Interobserver Variation in the Assessment of Immunohistochemistry Expression Levels in HER2-Negative Breast Cancer: Can We Improve the Identification of Low Levels of HER2 Expression by Adjusting the Criteria? An International Interobserver Study.

The classification of human epidermal growth factor receptor 2 (HER2) expression is optimized to detect HER2-amplified breast cancer (BC). However, novel HER2-targeting agents are also effective for BCs with low levels of HER2. This raises the question whether the current guidelines for HER2 testing are sufficiently reproducible to identify HER2-low BC. The aim of this multicenter international study was to assess the interobserver agreement of specific HER2 immunohistochemistry scores in cases with negative HER2 results (0, 1+, or 2+/in situ hybridization negative) according to the current American Society of Clinical Oncology/College of American Pathologists (ASCO/CAP) guidelines. Furthermore, we evaluated whether the agreement improved by redefining immunohistochemistry (IHC) scoring criteria or by adding fluorescent in situ hybridization (FISH). We conducted a 2-round study of 105 nonamplified BCs. During the first assessment, 16 pathologists used the latest version of the ASCO/CAP guidelines. After a consensus meeting, the same pathologists scored the same digital slides using modified IHC scoring criteria based on the 2007 ASCO/CAP guidelines, and an extra "ultralow" category was added. Overall, the interobserver agreement was limited (4.7% of cases with 100% agreement) in the first round, but this was improved by clustering IHC categories. In the second round, the highest reproducibility was observed when comparing IHC 0 with the ultralow/1+/2+ grouped cluster (74.3% of cases with 100% agreement). The FISH results were not statistically different between HER2-0 and HER2-low cases, regardless of the IHC criteria used. In conclusion, our study suggests that the modified 2007 ASCO/CAP criteria were more reproducible in distinguishing HER2-0 from HER2-low cases than the 2018 ASCO/CAP criteria. However, the reproducibility was still moderate, which was not improved by adding FISH. This could lead to a suboptimal selection of patients eligible for novel HER2-targeting agents. If the threshold between HER2 IHC 0 and 1+ is to be clinically actionable, there is a need for clearer, more reproducible IHC definitions, training, and/or development of more accurate methods to detect this subtle difference in protein expression levels.

Stromal Changes are Associated with High P4HA2 Expression in Ductal Carcinoma in Situ of the Breast.

Ductal carcinoma in situ (DCIS) of the breast is able to induce stromal changes, which likely reflect the crosstalk between DCIS and its microenvironment. These changes harbor prognostic information, although the interobserver variability of scoring stromal changes is moderate. A more robust evaluation of the DCIS-associated stroma is therefore needed. The aim of this study was to characterize P4HA2 expression, which is involved in collagen biosynthesis, in DCIS and to assess whether P4HA2 expression enables a more robust evaluation of the DCIS-associated stroma compared to histomorphology. This study included 410 patients with DCIS. Stromal changes were scored on hematoxylin/eosin-stained whole slides. P4HA2 expression in DCIS-associated stroma was assessed by whole slide immunohistochemistry. One hundred DCIS lesions were evaluated by seven pathologists to study the interobserver variability in the assessment of stromal changes and stromal P4HA2 expression. High P4HA2 expression in stromal fibroblasts was present in 14.1% of the patients. High P4HA2 expression was associated with the presence of periductal stromal changes (P = 0.004). The interobserver variability was similar for the assessment of stromal changes and the percentage of P4HA2-positive fibroblasts. Although we demonstrated a significant association between high P4HA2 expression in fibroblasts and the morphological presence of stromal changes, it seems unlikely that P4HA2 expression can be used as an alternative for the histopathological evaluation of the DCIS-associated stroma.

Interobserver variability in the assessment of stromal tumor-infiltrating lymphocytes (sTILs) in triple-negative invasive breast carcinoma influences the association with pathological complete response: the IVITA study.

High stromal tumor-infiltrating lymphocytes (sTILs) in triple-negative breast cancer (TNBC) are associated with pathological complete response (pCR) after neoadjuvant chemotherapy (NAC). Histopathological assessment of sTILs in TNBC biopsies is characterized by substantial interobserver variability, but it is unknown whether this affects its association with pCR. Here, we aimed to investigate the degree of interobserver variability in an international study, and its impact on the relationship between sTILs and pCR. Forty pathologists assessed sTILs as a percentage in digitalized biopsy slides, originating from 41 TNBC patients who were treated with NAC followed by surgery. Pathological response was quantified by the MD Anderson Residual Cancer Burden (RCB) score. Intraclass correlation coefficients (ICCs) were calculated per pathologist duo and Bland-Altman plots were constructed. The relation between sTILs and pCR or RCB class was investigated. The ICCs ranged from -0.376 to 0.947 (mean: 0.659), indicating substantial interobserver variability. Nevertheless, high sTILs scores were significantly associated with pCR for 36 participants (90%), and with RCB class for eight participants (20%). Post hoc sTILs cutoffs at 20% and 40% resulted in variable associations with pCR. The sTILs in TNBC with RCB-II and RCB-III were intermediate to those of RCB-0 and RCB-I, with lowest sTILs observed in RCB-I. However, the limited number of RCB-I cases precludes any definite conclusions due to lack of power, and this observation therefore requires further investigation. In conclusion, sTILs are a robust marker for pCR at the group level. However, if sTILs are to be used to guide the NAC scheme for individual patients, the observed interobserver variability might substantially affect the chance of obtaining a pCR. Future studies should determine the 'ideal' sTILs threshold, and attempt to fine-tune the patient selection for sTILs-based de-escalation of NAC regimens. At present, there is insufficient evidence for robust and reproducible sTILs-guided therapeutic decisions.

Interobserver variability in upfront dichotomous histopathological assessment of ductal carcinoma in situ of the breast: the DCISion study.

Histopathological assessment of ductal carcinoma in situ, a nonobligate precursor of invasive breast cancer, is characterized by considerable interobserver variability. Previously, post hoc dichotomization of multicategorical variables was used to determine the "ideal" cutoffs for dichotomous assessment. The present international multicenter study evaluated interobserver variability among 39 pathologists who performed upfront dichotomous evaluation of 149 consecutive ductal carcinomas in situ. All pathologists independently assessed nuclear atypia, necrosis, solid ductal carcinoma in situ architecture, calcifications, stromal architecture, and lobular cancerization in one digital slide per lesion. Stromal inflammation was assessed semiquantitatively. Tumor-infiltrating lymphocytes were quantified as percentages and dichotomously assessed with a cutoff at 50%. Krippendorff's alpha (KA), Cohen's kappa and intraclass correlation coefficient were calculated for the appropriate variables. Lobular cancerization (KA = 0.396), nuclear atypia (KA = 0.422), and stromal architecture (KA = 0.450) showed the highest interobserver variability. Stromal inflammation (KA = 0.564), dichotomously assessed tumor-infiltrating lymphocytes (KA = 0.520), and comedonecrosis (KA = 0.539) showed slightly lower interobserver disagreement. Solid ductal carcinoma in situ architecture (KA = 0.602) and calcifications (KA = 0.676) presented with the lowest interobserver variability. Semiquantitative assessment of stromal inflammation resulted in a slightly higher interobserver concordance than upfront dichotomous tumor-infiltrating lymphocytes assessment (KA = 0.564 versus KA = 0.520). High stromal inflammation corresponded best with dichotomously assessed tumor-infiltrating lymphocytes when the cutoff was set at 10% (kappa = 0.881). Nevertheless, a post hoc tumor-infiltrating lymphocytes cutoff set at 20% resulted in the highest interobserver agreement (KA = 0.669). Despite upfront dichotomous evaluation, the interobserver variability remains considerable and is at most acceptable, although it varies among the different histopathological features. Future studies should investigate its impact on ductal carcinoma in situ prognostication. Forthcoming machine learning algorithms may be useful to tackle this substantial diagnostic challenge.

Dichotomous histopathological assessment of ductal carcinoma in situ of the breast results in substantial interobserver concordance.

AIMS: Robust prognostic markers for ductal carcinoma in situ (DCIS) of the breast require high reproducibility and thus low interobserver variability. The aim of this study was to compare interobserver variability among 13 pathologists, in order to enable the identification of robust histopathological characteristics. METHODS AND RESULTS: One representative haematoxylin and eosin-stained slide was selected for 153 DCIS cases. All pathologists independently assessed nuclear grade, intraductal calcifications, necrosis, solid growth, stromal changes, stromal inflammation, and apocrine differentiation. All characteristics were assessed categorically. Krippendorff's alpha was calculated to assess overall interobserver concordance. Cohen's kappa was calculated for every observer duo to further explore interobserver variability. The highest concordance was observed for necrosis, calcifications, and stromal inflammation. Assessment of solid growth, nuclear grade and stromal changes resulted in lower concordance. Poor concordance was observed for apocrine differentiation. Kappa values for each observer duo identified the 'ideal' cut-off for dichotomisation of multicategory variables. For instance, concordance was higher for 'non-high versus high' nuclear grade than for 'low versus non-low' nuclear grade. 'Absent/mild' versus 'moderate/extensive' stromal inflammation resulted in substantially higher concordance than other dichotomous cut-offs. CONCLUSIONS: Dichotomous assessment of the histopathological features of DCIS resulted in moderate to substantial agreement among pathologists. Future studies on prognostic markers in DCIS should take into account this degree of interobserver variability to define cut-offs for categorically assessed histopathological features, as reproducibility is paramount for robust prognostic markers in daily clinical practice. A new prognostic index for DCIS might be considered, based on two-tier grading of histopathological features. Future research should explore the prognostic potential of such two-tier assessment.

Bone marrow-derived mesenchymal stem cells promote colorectal cancer progression through paracrine neuregulin 1/HER3 signalling.

OBJECTIVE: Bone marrow-derived mesenchymal stem cells (BM-MSC) migrate to primary tumours and drive tumour progression. This study aimed to identify the molecular mechanisms associated with these heterotypic cellular interactions and analyse their relevance in colorectal cancer (CRC). DESIGN: Paracrine interactions of BM-MSC with CRC cells were studied using collagen invasion assays, cell counts, flow cytometric cell-cycle analysis and tumour xenograft models. The role of neuregulin 1 (NRG1) and the human epidermal growth factor receptor (HER) family pathways were investigated using tyrosine kinase assays, mass spectrometry, pharmacological inhibition, antibody-mediated neutralisation and RNA interference. Transmembrane neuregulin 1 (tNRG1), HER2 and HER3 expression was analysed in primary CRC (n=54), adjacent normal colorectal tissues (n=4), liver metastases (n=3) and adjacent normal liver tissues (n=3) by immunohistochemistry. RESULTS: BM-MSC stimulate invasion, survival and tumorigenesis of CRC through the release of soluble NRG1, activating the HER2/HER3-dependent PI3K/AKT signalling cascade in CRC cells. Similarly, tumour-associated mesenchymal cells (T-MC) in CRC demonstrate high tNRG1 expression, which is significantly associated with advanced Union for International Cancer Control stage (p=0.005) and invasion depth (p=0.04) and decreased 5-year progression-free survival (p=0.01). HER2 and HER3 show membrane localisation in cancer cells of CRC tissue. CONCLUSION: Paracrine NRG1/HER3 signals initiated by BM-MSC and T-MC promote CRC cell progression, and high tNRG1 expression is associated with poor prognosis in CRC.

A nanobody targeting the F-actin capping protein CapG restrains breast cancer metastasis.

INTRODUCTION: Aberrant turnover of the actin cytoskeleton is intimately associated with cancer cell migration and invasion. Frequently however, evidence is circumstantial, and a reliable assessment of the therapeutic significance of a gene product is offset by lack of inhibitors that target biologic properties of a protein, as most conventional drugs do, instead of the corresponding gene. Proteomic studies have demonstrated overexpression of CapG, a constituent of the actin cytoskeleton, in breast cancer. Indirect evidence suggests that CapG is involved in tumor cell dissemination and metastasis. In this study, we used llama-derived CapG single-domain antibodies or nanobodies in a breast cancer metastasis model to address whether inhibition of CapG activity holds therapeutic merit. METHODS: We raised single-domain antibodies (nanobodies) against human CapG and used these as intrabodies (immunomodulation) after lentiviral transduction of breast cancer cells. Functional characterization of nanobodies was performed to identify which biochemical properties of CapG are perturbed. Orthotopic and tail vein in vivo models of metastasis in nude mice were used to assess cancer cell spreading. RESULTS: With G-actin and F-actin binding assays, we identified a CapG nanobody that binds with nanomolar affinity to the first CapG domain. Consequently, CapG interaction with actin monomers or actin filaments is blocked. Intracellular delocalization experiments demonstrated that the nanobody interacts with CapG in the cytoplasmic environment. Expression of the nanobody in breast cancer cells restrained cell migration and Matrigel invasion. Notably, the nanobody prevented formation of lung metastatic lesions in orthotopic xenograft and tail-vein models of metastasis in immunodeficient mice. We showed that CapG nanobodies can be delivered into cancer cells by using bacteria harboring a type III protein secretion system (T3SS). CONCLUSIONS: CapG inhibition strongly reduces breast cancer metastasis. A nanobody-based approach offers a fast track for gauging the therapeutic merit of drug targets. Mapping of the nanobody-CapG interface may provide a platform for rational design of pharmacologic compounds.

Vacuolar H+ ATPase expression and activity is required for Rab27B-dependent invasive growth and metastasis of breast cancer.

The secretory Rab27B small GTPase promotes invasive growth and metastasis in estrogen receptor (ER) α-positive breast cancer cells by orchestrating the peripheral targeting of vesicles secreting proinvasive growth regulators. Increased Rab27B expression is associated with poor prognosis in breast cancer patients. The molecular mechanisms of peripheral Rab27B secretory vesicle distribution are poorly understood. Mass spectrometry analysis on green fluorescent protein (GFP)-Rab27B vesicles prepared from GFP-Rab27B transfected MCF-7 human breast cancer cells detected eight subunits of the vacuolar H(+)-ATPase (V-ATPase) and the presence of V0a1 and V0d1 subunits was confirmed by Western blot analysis. Reversible inhibition of V-ATPase activity by bafilomycin A1 or transient silencing of V0a1 or V0d1 subunits demonstrated that V-ATPase controls peripheral localization and size of Rab27B vesicles. V-ATPase expression and activity further controls Rab27B-induced collagen type I invasion, cell-cycle progression and invasive growth in the chorioallantoic membrane assay. In agreement, Rab27B-dependent extracellular heat shock protein90α release and matrix metalloprotease-2 activation is markedly reduced by bafilomycin A1 and transient silencing of V0a1 and V0d1 subunits. Poor prognosis ERα-positive primary breast tumors expressing high levels of Rab27B also expressed multiple V-ATPase subunits and showed a strong cytoplasmic and peripheral V-ATPase V1E expression. In conclusion, inhibiting V-ATPase activity by interfering agents and drugs might be an effective strategy for blocking Rab27B-dependent proinvasive secretory vesicle trafficking in ERα-positive breast cancer patients.

Stromal architecture and periductal decorin are potential prognostic markers for ipsilateral locoregional recurrence in ductal carcinoma in situ of the breast.

AIMS: The incidence of ductal carcinoma in situ (DCIS) has increased since the introduction of screening mammography. Recurrence prediction is still not accurate, and could be improved by identifying additional prognostic markers. Periductal stroma actively participates in early breast cancer progression. Therefore, the aim of this study was to explore the prognostic potential of stromal characteristics in DCIS. METHODS AND RESULTS: Histopathological features and hormone receptor/HER2 status were analysed in a first cohort of 65 cases of DCIS with a median follow-up of 112 months. Cox regression analysis revealed that myxoid stromal architecture was significantly associated with increased ipsilateral locoregional recurrence (P = 0.015). Next, we performed immunohistochemical screening of nine stromal proteins in a second cohort of 82 DCIS cases, and correlated their expression with stromal architecture. Because reduced stromal decorin expression correlated most strongly with myxoid stroma (P < 0.001), it was selected for further analysis in the first cohort. Patients with reduced periductal decorin expression had a higher risk of recurrence (P = 0.008). Furthermore, HER2 overexpression was significantly associated with invasive but not with in situ recurrence (P = 0.007). CONCLUSIONS: Periductal myxoid stroma and reduced periductal decorin expression seem to be prognostic for overall ipsilateral locoregional recurrence in DCIS, whereas HER2 expression might be a more specific biomarker for invasive recurrence.

Completion surgery after intensity-modulated arc therapy in the treatment of locally advanced cervical cancer: feasibility, surgical outcome, and oncologic results.

INTRODUCTION: Since the addition of chemotherapy to radiotherapy, the survival rates of locally advanced cervical cancer (LACC) have improved but are still disappointing. Therefore, the idea of surgery after chemoradiation in case of LACC or bulky disease was adopted. One of the concerns regarding surgery following chemoradiotherapy is surgery-related morbidity. AIM: The objectives of this study were to investigate the feasibility of surgery after advanced radiotherapy techniques such as intensity-modulated arc therapy (IMAT) and to describe the morbidity. METHODS: This was a prospective study of primary inoperable LACC patients primary treated with IMAT, in most cases combined with weekly cisplatin. Then the resectability was reevaluated. If resectable patients were treated with Wertheim type 2 surgery ± pelvic lymphadenectomy (on positron emission tomography-computed tomography indication). If tumor is not resectable, patients were treated with brachytherapy. RESULTS: Since 2006, 41 consecutive patients were included. After neoadjuvant IMAT, 34 were considered resectable and underwent surgery, whereas 7 proceeded with brachytherapy. The operative mortality rate was nil. There were no major perioperative complications. No ureter, bladder, or bowel injuries occurred. No postoperative urinary/digestive fistulae or stenoses were noted. Eleven patients had postoperatively urinary retention problems. At the time of discharge, 5 patients still needed self-catheterization. All problems resolved within 3 months. In 4 cases, we saw significant lymphoceles. In all patients intended to treat, overall survival and disease-free survival at 3 years were 63% and 74%. In the Wertheim group, overall survival and disease-free survival at 3 years were 81% and 91%. CONCLUSIONS: Completing surgery after chemoradiation therapy (with IMAT) for LACC or bulky disease is feasible, and complication rates are comparable with those of primary surgery for cervical cancer.

Value of magnetic resonance and ¹8FDG PET-CT in predicting tumor response and resectability of primary locally advanced cervical cancer after treatment with intensity-modulated arc therapy: a prospective pathology-matched study.

OBJECTIVE: To report on the value of magnetic resonance imaging (MRI) and 2-deoxy-2-[18] fluoro-D-glucose positron emission tomography computed tomography (¹8FDG PET-CT) in predicting resectability and pathological response of primary locally advanced cervical cancer after neoadjuvant intensity-modulated arc therapy (IMAT) with or without cisplatin (C). METHODS AND MATERIALS: Twenty-seven patients with International Federation of Gynecology and Obstetrics stages IB2 to IVA cervical cancer were treated with IMAT-C followed by extrafascial hysterectomy (EH). All patients received MRI and ¹8FDG PET-CT after IMAT-C. The end points of this study were to: 1. Assess the ability of MRI to predict negative surgical margins (R0). 2. Assess the sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of MRI in predicting the following situation at the EH specimen: "no residual disease or minimal microscopically visible residual tumor." 3. Assess the sensitivity, specificity, PPV, and NPV value of ¹8FDG PET-CT in predicting "no residual viable tumor cells" at the EH specimen. RESULTS: An R0 resection was obtained in all patients. None of the EH specimens contained macroscopically visible tumor. In 13 patients, no viable tumor cells were found and only 14 had residual microscopic disease. Twenty-four of 27 MRIs were able to correctly predict R0 resection. A negative MRI was 100% predictive for the end point "R0 resection." The specificity and NPV of MRI (end point 2) were 74% and 100%, respectively. No sensitivity or PPV could be calculated. The sensitivity, specificity, PPV, and NPV of ¹8FDG PET-CT were 29%, 62%, 44%, and 44%, respectively (end point 3). CONCLUSIONS: A negative MRI after IMAT-C predicts 100% correctly for R0 resection. The role of FDG PET-CT in predicting viable tumor cells at EH specimen is at least debatable.

Fine tuning of the Van Nuys prognostic index (VNPI) 2003 by integrating the genomic grade index (GGI): new tools for ductal carcinoma in situ (DCIS).

Ductal carcinoma in situ (DCIS) is considered a heterogeneous premalignant condition of the breast with a certain probability for progressing to malignancy. There is no standard of care. The updated Van Nuys Prognostic Index (VNPI) 2003 is a clinical tool in treatment decision making. This study assessed the prognostic value of the VNPI after integration of proliferative biomarkers (GGI and Ki-67). DCIS samples were divided into three VNPI subgroups (low risk [score 4-6], intermediate risk [score 7-9], high risk [score 10-12]) based on nuclear grade ± necrosis, tumor size, margin width, and age. Nuclear grade was substituted by the genomic grade index (GGI) to generate the VNPI-GGI and combined with the Ki-67 to generate the VNPI-Ki67. Disease-free survival was calculated by Kaplan-Meier survival plots with log-rank significance. Multiple regression analysis was carried out using Cox proportional hazard regression analysis. A total of 88 cases (median age 54 years) with representative tissue were identified out of 168 DCIS patients. Median follow-up was more than 5 years. Ten patients developed an ipsilateral recurrence of whom nine were invasive: six patients were classified in the VNPI subgroup 2 and three patients in the VNPI subgroup 3. One non-invasive recurrence (DCIS) was classified in the VNPI subgroup III. A statistical association was observed between a high VNPI score and a higher risk of recurrence (HR = 7.72 [95% CI 1.01-58.91], p = 0.049). Ki-67 did not improve the prognostic value of VNPI (HR = 6.5, [95% CI 0.80-53.33], p = 0.08). In contrast, the VNPI-GGI could identify more accurately high-risk DCIS patients with early relapses within 5 years (HR = 18.14 [95% CI 1.75-188], p = 0.015). GGI incorporated into the VNPI improved its prognostic value for DCIS, especially for identifying early relapses. This method should be validated and incorporated in future prospective clinical DCIS trials.

Comparison of the tumor immune microenvironment of primary hormone receptor-negative HER2-positive and triple negative breast cancer.

The vast majority of studies investigating immune checkpoint inhibition (ICI) in patients with breast cancer have focused on triple-negative breast cancer (TNBC). In this study, we compared the tumor immune microenvironment (TIME) between TNBC and hormone receptor-negative HER2-positive breast cancer based on a selection of immune markers at the protein level in an institutional retrospective series. Additionally, we performed a similar comparison using publicly available transcriptomics data. Altogether, the results show a comparable TIME in both groups, with possible implications for the use of ICI in patients with hormone receptor-negative HER2-positive breast tumors.

A single-cell map of intratumoral changes during anti-PD1 treatment of patients with breast cancer.

Immune-checkpoint blockade (ICB) combined with neoadjuvant chemotherapy improves pathological complete response in breast cancer. To understand why only a subset of tumors respond to ICB, patients with hormone receptor-positive or triple-negative breast cancer were treated with anti-PD1 before surgery. Paired pre- versus on-treatment biopsies from treatment-naive patients receiving anti-PD1 (n = 29) or patients receiving neoadjuvant chemotherapy before anti-PD1 (n = 11) were subjected to single-cell transcriptome, T cell receptor and proteome profiling. One-third of tumors contained PD1-expressing T cells, which clonally expanded upon anti-PD1 treatment, irrespective of tumor subtype. Expansion mainly involved CD8+ T cells with pronounced expression of cytotoxic-activity (PRF1, GZMB), immune-cell homing (CXCL13) and exhaustion markers (HAVCR2, LAG3), and CD4+ T cells characterized by expression of T-helper-1 (IFNG) and follicular-helper (BCL6, CXCR5) markers. In pre-treatment biopsies, the relative frequency of immunoregulatory dendritic cells (PD-L1+), specific macrophage phenotypes (CCR2+ or MMP9+) and cancer cells exhibiting major histocompatibility complex class I/II expression correlated positively with T cell expansion. Conversely, undifferentiated pre-effector/memory T cells (TCF7+, GZMK+) or inhibitory macrophages (CX3CR1+, C3+) were inversely correlated with T cell expansion. Collectively, our data identify various immunophenotypes and associated gene sets that are positively or negatively correlated with T cell expansion following anti-PD1 treatment. We shed light on the heterogeneity in treatment response to anti-PD1 in breast cancer.

Comparison of miRNA profiles of microdissected Hodgkin/Reed-Sternberg cells and Hodgkin cell lines versus CD77+ B-cells reveals a distinct subset of differentially expressed miRNAs.

Classical Hodgkin lymphoma (cHL) is characterized by the presence of malignant Hodgkin and Reed Sternberg (HRS) cells. The scarcity of tumour cells in lymphoma biopsies has hampered genetic analyses of HRS cells, including microRNA (miRNA) expression profiling. We determined the expression of 360 miRNAs in microdissected HRS cells from nine cHL patients. These miRNA profiles were compared to those from four cHL cell lines and CD77+ B-cells, yielding a distinct cHL signature of 12 over- and three underexpressed miRNAs. Our data suggest that miRNAs are implicated in the pathogenesis of Hodgkin lymphoma and prompt further investigations concerning their role in cHL.

Prognostic significance of oncogenic markers in ductal carcinoma in situ of the breast: a clinicopathologic study.

Ductal carcinoma in situ (DCIS) is a heterogeneous malignant condition of the breast with an excellent prognosis. Until recently mastectomy was the standard treatment. As the results of the National Surgical Adjuvant Breast and Bowel Project-17 trial and the introduction of the Van Nuys Prognostic Index (VNPI) less radical therapies are used. Objectives are to identify clinicopathologic and biologic factors that may predict outcome. Cases of DCIS diagnosed in two Belgian University Centers were included. Paraffin-embedded material and Hematoxylin and Eosin stained slides of DCIS cases were reviewed and tumor size, margin width, nuclear grade, and comedo necrosis were assessed. Molecular markers (estrogen receptor, progesterone receptor, HER1-4, Ki67, and c-myc) were assayed immunohistochemically. Applied treatment strategies were correlated with the prospective use of the VNPI score. Kaplan-Meier survival plots were generated with log-rank significance and multiple regression analysis was carried out using Cox proportional hazards regression analysis; 159 patients were included with a median age of 54 years (range 29-78); 141 had DCIS and 18 DCIS with microinvasion. The median time of follow-up was 54 months (range 5-253). Twenty-three patients developed a recurrence (14.5%). The median time to recurrence was 46 months (range 5-253). Before the introduction of the VNPI, 37.5% of the DCIS patients showed a recurrence while thereafter 6.7% recurred (p < 0.005). Two recurrences occurred in the VNPI group I (7.1%); seven in the VNPI group II (8.5%) (median time to recurrence 66.3 months) and 14 in the VNPI group III (28.5%) (median time to recurrence 40.2 months) (disease-free survival [DFS]: p < 0.05). A Cox proportional hazards regression analysis indicated that tumor size, margin width, pathologic class, and age were independent predictors of recurrence, but none of the studied molecular markers showed this. Overexpression of HER4 in the presence of HER3 was found to be associated with a better DFS (p < 0.05). This study confirms the value of the VNPI score and questions the benefit of an aggressive approach in the low-risk DCIS lesions. Independent predictors for recurrence included size, margin width, pathologic class, and age, but none of the molecular markers were part of it. Overexpression of HER4 in the presence of HER3 was associated with a better DFS.

Stromal characteristics are adequate prognosticators for recurrence risk in ductal carcinoma in situ of the breast.

BACKGROUND: Ductal carcinoma in situ (DCIS) of the breast constitutes a heterogeneous group of non-obligate precursors for invasive breast cancer. To date, adequate risk stratification is lacking, which is presumed to result in overtreatment. We previously identified myxoid stromal architecture as a potential prognosticator for loco-regional recurrence. In the present study, we investigated the prognostic potential of stromal characteristics. METHODS: Hematoxylin and eosin stained slides from 211 DCIS patients were reviewed. The following histological features were dichotomously assessed: nuclear grade, DCIS architecture, presence of necrosis, intraductal calcifications, stromal inflammation and myxoid stromal architecture. Loco-regional recurrences constituted the primary endpoint. RESULTS: Cox regression analysis showed that high nuclear grade, myxoid stromal architecture and moderate to extensive stromal inflammation were significantly associated with decreased recurrence-free survival, independent of radiotherapy. Based on these features, a combined risk score (CRS) was calculated, ranging from zero to three. A high CRS of three was associated with significantly shorter recurrence-free survival. Nineteen patients had a CRS of three, of which three relapsed (15.7%), whereas only one out of 113 patients with a CRS of zero relapsed (0.9%). CONCLUSIONS: We were able to validate our previously reported findings regarding the prognostic potential of myxoid periductal stroma in an independent DCIS patient cohort. A CRS based on nuclear grade, myxoid stromal architecture and stromal inflammation might facilitate discrimination of low risk from high risk patients. Consequently, the CRS may tailor adjuvant therapy. Future research should investigate whether radiotherapy can be safely omitted in patients with a low CRS.

A plea for appraisal and appreciation of immunohistochemistry in the assessment of prognostic and predictive markers in invasive breast cancer.

This viewpoint is a personal reflection on the values and merits of immunohistochemistry in current breast cancer diagnosis. Immunohistochemistry is a validated mainstay in molecular subtyping of invasive breast cancer. Immunohistochemical assessment of hormone receptor status and HER2 expression is used to determine the clinico-pathological surrogate of breast cancer intrinsic subtypes, which guide neoadjuvant and adjuvant therapy. The advent of genomic prognostic signatures and qualitative mRNA-based assays makes some clinicians and researchers wonder whether immunohistochemistry should be abandoned. However, the perils and pitfalls of these mRNA-based tests cannot be neglected. This viewpoint offers a brief overview of quality issues in immunohistochemistry and qPCR, as well as a concise summary of currently available evidence on the correlation of immunohistochemistry and mRNA-based testing for prognostic and predictive markers in invasive breast cancer. We strongly advocate the use of immunohistochemistry as it integrates valuable spatial information with quantification of protein expression.