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Biomedical subjects

W Hanna

Publications and source records attributed to W Hanna.

At least 19 recordsLinked to original sources
PubMed2001

Testing for HER2 status.

Incorporation of a new biological marker such as HER2 into routine clinical practice requires proof that it provides reproducible information independent of, and better than, conventional pathologic criteria, and that it influences treatment decisions. In breast cancer, HER2 amplification/overexpression predicts for a poor clinical outcome and an enhanced survival benefit from the HER2-targeted therapy, Herceptin, and may predict for resistance to some conventional therapies. Thus, HER2 is considered to be a clinically important molecule and testing for HER2 abnormalities is already part of routine patient assessment in many parts of the world. There is currently no gold standard for HER2 testing. The main challenge is to standardize and technically validate HER2 testing methodologies. Immunohistochemistry (IHC) and fluorescence in situ hybridization (FISH) are the most common HER2 tests used, and show a high level of concordance. HER2 testing approaches based on the polymerase chain reaction (PCR) are under extensive investigation and appear promising. A Canadian HER2 testing algorithm designed to increase the validity and reproducibility of HER2 testing has been compiled. HER2-positive cases are defined as those with >10% of tumor cells with moderate/strong, complete membrane staining in the invasive component, by IHC. Confirmatory HER2 testing using either FISH or quantitative PCR is recommended for indeterminate cases. Additional studies are required to calibrate HER2 testing results to clinical outcome.

Algorithms↗
PubMed2001

Growth factors and stromal matrix proteins associated with mammographic densities.

Extensive radiologically dense breast tissue is associated with a marked increase in breast cancer risk. To explore the biological basis for this association, we have examined the association of growth factors and stromal matrix proteins in breast tissue with mammographic densities. Ninety-two formalin-fixed paraffin blocks of breast tissues surrounding benign lesions were obtained, half from breasts with little or no density and half from breasts with extensive density, matched for age at biopsy. Sections were stained for cell nuclei, total collagen, the stromal matrix regulatory protein tissue metalloproteinase-3 (TIMP-3), and the growth factors, transforming growth factor-alpha and insulin-like growth factor (IGF-I). The area of immunoreactive staining was measured using quantitative microscopy. Breast tissue from subjects with extensive densities had a greater nuclear area (P = 0.007), as well as larger stained areas of total collagen (P = 0.003), TIMP-3 (P = 0.08), and IGF-I (P = 0.02) when compared with subjects with little breast density. Differences were greater for subjects less than 50 years of age. These data indicate that increased tissue cellularity, greater amounts of collagen, and increased IGF-I and TIMP-3 expression are found in tissue from mammographically dense breasts and suggest mechanisms that may mediate the associated increased risk of breast cancer.

Age Factors↗
PubMed2000

RT-PCR amplification of CK19 mRNA in the blood of breast cancer patients: correlation with established prognostic parameters.

We optimized the assay for detection of cytokeratin 19 (CK19) mRNA by the reverse transcriptase-polymerase chain reaction (RT-PCR) in blood as an index of circulating tumor cells in breast cancer patients. The limit of detection of < 1 MCF7 tumor cells per 10(6) peripheral blood leukocytes (PBL) was achieved in mixing experiments. We did not detect CK19 mRNA in control bloods (0/30) or in the blood of patients with benign breast disease (0/15). In blood samples from 109 patients with invasive breast cancer, CK19 mRNA was detected in 7/23 patients with node-negative disease, in 21/58 with node-positive disease, and in 20/28 with distant metastases. There was a significant association (P < 0.01) of CK19 positivity with distant metastatic versus both node-negative and node-positive disease, but not with any other histopathological parameter examined. In a small number of patients with distant metastases, increased intensity of the CK19 RT-PCR signal was associated with a reduced survival.

Biomarkers, Tumor↗
PubMed1999

Evaluation of HER-2/neu (erbB-2) status in breast cancer: from bench to bedside.

Molecular alterations in breast cancer are being incorporated into the development of new treatment strategies. The HER-2/neu oncogene has been extensively investigated as a prognostic factor and recently as a predictor of response to chemotherapy or endocrine therapy. The development of a humanized anti-HER-2 monoclonal antibody (Herceptin) and the encouraging results obtained in the treatment of patients with HER-2 overexpressing metastatic breast cancer with this antibody have resulted in renewed interest in HER-2/neu. This article reviews the current knowledge of HER-2/neu both as a prognostic and a predictive factor. Problems associated with the standardization of the methodology for assessing HER-2/neu status and clinically significant cut-off points are addressed.

Antibodies, Monoclonal↗
PubMed1998

Light and electron microscopic evaluation of the pectoralis major muscle following tissue expansion for breast reconstruction.

The placement of tissue expanders under the pectoralis major muscle has become a common procedure in breast reconstruction after mastectomy. Little information is available regarding the changes caused by tissue expansion on human skeletal muscle. In this study, we report the light and electron microscopic changes observed in 20 expanded pectoralis major muscles from 12 patients undergoing two-stage breast reconstruction procedures. Standard 400-cc round Radovan tissue expanders were placed, eight bilaterally and four unilaterally. Three biopsies were taken from each muscle at different locations during both the first stage (pre-expansion) and 23 weeks later at the second stage (postexpansion). The operative procedures and expansion protocol were the same in all reconstructions. No postoperative radiation therapy was added. The histologic changes were reported in a blind fashion by one pathologist. Light microscopy did not show significant pathologic changes. All but one of the pre-expansion specimens examined by electron microscope were reported as normal, whereas all of the postexpansion biopsies were grossly altered. Focal muscle fiber degeneration with glycogen deposits and mild interstitial fibrosis was noted. In addition, some fibers showed disorganization of the myofilaments in the sarcomeres. The above ultrastructural changes are significant morphologic alterations, which may be the result of muscle hypoxia. Whether these changes indicate permanent or transient transformation is yet unclear. Patient follow-up did not reveal any functional muscular deficit. We conclude that there is definite evidence to suggest significant muscular structural damage after routine subpectoral expansion for breast reconstruction.

Adult↗
PubMed1998

neu/erbB-2 amplification identifies a poor-prognosis group of women with node-negative breast cancer. Toronto Breast Cancer Study Group.

PURPOSE: It remains a challenge to predict which women with axillary node-negative (ANN) breast cancer at greatest risk of relapse may benefit most from adjuvant therapy. Increases in neu/erbB-2 have been implicated in breast cancer prognosis. Although overexpression has been investigated extensively, this study represents the first prospective assessment of the prognostic value of neu/erbB-2 DNA amplification in a cohort of women with newly diagnosed ANN. METHODS: A consecutive series of women was monitored for recurrence (median follow-up duration, 36 months) and tumors from 580 individuals were analyzed for amplification. The association of amplification with risk of recurrence was examined in survival analyses with traditional and histologic markers as prognostic factors. RESULTS: Neu/erbB-2 was amplified in 20% of cases. We found an increased risk of disease recurrence when neu/erbB-2 was amplified > or = twofold that persisted with adjustment for other prognostic factors (relative risk, 2.36; P = .002). We found some evidence that amplification was more important in patients who received chemotherapy compared with untreated patients. CONCLUSION: neu/erbB-2 amplification is an independent prognostic factor for risk of recurrence in ANN breast cancer. Women with tumors without neu/erbB-2 amplification have a good prognosis; aggressive therapy in this group is therefore difficult to justify. On the other hand, even with adjuvant chemotherapeutic treatment, women whose tumors exhibit neu/erbB-2 amplification have an increased risk of recurrence. We encourage a randomized trial to compare more aggressive adjuvant chemotherapy versus standard chemotherapy for ANN women whose tumors exhibit neu/erbB-2 amplification.

Axilla↗
PubMed1998

Fibroblastic rheumatism: clinical and histologic evolution of cutaneous manifestations.

Correlation of the clinical manifestations of a patient with fibroblastic rheumatism with sequential skin biopsy findings revealed an early inflammatory stage with cutaneous nodules, patchy erythematous skin lesions, polyarthritis, dermal lymphomonocytic infiltrates, and fibroblastic and myofibroblastic proliferation, followed by a chronic stage with sclerodactyly, joint ankylosis, deformities and dense dermal fibrosis. Treatment of this rare disorder in its early active stages may prevent the development of incapacitating joint sequelae.

Arthritis↗
PubMed1997

Elevated levels of plasma triglycerides are associated with histologically defined premenopausal breast cancer risk.

Lipids and lipoproteins have been associated with breast cancer risk; however, published results have been inconsistent. To clarify these associations, we measured fasting lipids in women undergoing breast biopsies. A case-control study examined the association of fasting levels of lipids with histologically defined breast cancer risk. Four groups of premenopausal women were assembled on the basis of histological appearance of breast tissue: 1) no epithelial proliferation (n = 102), 2) proliferation without atypia (n = 53), 3) atypical hyperplasia or carcinoma in situ (n = 53), and 4) node-negative invasive cancer (n = 102). A postoperative fasting blood specimen was analyzed for cholesterol, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, and triglycerides. Demographics, risk factors, diet, physical activity, fasting weight, and skin-fold thickness were measured. Triglyceride levels were significantly higher in women with node-negative invasive cancer (0.94 +/- 1.04 mg/ml) than in those with no epithelial proliferation (0.83 +/- 1.04 mg/ml, p = 0.03). This association persisted after adjustment for age, body size, lipids, reproductive and familial risk factors, and previous benign breast problems (p < 0.01), in keeping with an independent association of elevated triglycerides with breast cancer risk.

Adult↗
PubMed1996

Human perforin: rapid enrichment by immobilized metal affinity chromatography (IMAC) for whole cell cytotoxicity assays.

Perforin, a potent pore-forming protein, plays an important role in lymphocyte-mediated cytolysis causing necrosis or, when combined with the granzymes, apoptosis. The studies on perforin, although already extensive, have been hampered by the limited amount of material available from killer lymphocytes. Using a cell line that expresses high levels of human perforin, we describe a straightforward purification scheme that allows isolation of the lytic protein in approximately 8 hours. Perforin is enriched from the YT-INDY cell line by cavitation followed by differential centrifugation and ion metal affinity chromatography. In addition to demonstrating the lytic activity of human perforin toward various cell lines, we show that the conditions of the cytotoxicity assay influence both the kinetics and magnitude of perforin-mediated cytotoxicity.

Apoptosis↗
PubMed1996

New paradigm for lymphocyte granule-mediated cytotoxicity. Target cells bind and internalize granzyme B, but an endosomolytic agent is necessary for cytosolic delivery and subsequent apoptosis.

Lymphocyte granule-mediated apoptosis is postulated to entail the formation of membrane pores by perforin. Then soluble granzyme reaches the cytosol either through these pores or by reparative pinocytosis. We demonstrate here that Jurkat cells bind and internalize granzyme B via high affinity binding sites without toxic consequence. Apoptosis occurs, however, if sublytic perforin is added to targets washed free of soluble granzyme B. We suggest that granule-mediated apoptosis mimics viral strategies for cellular entry. Accordingly, co-internalization of granzyme B with adenovirus, a virus that escapes endosomes to reach the cytosol, also induced apoptosis. Poly(ADP-ribose) polymerase cleavage and processing of CPP32, ICE-LAP3, and Mch2 were detected at 30 min, while cytosolic acidification and DNA fragmentation occurred at 60 min. Annexin V binding and membrane permeabilization arose at 4 h. The concurrent activation of the Ced-3 proteases differed from the rate at which each cysteine protease is cleaved in vitro by granzyme B. Thus, granzyme B may not directly process these proteases in whole cells but rather may function by activating a more proximal enzyme. These results indicate that adenovirus-mediated delivery of granzyme B is suitable for elucidating biochemical events that accompany granule-mediated apoptosis.

Apoptosis↗
PubMed1996

Extracellular activities of human granzymes. I. Granzyme A induces IL6 and IL8 production in fibroblast and epithelial cell lines.

Situated in secretory granules of cytotoxic cells, granzymes are essential for induction of target cell apoptosis with perforin. However, since cytotoxic cells constitutively secrete a portion of their synthesized granzymes, these proteases could mediate extracellular functions independently of their role in the lytic event. Thrombin has been shown to function as an activation molecule by cleaving its receptor. We hypothesize that granzymes may act similarly. In this report, we show that purified human granzyme A can induce human lung fibroblasts to produce IL6 and IL8. Cytokine induction is abrogated by treating the serine protease with the suicide serine protease inhibitor 3,4-dichloroisocoumarin. Other fibroblast lines as well as epithelial cells produced cytokines in response to granzyme A. Our data suggest that granzyme A can function as an activation molecule with potentially important immunoregulatory functions.

Cell Line↗
PubMed1996

Extracellular Activities of Human Granzymes

Situated in secretory granules of cytotoxic cells, granzymes are essential for induction of target cell apoptosis with perforin. However, since cytotoxic cells constitutively secrete a portion of their synthesized granzymes, these proteases could mediate extracellular functions independently of their role in the lytic event. Thrombin has been shown to function as an activation molecule by cleaving its receptor. We hypothesize that granzymes may act similarly. In this report, we show that purified human granzyme A can induce human lung fibroblasts to produce IL6 and IL8. Cytokine induction is abrogated by treating the serine protease with the suicide serine protease inhibitor 3,4-dichloroisocoumarin. Other fibroblast lines as well as epithelial cells produced cytokines in response to granzyme A. Our data suggest that granzyme A can function as an activation molecule with potentially important immunoregulatory functions.

Journal Article↗
PubMed1996

Factors associated with local breast cancer recurrence after lumpectomy alone.

BACKGROUND: The purpose was to determine the rate of local breast relapse in patients with breast cancer uniformly treated with partial mastectomy but without postoperative radiotherapy and without systemic adjuvant therapy. We also systematically examined the factors associated with local recurrence to determine whether a low-risk subgroup existed. METHODS: A retrospective review of a prospectively followed (median, 8 years) cohort of 293 patients was performed. The end-point was ipsilateral local breast cancer recurrence. The patient's age, tumor size, nodal status, estrogen and progesterone receptor status, histology, and tumor and nuclear grade were studied, as were the presence and amount of carcinoma in situ and the presence of tumor emboli using univariate Kaplan-Meier and Cox step-wise multivariate analyses. RESULTS: The overall local relapse rate was 26% (77 recurrences). Univariate factors significantly associated with decreased local relapse included older age, negative nodes, small tumor size, positive estrogen receptor status, and absence of tumor emboli. Significant multivariate variables were age, nodal status, estrogen receptor status, absence of comedo carcinoma in situ, and tumor emboli. A low-risk subgroup of 66 patients was defined with a 6% 10-year local recurrence rate. CONCLUSION: Important patient and tumor variables associated with local breast cancer relapse after breast-conserving surgery can define a low-risk subgroup.

Adult↗
PubMed1996

Clinical behavior of untreated axillary nodes after local treatment for primary breast cancer.

BACKGROUND: The purpose of this study was to examine the rate of axillary failure in patients with primary breast cancer treated without axillary dissection or radiation and to determine what factors may be associated with axillary failure. METHODS: We studied 112 patients with invasive breast cancer treated for primary disease with breast-conserving surgery without axillary dissection or radiation to the breast or axilla, accrued between 1977 and 1986. Data for these patients were prospectively gathered for a research database and reviewed retrospectively to determine axillary failure. The effects of age, tumor size, estrogen receptor (ER) status, progesterone receptor (PgR) status, histologic grade, nuclear grade, and tumor emboli on time to axillary failure were examined. RESULTS: The median follow-up was 9.6 years. There were 26 axillary recurrences, resulting in a 10-year actuarial nodal control rate of 72%. Patients with nodal failure proceeded to axillary dissection with minimal morbidity. In both univariate and multivariate analyses, only tumor size was significantly associated with axillary failure (p = 0.04 and p = 0.06, respectively). CONCLUSIONS: This study demonstrates a significant effect of tumor size on axillary failure and a reasonable rate of local control in small tumors. Further research should examine the utility of axillary dissection in women with small breast cancers.

Actuarial Analysis↗
PubMed1996

An improved statistical approach: can it clarify the role of new prognostic factors for breast cancer?

Recently, there has been a proliferation of new biomarkers, some of which may lead to an improved prognostic index or may influence treatment selection. However, there are methodological and statistical issues that require attention in assessing the role and use of these prognostic factors. Between 1977 and 1986, 1097 primary breast cancer patients were accrued for multidisciplinary research at the Henrietta Banting Breast Centre, Women's College Hospital; follow-up to 1990 is complete for 96% of the patients. Data for these patients are used here to illustrate strategies: (1) for the comparison of results from diverse assessments of biomarkers; (2) for the improved comparability of inter-laboratory results; (3) for the examination of the results from monoclonal or polyclonal antibody assays for possible clinically relevant bimodality; (4) for good statistical resolution of overlapping distributions; (5) that involve the use of quantitative values for prognostic factors whenever possible; and (6) for improved multivariate analyses. Good data handling and analyses may enable more accurate and rapid assessment of new prognostic factors, thereby expediting and improving their clinical application.

Analysis of Variance↗
PubMed1996

An investigation of cut-points for primary breast cancer oestrogen and progesterone receptor assays.

Oestrogen and progesterone receptor (ER and PgR) assay values are frequently used in medical decision-making for breast cancer patients. We have proposed statistical standardization of receptor assay values to improve inter-laboratory comparability, and now report the use of standardized log units (SLU) to investigate the effects of ER and PgR cut-points on time to first recurrence outside the breast (DFS). Between 1980 and 1986, there were 678 primary breast cancer patients treated at the Henrietta Banting Breast Centre (HBBC). The effects of ER and PgR cut-points were examined with multivariate analyses considering the variables: age, tumour size, nodal status, weight and adjuvant treatment. We considered receptor assay cut-points ranging from - 1.0 to + 1.0 SLU (ER between 7 and 166 fmol/mg protein; PgR between 7 and 181 fmol/mg protein). PgR was included in the multivariate prognostic models more often than ER, although patients had a better prognosis with both larger ER and PgR values. There was no best cut-point for ER or PgR, and there was strong evidence that ER and PgR should be considered as continuous rather than dichotomous (negative, positive) variables. Patient prognosis should also be more comparable with SLU.

Breast Neoplasms↗
PubMed1996

Proliferative activity and p53 expression in adenoid cystic carcinoma of the breast.

Adenoid cystic carcinoma is a rare type of invasive breast carcinoma that has a good prognosis. We studied a series of four cases of adenoid cystic carcinoma in which we correlated the clinical and pathological features. The pathological features examined included light microscopy; electron microscopy; immunohistochemistry using antibodies to keratin, vimentin, S100 protein, actin, estrogen and progesterone receptors, and proliferation marker MiB-1, and p53 suppressor protein; image cytometric analysis for measurement of DNA ploidy; and molecular analysis using polymerase chain reaction single strand conformation polymorphism to assess point mutation of the p53 gene. All of the cases had a low nuclear grade, were negative for estrogen and progesterone receptors, and were DNA diploid. Three of the cases showed no evidence of metastases and had small primary tumors with low proliferative activity and absence of p53 protein expression. In contrast, one of the cases showed axillary lymph node metastases and in this case the primary tumor was large with a higher proliferative activity and expression of p53 protein, suggesting that these factors might play a role in the biological behavior of adenoid cystic carcinoma.

Adult↗