Glycoprotein IIb/IIIa receptor targeted PET/CT imaging: a novel diagnostic tool for detecting bioprosthetic valve thrombosis

Background/Introduction

Bioprosthetic valve thrombosis (BPVT) is an important clinical entity eventually following both bioprosthetic surgical and transcatheter aortic valve replacement. Although dynamic contrast-enhanced 4D-MDCT has improved the diagnosis of BPVT, more sensitive and pathology-specific non-invasive imaging tools are lacking. Recently, the glycoprotein IIb/IIIa receptor targeted, elarofiban-derived PET/CT imaging radiotracer [18F]GP1 has been successfully used for visualization of acute venous and arterial thrombi.

Purpose

We hypothesized that [18F]GP1 PET/CT imaging is suitable to detect BPVT.

Methods

In this proof-of-concept study, patients after bioprosthetic aortic valve replacement with symptomatic, severe hemodynamic valve dysfunction and confirmed hypoattenuated leaflet thickening (HALT) in dynamic 4D-MDCT were offered to participate in compassionate use examinations to undergo PET/CT imaging with the investigational [18F]GP1 PET tracer at baseline and after a 12-week course of therapeutic oral anticoagulation.

Results

This case series reports on three patients after aortic valve replacement. Two patients with symptomatic, obstructive BPVT as confirmed by echocardiography and 4D-MDCT fulfilled specified criteria and underwent [18F]GP1 PET/CT imaging. [18F]GP1 PET/CT clearly distinguished between blood pool activity and thrombotic foci. Clot-to-blood ratios at baseline were 8.2 and 4.5, respectively. A 12-week trial of therapeutic oral anticoagulation was associated with a regression of mean transprosthetic pressure gradient and reversal of HALT. Follow-up 4D-MDCT corroborated thrombus resolution in both patients. Correspondingly, [18F]GP1 PET/CT imaging demonstrated decreased tracer uptake in both patients. Clot-to-blood ratio at follow-up visit decreased to 1.2 and 2.9, respectively. While absent tracer uptake was seen in patient #1, residual tracer uptake was observed in patient #2 suggestive of ongoing platelet aggregation. One asymptomatic SAVR patient was examined with [18F]GP1 PET/CT for a different compassionate use and no thrombotic foci were detected on the leaflets.

Conclusions

[18F]GP1 PET/CT is a novel imaging technique in patients with obstructive BPVT. In a head-to-head comparison we show that [18F]GP1 PET/CT may have incremental diagnostic value over dynamic contrast-enhanced 4D-MDCT alone by detection of sites of ongoing platelet aggregation at the molecular level. [18F]GP1 PET/CT may serve as a novel, highly sensitive tool to overcome some limitations of current diagnostic imaging modalities for detecting BPVT and may prove useful for the monitoring and guidance of therapeutic interventions.

Funding Acknowledgement

Type of funding sources: Other. Main funding source(s): Life Molecular Imaging provided material for [18F]GP1 radiolabeling free of charge as part of an ongoing research collaboration.

Abstract P3-05-14: Recognition of glycan-epitopes by the macrophage glycoreceptor CLEC10A is associated with improved outcome in primary breast cancer

Background: Glycosylation of proteins and lipids is a frequent posttranslational modification involved in the regulation of many important biological processes such as cell proliferation, cell adhesion, cell migration, protein turnover and immune response. In breast cancer and other malignancies, alterations of glycan structures and changes in the expression of genes controlling glycosylation were frequently observed, implicating that aberrant glycosylation plays a pivotal role in tumor development and progression. Currently, plant lectins or glycan-specific antibodies are used in immunhistochemistry to characterize the cellular state of glycosylation. Recently, we introduced a novel strategy, named protein domain histochemistry (PDH), using the naturally expressed, human glycoreceptor CLEC10A as a probe to monitor the glycosylation state on formalin-fixed paraffin-embedded tissues (FFPE). CLEC10A belongs to the superfamily of C-type lectins, specifically recognizes terminal N-acetylgalactosamine-(GalNAc) structures and is expressed on dendritic cells and activated macrophages. As tumor-associated cells of the immune system are gaining increasing importance in the regulation of tumor development and progression, we applied CLEC10A as a “reader” of the state of glycosylation in human breast cancer and investigated the value of PDH on patient outcome.

Material and Methods: PDH was performed with the human glycoreceptor CLEC10A on FFPE breast cancer tissues (Nollau et al., J Histochem Cytochem 61, 199-205, 2013). In total, 146 primary breast cancers were retrospectively investigated by PDH with 8-year follow-up. Staining intensities were semi-quantitavely assessed by image analysis and statistics were performed with clinicopathological data, including disease-free interval (DFI) and overall survival (OS).

Results: Moderate and strong positivity for CLEC10A staining was observed in 36% of breast cancer specimens while 64% of tumors were weakly positive or stained negative. Kaplan Meier analysis demonstrated that positive staining by CLEC10A was significantly associated with increased DFI (p = 0,023) and OS (p = 0,006). DFI time was increased from 67,5 mo (95% ci: 60,1-74,9) to 86,7 mo (95% ci: 78,6-94,8) and OS time from 62,1 mo (95% ci: 55,2-68,9) to 75,8 mo (95% ci: 67,5-84,2), respectively. Multivariate Cox regression analysis proofed positive staining by CLEC10A as an independent prognostic marker for OS (p = 0,025; hazard ratio: 0,45 (95% ci: 0,23-0,90).

Discussion: This is the first study evaluating the diagnostic potential of CLEC10A PDH in breast cancer. Positive reactivity of CLEC10A against glycan-epitopes on breast cancer cells was significantly associated with improved patient outcome. Our results warrant further investigations and raise important questions regarding the immune response provoked by the interaction of terminal GalNAc structures in breast cancer with dendritic cells or macrophages expressing CLEC10A.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P3-05-14.

Abstract P2-18-14: MarginProbe® - Final results of the German post-market study in breast conserving surgery of ductal carcinoma in situ

Background: Surgical margins in breast conserving surgery (BCS) of ductal carcinoma in situ (DCIS) as well as invasive cancer are a subject of intense discussion. A positive margin is still one of the strongest predictor for risk of local recurrence of intraductal and invasive breast cancer. Intraoperative margin assessment of DCIS is difficult and existing options are unsatisfying.

Aim of our study was to evaluate the performance of MarginProbe®(Dune Medical Devices, Boston, MA, USA) in assessing surgical margins for DCIS and the contribution to lowering the re-excision rate after initial BCS.

Material and methods: The device includes a disposable hand-held probe and a console, is based on radiofrequency spectroscopy, and detects differences in dielectric properties between normal and malignant breast tissue.

The multicentre single arm, post market study was performed on 55 patients at 3 German sites under approval of institutional review boards. MarginProbe® was used as an adjunctive tool to the current practice. All specimens were sent for paraffin embedded pathological analysis.

The procedure success was defined as both: negative margins after initial BCS; and early identification of an extended lesion, with conversion to mastectomy instead of performing a re-excision BCS.

Results: From September 2009 - May 2010, 42/55 patients were eligible for this analysis. In comparison with a historical re-excision rate of 39% for DCIS patients undergoing BCS, use of MarginProbe® led to a reduction of the re-excision rate by 56%, down to 17% (p = 0.018) (surgical margin width of 5 mm). The procedure success was also significantly improved by more than 3-fold (p<0.0001), from 14% (6/42) by standard of care (SOC) alone, to 57% (24/42) with use of the device. In 21% (9/42) of the cases use of the device led to a direct conversion to mastectomy due to extensive disease identified, sparing an additional re-excision BCS. Resected average main specimen tissue volume was 34.6 cc. Tissue volume associated with false positive margins was, on average, 7.5 cc per patient. Cosmetic outcomes were not different.

Discussion: In synopsis with the other two clinical trials (MAST and US pivotal study) we found our data consistent. Each trial reported a reduction of the re-resection rate by more than 50%.

Our results demonstrate that adjunctive use of the device is effective in achieving procedure success and reducing re-excisions for DCIS patients. Several options for intraoperative margin assessment exist, but for DCIS they are time-consuming and insufficient (frozen section, touch prep cytology) or experimental (near-infrared fluorescence optical imaging, high-frequency ultrasound). Usually, the pathologist provides final analysis of the lesion extension and margin assessment several days after operation.

Conclusion: MarginProbe® is a device that provides a fast and effective technique for intraoperative margin assessment that is already used in daily routine. It lowers the re-excision rate for both DCIS and invasive cancer significantly, by >50%, without any influence on patient's cosmesis. It may allow the surgeon to perform oncoplastic or reconstructive breast surgery and IORT more safely in the future.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P2-18-14.

Using the 21-gene assay to guide adjuvant chemotherapy decision-making in early-stage breast cancer: a cost-effectiveness evaluation in the German setting

OBJECTIVE

The 21-gene assay (Oncotype DX Breast Cancer Test (Genomic Health Inc., Redwood City, CA)) is a well validated test that predicts the likelihood of adjuvant chemotherapy benefit and the 10-year risk of distant recurrence in patients with ER+, HER2- early-stage breast cancer. The aim of this analysis was to evaluate the cost-effectiveness of using the assay to inform adjuvant chemotherapy decisions in Germany.

METHODS

A Markov model was developed to make long-term projections of distant recurrence, survival, quality-adjusted life expectancy, and direct costs for patients with ER+, HER2-, node-negative, or up to 3 node-positive early-stage breast cancer. Scenarios using conventional diagnostic procedures or the 21-gene assay to inform treatment recommendations for adjuvant chemotherapy were modeled based on a prospective, multi-center trial in 366 patients. Transition probabilities and risk adjustment were based on published landmark trials. Costs (2011 Euros (€)) were estimated from a sick fund perspective based on resource use in patients receiving chemotherapy. Future costs and clinical benefits were discounted at 3% annually.

RESULTS

The 21-gene assay was projected to increase mean life expectancy by 0.06 years and quality-adjusted life expectancy by 0.06 quality-adjusted life years (QALYs) compared with current clinical practice over a 30-year time horizon. Clinical benefits were driven by optimized allocation of adjuvant chemotherapy. Costs from a healthcare payer perspective were lower with the 21-gene assay by ∼€561 vs standard of care. Probabilistic sensitivity analysis indicated that there was an 87% probability that the 21-gene assay would be dominant (cost and life saving) to standard of care.

LIMITATIONS

Country-specific data on the risk of distant recurrence and quality-of-life were not available.

CONCLUSIONS

Guiding decision-making on adjuvant chemotherapy using the 21-gene assay was projected to improve survival, quality-adjusted life expectancy, and be cost saving vs the current standard of care women with ER+, HER2- early-stage breast cancer.

Abstract P5-21-02: Hormone receptor status and endocrine therapy in a prospective observation study on trastuzumab (Herceptin®) in the adjuvant treatment of breast cancer

Background: Based on the findings from large randomized studies, Trastuzumab (T) was registered in 2006 for the treatment of early stage, HER2+ breast cancer (BC), after surgery, (neo)adjuvant chemotherapy (CT) and/or radiotherapy. However, limited systematic evidence is available on preceding, concomitant or sequential endocrine treatment (ET) based on the hormone receptor (HR) status. This large prospective observation study, reflecting the unrestricted routine practice of HER2 antibody treatment in Germany, allows to examine this topic.

Methods: At present, more than 4000 patients (pts) have been enrolled in this ongoing study; 3446 pts from more than 316 centres were already sufficiently documented to be analysed. Details on concomitant treatment was collected at baseline and for 12 months after start of T.

Results: With respect to an overall HR positivity (HR+), i.e. estrogen and/or progesterone receptor (ER, PR) being positive, of 2181/3446 (63%), these HER2+ pts do not differ from the general BC population. Both hormone receptor types are positive in 47%, while ER+ only or PR+ only was detected in 13% and 3%, respectively. Adjuvant ET of any type, starting before or during T treatment, was given in 87% of HR+ and in 3% of HR- pts. 6% of HR+ pts received T and ET without concomitant CT. Details on the adjuvant treatment options are provided in the table:

The 21-gene recurrence score assay impacts adjuvant therapy recommendations for ER-positive, node-negative and node-positive early breast cancer resulting in a risk-adapted change in chemotherapy use

Background

We carried out a prospective clinical study to evaluate the impact of the Recurrence Score (RS) on treatment decisions in early breast cancer (EBC).

Patients and methods

A total of 379 eligible women with estrogen receptor positive (ER+), HER2-negative EBC and 0–3 positive lymph nodes were enrolled. Treatment recommendations, patients' decisional conflict, physicians' confidence before and after knowledge of the RS and actual treatment data were recorded.

Results

Of the 366 assessable patients 244 were node negative (N0) and 122 node positive (N+). Treatment recommendations changed in 33% of all patients (N0 30%, N+ 39%). In 38% of all patients (N0 39%, N+ 37%) with an initial recommendation for chemoendocrine therapy, the post-RS recommendation changed to endocrine therapy, in 25% (N0 22%, N+ 39%) with an initial recommendation for endocrine therapy only to combined chemoendocrine therapy, respectively. A patients' decisional conflict score improved by 6% (P = 0.028) and physicians' confidence increased in 45% (P < 0.001) of all cases. Overall, 33% (N0 29%, N+ 38%) of fewer patients actually received chemotherapy as compared with patients recommended chemotherapy pre-test. Using the test was cost-saving versus current clinical practice.

Conclusion

RS-guided chemotherapy decision-making resulted in a substantial modification of adjuvant chemotherapy usage in node-negative and node-positive ER+ EBC.

Isolation and characterisation of cancer stem cells from canine osteosarcoma

There is increasing evidence that cancer is a stem cell disease. This study sought to isolate and characterise cancer stem cells from canine osteosarcoma. One human and three canine cell lines were cultured in non-adherent culture conditions using serum-starved, semi-solid media. Primitive sarcosphere colonies from all cell lines were identified under these conditions and were characterised using molecular and cytochemical techniques for embryonic stem cell markers. Expression of the embryonic stem cell-associated genes Nanog, Oct4 and STAT3 indicated a primitive phenotype. Sarcospheres could be reproduced consistently when passaged multiple times and produced adherent cell cultures when returned to normal growth conditions. Similarities between human and canine osteosarcoma cell lines add credence to the potential of the dog as a model for human disease.

Ductal carcinoma in situ (DCIS) breast specimens need to be embedded completely in order to determine the correct extent of the disease

11061

Background: The processing of breast specimens suspicious of ductal carcinoma in situ (DCIS) is hampered by the fact that DCIS is not regularily visible at the gross level. There is no general consensus as how to process those breast specimens. Suggestions lead from examination of the entire tissue sample with a special focus on the resection margins to algorithms such as cutting only those paraffin blocks containing calcifications. Methods: In order to identify the influence of the diagnostic method on the measured extent of a DCIS lesion we compared two approaches. One was based on the examination of a single section and the other on examination of the entire specimen, i.e. cutting multiple 0.5 cm slices to be analyzed as max. 52 x 76 mm whole mount sections. 187 consecutive breast specimens from 186 patients (median patient age 60 years, range 31 to 87 years) from three gynecological institutions between Jan 2004 and Nov 2006 were searched for DCIS. We compared the largest tumor diameter from a single section of a specimen (‘apparent diameter‘, AD) with a ‘reconstructed diameter‘ RD calculated on the basis of the number of 0.5 cm slices taken from a sample and the number of slices containing the DCIS lesion. Results: Complete histological examination of these 187 cases (90 high and 97 low grade DCIS lesions) revealed a statistically significant difference (p=7.5E-9) between the apparent diameter AD (mean 22.4 mm, range 2 to 80 mm) and the reconstructed diameter RD (mean 31.6 mm, range 6 to 76 mm). In 138 cases (73.8%) the true extent of the disease would have been underestimated (RD > AD) if the diagnosis had been based only on a single exemplary section, the mean difference RD-AD being 14.8 mm (range 1–50 mm). In addition, we found 40 invasive cancers (multifocal inside the DCIS lesion, unifocal inside the DCIS and unifocal outside the DCIS). Conclusions: We conclude that the complete examination of a breast specimen helps to determine the true extent of DCIS and additionally helps to identify cases that turn out to be already invasive. Both findings may have important impact on the patients’ further treatment and outcome.

No significant financial relationships to disclose.

HER-2/neu as a Predictive Marker in a Population of Advanced Breast Cancer Patients Randomly Treated Either with Single-agent Doxorubicin or Single-agent Docetaxel

PURPOSE

To evaluate the predictive value of HER-2 in a population of advanced breast cancer patients randomly treated either with single-agent doxorubicin (A) or with single-agent docetaxel (T).

EXPERIMENTAL DESIGN

Patients from this study participated in a phase III clinical trial in which doxorubicin or docetaxel was administered for advanced disease. HER-2 was evaluated by IHC. In all positive cases, FISH was used to confirm the HER-2 positive status. The different cohorts of patients identified by HER-2 were examined to assess a possible relationship between HER-2 status and treatment effect.

RESULTS

Tumor samples were available for 176 of the 326 patients entered in the clinical trial (54%). HER-2 positivity was observed in 20% of the study population. A statistically significant interaction was found between response rates to the study drugs and HER-2 status, with HER-2 positive patients deriving the highest benefit from the use of T (odds ratio for HER-2 positive patients treated with T = 3.12 (95% CI 1.11-8.80), p = 0.03). The interaction between HER-2 and response rates to A and T was also confirmed by a multivariate analysis. No statistically significant interaction was found between HER-2 and drugs efficacy evaluated in terms of time to progression and overall survival, although in the HER-2 negative cohort A was at least as effective as T in term of overall survival.

CONCLUSIONS

These results suggest that in HER-2 positive breast cancer patients docetaxel might be more active than doxorubicin, while in HER-2 negative patients doxorubicin might be at least as effective as docetaxel. Although the present results cannot have an impact on current practice, they allow us to formulate the hypothesis that HER-2 positive breast cancer is a heterogeneous disease with regard to sensitivity to anthracyclines and taxanes, and that this might be dependent upon other molecular markers including the p-53 and topoisomerase II alpha genes. This hypothesis is currently being tested prospectively in two different 'bench to bed-side' clinical trials.

Combination of taxanes and anthracyclines in first-line chemotherapy of metastatic breast cancer: an interim report

Anthracyclines and taxanes are among the most effective agents in the treatment of advanced breast cancer, refractory or non-responsive to endocrine manipulation. Several recently published phase III studies have addressed the role of these compounds in combination compared with established chemotherapy regimens. This report considering a total of 4244 patients evaluates the data of those trials with respect to the efficacy and toxicity of the treatment regimens. Currently, evidence is growing that especially patients with symptomatic visceral tumour spread may benefit from the combined application of anthracyclines and taxanes. Adequately dosed polychemotherapy appears to be more successful than monotherapy, and, at present, the combination of anthracyclines (doxorubicin, epirubicin) and taxanes (docetaxel (Doc), paclitaxel (Pac)) might lead to a promising approach to improve the course of the metastatic disease.

Epidermal barrier lipids in human vernix caseosa: corresponding ceramide pattern in vernix and fetal skin

BACKGROUND

Vernix caseosa is a protective biofilm covering the fetus during the last trimester. Vernix and epidermal barrier lipids (i.e. cholesterol, free fatty acids and ceramides) appear to share protective functions for fetal and neonatal skin.

OBJECTIVES

To analyse vernix samples for epidermal barrier lipid content, and to compare lipid profiles of vernix with those of fetal and postnatal epidermis.

METHODS

Vernix samples were collected from 21 healthy term neonates. Skin samples were collected from 10 fetuses aborted between gestational week (GW) 16 and 25, nine infants and 11 older children. Lipids were extracted according to standard protocols and analysed by high-performance thin-layer chromatography.

RESULTS

Vernix contained 196.5 +/- 70.1 microg barrier lipids mg-1 protein (mean +/- SD). Cholesterol formed the major barrier lipid fraction (52.8%), followed by free fatty acids (27.7%) and ceramides (20.1%). The ceramide composition of vernix resembled that of mid-gestational (GW 23-25) fetal epidermis both qualitatively and quantitatively, while there were major differences from postnatal epidermis. The total epidermal ceramide concentration increased significantly between prenatal and postnatal samples.

CONCLUSIONS

The composition pattern of ceramides mirrors that of mid-gestational fetal epidermis. Vernix thus represents a 'homologous' substitute for the immature epidermal barrier in fetal skin. The differential role of individual ceramides in this process remains to be established.

Prospective randomized trial of docetaxel versus doxorubicin in patients with metastatic breast cancer

PURPOSE

This phase III study compared docetaxel and doxorubicin in patients with metastatic breast cancer who had received previous alkylating agent-containing chemotherapy.

PATIENTS AND METHODS

Patients were randomized to receive an intravenous infusion of docetaxel 100 mg/m(2) or doxorubicin 75 mg/m(2) every 3 weeks for a maximum of seven treatment cycles.

RESULTS

A total of 326 patients were randomized, 165 to receive doxorubicin and 161 to receive docetaxel. Overall, docetaxel produced a significantly higher rate of objective response than did doxorubicin (47.8% v 33.3%; P =.008). Docetaxel was also significantly more active than doxorubicin in patients with negative prognostic factors, such as visceral metastases (objective response, 46% v 29%) and resistance to prior chemotherapy (47% v 25%). Median time to progression was longer in the docetaxel group (26 weeks v 21 weeks; difference not significant). Median overall survival was similar in the two groups (docetaxel, 15 months; doxorubicin, 14 months). There was one death due to infection in each group, and an additional four deaths due to cardiotoxicity in the doxorubicin group. Although neutropenia was similar in both groups, febrile neutropenia and severe infection occurred more frequently in the doxorubicin group. For severe nonhematologic toxicity, the incidences of cardiac toxicity, nausea, vomiting, and stomatitis were higher among patients receiving doxorubicin, whereas diarrhea, neuropathy, fluid retention, and skin and nail changes were higher among patients receiving docetaxel.

CONCLUSION

The observed differences in activity and toxicity profiles provide a basis for therapy choice and confirms the rationale for combination studies in early breast cancer.

[Aromatase inhibitors--new possibilities in treatment of breast carcinoma]

Aromatase inhibition is now an acknowledged second line treatment modality for advanced breast cancer in postmenopausal women. Aminoglutethimide is an inhibitor of adrenal steroid biosynthesis and blocks the conversion of cholesterol to pregnenolone, and therefore reduces levels of adrenal androgens, which are a source of estrogens in both premenopausal and postmenopausal women. Aminoglutethimide has produced antitumor response rates of 35% in unselected patients, most of whom have undergone prior therapy with either chemotherapy or hormonal manipulation. As is true of other hormonal responses, high response rates of up to 70% are observed in patients who are ER and/or PR positive. The reason why these drugs are currently used after tamoxifen is mainly due to the side effects of aminoglutethimide, which impairs the mineralocorticoid and glucocorticoid synthesis. New, less toxic compounds appear, which block the conversion of androstenedione to estrone and efficiently suppress plasma estrogen levels., e.g. formestane, anastrozole and letrozole. Aromatase inhibitors are now being compared to tamoxifen as first-line endocrine treatment in relapsing patients. If these trials confirm a similar or better response rate to new aromatase inhibitors compared to tamoxifen, the time will come to study them as the first line adjuvant treatment in non-metastatic disease.

CD44 isoforms correlate with cellular differentiation but not with prognosis in human breast cancer

CD44 is a transmembrane glycoprotein occurring in several isoforms with different extracellular regions. The various transcripts are encoded by one gene locus containing 20 exons, of which at least 10 can be alternatively spliced in nascent RNA. Isoforms encoded by the variant exons (termed CD44v) are highly restricted in their distribution in nonmalignant tissue as opposed to the standard form of CD44 (CD44s) abundant in many tissues. Specific variant isoforms containing exon 6v have been shown to render nonmetastatic rat tumor cells metastatic. Based on the prominent role in rat metastasis formation, CD44v isoforms were suggested to be involved in human tumor progression. Correlations between prognosis and expression of CD44v have been reported for gastric and colon carcinoma, for non-Hodgkin's lymphoma, and recently for breast carcinoma. We evaluated the expression of CD44 isoforms in node-positive (n = 119) and node-negative (n = 108) cases of breast carcinoma by immunohistochemistry using CD44v exon-specific mAbs. In a subset of 43 cases of high-risk patients, reverse transcription-PCR was used to determine the exon composition of the transcripts. Protein and RNA expression data were probed statistically for their correlation to survival of the patients and clinical risk factors. In contrast to recently published data (M. Kaufmann et al., Lancet, 345: 615-619, 1995), in our cohort disease-free and overall survival data did not indicate significant correlations with the expression of the analyzed isoforms in univariate and multivariate analyses. Comparison of CD44 protein expression with established clinical risk factors for survival such as tumor size (pT1+pT2) and histological grading revealed correlations with the presence of CD44s (P = 0.02 and P = 0.03, respectively) and CD44-9v (P = 0.05 for histological grading). Carcinoma tissues with elevated estrogen and progesterone receptor levels showed positive correlation with CD44-6v (P = 0.001), while a trend for significant coexpression of CD44s and CD44-9v isoforms was observed in estrogen receptor-positive tissues (P = 0.08 and 0.06, respectively). In breast cancer, CD44s, CD44-9v, and CD44-6v are apparently markers for cellular differentiation but not for tumor progression. Our data suggest that steroid hormone receptors may be associated with the in vivo expression of CD44-6v-containing isoforms in human mammary carcinoma.

[Determination of dithiocarbamate residues in foodstuff by head space gas chromatography and flame photometric detection]

With headspace-technique in conjunction with a flamephotometric detector (FPD) a fast and sensitive method for the determination of dithiocarbamates from organic foodstuff is presented. The dithiocarbamates are treated with tin-(II)-chloride and determined quantitatively as carbon disulfide (CS2). The evaluation of the data is performed by calibration curves.

High expression level of alpha 6 integrin in human breast carcinoma is correlated with reduced survival

We recently reported that alpha 6 integrin mediates experimental metastasis in mice by functioning in the adhesion of tumor cells to the vascular endothelium. In the current study, we investigated the expression of human alpha 6 integrin in invasive breast carcinomas of 119 women. In 50% of the tumors alpha 6 integrin was expressed in the majority of the cells, and this expression was correlated with reduced survival time. By contrast, the 24% of patients with breast tumors devoid of alpha 6 integrin expression all survived. The tumors were also evaluated for clinical risk factors including histological grading and steroid receptor level. The combination of these factors with alpha 6 integrin expression was superior in predicting overall survival than considering the other factors alone. The correlation with decreased survival time was consistent, regardless of whether the tumors expressed the alpha 6 integrin A or B forms, which differ in their cytoplasmic domain. On the basis of this pilot study we consider alpha 6 integrin expression to be a novel prognostic marker for human breast cancer.

Are CD44 variant isoforms involved in human tumour progression?

The transmembrane glycoprotein CD44 exists in a variety of isoforms generated by alternative splicing of the pre-mRNA. In a rat metastasis model, certain variant isoforms (containing exon 6v) are causally involved in lung metastasis formation. We have summarized the data obtained to date on the expression of CD44 variant isoforms in human tumour progression. In non-Hodgkin lymphomas, expression of exon 6v containing isoforms is an independent prognostic factor indicating an adverse prognosis. Upregulation of exon 9v containing isoforms in gastric and renal cell carcinomas relates to a poor prognosis of patients. In colorectal carcinomas, CD44-9v isoforms are strongly expressed already in early adenomas; CD44-6v isoforms are upregulated in late adenomas along with ras and TP53 mutations. No expression of variant isoforms has been detectable in neuroblastomas, but significant downregulation of CD44s correlates inversely with tumour progression and N-myc amplification. Only in breast carcinoma has no correlation of CD44 expression with survival or any other prognostic marker been established. Evaluation of CD44 isoform expression by immunohistochemistry in cases of non-Hodgkin lymphoma, gastric, colon and renal cell carcinomas, as well as neuroblastomas, may be a useful diagnostic parameter indicating invasive processes.

Overexpression of p53 and prognosis in breast cancer

BACKGROUND

Assessment of prognostic markers in breast cancer independent of the axillary lymph node status is of major concern for the application of adjuvant treatment regimens. The current treatment decision is based mainly on the axillary lymph node status. Because of improved screening methods, the number and proportion of patients with node-negative disease are increasing, which warrants a search for reliable prognostic parameters. The application of tumor suppressor gene expression appears to be especially suited as a marker of the progress in malignant cellular dedifferentiation.

METHODS

Tumor tissues of 156 patients with primary invasive breast cancer were analyzed immunohistochemically for the presence of p53 protein in paraffin-embedded material. The reaction to monoclonal antibody PAb1801 yielded better results than did reactions to monoclonal antibody DO1 and polyclonal antibody CM-1. The significance of the immunohistochemical data was compared with a panel of established risk factors.

RESULTS

Nuclear accumulation of p53 protein proved to be an independent marker of dedifferentiation, regardless of the lymph node status. Tumors showing p53 immunoreactivity were significantly more often related with histological Grade 3 and the absence of steroid hormone receptors. Kaplan-Meier estimation and multivariate analysis of disease-free and overall survival rate corroborated the importance of p53 as a prognostic parameter.

CONCLUSION

Overexpression of p53 protein emerged as a reliable and independent predictor for disease recurrence and reduced survival rates in patients with breast cancer.

Overexpression of p53 and prognosis in breast cancer

BACKGROUND

Assessment of prognostic markers in breast cancer independent of the axillary lymph node status is of major concern for the application of adjuvant treatment regimens. The current treatment decision is based mainly on the axillary lymph node status. Because of improved screening methods, the number and proportion of patients with node-negative disease are increasing, which warrants a search for reliable prognostic parameters. The application of tumor suppressor gene expression appears to be especially suited as a marker of the progress in malignant cellular dedifferentiation.

METHODS

Tumor tissues of 156 patients with primary invasive breast cancer were analyzed immunohistochemically for the presence of p53 protein in paraffin-embedded material. The reaction to monoclonal antibody PAb1801 yielded better results than did reactions to monoclonal antibody DO1 and polyclonal antibody CM-1. The significance of the immunohistochemical data was compared with a panel of established risk factors.

RESULTS

Nuclear accumulation of p53 protein proved to be an independent marker of dedifferentiation, regardless of the lymph node status. Tumors showing p53 immunoreactivity were significantly more often related with histological Grade 3 and the absence of steroid hormone receptors. Kaplan-Meier estimation and multivariate analysis of disease-free and overall survival rate corroborated the importance of p53 as a prognostic parameter.

CONCLUSION

Overexpression of p53 protein emerged as a reliable and independent predictor for disease recurrence and reduced survival rates in patients with breast cancer.

Overexpression of p53 and prognosis in breast cancer

BACKGROUND

Assessment of prognostic markers in breast cancer independent of the axillary lymph node status is of major concern for the application of adjuvant treatment regimens. The current treatment decision is based mainly on the axillary lymph node status. Because of improved screening methods, the number and proportion of patients with node-negative disease are increasing, which warrants a search for reliable prognostic parameters. The application of tumor suppressor gene expression appears to be especially suited as a marker of the progress in malignant cellular dedifferentiation.

METHODS

Tumor tissues of 156 patients with primary invasive breast cancer were analyzed immunohistochemically for the presence of p53 protein in paraffin-embedded material. The reaction to monoclonal antibody PAb1801 yielded better results than did reactions to monoclonal antibody DO1 and polyclonal antibody CM-1. The significance of the immunohistochemical data was compared with a panel of established risk factors.

RESULTS

Nuclear accumulation of p53 protein proved to be an independent marker of dedifferentiation, regardless of the lymph node status. Tumors showing p53 immunoreactivity were significantly more often related with histological Grade 3 and the absence of steroid hormone receptors. Kaplan-Meier estimation and multivariate analysis of disease-free and overall survival rate corroborated the importance of p53 as a prognostic parameter.

CONCLUSION

Overexpression of p53 protein emerged as a reliable and independent predictor for disease recurrence and reduced survival rates in patients with breast cancer.

Detection of HER-2 oncogene amplification in breast cancer by differential polymerase chain reaction from single cryosections

Amplification of genomic DNA encoding oncogenes such as HER-2 (syn.c-erbB2/c-neu) may be substantially involved in the initiation and progression of breast cancer. In order to refine and facilitate the quantitative analysis of HER-2 amplification in breast cancer, differential polymerase chain reaction (PCR) was performed on DNA derived from single cryosections of tumor tissue. This technique is based on the simultaneous amplification of a potentially amplified oncogene (HER-2) and a reference gene (IFN-gamma). Differential PCR yielded reproducible results that were in agreement with gene copy quantification using the dot blot technique. Thus we suggest differential PCR to be a reliable and rapid method for determining relative gene dosage in a minute amount of tumour tissue.

[Follow-up of 551 patients with node-negative breast cancer]

To evaluate the prognostic significance of established clinical, histological, and biochemical factors, we examined the survival data of 551 node-negative breast cancer patients. At a median follow-up of 5 years, we found 114 recurrences, 79 of them at distant sites. 41 patients died. 84 patients with less than 8 examined lymph nodes, adjuvant systemic treatment, or treatment differing from standard procedures, had a statistically significant shorter overall survival and were excluded from further analysis. With regard to relapse-free and overall survival univariate and multivariate analyses of the remaining 467 patients revealed only few factors with prognostic significance. In multivariate analysis of overall survival by the Cox regression model, statistically significant prognostic value was limited to three factors: lymphangiosis carcinomatosa (relative risk 4.8, 95%-confidence interval 2.0-11.7), postmenopausal status (0.38, 0.17-0.84), and positive progesterone receptor status (0.37, 0.14-1.0). In addition, there was a trend (p = 0.075) of prolonged survival in patients with Bloom and Richardson grade I cancers. The few prognostic factors found were able to identify patients with very good, as well as very bad prognosis. However, for the majority of node-negative breast cancer patients, estimation of prognosis remains unsatisfactory. Therefore, further independent prognostic factors are necessary.