Prognostic utility of atypical mitoses in patients with breast cancer: A comparative study with Ki67 and phosphohistone H3.

BACKGROUND AND OBJECTIVES: Emerging evidence suggests that the presence of atypical mitoses is associated with poor prognosis in some types of cancer, but its clinical significance remains uncertain. Here, we investigated the occurrence of atypical mitoses in breast cancers. METHODS: Mitotic figures, including normal and atypical mitoses, were assessed in resected histological sections from 109 patients with invasive carcinoma of no special type (ICNST). Comparisons with clinicopathological features and biomarkers such as Ki67 and phosphohistone H3 (PHH3) were performed. RESULTS: The total number of mitotic figures, including atypical mitoses, was higher in situ and invasive ductal carcinoma components than in normal ducts. Morphological characteristics of atypical mitoses included multipolar, lagged, ring, asymmetrical mitoses, and anaphase bridge. Patients with higher total mitoses and PHH3, and the presence of atypical mitoses showed reduced overall survival (OS), compared to those with lower total mitoses and PHH3, and without atypical mitoses (P = 0.03, 0.02, and <0.001, respectively). In multivariate analysis, the presence of atypical mitoses alone attained significant correlation with shorter OS (P < 0.001). CONCLUSIONS: Atypical mitoses in routinely resected specimens have a robust prognostic value for ICNST of the breast, but its clinical utility remains to be validated in a multicenter large material.

Clinicopathological significance of a solid component in papillary thyroid carcinoma.

AIMS: Solid variant of papillary thyroid carcinoma (SVPTC) is characterized by a solid component (SC) involving more than 50% of the tumour with the preservation of the classical cytological features of papillary thyroid carcinoma (PTC). However, the clinical significance of SC in PTC has been rarely examined. Herein, we investigated retrospectively the clinicopathological features of PTC with various degrees (10-85%) of SC (PTCSC). METHODS AND RESULTS: Patients with PTCSC (n = 27) were stratified into SC-major (SC > 50% of the tumour) and SC-minor (SC < 49%) groups. The clinicopathological parameters were compared to the well-differentiated PTC (WPTC) group (n = 47). Both SC-minor (n = 18) and SC-major (n = 9) groups had increased incidence of a large-sized tumour, extracapsular extension and a high recurrence rate, compared to WPTC. Disease-free survival (DFS) of both SC-minor and SC-major was shorter than that of WPTC (P = 0.035 and P = 0.016, respectively). Overall survival was similar among all the groups. Univariate analysis revealed that SC was associated significantly with a recurrence rate (P = 0.018). Using multivariate analysis, SC appeared to be associated with a recurrence rate with borderline significance (P = 0.055). CONCLUSIONS: Our findings indicate that the presence of SC in PTC, regardless of the proportion, is associated with adverse clinical parameters and a shorter DFS.

IMP3 contributes to poor prognosis of patients with metaplastic breast carcinoma: A clinicopathological study.

Metaplastic breast carcinoma (MBC) is a rare type of tumor with heterogenous histological patterns. We investigated the immunohistochemical expression of IMP3, an oncofetal protein, in 31 MBC patients in association with histological subtypes and clinical outcomes. The cohort consisted of spindle cell carcinoma (SPC) (n=11), squamous cell carcinoma (SCC) (n=14), matrix-producing carcinoma (MPC) (n=4), carcinoma with osteocartilaginous elements (COC) (n=1), and low grade adenosquamous cell carcinoma (ASC) (n=1). IMP3 expression was identified in 7 cases of SPC (64%) and 6 patients of all the other subtypes (p=0.051). In comparison between IMP3 high (n=13) and low (n=18) groups, a large-sized tumor (≥4.0cm) was identified in 9 IMP3 high patients, and 14 IMP3 low patients had a small-sized tumor (p=0.01). High Ki67 positivity was detected in all of the IMP3 high patients and in 7 of the IMP3 low patients (p=0.002). During the follow-up period, 9 IMP3 high patients died, whereas 15 of the 18 IMP3 low patients remained alive (p=0.004). A univariate analysis revealed that IMP3 expression and tumor size were significantly associated with poor clinical outcomes (p=0.03 and <0.001, respectively). The IMP3 high group was likely to be associated with reduced overall survival compared to the IMP3 low group (p=0.06). These findings indicate that IMP3 may contribute to the aggressive behavior of MBC, and that this expression could potentially be a prognostic marker of MBC.

Osteoclast-like giant cells in invasive breast cancer predominantly possess M2-macrophage phenotype.

Breast carcinoma with osteoclast-like giant cells (OGCs) is a rare tumor; however, their clinicopathological aspects remain unclear. We described the clinicopathological characteristics of 8 patients with breast carcinoma with OGCs. Immuno-phenotypes of the OGCs were comparatively examined with that of foreign body giant cells (FBGCs) in 4 cases of granulomatous reaction (GR) without cancerous elements. In most cancers, tumors displayed cribriform and tubular growth patterns. Three cases showed moderate to high nuclear grade, while all the other tumors had low nuclear grade. Six patients were estrogen receptor (ER) positive, while triple negative phenotype was identified in 2 patients. During the follow-up period, 1 patient had local recurrence of the tumor, and all the patients remained alive. All OGCs and FBGCs expressed CD68, a pan-macrophage marker. OGCs in all the breast cancers showed moderate to high expression of CD163 - a marker of M2-macrophage with pro-tumoral function - whereas its expression in FBGCs was low to moderate (p=0.04). CD86 - a marker of M1-macrophage with a tumoricidal activity - was positive in the OGCs of 3 breast cancers, and in the FBGCs of 3 GR cases (p=0.15). The expression of CD163 was significantly higher than that of CD86 in the OGCs of breast cancer (p<0.001), whereas they were comparable in the FBGCs of GR (p=0.79). In summary, we found that breast carcinoma with OGCs mostly exhibited cribriform and tubular growth pattern, ER positivity, and predominantly possessed the M2-macrophage phenotype. However, the clinical significance of OGCs in breast cancer needs to be elucidated in further studies involving a larger number of cases.

Histochemistry for placenta research: theory and application.

Histochemical techniques have contributed significantly to advances in placental biology and cell biology. In this mini-review, we describe recent advances in histochemical technologies and show how these technologies can profoundly improve our understanding of placenta morphological function related to health and disease. Fundamental theories and applications of five separate methods discussed here are 1) tissue-based polymerase chain reaction by laser microdissection, 2) a novel antigen retrieval method using citraconic anhydride plus heating, 3) immunohistochemical detection of Lewis-related antigen expression and galectin-1 binding in the human placenta, 4) confocal microscopy analysis of IgG transport in placental trophoblasts, and 5) high-resolution immunofluorescence and correlative microscopy using ultrathin cryosections in placental research. This review article is based on a presentation given in a workshop entitled Histochemistry: Theory and Application at the 12th International Federation of Placenta Associations Meeting held in Kobe, Japan, on September 9, 2006.

Expression of MRP1 and ABCG2 is associated with adverse clinical outcomes of papillary thyroid carcinoma with a solid component.

Solid variant of papillary thyroid carcinoma (PTC) is characterized by a solid component (SC) retaining classical cytological features of PTC. Despite some controversies, PTC with SC (PTCSC) cases have poor prognosis compared with well-differentiated PTC. We investigated if cancer stem cells (CSCs) may have a role in pathogenesis of PTCSC. PTCSC tumors (n=27) were histologically represented by a mixture of papillary component (PC) and varying degrees of SC involving 10% to 85% of the tumor. Immunohistochemical expression of CSC markers ABCG2 and MRP1, and HBME1 and CK19 was compared between SC and PC within each tumor in association with clinicopathological parameters. ABCG2 and MRP1 were highly expressed in SC, whereas their expression was limited or absent in PC (P=.04 and .002, respectively). In contrast, expression of HBME1 and CK19 appeared higher in PC than in SC (P=.08 and .02, respectively). Higher expression of ABCG2 was associated with higher incidence of large-sized SC (P=.01). Higher expression of MRP1 was associated with higher incidence of lymphovascular invasion (P=.049). Higher expression of ABCG2 and MRP1, and lower expression of CK19 in SC were associated with higher tumor recurrence rate (P=.02, .01, and .02, respectively), and shorter disease-free survival (P<.001 for all the variables). Our findings indicate that the tumor cells harboring CSC-like characteristics in SC could contribute to the pathogenesis of PTCSC and might account for the poor disease prognosis.

Prognostic value of IMP3 expression as a determinant of chemosensitivity in triple-negative breast cancer.

Triple negative breast cancer (TNBC) has an aggressive phenotype and poor prognosis. Neoadjuvant chemotherapy (NAC) is often used to treat TNBC, but some patients are resistant to NAC. We postulated that a subpopulation of TNBC cells expressing IMP3, an oncofetal protein, could be resistant to NAC, contributing to the poor prognosis. We investigated immunohistochemical expression of IMP3 in 42 TNBC patients who underwent NAC in association with clinical outcomes. The patients were divided into IMP3 positive (+) (n=19) and negative (-) (n=23) groups. High Ki67 positivity was detected in 13 patients of the IMP3+group and 8 cases in the IMP3 - group (p=0.03). While 9 patients in the IMP3 - group (39%) were responders, the majority of the IMP3+patients (84.2%) were non-responders (p=0.01). In a Cox proportional hazard model, IMP3 expression was independently associated with poor NAC response and clinical outcomes (p=0.03 and 0.046, respectively). The IMP3+group showed a tendency toward shorter overall survival compared to the IMP3 - group with marginal significance (p=0.07). These findings suggest that IMP3+tumor cells contributed to the poor clinical outcomes by exerting a chemoresistance to NAC, and that IMP3 expression has prognostic value as a biomarker for chemosensitivity and overall survival in TNBC.

Reversing the effects of formalin fixation with citraconic anhydride and heat: a universal antigen retrieval method.

Formalin is a commonly used fixative for tissue preservation in pathology laboratories. A major adverse effect of this fixative is the concealing of tissue antigens by protein cross-linking. To achieve a universal antigen retrieval method for immunohistochemistry under a constant condition, we developed a new method in which the effects of formalin fixation were reversed with citraconic anhydride (a reversible protein cross-linking agent) plus heating. Formalin-fixed, paraffin-embedded tissues from various organs were examined for immunohistochemical localization of a wide variety of antigens. Deparaffinized tissue sections were placed in an electric kitchen pot containing 0.05% citraconic anhydride solution, pH 7.4, and the pot was set at "keep warm" temperature mode of 98C for 45 min. This mode allowed heating the sections at a constant temperature. The sections were then washed in buffer solution and immunostained using a labeled streptavidin-biotin method using an automated stainer. In general, formalin-fixed tissues demonstrated specific immunostainings comparable to that in fresh frozen tissues and significantly more enhanced than after conventional antigen retrieval methods. In particular, even difficult-to-detect antigens such as CD4, cyclin D1, granzyme beta, bcl-6, CD25, and lambda chain revealed distinct immunostainings. Different classes of antigens such as cellular markers and receptors, as well as cytoplasmic and nuclear proteins, consistently produced enhanced reactions. This method provides efficient antigen retrieval for successful immunostaining of a wide variety of antigens under an optimized condition. It also allows standardization of immunohistochemistry for formalin-fixed tissues in pathology laboratories, eliminating inter-laboratory discrepancies in results for accurate clinical and research studies.

Immunohistochemical, biochemical and immunoelectron microscopic analysis of antigenic proteins on neuroendocrine cell tumors using monoclonal antibody HISL-19.

The monoclonal antibody HISL-19 was originally generated after immunizing BALB/c mice with human islet cells. We used this antibody to study a wide variety of neuroendocrine (NE) and non-NE tumors by immunohistochemical, immunoelectron microscopic, and biochemical (Western blotting) techniques. Of the thyroid tumors, HISL-19 specifically immunoreacted with medullary carcinoma of the thyroid (MCT); of the pancreatic tumors, it reacted with islet cell tumors such as insulinomas and a gastrinoma; of the adrenal tumors, it reacted with pheochromocytoma. HISL-19 showed particularly strong immunoreactivity to a gross granular material at the perinuclear area in the MCT and malignant pheochromocytoma but not in the benign pheochromocytoma, although the latter cells showed a faint and homogenous positive reactivity in the cytoplasm. The strongly HISL-19-positive material was found to consist of newly synthesized antigenic proteins with a molecular weight between 60 and 65 kilodaltons (kDa) by Western blotting. Immunoelectron microscopic analysis revealed that this antigenic protein was located in the secretory granules that appear markedly in malignant endocrine tumors, usually located close to the nucleus. Thus, HISL-19 is a useful and specific marker for the immunohistochemical diagnosis of NE cell tumors. The specific antigenic proteins of HISL-19 were defined in MCT and malignant pheochromocytoma. These proteins are speculated to be actively synthesized and more highly produced in the secretory granules of malignant endocrine tumors than benign ones. Thus, a preoperative immunohistochemical study using HISL-19 might be useful for predicting the grade of malignancy of endocrine malignant tumors and thus help determine an appropriate operative procedure, in addition to being a useful marker of neuroendocrine cell tumors.

Use of oolong tea extract (OTE) for elastin staining and enhancement in ultrathin sections.

To assess the usefulness of oolong tea extract (OTE) staining for connective tissue observation, we examined the visceral pleural mesothelium of rat lung by transmission electron microscope. Four kinds of electron microscopic staining methods (routine, tannic acid, OTE in distilled water, and OTE in 0.1 M phosphate buffer) were compared to determine the most suitable method for electron microscopic observation of ultrathin sections. Elastin (elastic laminae) was selectively stained by tannic acid and both water and buffered OTE. Except for elastin, connective tissue and cell ultrastructures were also electron enhanced by tannic acid and both water and buffered OTE staining. However, using water OTE, the electron-dense filaments (10-12 nm in diameter) were obscured. In tannic acid staining, the unit membranes of the visceral pleural mesothelial cells were weaker as compared with routine and buffered OTE stains. Thus, the buffered OTE staining method is a highly useful technique for connective tissue observation and electron-enhanced staining in transmission electron microscopic preparations.