Circulating tumour cell-derived plastin3 is a novel marker for predicting long-term prognosis in patients with breast cancer

BACKGROUND

Identification of promising biomarkers that predict the prognosis of patients with breast cancer is needed. In this study, we hypothesised that the expression of the epithelial-mesenchymal transition-related biomarker plastin3 (PLS3) in peripheral blood could be a prognostic factor in breast cancer.

METHODS

We examined PLS3 expression in breast cancer cell lines with epithelial and mesenchymal traits and in circulating tumour cells (CTCs) obtained from the peripheral blood of breast cancer patients. We investigated PLS3 expression in the peripheral blood of 594 patients with breast cancer to evaluate the clinical significance of PLS3 expression.

RESULTS

Robust PLS3 expression was observed in different breast cancer cell lines (Hs578t, MCF-7, MDA-MB-468, and MDA-MB-231) as well as in a bone marrow derived cancer cell line (BC-M1). In both the training (n=298) and validation (n=296) sets, PLS3 expression was observed in CTCs of patients with breast cancer. PLS3-positive patients showed significantly poorer overall and disease-free survival than PLS3-negative patients (P=0.0001 and 0.003, respectively). Subset analysis revealed that this prognostic biomarker was relevant in patients with stage I-III cancer, particularly in patients with luminal-type and triple-negative-type tumours.

CONCLUSIONS

These data demonstrated that PLS3 was expressed in CTCs undergoing the epithelial-mesenchymal transition in patients with breast cancer. Furthermore, PLS3 may be an excellent biomarker for identifying groups at risk of recurrence or with a poor prognosis.

[Tumor cells in the peripheral blood of patients with urothelial carcinoma of the bladder: detection and impact of circulating]

Circulating tumor cells (CTC) play a crucial role in the natural history of several malignancies and, thus, are the subject of intense research efforts. This review summarizes the most contemporary literature data regarding detection of CTC and their impact on the oncological prognosis of patients with urothelial carcinoma of the bladder (UCB). Despite the availability of different methods for CTC detection and isolation in the peripheral blood, the standardized and Food and Drug Administration-approved CellSearch® assay is currently the most commonly used system for CTC detection. The majority of studies did not find any association between presence of CTC and clinicopathologic features. However, CTC have been demonstrated to represent a strong, independent predictor for unfavorable oncological outcomes in UCB. Since the peripheral blood is an easily accessible source, CTC represent a promising biomarker to effectively monitor early disease progression and therapy response in the near future. CTC hold the potential to individualize patient counseling regarding the optimal timing of radical surgery or bladder-sparing treatment as well as multimodal therapies.

Role of Growth arrest-specific gene 6-Mer axis in multiple myeloma

Multiple myeloma is a mostly incurable malignancy characterized by the expansion of a malignant plasma cell (PC) clone in the human bone marrow (BM). Myeloma cells closely interact with the BM stroma, which secretes soluble factors that foster myeloma progression and therapy resistance. Growth arrest-specific gene 6 (Gas6) is produced by BM-derived stroma cells and can promote malignancy. However, the role of Gas6 and its receptors Axl, Tyro3 and Mer (TAM receptors) in myeloma is unknown. We therefore investigated their expression in myeloma cell lines and in the BM of myeloma patients and healthy donors. Gas6 showed increased expression in sorted BMPCs of myeloma patients compared with healthy controls. The fraction of Mer(+) BMPCs was increased in myeloma patients in comparison with healthy controls whereas Axl and Tyro3 were not expressed by BMPCs in the majority of patients. Downregulation of Gas6 and Mer inhibited the proliferation of different myeloma cell lines, whereas knocking down Axl or Tyro3 had no effect. Inhibition of the Gas6 receptor Mer or therapeutic targeting of Gas6 by warfarin reduced myeloma burden and improved survival in a systemic model of myeloma. Thus, the Gas6-Mer axis represents a novel candidate for therapeutic intervention in this incurable malignancy.

Circulating cell-free cancer-testis MAGE-A RNA, BORIS RNA, let-7b and miR-202 in the blood of patients with breast cancer and benign breast diseases

BACKGROUND

MAGE-A (melanoma-associated antigen-A) are promising targets for specific immunotherapy and their expression may be induced by the epigenetic factor BORIS.

METHODS

To determine their relevance for breast cancer, we quantified the levels of MAGE-A1, -A2, -A3, -A12 and BORIS mRNA, as well as microRNAs let-7b and miR-202 in pre- and postoperative serum of 102 and 34 breast cancer patients, respectively, and in serum of 26 patients with benign breast diseases and 37 healthy women by real-time PCR. The mean follow-up time of the cancer patients was 6.2 years.

RESULTS

The serum levels of MAGE-A and BORIS mRNA, as well as let-7b were significantly higher in patients with invasive carcinomas than in patients with benign breast diseases or healthy women (P<0.001), whereas the levels of miR-202 were elevated in both patient cohorts (P<0.001). In uni- and multivariate analyses, high levels of miR-202 significantly correlated with poor overall survival (P=0.0001). Transfection of breast cancer cells with synthetic microRNAs and their inhibitors showed that let-7b and miR-202 did not affect the protein expression of MAGE-A1.

CONCLUSIONS

Based on their cancer-specific increase in breast cancer patients, circulating MAGE-A and BORIS mRNAs may be further explored for early detection of breast cancer and monitoring of MAGE-directed immunotherapies. Moreover, serum miR-202 is associated with prognosis.

Abstract P3-12-09: The prevalence and quantity of circulating tumor cells (CTCs) after adjuvant chemotherapy with and without anthracyclines in patients with HER2-negative early breast cancer (EBC)

Background: The use of anthracycline based chemotherapy in early breast cancer (EBC) patients has been well established. However, adverse effects like cardiotoxicity and efficacy in certain subgroups continue to be subjects of discussion. Based on data suggesting a limited benefit of anthracyclines in HER2-negative patients, the German SUCCESS C study randomly assigned patients with EBC to be treated with either anthracycline-containing or anthracycline-free chemotherapy. Since the prognostic value of CTCs in EBC has already been demonstrated in several trials, we compared the prevalence of CTCs after the completion of chemotherapy between both treatment arms.

Methods: The SUCCESS C trial was a randomized, open-label, Phase III study comparing disease free survival (DFS) in patients with HER2-negative EBC. Treatments were either 3 cycles epirubicin, 5-fluorouracil and cyclophosphamide followed by 3 cycles of docetaxel (FEC–DOC), or 6 cycles of an anthracycline-free regimen with docetaxel and cyclophosphamide (DOC-C). The CTC status at chemotherapy cycle 6 was prospectively evaluated using the FDA-approved CellSearch System (Veridex, USA).

Results: Data on CTC status after chemotherapy are available for 1757 patients. Overall, CTCs were found in 220 (12.5%) patients (median 1, range 1 – 18 CTCs). One CTC was detected in 123 (55.9%), two CTCs in 53 (24.1%), three to five CTCs in 37 (16.8%), and more than five CTCs in 7 (3.2%) of these patients. Univariate analyses revealed that CTC prevalence was not significantly associated with tumor size (pT1, pT2, pT3, pT4), nodal stage (pN0, pN1, pN2, pN3), grading (G1, G2, G3), histological type (invasive ductal, invasive lobular, other), estrogen-receptor status, or progesterone-receptor status (Chi-square tests, all p &gt; 0.1). There was no significant difference with respect to the prevalence of CTCs after chemotherapy between the two treatment arms (Chi-square test, p = 0.23), as CTCs were detected in 11.6% (103 out of 889) of patients treated with the anthracycline-containing chemotherapy regimen and in 13.5% (117 out of 868) of patients treated with the anthracycline-free chemotherapy regimen. In addition, there was no significant difference between the two treatment arms with regard to the number of CTCs detected after chemotherapy in CTC-positive patients (FEC-DOC: median = 1, range 1 – 18; DOC-C: median = 1, range 1 – 8; Mann-Whitney U test, p = 0.30).

Conclusions: The comparable prevalence and number of CTCs after the completion of chemotherapy may indicate that anthracycline-free chemotherapy is not inferior to anthracycline-containing chemotherapy in this study. This however, has to be confirmed by survival analyses, which will be available in 2014.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P3-12-09.

Abstract PD6-5: Pooled analysis of circulating tumor cells in metastatic breast cancer: Findings from 1944 individual patients data

Background: Clinical validity of CTCs (CellSearch®) in metastatic breast cancer (MBC) patients has previously been assessed in studies with limited statistical power. We aimed to pool all European studies to obtain high-level evidence on the prognostic value of CTCs, to investigate their effects across different clinico-pathological characteristics and therapies and to further validate the MD Anderson/Institut Curie/Fox Chase CTC-based prognostic nomogram established in first-line treated MBC patients (Giordano et al, Clin Cancer Res 2013).

Material and methods: Methods were predefined in a written protocol. In December 2012, we searched for eligible studies that accrued patients in 2003-2012. We contacted all European laboratories using CellSearch®. We used likelihood ratio tests (LR) in Cox regression models stratified by study to assess the independent prognostic value of CTC when added to a clinicopathological (CP) model for progression-free (PFS) and overall survival (OS). Landmark analyses were used to assess the prognostic effect of early changes in CTC. The CTC-based nomogram (http://cancernomograms.com/CTCOnline.html) score was retrieved for every patient; we calculated C-indices, drew calibration plots and Kaplan-Meier curves according to quintiles of the nomogram score.

Results: We collected individual data of 1944 MBC patients, from 20 different studies (some unpublished), from 17 centers in 7 European countries. We observed 1507 PFS events and 929 deaths. Baseline CTC count was significantly associated with several patient characteristics, such as performance status (PS, p&lt;10-4), synchronous metastasis (p&lt;10- 2) tumor subtype (p&lt;10-4), liver & bone metastases (p&lt;10-4), CEA & CA15-3 levels (p&lt;10-4). The CP model for OS included PS, MBC subtypes, number of previous lines of treatment, patient's age, metastasis-free interval, metastatic sites (p&lt;0.01 for all). In a multivariate analysis containing the CP model parameters and CTC count at baseline, elevated CTC count (≥5) was a significant independent predictor of OS (n = 1444, HR = 2.7, 95%CI [2.2-3.2], LR p&lt;10-4). Baseline serum markers added either no or marginal effect to the CP plus baseline CTC model for OS. In contrast, early changes in CTC status at week 3-5 significantly added prognostic information for OS to the model with CP factors and baseline CTC+ (n = 569, HR = 1.8 [2.2-3.2], LR p&lt;0.001). In the population of interest (MBC treated by first line chemotherapy, n = 402 patients, 176 deaths), the CTC-based nomogram exhibited a good C-index for OS (0.69), was well calibrated and showed clear separation of the survival curves. Additional results, including subgroup analyses by tumor subtype and treatments will be presented at the meeting.

Conclusions: This pooled analysis is the largest study ever reported on CTC in MBC, with a previously unreached statistical power. It provides a clear level-of-evidence 1 on the independent prognostic value of CTCs before and during treatment in MBC. Also, the CTC-based prognostic nomogram is independently validated.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr PD6-5.

Abstract P2-01-02: Circulating Tumor Cells (CTC) may Express HER2/neu in Patients With Early HER2/neu Negative Breast Cancer – Results of the German SUCCESS C Trial

Background: There is growing evidence that the HER2/neu-status of distant metastases or minimal residual disease in blood and bone marrow may differ from the primary tumor in patients with breast cancer. The HER2/neu-status of CTCs was prospectively evaluated in patients with HER2/neu negative primary breast cancer randomized into the German multicenter SUCCESS C study.

Methods: The SUCCESS C trial is a randomized Phase III study comparing FEC-Docetaxel (FEC-Doc) vs. Docetaxel-Cyclophosphamid (DC) as well as 2 years of a lifestyle-intervention in patients with early, HER2/neu negative, node positive or high-risk node negative primary breast cancer.

As part of the translational research program, 23ml peripheral blood were drawn after adjuvant chemotherapy. In 505 samples, the prevalence of CTCs and their HER2/neu-status were assessed using the CellSearch System (Veridex, USA). After immunomagnetic enrichment with an anti-Epcam-antibody, cells were labelled with anti-CK8/18/19 and anti-CD45 antibodies. A fluorescein conjugate antibody with anti-CK-Fluorescein Isothiocyanate (FITC) was used for HER2/neu phenotyping. The cut-off for CTC-positivity was ≥ 1 CTC and for HER2/neu ≥ 1 CTC with strong HER2/neu-staining (+++).

Results: 26,9% of pts (n = 136) were positive for CTCs (mean 1.78; range 1–7; median = 1). The number of detected CTC was distributed as follows: 1 CTC (n = 76; 55.9%), 2 CTCs (n = 35; 25.7%), 3 CTCs (n = 13; 9.6%), 4 CTCs (n = 7; 5.2%) and ≥ 5 CTCs (n = 5; 3.7%). HER2/neu staning of CTCs was not detectable or weak in 26.5% (n = 36) and 4.4% (n = 6) of CTC positive patients respectively and therefore categorized as HER2/neu negative. In 32.4% of the CTC-positive patients (n = 44), we detected moderate and in 36.8% (n = 50) strong HER2/neu-staining of ≥ 1 CTC per sample. No association was found between CTCs or the HER2/neu-status of CTCs with tumor size, histopathological grading, hormone receptor status or axillary lymph node involvement.

Conclusions: The data of this trial confirm previous findings that patients with HER2/neu negative primary breast cancer can show HER2/neu positive minimal residual disease. These results underline the importance of frequent HER2/neu determination during follow up and disease progression. Survival data within the Success C trial will give further insight into the tumor biology of HER2/neu negative disease.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P2-01-02.

Abstract OT1-1-10: DETECT III - A multicenter, randomized, phase III study to compare standard therapy alone versus standard therapy plus lapatinib in patients with initially HER2-negative metastatic breast cancer but with HER2-positive circulating tumorcells

Background: Despite a HER2-negative primary tumor approximately 20–30% of patients develop HER2-positive metastases (Zidan et al. 2005; Tewes et al. 2009). As previously described in the DETECT I trial (Fehm et al. 2010) determination of HER2 status on circulating tumor cells (CTCs) is one option for re-evaluating HER2-status in the metastatic setting. Currently it is unclear if HER2-targeted therapy based on the assessment of HER2-status of CTCs reveals a clinical benefit.

Trial design: DETECT III is a randomized, open-label, two arm phase III study comparing standard treatment alone vs. standard treatment plus HER2-targeted therapy with lapatinib in HER2-negative metastatic breast cancer patients with HER2-positive CTCs. Choices of chemotherapy and endocrine therapy include: docetaxel, paclitaxel, capecitabine, vinorelbine, non pegylated liposomal doxorubicin, letrozole, exemestane and anastrozole.

Main eligibility criteria: 1. metastatic breast cancer with HER2-negative primary tumor tissue and/or biopsies from metastatic sites or locoregional recurrences2. evidence of ≥ 1 HER2-positive CTC3. ≥ 1 evaluable metastatic lesion according to RECIST4. Tumor evaluation within 6 weeks before randomization

Specific aims: Objective: The objective of the trial is to prove the clinical efficacy of lapatinib in patients with metastasizing breast cancer who exhibit HER2-positive circulating tumor cells (CTC) although the primary tumor tissue and/or biopsies from metastatic sites were investigated for HER2 status and showed HER2-negativity.

Primary endpoint: Progression free survival

Secondary endpoints: Overall response rateClinical benefit rateOverall survivalDynamic of CTCQuality of lifeSafety and tolerability of lapatinib

Statistical methods: The primary endpoint will be analyzed by Kaplan-Meier method using the logrank test in order to compare the PFS distributions of the two arms. Efficacy, toxicity and other event rates are calculated, providing confidence intervals. In case of comparison between patient groups, these rates will be analyzed by Fisher's exact test or test. The Kaplan Meier analysis for all event related data will be carried out overall for the whole patient population. Furthermore a Cox regression analysis will be done using the following covariates Hormone receptor status (positive/negative)Number of prior chemotherapy lines for metastatic diseasePrior endocrine therapy for metastatic diseaseEndocrine treatment vs. cytotoxic treatmentOne metastatic site vs. multiple metastatic sitesBone metastases vs. no bone involvementPerformance status ECOG Score (0/&gt; 0)

Present accrual and target accrual: As only half of the patients with HER2-negative metastatic breast cancer show CTC-positivity and of those approximately 32% will exhibit HER2-positive CTC (Fehm et al. 2010), screening of about 1420 patients is required to enroll 228 patients. First patient was screened in February 2012. As of July 27th 2012 117 patients were screened and 21 were found to have HER2-positive CTCs

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr OT1-1-10.

P4-07-13: Prognostic Impact of Circulating Tumor Cells Assessed with the Cell Search Assay and Adna Test Breast in Metastatic Breast Cancer Patients – The DETECT Study

Background

Over the last decade circulating tumor cells (CTC) were established as a prognostic factor in breast cancer patients. However, there are very limited studies comparing different test methods, although several are available.The DETECT trial for metastatic breast cancer patients was designed to investiate the prognostic impact of CTC. Here, we report on the prognostic relevance of CTC testing with different detection methods.

Material and Methods: Patients with primary metastatic breast cancer or metastatic recurrence were prospectively enrolled in this multicenter trial. CTC were detected using the FDA-approved Cell Search® assay applying immunocytochemistry and the RNA-based Adna Test Breast Cancer™. After a median follow-up of 11 months the first survival data are now presented.

Results: Both methods could be performed in 221 patients. Using the CellSearch™ assay 116 of 221 patients were CTC-positive based on the cut-off level of 5 cells. Presence of CTC was associated with the site of metastatic disease. The OS was 15.4 months in CTC positive pts. (95%-CI: 13.5−17.1 mths) compared to 20.4 mths. in CTC negative pts. (19.1−21.9 mths.; p&lt;0.001). In the multivariate analysis presence of CTC was the only independent predictor for overall survival (HR: 3.4, 95%-CI: 1.7−6.3) including tumorbiological factors, menopausal status, number and sites of metastatic disease. The progression-free survival was not correlated with CTC status in our cohort receiving different types of systemic treatment (p=0.197). When the AdnaTest Breast was performed, 88 of 221 (40%) patients were CTC positive. Except for HER2 status, no correlation could be observed between CTC positivity and any of the clinicopathological factors. CTC positivity assessed by the AdnaTest Breast has no impact on PFS and OS. A multivariate analysis was therefore not performed.

Conclusions: Currently, several different tests are available for CTC detection. Only a few tests have been approved by the FDA and been validated in large clinical trials. Therfore, it will be important to compare new techniques with the Cell Search assay.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P4-07-13.

P4-07-14: Circulating Tumor Cells (CTCs) Detection and HER2 Profiling by CellSearch® in Non-Metastatic Breast Cancer: An International Ring Study To Assess Inter-Reader Variability

Background: Preliminary results from the Success and Remagus trials showed that CTC detection by CellSearch® has adverse prognostic value in non-metastatic breast cancer. Moreover, several investigators have characterized HER2 expression on CTCs in early breast cancer. Since the majority of CTC-positive women with non-metastatic breast cancer have only 1 CTC detected / blood volume analyzed, we wanted to evaluate the inter-reader variability in this setting. This is a crucial step before moving forward with multi-lab/multi-center prospective testing of the clinical utility of the CellSearch® technology in non-metastatic breast cancer.

Methods: Five galleries of CellSearch® images from 3 European and one US institution (a total of 307 images) were mailed to 22 independent readers from 14 European and US academic laboratories and 8 readers from two CellSearch® Veridex laboratories in a blinded fashion. These images came mainly from studies on CTC and/or HER2−positive CTC detection in breast cancer and included healthy women (negative controls), women with metastatic (positive controls) and non-metastatic disease (Pierga et al SABCS 2010, Pierga et al ASCO 2011, Riedthorf et al CCR 2010, Ignatiadis et al PLoS ONE 2011). Each reader reported the images as either CTC-negative or CTC-positive/HER2−negative or CTC-positive/HER2−positive. Kappa statistics were used to assess inter-reader agreement. The 8 Veridex readers were summarized by a majority voting system to derive a gold standard in order to compare each independent reader using discordance rates.

Results: Kappa statistics showed moderate to good agreement between independent readers depending on the gallery evaluated (gallery 1 K: 0.55, gallery 2 K:0.57 gallery 3 K:0.64, gallery 4 K:0.72, gallery 5 K:0.85). These differences were attributed to differences in scoring difficulty of each gallery. Discordances in CTC-positive vs CTC-negative events between each reader and the gold standard ranged from 2.3%-31.3% with 7 readers showing discordance rates &lt;5%, 11 readers between 5–10%, 10 readers between 10–14% and only 2 readers showing discordance rates &gt;14% as compared to the gold standard (median discordance rate: 9.3%). Image analysis showed that investigators with high discordance rates compared to the Veridex gold standard were not always taking into account “morphological characteristics” for defining an event as CTC-positive. Discordant results between readers were mainly due to discordance in CTC definition and to a lesser extent in the definition of HER2−positivity. Indeed, discordances in assigning a CTC-positive event as either HER2−negative or HER2−positive ranged from 0.3−13.7% with 19 readers showing discordance rates &lt;5%, 7 readers between 5–10% and 4 readers with discordance rates &gt;10% (median discordance rate: 3.9%).

Conclusion: In non-metastatic breast cancer, we observed low discordance between most independent readers and the gold standard for defining a CellSearch® event as CTC with very few readers showing high discordance rates. Concordance can be improved through appropriate training and the use of all the tools provided by the CellSearch® system for image interpretation.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P4-07-14.

Abstract PD04-08: Circulating tumor cells (CTC) in peripheral blood of breast cancer patients two years after adjuvant chemotherapy depending on endocrine treatment — The German SUCCESS-Trial

Background: The prognostic significance of CTC in metastatic, as well as in primary breast cancer has been demonstrated (Rack et al., ASCO 2010). The optimal endocrine treatment strategy for postmenopausal patients (pts) with hormone sensitive breast cancer remains unclear.We analyzed the prevalence of CTC two years after primary diagnosis in patients with tamoxifen or anastrozole treatment.

Methods: As part of the translational research project of the German SUCCESS-trial, we analyzed 23ml of peripheral blood from 307 N+ and high risk N-postmenopausal pts with hormone sensitive breast cancer two years after adjuvant taxane based chemotherapy and with tamoxifen or anastrozole treatment. The presence of CTCs was assessed with the CellSearchSystem (Veridex, USA). After immunomagnetic enrichment with an anti-Epcam-antibody, cells were labelled with anti-cytokeratin (8,18,19) and anti-CD45 antibodies to distinguish between epithelial cells and leukocytes. Standard within the study was early switch treatment (tamoxifen for 2 years, followed by anastrozle), while pts with contraindications against tamoxifen were allowed to receive anastrozole up-front.

Results: In 10.1% of pts (n=31) &gt;1 CTC was detected after the completion of chemotherapy (range 2-33), while 7.8% (n=24) presented with &gt;1 CTC (range 2-99) two years after completion of chemotherapy. The median age in the tamoxifen group was 59.9 years and 59.8 in the anastrozole group. In the tamoxifen group, 33.0% of the pts had a pT1 tumor, 5.3% G1 grading and 21.6% of the pts were node negative. In the anastrozole group, 30.0% of the pts had a pT1 tumor, 7.5% G1 grading and 22.5% of the pts were node negative, respectively. None of these differences were statistically significant. After the completion of chemotherapy, 9.7% of the pts were CTC positive in the tamoxifen group (range number of cells: 2-33) and 11.3% in the anastrozole group (range of cells: 2-24), p=0.69. Two years after primary diagnosis, 7.9% of the pts were CTC positive in the tamoxifen group (range number of cells:2-99) and 7.5% in the anastrozole group (range cells: 2-5), p=0.90. Actuarial disease free and overall survival will be presented at the meeting.

Conclusions: The prognostic relevance of CTC in peripheral blood of early breast cancer patients both before and after chemotherapy has been demonstrated. The presented data will add information on the monitoring potential of CTC during adjuvant endocrine treatment.

Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr PD04-08.

Overexpression of TACE and TIMP3 mRNA in head and neck cancer: association with tumour development and progression

BACKGROUND

TACE/ADAM17 is a transmembranous protease that cleaves membrane-bound growth factors like EGFR ligands. TACE-dependent proteolysis is regulated by its inhibitor, tissue inhibitor of metalloproteinases 3 (TIMP3). This study analyses the role of TACE and TIMP3 mRNA expression in squamous cell carcinomas of the head and neck (HNSCCs).

METHODS

We analysed TACE and TIMP3 mRNA expression in HNSCCs from 106 patients by RNA in situ hybridisation.

RESULTS

TACE mRNA was upregulated in HNSCCs compared with dysplastic (P<0.05) and normal epithelia (P<0.001), with strong hybridisation signals in 21.9% of invasive tumour tissues and 4.5% of dysplasia. Elevated mRNA levels were accompanied by increased amounts of TACE protein in HNSCCs. TIMP3 mRNA expression in HNSCC-associated stroma was significantly higher than in the stroma adjacent to dysplastic or normal epithelia. Expression of TACE mRNA in HNSCCs was associated with tumour stage (P=0.019) and regional lymph node metastasis (P=0.009). Furthermore, levels of TACE mRNA in HNSCCs correlated with the expression of TIMP3 mRNA in HNSCC-associated stroma. Concomitantly, patients expressing high levels of TACE and TIMP3 mRNA showed significantly reduced overall survival compared with those with low mRNA levels.

CONCLUSION

Our results indicate an important role of TACE and TIMP3 during development and progression of HNSCCs.

Standardization of the immunocytochemical detection of cancer cells in BM and blood: I. establishment of objective criteria for the evaluation of immunostained cells

BACKGROUND

Detection of isolated tumor cells (TC) in BM from carcinoma patients can predict future relapse. Various molecular and immunocytochemical (ICC) methods have been used to detect these cells, which are present at extremely low frequencies of 10(-5) - 10(-6). The specificity and sensitivity of these techniques may vary widely. In 1996, a European ISHAGE Working Group was founded to standardize and optimize procedures used for the detection of minimal residual disease. We have attempted to develop objective criteria for the evaluation of immunocytochemically identifiable cancer cells.

METHODS

An interlaboratory ring experiment was performed, to compare the screening and detection of micrometastasis-positive events between different laboratories. The discrepant results induced us to establish a common consensus on morphological criteria applicable to the identification of immunostained micrometastatic TC.

RESULTS

Bared on this consensus evaluation, we propose a classification of stained elements into three groups: (1) 'TC's show pathognomonic signs of epithelial TC-nature, as defined by a clearly enlarged nucleus or clusters of > or = 2 immunopositive cells. (2) 'Probable TC's represent morphological overlap between hematopoietic cells (HC) and TC which lack pathognomonic signs of TC-nature, but do not exhibit clear morphological features of HC. These cells are considered as TC if control staining with an isotype-specific, unrelated Ab is negative. (3) 'TC-negative' cells are defined as 'false positive' HC, skin squamous epithelial cells and artefacts.

DISCUSSION

The proposed classification of immunostained events is a first step towards the development of standardized immunocytochemical assays for the detection of occult micrometastatic TC in BM or blood.