67 ≥25% (p = 0.002) and high tumor grade (p = 0.027) correlated with local recurrence. Most relapses developed in the subcutaneous tissue of the quadrant where the primary tumor was located (12/14; 85.7%). No local relapses occurred in patients who received post-mastectomy radiotherapy as compared to patients who did not, although they had a higher rate of positive surgical margins (40.5 vs. 16.2%; p = 0.000).

CONCLUSIONS

NAC involvement can be predicted by MRI and intraoperative pathology of ND/SD. Local recurrences after NAC sparing mastectomy almost invariably develop in the same quadrant where the primary tumor was located and in highly proliferative tumors.

Invasive lobular carcinoma with extracellular mucin production-a novel pattern of lobular carcinomas of the breast. Clinico-pathological description of eight cases

Invasive lobular carcinoma of the breast is known to produce intracellular mucin and has been recognized in single-case reports to show extracellular mucin production, as well. This latter morphology is not only rare but must also be under- or misdiagnosed. The aim was to better characterize this entity. Cases of lobular cancers demonstrating extracellular mucin formation were identified in a multi-institutional effort and their clinical and morphologic features were assessed. Immunohistochemistry was used to characterize the E-cadherin-membrane complex, neuroendocrine differentiation, and to some extent, mucin formation. All but one of the eight cases occurred in postmenopausal patients. Extracellular mucin production was present in 5 to 50% of the tumour samples and rarely also appeared in nodal and distant metastases. The tumours were completely E-cadherin negative and showed cytoplasmic p120 positivity. The majority (n = 6/8) was also completely negative for β-catenin, but two tumours displayed focal β-catenin positivity in the mucinous area. MUC1 and MUC2 expression was observed in all and 7/8 tumours, respectively; neuroendocrine differentiation was present in only one. Invasive lobular carcinoma with extracellular mucin formation is a rare morphologic variant of lobular carcinoma prone to be misdiagnosed and warranting further studies.

Feasibility of reusing time-matched controls in an overlapping cohort

The methods developed for secondary analysis of nested case-control data have been illustrated only in simplified settings in a common cohort and have not found their way into biostatistical practice. This paper demonstrates the feasibility of reusing prior nested case-control data in a realistic setting where a new outcome is available in an overlapping cohort where no new controls were gathered and where all data have been anonymised. Using basic information about the background cohort and sampling criteria, the new cases and prior data are "aligned" to identify the common underlying study base. With this study base, a Kaplan-Meier table of the prior outcome extracts the risk sets required to calculate the weights to assign to the controls to remove the sampling bias. A weighted Cox regression, implemented in standard statistical software, provides unbiased hazard ratios. Using the method to compare cases of contralateral breast cancer to available controls from a prior study of metastases, we identified a multifocal tumor as a risk factor that has not been reported previously. We examine the sensitivity of the method to an imperfect weighting scheme and discuss its merits and pitfalls to provide guidance for its use in medical research studies.

Predicting discordant HER2 results in ipsilateral synchronous invasive breast carcinomas: experience from a single institution

With the emergence of multiple lines of highly effective Human Epidermal Growth Factor Receptor 2 (HER2) directed therapy, accurate identification of HER2 positive tumour has become a critical aspect in the histopathological analysis of breast cancers. Multifocal invasive breast carcinomas are relatively common, and given the aggressive inherent biology of HER2 positive disease, identification of even small tumours with HER2 positive status may be of importance for treatment planning. There are currently no clear guidelines as to whether all of these foci should be tested for HER2 status. We reviewed the results of 172 patients in whom HER2 in situ hybridisation (ISH) testing was performed on at least two ipsilateral synchronous invasive carcinomas. Discordant results in different invasive foci were relatively uncommon and occurred in only eight (5%) of the 172 patients. This showed a statistically significant correlation with similarly discordant oestrogen receptor (ER) results. In addition HER2 discordance was more likely amongst different tumour foci if these arose in distinct and separate areas of DCIS. An algorithm based on a combination of College of American Pathologists (CAP) recommendation for HER2 testing, differing ER status and background DCIS profile may be useful in detecting these discordant cases.

Diffuse invasive breast carcinoma of no special type

Diffuse invasive breast carcinomas are rare tumors associated with unfavorable prognostic parameters. This growth pattern is often related to invasive lobular cancer (ILC). Diffuse ductal breast carcinoma of no special type (NST) is largely under-recognized in the literature. We identified 70 diffuse invasive breast carcinomas in a consecutive series of 1249 invasive tumors. Based on morphology and E-cadherin expression, 15/70 were NST and 55/70 were ILC. Subgroups differed in mammographic appearance, as more NST tumors than ILCs formed stellate masses (53 vs. 18 %, p = 0.000436) while ILCs displayed more architectural distortion. NST tumors were significantly more often radiologically extensive than ILCs (80 vs. 38 %, p = 0.0042987). Subgroups did not differ significantly in disease extent on histology, lymph node status, progesterone receptor status, and molecular phenotype, with a difference of borderline statistical significance in estrogen receptor status (87 vs. 100 %, p = 0.0434783). Significantly more NST tumors were HER2 positive (27 vs. 4 %, p = 0.0050463) and showed high Ki67 proliferation index (60 vs. 25 %, p = 0.0121808). The most striking differences occurred in the histology grade of the in situ (high grade in 53 vs. 4 %) and invasive (high grade in 27 vs. 2 %) tumor components and in the distribution of the in situ component (diffuse in 73 vs. 11 %). We conclude that diffuse invasive breast carcinomas of NST comprise a small subgroup of breast carcinomas. Most of these cancers are non-high grade and of luminal phenotype, but extensive and lymph node positive with worse prognostic parameters than diffuse ILC.

[Sentinel lymph node-multicentric and multifocal tumors: a valid technique?]

Sentinel node biopsy without complementary axillary lymph node dissection was validated for T1-2 N0 unifocal breast cancer without previous treatment since several years. In the situation of multifocal multicentric breast tumors, this procedure was considered as a contraindication. The aim of this work was to analyse literature results to determine if sentinel lymph node biopsy can be considered as a valid option without complementary axillary lymph node dissection for negative sentinel lymph node.

Early (<10 mm) HER2-Positive Invasive Breast Carcinomas are Associated with Extensive Diffuse High-Grade DCIS: Implications for Preoperative Mapping, Extent of Surgical Intervention, and Disease-Free Survival

BACKGROUND

The few publications on <10-mm invasive breast carcinomas have reported worse outcomes for women with human epidermal growth factor receptor 2 (HER2)-positive cancer compared with HER2-negative cases and indicated that the high risk of recurrence in HER2-positive cases is related to the high grade, hormone receptor negativity, and high proliferation index of the invasive tumor component.

METHODS

We studied the subgross morphology of such tumors in a consecutive series of 203 cases documented in large-format histology slides and worked up with detailed radiological-pathological correlation.

RESULTS

The invasive component was associated with a diffuse in situ component in 78 % of the HER2-positive and 26 % of HER2-negative tumors <10 mm in size (odds ratio [OR], 11.3936; P < .0001). The in situ component was of high grade in 75 % of HER2-positive and 9 % of HER2-negative cases (OR, 29.6000; P < .0001). Significant associations were also found between the HER2 positivity of the invasive component and diffuse combined lesion distribution (P > .0001), invasive tumor grade 3 (P = .0004), presence of vascular invasion (P = .0026), extensive disease (P = .0170), "not special" (ductal) histological tumor type (P = .0302), estrogen receptor negativity (OR, 7.8846; P < .0001), and high Ki67 proliferation index (OR, 5.0000; P = .0007). The HER2-positive tumors tended to be multifocal (OR, 2.000) and lymph node-positive (OR, 3.0147), but the tendency was not statistically significant.

CONCLUSIONS

The vast majority of <10-mm HER2-positive breast carcinomas exhibited a high-grade, diffuse, and extensive in situ component, which may explain the high risk of recurrence among these tumors.

Obstetrics and gynecology physicians: a critical part of the health care team for women with newly diagnosed breast cancer

Most obstetrics and gynecology (OB/GYN) physicians assist their patients at the time of a new breast cancer diagnosis. OB/GYN physicians can assure women that the tests being performed to map the individual features of the breast cancer follow a predictable and organized process. In many cases, it is appropriate to confidently reassure the patient of a good outcome based on the diagnostic mammography features. Regular attendance at interdisciplinary breast cancer conferences will help OB/GYN physicians develop the required knowledge to counsel women with newly diagnosed breast cancer.

The classification of invasive carcinoma of the breast

The classification of invasive breast carcinoma assists diagnosis, allows for comparison of different patient groups in clinical trials and facilitates epidemiological analysis. For the individual patient, accurate tumor classification informs clinical decision-making with emphasis on assessment of prognosis and treatment formulation. Tumor grade is an independent prognostic indicator and is calculated by assessing specific tumor characteristics microscopically. The Tumor Node Metastasis staging system, produced by the American Joint Committee on Cancer Union for International Cancer Control, combines information about the primary tumor size, the status of the regional lymph nodes and the presence or absence of distant metastases at diagnosis to classify disease. In recent years, the use of gene expression profiling technology has led to the development of the molecular classification of breast cancer and has highlighted the importance of hormone receptor and HER2 oncogenic pathways, with particular reference to targeted chemotherapy. Tumor typing involves the identification of 'no special type' carcinoma with variable clinical, histological and molecular characteristics and 'special type' carcinomas that are usually associated with a particular set of prognostic and predictive indices. Some special type carcinomas have unique biological features that influence diagnostic investigation and clinical management.

A Proposal to Unify the Classification of Breast and Prostate Cancers Based on the Anatomic Site of Cancer Origin and on Long-term Patient Outcome

The similarity between the structure and function of the breast and prostate has been known for a long time, but there are serious discrepancies in the terminology describing breast and prostate cancers. The use of the large, thick-section (3D) histology technique for both organs exposes the irrationality of the breast cancer terminology. Pathologists with expertise in diagnosing prostate cancer take the anatomic site of cancer origin into account when using the terms AAP (acinar adenocarcinoma of the prostate) and DAP (ductal adenocarcinoma of the prostate) to distinguish between the prostate cancers originating primarily from the fluid-producing acinar portion of the organ (AAP) and the tumors originating either purely from the larger ducts (DAP) or from both the acini and the main ducts combined (DAP and AAP). Long-term patient outcome is closely correlated with the terminology, because patients with DAP have a significantly poorer prognosis than patients with AAP. The current breast cancer terminology could be improved by modeling it after the method of classifying prostate cancer to reflect the anatomic site of breast cancer origin and the patient outcome. The long-term survival curves of our consecutive breast cancer cases collected since 1977 clearly show that the non-palpable, screen-detected breast cancers originating from the milk-producing acini have excellent prognosis, irrespective of their histologic malignancy grade or biomarkers. Correspondingly, the breast cancer subtypes of truly ductal origin have a significantly poorer outcome, despite recent improvements in diagnosis and therapy. The mammographic appearance of breast cancers reflects the underlying tissue structure. Addition of these "mammographic tumor features" to the currently used histologic phenotypes makes it possible to distinguish the breast cancer cases of ductal origin with a poor outcome, termed DAB (ductal adenocarcinoma of the breast), from the more easily managed breast cancers of acinar origin, termed AAB (acinar adenocarcinoma of the breast), which have a significantly better outcome. This simple and easily communicable terminology could lead to better communication between the diagnostic and therapeutic team members and result in more rational treatment planning for the benefit of their patients.

Genetic clonal mapping of in situ and invasive ductal carcinoma indicates the field cancerization phenomenon in the breast

Nearly 80% of well-differentiated in situ duct carcinomas (g1 DCIS) have been shown to be multicentric (multilobar) lesions, while most in situ poorly differentiated duct carcinomas (g3 DCIS) were unifocal (unilobar) lesions. Here we present a clonality study of 15 cases of DCIS, all showing multiple foci. Twelve of these cases were associated with an invasive duct carcinoma. Fifteen cases of female breast cancer patients all showing multiple DCIS foci (5 g1 DCIS, 5 g2 DCIS, 5 g3 DCIS) were randomly selected and histologically studied using large histological sections. Care was taken to laser-microdissect DCIS foci that were most distantly located from one another in the same large section, and pertinent cells were genetically studied. Invasive duct carcinoma and ipsilateral lymph node metastases and/or contralateral lesions, whenever present, were additionally microdissected. DNA of neoplastic cells was purified, and the mtDNA D-loop region was sequenced. Genetic distance of different foci from the same case was visualized by phylogenetic analyses using the neighbor-joining method. Patients ranged in age from 36 to 87 years (mean 65.1). All 9 cases of widely spread DCIS were not clonal. Four of 6 cases that showed multiple adjacent foci were clonally related on mtDNA analysis. In the present series, 11/15 DCIS appeared as multiple synchronous primary breast tumors, genetically not related to one another. The present data enhance the view that breast can also show the field cancerization phenomenon, paralleling what has already been proposed in other organs.

Multifocal breast cancer documented in large-format histology sections: long-term follow-up results by molecular phenotypes

BACKGROUND

The prognostic significance of molecular phenotype in breast cancer is well established in the literature. Recent studies have demonstrated that subgross lesion distribution (unifocal, multifocal, and diffuse) and disease extent also carry prognostic significance in this disease. However, the correlation of molecular phenotypes with subgross parameters has not yet been investigated in detail.

METHODS

In total, 444 consecutive invasive breast cancers that were documented in large-format histology slides and worked up with detailed radiologic-pathologic correlation were sampled into tissue microarray blocks and stained immunohistochemically to delineate the molecular subtypes.

RESULTS

Diffuse or multifocal distribution of the invasive component of breast carcinomas in this series was associated with a 4.14-fold respectively 2.75-fold risk of cancer-related death compared with unifocal tumors irrespective of molecular phenotype. Patients who had human epidermal growth factor receptor 2 (HER2)-positive cancers; estrogen receptor-negative, progesterone receptor-negative, and HER2-negative (triple-negative) cancers; or basal-like cancers had a 2.18-fold, 2.33-fold, and 4.07-fold risk of dying of disease, respectively, compared with patients who had luminal A carcinomas. Unifocal luminal A, HER2-positive, and basal-like cancers were associated with significantly better long-term survival outcomes than their multifocal or diffuse counterparts; luminal B and triple-negative tumors also had the same tendency. In multivariate analysis, patient age, tumor size category, lymph node status, lesion distribution, and molecular phenotypes remained significant.

CONCLUSIONS

Multifocality and diffuse distribution of the invasive component were associated with significantly poorer survival in women with breast carcinomas compared with unifocal disease in patients with luminal A, HER2 type, and basal-like cancers. Molecular classification of breast cancer is a powerful tool but gains in power when combined with conventional and subgross morphologic parameters.

Imaging-assisted large-format breast pathology: program rationale and development in a nonprofit health system in the United States

Modern breast imaging, including magnetic resonance imaging, provides an increasingly clear depiction of breast cancer extent, often with suboptimal pathologic confirmation. Pathologic findings guide management decisions, and small increments in reported tumor characteristics may rationalize significant changes in therapy and staging. Pathologic techniques to grossly examine resected breast tissue have changed little during this era of improved breast imaging and still rely primarily on the techniques of gross inspection and specimen palpation. Only limited imaging information is typically conveyed to pathologists, typically in the form of wire-localization images from breast-conserving procedures. Conventional techniques of specimen dissection and section submission destroy the three-dimensional integrity of the breast anatomy and tumor distribution. These traditional methods of breast specimen examination impose unnecessary limitations on correlation with imaging studies, measurement of cancer extent, multifocality, and margin distance. Improvements in pathologic diagnosis, reporting, and correlation of breast cancer characteristics can be achieved by integrating breast imagers into the specimen examination process and the use of large-format sections which preserve local anatomy. This paper describes the successful creation of a large-format pathology program to routinely serve all patients in a busy interdisciplinary breast center associated with a community-based nonprofit health system in the United States.

The value of large sections in surgical pathology

Large format sections (LS) first have been introduced in breast pathology more than a century ago. Since then, they constituted for longtime a research tool to better understand breast microanatomy and the relationship between radiological images and pathological features. Similarly LS have been used to study neoplastic, inflammatory, and degenerative diseases affecting various organs, as brain, lung, gastrointentinal tract, bone, urinary tract, prostate, and placenta. Currently LS are mostly applied to diagnostic routine to better stage tumours such as prostate and breast carcinomas or to correlate radiologic imaging to gross specimens. The purpose of the present paper is to review the historical background and the basis of the applications of LS in surgical pathology, with special emphasis on breast tumours.

Loco-regional therapy and breast cancer survival: searching for a link

OBJECTIVE

The relationship between loco-regional (LR) control and breast cancer survival was investigated with the intention of generating a new biological hypothesis to explain some of the paradoxes unaccounted for by the prevailing conceptual model of the disease.

BACKGROUND

The progressive reduction of surgical aggressiveness has been accompanied by an increase of breast cancer survival mainly attributed to the adoption of adjuvant systemic therapies. More recently, it has been recognized that effective LR control may prolong the survival of breast cancer patients, although the reasons for this improvement have not yet been clearly defined.

METHODS

The literature (PubMed) was reviewed for publications related to breast cancer LR treatments using the following key words: breast cancer surgery, breast cancer radiotherapy, breast cancer loco-regional control, breast cancer survival.

RESULTS

Although breast cancer is frequently a multifocal disease, neither mastectomy nor whole breast irradiation are always mandatory to obtain adequate local control. Conversely, selected groups of patients carry a particularly elevated risk of LR relapse and require more effective treatments to be developed. True LR recurrences are associated with a decreased overall survival and this may be related to a complex relationship between circulating tumor cells, re-seeding of the primary tumor site and several metabolic effects linked to the act of surgery.

CONCLUSION

The prevention of LR recurrences is a major goal of breast cancer care, which requires a better understanding of the complex relationships between the primary tumor and its metastatic process.

The role of large-format histopathology in assessing subgross morphological prognostic parameters: a single institution report of 1000 consecutive breast cancer cases

Breast cancer subgross morphological parameters (disease extent, lesion distribution, and tumor size) provide significant prognostic information and guide therapeutic decisions. Modern multimodality radiological imaging can determine these parameters with increasing accuracy in most patients. Large-format histopathology preserves the spatial relationship of the tumor components and their relationship to the resection margins and has clear advantages over traditional routine pathology techniques. We report a series of 1000 consecutive breast cancer cases worked up with large-format histology with detailed radiological-pathological correlation. We confirmed that breast carcinomas often exhibit complex subgross morphology in both early and advanced stages. Half of the cases were extensive tumors and occupied a tissue space ≥40 mm in its largest dimension. Because both in situ and invasive tumor components may exhibit unifocal, multifocal, and diffuse lesion distribution, 17 different breast cancer growth patterns can be observed. Combining in situ and invasive tumor components, most cases fall into three aggregate growth patterns: unifocal (36%), multifocal (35%), and diffuse (28%). Large-format histology categories of tumor size and disease extent were concordant with radiological measurements in approximately 80% of the cases. Noncalcified, low-grade in situ foci, and invasive tumor foci <5 mm were the most frequent causes of discrepant findings.

Comparison of the subgross distribution of the lesions in invasive ductal and lobular carcinomas of the breast: a large-format histology study

To compare the lesion distribution and the extent of the disease in ductal and lobular carcinomas of the breast, we studied 586 ductal and 133 lobular consecutive cancers. All cases were documented on large-format histology slides. The invasive component of ductal carcinomas was unifocal in 63.3% (371/586), multifocal in 35.5% (208/586), and diffuse in 1.2% (7/586) of the cases. The corresponding figures in the lobular group were 27.8% (37/133), 45.9% (61/586), and 26.3% (35/133), respectively. When the distribution of the in situ and invasive component in the same tumors was combined to give an aggregate pattern, the ductal carcinomas were unifocal in 41.6% (244/586), multifocal in 31.6% (185/586), and diffuse in 26.8% (157/586) of the cases. The corresponding figures in the lobular category were 15.0% (20/133), 54.2% (72/133), and 30.8% (41/133), respectively. Ductal cancers were extensive in 45.7% (268/586), lobular in 65.4% (87/133) of the cases. All these differences were statistically highly significant (P < 0.0001). While the histological tumor type itself (ductal versus lobular) did not influence the lymph node status, multifocal and diffuse distribution of the lesions were associated with significantly increased risk of lymph node metastases in both ductal and lobular cancers.

Morphological heterogeneity of the simultaneous ipsilateral invasive tumor foci in breast carcinoma: a retrospective study of 418 cases of carcinomas

The aim of this paper was to assess whether the morphological appearance (i.e. histological tumor type and histological grade) of simultaneous invasive breast carcinoma foci is heterogeneous, since it is known that adjuvant therapy is established according to these parameters. Patients with simultaneous breast tumors in which only the features of the largest neoplastic focus are reported could thus be undertreated. A retrospective study of 418 cases of breast carcinomas was conducted over a 3-year period. The histological tumor types and histological grades of multifocal/multicentric carcinomas in each tumor focus were compared, and mismatches among foci were recorded. Ninety-one of the 418 cases reviewed had multiple carcinomas (21.77%). A comparison between multiple synchronous tumor foci revealed that their histological type was different in 12.08% of the cases. Mismatches among foci were also observed in 9.89% of the cases when evaluating the histological grade, and 5 out of 9 additional tumor foci with a different grade from the largest (index) tumor (55.55%) displayed a higher grade compared to the index tumor. Since the histological tumor type and histological grade of the individual foci may vary considerably within the same tumor and the additional foci may be of higher grade than the index tumor, we believe that reporting morphologic parameters with more unfavorable characteristics in addition to the parameters of the index tumor is imperative.

Axillary lymph node status in unifocal, multifocal, and diffuse breast carcinomas: differences are related to macrometastatic disease

BACKGROUND

Multifocality in breast carcinoma is associated with an increased propensity to metastasis. However, it is not clear whether this propensity manifests in the form of macrometastases or as presumably less-significant low-volume metastatic disease.

METHODS

A total of 948 cases of invasive breast carcinoma documented in large-format histology sections and assessed with detailed radiologic-pathologic correlation were categorized as unifocal, multifocal, or diffuse on the basis of the subgross distribution of the invasive component. Rates of macrometastases (>2 mm), micrometastases (0.2-2 mm), and isolated tumor cells (<0.2 mm) in these categories were compared. The influence of tumor size and histology grade on lymph node positivity rates was also tested.

RESULTS

Macrometastases were present in 20.4% (112 of 550) of unifocal, 48.3% (172 of 356) of multifocal, and 61.9% (26 of 42) of diffuse cases (P < 0.0001). Among the macrometastatic cases, more than three nodes were involved in 18.9% (21 of 112) of unifocal, 35.5% (61 of 172) of multifocal, and 50.0% (13 of 26) of diffuse cases. The rates of micrometastases (5.1, 5.1, and 2.4% unifocal, multifocal, and diffuse, respectively) and isolated tumor cells (4.5, 3.7, and 2.4% unifocal, multifocal, and diffuse, respectively) were low and similar in all examined categories. The relative risk (RR) of having macrometastatic disease was approximately doubled (RR 2.3726, P < 0.0001) in multifocal and tripled (RR 3.0562, P < 0.0001) in diffuse compared to unifocal cases. The findings were similar for all size categories, tumor grade categories, and sentinel lymph nodes, as well as all examined lymph nodes.

CONCLUSIONS

The significantly increased lymph node positivity rates in multifocal and diffuse invasive breast carcinomas results from large-volume macrometastatic disease.

Disease Extent ≥4 cm Is a Prognostic Marker of Local Recurrence in T1-2 Breast Cancer

Despite improvements of the therapy for breast cancer, a proportion of the patients still get local recurrence. The status of the surgical margins is the most often used parameter for decision regarding additional treatment. However, a negative margin is not a guarantee that there is not residual cancer left in the breast; additional parameters are needed to better predict the risk of local recurrence. The disease extent was evaluated in the surgical specimen from 313 women after breast-conserving therapy using large-section histology and was correlated to the incidence of local recurrence. A disease extent ≥4 cm was shown to be an independent marker for local recurrence; the cumulative 10-year local relapse rate for the group with a disease extent ≥4 cm was 20.5%, and for the rest 6.7%. We conclude that disease extent ≥4 cm seems to be an important factor when evaluating the risk for local recurrence.

The hormone receptor, human epidermal growth factor receptor 2, and molecular subtype status of individual tumor foci in multifocal/multicentric invasive ductal carcinoma of breast

Multifocal/multicentric breast cancers are common. However, investigations of biomarkers such as estrogen receptor, progesterone receptor, and human epidermal growth factor receptor 2 in individual tumor foci of such cancers are rare. This study was designed to evaluate the status of the hormone receptors, human epidermal growth factor receptor 2, and its molecular subtypes in individual foci of multifocal/multicentric invasive ductal carcinoma of the breast and to identify the factors associated with the different phenotypes of individual foci. We performed immunohistochemical analyses of the estrogen receptor, progesterone receptor, cytokeratin 5/6, epidermal growth factor receptor, and p53 and fluorescence in situ hybridization of human epidermal growth factor receptor 2 in individual foci of 65 cases of multifocal/multicentric invasive ductal carcinoma and the associated ductal carcinoma in situ components using tissue microarrays. The estrogen receptor status differed in 2 (3%) of the 65 invasive ductal carcinomas, progesterone receptor status in 7 (11%), human epidermal growth factor receptor 2 status in 4 (6%), and molecular subtypes in 5 (8%). The presence of different molecular subtypes in the invasive tumor foci was associated with differences in histologic features (P = .005), high histologic and nuclear grade (P = .012 and P = .021, respectively), p53 overexpression (P = .006), and mixed molecular subtypes in the ductal carcinoma in situ components (P = .011). Multifocal/multicentric invasive ductal carcinomas usually have a single phenotype in terms of hormone receptors, human epidermal growth factor receptor 2, and molecular subtypes; and thus, immunohistochemical analyses of the index tumor may be sufficient in routine practice. However, if multifocal/multicentric invasive ductal carcinomas are of high grade, of different histologic features, or of heterogeneous ductal carcinoma in situ component, biomarkers of the various foci need to be evaluated separately.