BCL-2 expression aids in the immunohistochemical prediction of the Oncotype DX breast cancer recurrence score.

BACKGROUND: The development of molecular techniques to estimate the risk of breast cancer recurrence has been a significant addition to the suite of tools available to pathologists and breast oncologists. It has previously been shown that immunohistochemistry can provide a surrogate measure of tumor recurrence risk, effectively providing a less expensive and more rapid estimate of risk without the need for send-out. However, concordance between gene expression-based and immunohistochemistry-based approaches has been modest, making it difficult to determine when one approach can serve as an adequate substitute for the other. We investigated whether immunohistochemistry-based methods can be augmented to provide a useful therapeutic indicator of risk. METHODS: We studied whether the Oncotype DX breast cancer recurrence score can be predicted from routinely acquired immunohistochemistry of breast tumor histology. We examined the effects of two modifications to conventional scoring measures based on ER, PR, Ki-67, and Her2 expression. First, we tested a mathematical transformation that produces a more diagnostic-relevant representation of the staining attributes of these markers. Second, we considered the expression of BCL-2, a complex involved in regulating apoptosis, as an additional prognostic marker. RESULTS: We found that the mathematical transformation improved concordance rates over the conventional scoring model. By establishing a measure of prediction certainty, we discovered that the difference in concordance between methods was even greater among the most certain cases in the sample, demonstrating the utility of an accompanying measure of prediction certainty. Including BCL-2 expression in the scoring model increased the number of breast cancer cases in the cohort that were considered high certainty, effectively expanding the applicability of this technique to a greater proportion of patients. CONCLUSIONS: Our results demonstrate an improvement in concordance between immunohistochemistry-based and gene expression-based methods to predict breast cancer recurrence risk following two simple modifications to the conventional scoring model.

Association of autotaxin and lysophosphatidic acid receptor 3 with aggressiveness of human breast carcinoma.

In vitro and in vivo experimental studies have demonstrated the role of lysophosphatidic acid (LPA) signaling in tumor proliferation, invasiveness, and metastasis. Among LPA receptors, the overexpression of LPA receptor 3 (LPAR3) in transgenic mice has resulted in the highest rate of breast cancer metastasis. Our goal is to evaluate the LPA-producing enzyme autotaxin and LPAR3 as potential therapeutic targets in breast cancer patients. The expression of autotaxin and LPAR3 was examined by immunohistochemical analysis of 87 invasive human breast carcinomas. Carcinomas were more frequently positive for autotaxin and LPAR3 (24.4 and 43 %, respectively) compared to adjacent normal breast tissue (6.1 and 2.9 %, respectively). Increased stromal autotaxin expression was found in 16.3 % of the tumors. LPAR3 overexpression was associated with less differentiated tumors, human epidermal growth factor receptor 2 expression, and absence of progesterone receptors. The luminal type A carcinomas showed the lowest frequency of autotaxin and LPAR3 expression. Strong desmoplastic stromal reaction was more frequent among the carcinomas with autotaxin-positive tumor cells or autotaxin-positive stroma. Patients with carcinomas overexpressing LPAR3 in epithelial cells or autotaxin in stromal cells were more likely to have larger tumors, nodal involvement, and higher stage disease. Autotaxin overexpression in tumor cells also correlated with tumor size and clinical stage. Our data indicate that the increased expression of LPAR3 and autotaxin in human breast cancer is associated with tumor aggressiveness. They also suggest that LPA mediates tumor metastatic ability and peritumoral desmoplastic reaction through autocrine-paracrine mechanisms. A substantial portion of breast cancer patients might benefit from autotoxin/LPA receptor-targeted therapies.

Downregulation of TNF-related apoptosis-inducing ligand (TRAIL)/Apo2L in Barrett's esophagus with dysplasia and adenocarcinoma.

TRAIL/Apo2L is a CD95 ligand-related member of the TNF family that initiates apoptosis in immune and neoplastic cells after binding to specific surface receptors. The authors previously reported a specific topographic pattern of TRAIL expression in the normal colonic mucosa and the loss of TRAIL expression in tubular adenomas as well as in most colon carcinomas. Therefore, they hypothesized that similar changes may occur during the malignant transformation of Barrett's esophagus. The aim of this study was to compare TRAIL/Apo2L expression in normal gastroesophageal (GE) junction, Barrett's esophagus with and without dysplasia, and associated adenocarcinoma. Immunohistochemical evaluation of TRAIL expression was performed on formalin-fixed paraffin-embedded sections from 29 GE junction/esophageal biopsies, 20 gastric biopsies, 6 esophagectomies, 2 small bowel resection specimens, and 5 colon biopsies. The expression was graded semiquantitatively on a 4-point scale (0-3). TRAIL was expressed in the foveolar epithelium of the histologically normal GE junctional mucosa and stomach as well as in the normal intestinal epithelium, with maximal expression in the surface epithelium. TRAIL was always detected in Barrett's metaplasia (21/21, 100%), and the overall expression was similar to that of the columnar portion of the normal GE junction (8/8, 100%). TRAIL was rarely and weakly (1+) expressed in Barrett's esophagus with dysplasia (3/18, 16.7%) and adenocarcinoma (1/10, 10.0%) (P<0.001). Similarities in the topographic pattern of TRAIL expression in the normal GE junction, stomach, small intestine, and colon suggest a common function of TRAIL throughout the gastrointestinal tract. These results show that the downregulation of TRAIL is associated with development of dysplasia in Barrett's esophagus. Thus, the immunohistochemically detected downregulation of TRAIL expression appears to be a promising indicator of dysplasia in Barrett's esophagus.

Diagnostic utility of p75 neurotrophin receptor (p75NTR) as a marker of breast myoepithelial cells.

We evaluated the low affinity neurotrophin receptor (p75NTR) as a marker of breast myoepithelial cells. Immunohistochemical staining for p75NTR was performed on paraffin sections of 122 malignant breast lesions, 28 benign lesions and the adjacent normal breast tissue. The staining pattern was compared to those of myosin heavy chain and p63. p75NTR immunostain was consistently positive and compatible with p63 and myosin immunoreactivity in the myoepithelial cells of the normal mammary gland, benign breast lesions (six usual ductal hyperplasias, six specimens with sclerosing adenosis, eight intraductal papillomas, six fibroadenomas), and carcinoma in situ (18 ductal carcinomas in situ, two noninvasive papillary carcinomas, two lobular carcinomas in situ). The luminal cells were negative for p75NTR, but rare positive cells were noticed in the solid areas of some of the usual ductal hyperplasias. Four of 64 invasive ductal carcinomas (6%) and all metaplastic carcinomas (n = 3, 100%) showed a variable degree of p75(NTR) positivity. No p75NTR expression was found in the malignant cells in all in situ carcinomas, invasive lobular carcinomas (n = 11), tubular carcinomas (n = 10), invasive papillary carcinomas (n = 6), mucinous carcinomas (n = 4), and medullary carcinomas (n = 2). No myosin immunoreactivity was seen in the luminal/tumor cells, but p63 pattern of staining in the luminal/tumor cells was quite similar to that of p75NTR. Although significant p75NTR immunoreactivity was noticed in the vessels, nerves, and stromal component of fibroadenomas, no difficulties in the evaluation of the immunostain of myoepithelial cells were encountered. Our study shows that p75NTR is a useful marker for breast myoepithelial cells and can be used to rule out invasive disease as well as to evaluate difficult for diagnosis sclerosing lesions. Our data suggest a role of neurotrophins in the development of fibroepithelial breast tumors and some of the breast carcinomas.

Benign myoepithelial tumors of the breast have immunophenotypic characteristics similar to metaplastic matrix-producing and spindle cell carcinomas.

We immunohistochemically compared benign myoepithelial tumors (adenomyoepitheliomas [AMEs]) and metaplastic matrix-producing (MMP-CA) and spindle cell (MSC-CA) carcinomas of the breast to identify helpful diagnostic markers. Normal myoepithelial cells (MECs) consistently expressed cytokeratin, alpha-smooth muscle actin (SMA), myosin, S-100, CD10, and maspin. They were variably positive for vimentin and negative for epithelial membrane antigen (EMA), steroid receptors, p53, and HER-2/neu. MECs in AMEs less frequently expressed CD10 (4/8 [50%]) and myosin (6/8 [75%]) but frequently acquired characteristics of luminal cells, such as expression of EMA (5/8 [63%]) and steroid receptors (5/8 [63%]). No abnormal p53 or HER-2/neu expression was seen in AMEs. MMP-CA and MSC-CA were similar to AMEs in cytokeratin, vimentin, S-100, maspin, and HER-2/neu expression. MMP-CAs expressed less alpha-SMA (2/8 [25%]) and myosin (2/7 [29%]) and lacked estrogen receptor (0/9 [0%]). MSC-CAs were consistently CD10+ (4/4 [100%]) yet failed to express myosin (0/3 [0%]). p53 overexpression was seen frequently in MMP-CAs (4/8 [50%]) and MSC-CAs (1/3 [33%]). Benign myoepithelial mammary tumors differ immunophenotypically from normal MECs; a panel of immunohistochemical markers may be required to establish their myoepithelial origin. A similarly altered myoepithelial phenotype also is characteristic of metaplastic mammary carcinomas. The abnormal expression of oncogenes or antioncogenes, such as p53, may be more useful for distinguishing between those entities than the expression of the classic myoepithelial markers.

Loss of mismatch repair proteins in sebaceous gland tumors.

BACKGROUND: Sebaceous gland neoplasms are rare tumors that are associated with visceral malignancies in patients with Muir-Torre syndrome (MTS). The majority of the MTS-associated tumors reveal mutations in DNA mismatch repair (MMR) genes (most often hMSH-2 and hMLH-1) and microsatellite instability. The sebaceous gland lesions in patients with MTS can often precede or occur concurrently with the visceral neoplasms. The early recognition of those lesions and their differentiation from sporadic sebaceous gland tumors are critical for proper patient management. Here we investigate the MMR gene expression in a variety of sebaceous gland tumors, with or without associated visceral malignancy. METHODS: We studied the expressions of hMLH-1 and hMSH-2 in 10 consecutive sebaceous hyperplasias, 10 sebaceus nevi, 12 sebaceous adenomas, seven sebaceous carcinomas and the adjacent normal sebaceous glands using immunohistochemistry and paraffin-embedded sections. RESULTS: The normal sebaceous glands and the glands of all the sebaceus nevi were positive for hMLH-1 and hMSH-2. Loss of hMSH-2 expression was found in 1/10 (10%) sebaceous hyperplasias, 3/12 (25.0%) sebaceous adenomas, and 2/7 (28.6%) sebaceous carcinomas. Loss of hMLH-1 expression was seen in 1/10 (10%) hyperplasias, 3/12 (25.0%) adenomas, and 1/7 (14.3%) carcinomas. No concurrent loss of both hMLH-1 and hMSH-2 was observed. Loss of MMR (either hMLH-1 or hMSH-2) was detected in 80% of the benign sebaceous lesions associated with malignancy. In comparison, only 23% of sebaceous lesions not associated with malignancy showed loss of MMR proteins. No loss of hMSH-2 protein was found in the visceral cancer in one patient with hMSH-2-negative sebaceous adenoma. CONCLUSIONS: Our results confirm the previous reports of alterations of mismatch repair genes in the sebaceous neoplasms of patients with MTS. However, we showed that those changes also occur early at the stage of sebaceous hyperplasia, even in the absence of a visceral malignancy. This indicates the importance of the abnormal DNA mismatch repair in the progression of this disease.