Automated Prostate Cancer Identification Facilitates Prognosis Marker Assessment in 11,845 Prostate Cancers Using Artificial Intelligence and BLEACH&STAIN Multiplex Fluorescence Immunohistochemistry

Introduction/Objective

Although most prostate cancers behave in an indolent manner, a small proportion is highly aggressive. To evaluate the patient’s risk, several prognosis parameters, that can be accompanied by a high interobserver variability has been established. A reproducible prognostic evaluation is lacking.

Methods/Case Report

To enable automated prognosis marker quantification, we have developed and validated a framework for automated prostate cancer detection that comprises three different artificial intelligence analysis steps and an algorithm for cell-distance analysis of BLEACH&STAIN multiplex fluorescence immunohistochemistry (mfIHC). We have used the analysis framework to measure PSA, PSMA, INSM1, AR, Ki-67, CD56, Chromogranin A, Synaptophysin, CD8 in a cohort of 11,845 prostate cancers.

Results (if a Case Study enter NA)

The Ki-67 labeling index provided the strongest prognostic information among all analyzed prognosis marker in 11,845 successfully analyzed prostate cancers (p<0.001 each). The combined analysis of the Ki67-LI and Gleason grades obtained on identical tissue spots showed that the Ki67-LI added significant additional prognostic information in case of classical ISUP grades (AUC:0.82 [p=0.002]) and quantitative Gleason grades (AUC:0.83 [p=0.018]). Several combinations of these 8 prognosis markers were combined to prognosis scores and used for unsupervised clustering to identify a proportion of prostate cancers with a particularly poor prognosis (p<0.001 each).

Conclusion

Automated prostate cancer identification enables fully automated prognosis marker assessment in routine clinical practice using deep learning and BLEACH&STAIN mfIHC.

Automated prognosis marker assessment in 2,004 breast cancers using an artificial intelligence-based framework for BLEACH&STAIN multiplex fluorescence immunohistochemistry

Introduction/Objective

Introduction: Prognostic markers in routine clinical practice of breast cancer are currently assessed using multi-gene panels. However, the fluctuating tumor purity can reduce the predictive value of such tests. Immunohistochemistry holds the potential for a better risk assessment.

Methods/Case Report

Methods: To enable automated prognosis marker detection (i.e. HER2, GATA3, progesterone-[PR], estrogen- [ER], and androgen receptor [AR], TOP2A, Ki-67, TROP2), we have developed and validated a framework for automated breast cancer identification, which comprises three different artificial intelligence analysis steps and an algorithm for cell-distance analysis of 11 + 1 marker BLEACH&STAIN multiplex fluorescence immunohistochemistry (mfIHC) staining in 2,004 breast cancers.

Results (if a Case Study enter NA)

Results: The optimal distance between Myosin+ basal cells and benign panCK+ cells was identified as 25 µm and used to exclude benign glands from the analysis combined with several deep learning-based algorithms. Our framework discriminated normal glands from malignant glands with an AUC of 0.96. The accuracy of the approach was also validated by well-characterized biological findings, such as the identification of 13% HER2+, 73% PR+/ER+, and 14 triple negative cases. Furthermore, the automated assessment of GATA3, PR, ER, TOP2A-LI, Ki-67-LI and TROP2 was significantly liked to the tumor grade (p<0.001each). Furthermore, a high expression level of HER2, GATA3, PR, and ER was associated with a prolonged overall survival (p≥0.002 each).

Conclusion

Conclusion: A deep learning-based framework for automated breast cancer identification using BLEACH&STAIN multiplex fluorescence IHC facilitates automated prognosis marker quantification in breast cancer.

Cadherin-16 (CDH16) Immunohistochemistry: A Novel Diagnostic Tool for Renal Cell Carcinoma and Papillary Carcinomas of the Thyroid

Introduction/Objective

Introduction: Cadherin-16 (CDH16), also termed kidney specific cadherin (ksp-cadherin), is a membrane-associated glycoprotein with a role in the embryonal development of tubules in kidney and thyroid. Downregulation of CDH16 RNA was found in papillary carcinomas of the thyroid.

Methods/Case Report

Methods: A set of tissue microarrays containing 14,978 samples from 149 different tumor types and subtypes as well as 608 samples of 76 different normal tissue types was analyzed by immunohistochemistry to determine the expression of CDH16 in cancer and to assess the diagnostic utility of immunohistochemical CDH16 analysis.

Results (if a Case Study enter NA)

Results: Among normal tissues, a membranous CDH16 immunostaining predominated in thyroid, kidney, cauda epididymis, and in mesonephric remnants. In the thyroid, CDH16 staining was seen in 100% of normal samples, 83% of follicular adenomas, 58% of follicular carcinomas, but in only 9% of papillary carcinomas (p<0.0001). Among non-thyroidal tumors, CDH16 positivity was particularly frequent in nephrogenic adenomas (100%), oncocytomas (98%), chromophobe (97%), clear cell (85%), and papillary (76%) renal cell carcinomas (RCCs), clear cell (56%), mucinous (36%), and endometroid (16%) carcinomas as well as carcinosarcomas (18%) of the ovary, adenocarcinomas of the cervix uteri (40%), serous (33%), clear cell (33%), and endometroid carcinomas (18%) of the endometrium and in various subtypes of neuroendocrine neoplasms (4-26%).

Conclusion

Given the massive loss of CDH16 expression in >90% of papillary carcinomas of the thyroid, CDH16 is a highly useful diagnostic marker for these tumors. CDH16 immunohistochemistry is also useful for the identification of nephrogenic adenomas and the distinction of renal cell carcinomas from other neoplasms.

A Comparative Analysis of CPA1, bcl10 and Chymotrypsin for the Distinction of Pancreatic Acinar Cell Carcinomas

Introduction/Objective

Introduction: Pancreatic acinar cell carcinoma (PACC) is a rare tumor of the pancreas with an intermediate prognosis as compared to pancreatic neuroendocrine tumors (PNE) and pancreatic ductal adenocarcinoma (PDAC) from which it may be difficult to distinguish by morphology alone.

Methods/Case Report

Methods: To study was the efficiency of immunohistochemical markers, 18 PACCs, 531 PDACs, 64 PNEs, 117 extra pancreatic neuroendocrine neoplasms (EPNN), 826 colorectal carcinomas (CRC) and 252 gastric carcinomas (GC) were analyzed with antibodies for CPA1 (MSVA-601M), bcl10 (Santa Cruz sc5273), and chymotrypsin (Biorad 2100-0657) in a tissue microarray format.

Results (if a Case Study enter NA)

Results: CPA1 was positive in 18 of 18 (100%) of PACCs, 0 of 49 (0%) of PNEs, 0 of 88 (0%) of EPNNs, 10 of 404 (2.5%) of CRCs, and 0 of 178 (0%) of GCs. Chymotrypsin was positive in 16 (87,5%) PACCs, 1 (2%) PNEs, 2 (2.3%) EPNNs, 10 (2.5%) CRCs, and 1 (0.6%) GCs. Bcl10 was positive in 18 (100%) PACCs, 2 (4.1%) PNEs, 5 (1%) EPNNs, 109 (27%) CRCs, and 18 (10%) GCs. These data resulted in a sensitivity and specificity of 100%/99.2% for CPA1, 100%/88.4% for bcl10, and 94.4%/98.6% for chymotrypsin.

Conclusion

CPA1 and chymotrypsin are both highly specific and sensitive for ACC while bcl10 is sensitive but has markedly lower specificity. Because all “false positive” cases identified by CPA1 were CRCs that only showed a positive staining in goblet cells and an identical staining pattern was observed in all these cases for chymotrypsin and bcl10, a pancreatic origin of the mucus in these goblet cells is concluded.

Consensus care recommendations for alfapump® in cirrhotic patients with refractory or recurrent ascites

Background

The alfapump^® is an implantable class III medical device that pumps ascitic fluid from the peritoneal space to the urinary bladder from where it is excreted. The pump reduces or abrogates the need for repeated paracentesis in patients with recurrent or refractory ascites.

Aims

To improve outcomes for alfapump^® implantation and pre- and post-implant patient management in both clinical trial and real-world settings by development of consensus recommendations.

Methods

The alfapump^® working group consisting of hepatologists and surgeons with extensive experience in implantation of the alfapump^® and patient management met on two occasions: (1) to determine the key areas where recommendations should be made; and (2) to discuss the experiences of the working group within those areas and formulate draft statements. Developed statements were submitted to the group and consensus sought on relevance and wording through a collaborative iterative approach in order to consolidate the recommendations into consensus statements. Only recommendations agreed upon unanimously were included.

Results

Twenty-three consensus recommendations were developed in the areas of pre-implantation procedure, (three statements), surgical implant procedure (11 statements), immediate post-implant care (three statements) and long-term management (six statements).

Conclusions

The consensus statements are a valuable reference resource for physicians managing patients with the alfapump^® and for those considering management strategies for patients with refractory ascites.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12876-022-02173-5.

Semi-automated validation and quantification of CTLA-4 in 90 different Tumor entities using multiple antibodies and artificial intelligence

Introduction/Objective

Introduction: CTLA-4 is an inhibitory immune checkpoint receptor and a negative regulator of anti-tumor T-cell function. This study aimed at a comparative analysis of CTLA-4+ entities. cells between different tumor

Methods/Case Report

Methods: To quantify CTLA-4+ cells, 4,582 tumor samples from 90 different tumor entities as well as 608 samples of 76 different normal tissue types were analyzed by immunohistochemistry in a tissue microarray format. Two different antibody clones (MSVA-152R and CAL49) were validated and quantified using a deep learning framework for automated exclusion of unspecific immunostaining.

Results (if a Case Study enter NA)

Results: Comparing both CTLA-4 antibodies revealed a clone dependent unspecific staining pattern in adrenal cortical adenoma (63%) for MSVA-152R and in pheochromocytoma (67%) as well as hepatocellular carcinoma (36%) for CAL49. After automated exclusion of non-specific staining reaction (3.6%), a strong correlation was observed for the densities of CTLA-4+ lymphocytes obtained by both antibodies (r=0.87; p<0.0001). The mean density of CTLA-4+cells was 674±1482 cells/ mm2 and ranged from 71±175 cells/mm2 in leiomyoma to 5916±3826 cells/mm2 in Hodgkin’s lymphoma. Within epithelial tumors, the density of CTLA-4+ lymphocytes were higher in squamous cell (421±467 cells/ mm2) and urothelial carcinomas (419±347 cells/ mm2) than in adenocarcinomas (269±375 cells/ mm2) and renal cell neoplasms (256±269 cells/ mm2). A high CTLA-4+ cell density was linked to low pT category (p<0.0001), absent lymph node metastases (p=0.0354), and PD-L1 expression in tumor cells or inflammatory cells (p<0.0001 each). A high CTLA-4/CD3-ratio was linked to absent lymph node metastases (p=0.0295) and to PD-L1 positivity on immune cells (p<0.0026).

Conclusion

Marked differences exist in the number of CTLA-4+ lymphocytes between tumors. Analyzing two independent antibodies by a deep learning framework can facilitate automated quantification of immunohistochemically analyzed target proteins such as CTLA-4.

P02.03 Automated cell type specific PD-L1 quantification by artificial intelligence using high throughput bleach & stain 15-marker multiplex fluorescence immunohistochemistry in human cancers

Background

The quantification of PD-L1 (programmed cell death ligand 1) has been used to predict patient’s survival, to characterize the tumor immune microenvironment, and to predict response to immune checkpoint therapies. However, a framework to assess the PD-L1 status with a high interobserver reproducibility on tumor cells and different types of immune cells has yet to be established.

Materials and Methods

To study the impact of PD-L1 expression on the tumor immune microenvironment and patient outcome, a framework for fully automated PD-L1 quantification on tumor cells and immune cells was established and validated. Automated PD-L1 quantification was facilitated by incorporating three different deep learning steps for the analysis of more than 80 different neoplasms from more than 10’000 tumor specimens using a bleach & stain 15-marker multiplex fluorescence immunohistochemistry panel (i.e., PD-L1, PD-1, CTLA-4, panCK, CD68, CD163, CD11c, iNOS, CD3, CD8, CD4, FOXP3, CD20, Ki67, CD31). Clinicopathological parameter were available for more than 30 tumor entities and overall survival data were available for 1517 breast cancer specimens.

Results

Comparing the automated deep-learning based PD-L1 quantification with conventional brightfield PD-L1 data revealed a high concordance in tumor cells (p<0.0001) as well as immune cells (p<0.0001) and an accuracy of the automated PD-L1 quantification ranging from 90% to 95.2%. Across all tumor entities, the PD-L1 expression level was significantly higher in distinct macrophage/dendritic cell (DC) subsets (identified by CD68, CD163, CD11c, iNOS; p<000.1) and in macrophages/DCs located in the Stroma (p<0.0001) as compared to intratumoral macrophages/DC subsets. Across all different tumor entities, the PD-L1 expression was highly variable and distinct PD-L1 driven immune phenotypes were identified based on the PD-L1 intensity on both tumor and immune cells, the distance between non-exhausted T-cell subsets (i.e. PD-1 and CTLA-4 expression on CD3+CD8+ cytotoxic T-cells, CD3+CD4+ T-helper cells, CD3+CD4+FOXP3+ regulatory T-cells) and tumor cells as well as macrophage/(DC) subtypes. In breast cancer, the PD-L1 fluorescence intensity on tumor cells showed a significantly higher predictive performance for overall survival with an area under receiver operating curves (AUC) of 0.72 (p<0.0001) than the percentage of PD-L1+ tumor cells (AUC: 0.54). In PD-L1 positive as well as negative breast cancers a close spatial relationship between T- cell subsets (CD3+CD4±CD8±FOXP3±PD-1±CTLA-4±) and Macrophage/DC subsets (CD68±CD163±CD11c±iNOS) was found prognostic relevant (p<0.0001).

Conclusions

In conclusion, multiplex immunofluorescence PD-L1 assessment provides cutoff-free/continuous PD-L1 data which are superior to the conventional percentage of PD-L1+ tumor cells and of high prognostic relevance. The combined analysis of spatial PD-L1/PD-1 data and more than 20 different immune cell subtypes of the immune tumor microenvironment revealed distinct PD-L1 immune phenotypes.

Disclosure Information

N.C. Blessin: None. E. Bady: None. T. Mandelkow: None. C. Yang: None. J. Raedler: None. R. Simon: None. C. Fraune: None. M. Lennartz: None. S. Minner: None. E. Burandt: None. D. Höflmayer: None. G. Sauter: None. S.A. Weidemann: None.

Abstract PD3-11: HER2/ERBB2 status in “HER2 equivocal” breast cancers by FISH and ASCO-CAP guidelines: False-positives due to heterozygous deletions of alternative control loci

Background. The ASCO-CAP guidelines for HER2 testing by fluorescence in situ hybridization (FISH) have a category, referred to as “equivocal” (average HER2 copies per tumor cell &gt;4-6 with HER2/CEP17 ratio &lt;2·0), which is neither “HER2-positive” nor “HER2-negative”. Approximately 4% - 12% of invasive breast cancers are “HER2-equivocal” based on FISH. Cancers in this category may be resolved as “negative” or “positive” by FISH alternative control probes (2013/2014 guidelines) or HER2 immunohistochemistry (IHC) (2018 update). Our objectives were to evaluate the following hypotheses: 1.) Genetic loci used as alternative controls show heterozygous deletion in a substantial proportion of breast cancers; 2.) Use of these loci for assessment of HER2 by FISH leads to false-positives; 3.) HER2 FISH false-positive breast cancer patients have outcomes that do not differ from clinical outcomes for HER2-negative breast cancer patients; and 4.) HER2-equivocal breast cancers seldom show HER2 protein overexpression (IHC 3+).

Methods. We retrospectively assessed the use of chromosome 17 p-arm and q-arm alternative control genomic sites (TP53, D17S122, SMS, RARA, TOP2A), as recommended by the 2013/2014 ASCO-CAP guidelines, in patients whose data were available through the Molecular Taxonomy of Breast Cancer International Consortium (METABRIC)(N=1980) or whose tissues were available from the BCIRG-005 clinical trial (N=3298). We used either FDA-approved HER2 IHC (HercepTest) or laboratory-developed HER2 (10H8) IHC assays to assess HER2 protein expression.

Results. Using METABRIC we found heterozygous deletions, particularly in specific p-arm sites, were common in both HER2-amplified and HER2-not-amplified breast cancers. Use of alternative control probes from these regions to assess HER2 by FISH in “HER2 equivocal” as well as HER2-not-amplified breast cancers resulted in high rates of false-positive ratios (HER2-to-alternative control ratio &gt;2·0) due to heterozygous deletions of control p-arm genomic sites used as ratio denominators. Misclassifications of HER2 status was observed not only in breast cancers with ASCO-CAP “equivocal” status but also in breast cancers with an average of &lt;4·0 HER2 copies per tumor cell. These deletions were also identified by FISH. IHC demonstrated &lt;1% of FISH “HER2-equivocal” breast cancers in BCIRG-005 had IHC3+ immunostaining, consistent with HER2-not-amplified status. Clinical outcomes of “HER2-equivocal” breast cancer patients with HER2-to-alternative control ratio &gt;2·0 did not differ significantly from clinical outcomes of those with HER2-to-alternative control ratio&lt;2·0.

Conclusion. Using chromosome 17 p-arm alternative controls, as recommended by 2013/2014 ASCO-CAP guidelines, instead of CEP17 for resolution of “HER2 equivocal” cases, is problematic due to frequent heterozygous deletions of these loci in breast cancers. The indiscriminate use of alternative control probes to calculate a HER2 FISH ratio in “HER2-equivocal” breast cancers leads to false-positive interpretations of HER2 status resulting from unrecognized heterozygous deletions in one or more of these alternative control genomic sites and incorrect HER2 ratio determinations.

Citation Format: Press MF, Seoane JA, Curtis C, Quinaux E, Guzman R, Sauter G, Eiermann W, Mackey JR, Robert N, Pienkowski T, Crown J, Martin M, Valero V, Bee V, Ma Y, Villalobos I, Slamon DJ. HER2/ERBB2 status in “HER2 equivocal” breast cancers by FISH and ASCO-CAP guidelines: False-positives due to heterozygous deletions of alternative control loci [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr PD3-11.

The branched-chain amino acid transaminase 1 sustains growth of antiestrogen-resistant and ERα-negative breast cancer

Antiestrogen-resistant and triple-negative breast tumors pose a serious clinical challenge because of limited treatment options. We assessed global gene expression changes in antiestrogen-sensitive compared with antiestrogen-resistant (two tamoxifen resistant and two fulvestrant resistant) MCF-7 breast cancer cell lines. The branched-chain amino acid transaminase 1 (BCAT1), which catalyzes the first step in the breakdown of branched-chain amino acids, was among the most upregulated transcripts in antiestrogen-resistant cells. Elevated BCAT1 expression was confirmed in relapsed tamoxifen-resistant breast tumor specimens. High intratumoral BCAT1 levels were associated with a reduced relapse-free survival in adjuvant tamoxifen-treated patients and overall survival in unselected patients. On a tissue microarray (n=1421), BCAT1 expression was detectable in 58% of unselected primary breast carcinomas and linked to a higher Ki-67 proliferation index, as well as histological grade. Interestingly, BCAT1 was predominantly expressed in estrogen receptor-α-negative/human epidermal growth factor receptor-2-positive (ERα-negative/HER-2-positive) and triple-negative breast cancers in independent patient cohorts. The inverse relationship between BCAT1 and ERα was corroborated in various breast cancer cell lines and pharmacological long-term depletion of ERα induced BCAT1 expression in vitro. Mechanistically, BCAT1 indirectly controlled expression of the cell cycle inhibitor p27^Kip1 thereby affecting pRB. Correspondingly, phenotypic analyses using a lentiviral-mediated BCAT1 short hairpin RNA knockdown revealed that BCAT1 sustains proliferation in addition to migration and invasion and that its overexpression enhanced the capacity of antiestrogen-sensitive cells to grow in the presence of antiestrogens. Importantly, silencing of BCAT1 in an orthotopic triple-negative xenograft model resulted in a massive reduction of tumor volume in vivo, supporting our findings that BCAT1 is necessary for the growth of hormone-independent breast tumors.

MALDI imaging mass spectrometry reveals multiple clinically relevant masses in colorectal cancer using large-scale tissue microarrays

For identification of clinically relevant masses to predict status, grade, relapse and prognosis of colorectal cancer, we applied Matrix-assisted laser desorption ionization (MALDI) imaging mass spectrometry (IMS) to a tissue micro array containing formalin-fixed and paraffin-embedded tissue samples from 349 patients. Analysis of our MALDI-IMS data revealed 27 different m/z signals associated with epithelial structures. Comparison of these signals showed significant association with status, grade and Ki-67 labeling index. Fifteen out of 27 IMS signals revealed a significant association with survival. For seven signals (m/z 654, 776, 788, 904, 944, 975 and 1013) the absence and for eight signals (m/z 643, 678, 836, 886, 898, 1095, 1459 and 1477) the presence were associated with decreased life expectancy, including five masses (m/z 788, 836, 904, 944 and 1013) that provided prognostic information independently from the established prognosticators pT and pN. Combination of these five masses resulted in a three-step classifier that provided prognostic information superior to univariate analysis. In addition, a total of 19 masses were associated with tumor stage, grade, metastasis and cell proliferation. Our data demonstrate the suitability of combining IMS and large-scale tissue micro arrays to simultaneously identify and validate clinically useful molecular marker. Copyright © 2017 John Wiley & Sons, Ltd.

Long-term outcomes after adjuvant treatment of sequential versus combination docetaxel with doxorubicin and cyclophosphamide in node-positive breast cancer: BCIRG-005 randomized trial

BACKGROUND

The optimal regimen for adjuvant breast cancer chemotherapy is undefined. We compared sequential to concurrent combination of doxorubicin and cyclophosphamide with docetaxel chemotherapy in women with node-positive non-metastatic breast cancer. We report the final, 10-year analysis of disease-free survival (DFS), overall survival (OS), and long-term safety.

PATIENTS AND METHODS

A total of 3298 women with HER2 nonamplified breast cancer were randomized to doxorubicin and cyclophosphamide every 3 weeks for four cycles followed by docetaxel (AC → T) every 3 weeks for four cycles or docetaxel, doxorubicin, and cyclophosphamide (TAC) every 3 weeks for six cycles. The patients received standard radiotherapy and endocrine therapy and were followed up for 10 years with annual clinical evaluation and mammography.

RESULTS

The 10-year DFS rates were 66.5% in the AC → T arm and 66.3% in the TAC arm (P = 0.749). OS was 79.9% in the AC → T arm and 78.9% in the TAC arm (P = 0.506). TAC was associated with higher rates of febrile neutropenia, although G-CSF primary prophylaxis greatly reduced this risk. AC → T was associated with a higher rate of myalgia, hand-foot syndrome, fluid retention, and sensory neuropathy.

CONCLUSION

This 10-year analysis of the BCIRG-005 trial confirmed that the efficacy of TAC was not superior to AC → T in women with node-positive early breast cancer. The toxicity profiles differ between arms and were consistent with previous reports. The TAC regimen with G-CSF support provides shorter adjuvant treatment duration with less toxicity.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier NCT00312208.

8p deletion is strongly linked to poor prognosis in breast cancer

Deletions of chromosome 8p occur frequently in breast cancers, but analyses of its clinical relevance have been limited to small patient cohorts and provided controversial results. A tissue microarray with 2,197 breast cancers was thus analyzed by fluorescence in-situ hybridization using an 8p21 probe in combination with a centromere 8 reference probe. 8p deletions were found in 50% of carcinomas with no special type, 67% of papillary, 28% of tubular, 37% of lobular cancers and 56% of cancers with medullary features. Deletions were always heterozygous. 8p deletion was significantly linked to advanced tumor stage (P < 0.0001), high-grade (P < 0.0001), high tumor cell proliferation (Ki67 Labeling Index; P < 0.0001), and shortened overall survival (P < 0.0001). For example, 8p deletion was seen in 32% of 290 grade 1, 43% of 438 grade 2, and 65% of 427 grade 3 cancers. In addition, 8p deletions were strongly linked to amplification of MYC (P < 0.0001), HER2 (P < 0.0001), and CCND1 (p = 0.001), but inversely associated with ER receptor expression (p = 0.0001). Remarkably, 46.5% of 8p-deleted cancers harbored amplification of at least one of the analyzed genes as compared to 27.5% amplifications in 8p-non-deleted cancers (P < 0.0001). In conclusion, 8p deletion characterizes a subset of particularly aggressive breast cancers. As 8p deletions are easy to analyze, this feature appears to be highly suited for future DNA based prognostic breast cancer panels. The strong link of 8p deletion with various gene amplifications raises the possibility of a role for regulating genomic stability.

Altered PTEN function caused by deletion or gene disruption is associated with poor prognosis in rectal but not in colon cancer

Colorectal cancer is the third most common malignancy worldwide. Anti-epidermal growth factor receptor (EGFR)-targeted therapy shows clinical evidence in this malignancy and improves outcome. The tumor suppressor gene phosphatase and tensin homologue (PTEN) is considered a potential predictor of nonresponse to anti-EGFR agents. The purpose of this study was to assess whether associations between PTEN alterations (PTEN gene deletion or PTEN gene disruption) and clinical outcome could be caused by a prognostic (and not predictive) effect of PTEN inactivation. Therefore, we analyzed 404 colorectal cancers not previously treated with anti-EGFR drugs in a tissue microarray format. PTEN deletion and PTEN gene rearrangements were analyzed by fluorescence in situ hybridization. Heterogeneity analysis of all available large tissue sections was performed in 6 cases with genomic PTEN alteration. Twenty-seven (8.8%) of 307 analyzable colorectal cancer spots showed genomic PTEN alterations including 24 hemizygous and 1 homozygous deletion as well as 2 PTEN gene disruptions. Genomic PTEN alterations were associated with reduced patient survival in rectal cancer in univariate and multivariate analyses (P = .012; hazard ratio, 2.675; 95% confidence interval, 1.242-5.759) but not in colon cancer. Large-section evaluation revealed a homogeneous distribution pattern in all 4 analyzed cases with PTEN deletion and in both cases with a PTEN gene disruption. In conclusion, genomic PTEN gene alterations caused by deletion or gene disruption characterize a fraction of rectal cancers with particularly poor outcome.

Prognostic relevance of AIB1 (NCoA3) amplification and overexpression in breast cancer

AIB1 (amplified in breast cancer 1) is an estrogen receptorα (ERα) co-activator, known to be amplified and overexpressed in a fraction of breast cancers. It has been linked to prognosis and tamoxifen resistance. However, results have been ambiguous. The different functions of AIB1 in ERα-positive and -negative disease are poorly understood. Therefore, we analyzed the clinical significance of AIB1 in breast cancer with respect to ERα-status and characterized the subgroups. 2,197 breast carcinomas sampled on a pre-existing tissue microarray (TMA) were analyzed for AIB1 expression and amplification by immunohistochemistry (IHC) and fluorescence in situ hybridization (FISH).

RESULTS

AIB1 expression was detected in 60 % of the tumors. It was associated with tumor size (p = 0.003), high histological grade (p < 0.0001), poor disease-specific, and overall survival (p = 0.0018 and p = 0.003). There was a strong inverse relationship between AIB1 and ERα expression (p < 0.0001). AIB1 overexpression was associated with increased Ki67 labeling index (p < 0.0001), even if analyzed for different ER expression levels. AIB1 amplification was found in 11 % of the carcinomas. It was associated with high histological grade (p = 0.0012), lymph node involvement (p = 0.0163), and poor disease-specific survival (p = 0.0032) but not with overall survival (p = 0.1672) or ER status (p = 0.4456). If ER-positive tumors were stratified according to their AIB1 amplification status, there was a significant worse disease-specific survival in cases showing AIB1 amplification (p = 0.0017). AIB1 expression is associated with unfavorable prognosis and tumor phenotype. It seems to unfold its oncogenic potential at least in part independent from its role as an ERα co-activator. AIB1 has an impact on cell cycle regulation in ERα-positive as well as ERα-negative tumors. Furthermore, AIB1 amplification characterizes a subgroup of ERα-positive breast cancer with worse outcome. Therefore, AIB1 might be helpful to identify those ERα-positive breast cancers patients who are candidates for adjuvant chemotherapy.

Staging and outcome depending on surgical treatment in adenocarcinomas of the oesophagogastric junction

BACKGROUND

Owing to controversial staging and classification of adenocarcinoma of the oesophago-gastric junction (AOG) before surgery, the choice of appropriate surgical approach remains problematic. In a retrospective study, preoperative staging of AOG and the impact of preoperative misclassification on outcome were analysed.

METHODS

Data from patients with AOG were analysed from a prospectively collected database with regard to surgical treatment, preoperative and postoperative staging, and outcome.

RESULTS

One-hundred and thirty patients with Siewert types I and II AOG who did not have neoadjuvant treatment were included in the study: 41 patients with an AOG type I who underwent oesophagectomy, 51 patients with an AOG staged before surgery as type I who underwent oesophagectomy but in whom the final histology showed a type II tumour, and 38 patients whose tumours were staged as AOG type II before and after operation who underwent gastrectomy. Among patients who had an oesophagectomy, lymph node metastases (P = 0.022), tumour relapse (P = 0.009) and recurrent distant metastases (P = 0.028) were significantly more frequent in patients with AOG type II; those with AOG type II had shorter overall survival than those with type I tumours (P = 0.024). Among those with AOG type II, recurrence-free survival was significantly shorter after oesophagectomy compared with extended gastrectomy (P = 0.019). Thoracoabdominal oesophagectomy had a favourable influence on outcome compared with the transhiatal approach.

CONCLUSION

Accurate preoperative staging of AOG and appropriate surgical therapy are crucial for outcome. AOG type II is a more aggressive tumour with higher recurrence rates than AOG type I. These patients therefore benefit from more radical surgical treatment.

p53 protein accumulation and p53 gene alterations (RFLP, VNTR and p53 gene mutations) in non-invasive versus invasive human transitional bladder cancer

Eleven non-invasive and 24 invasive transitional cell bladder cancers were analysed for molecular alterations to the p53 gene and nuclear accumulation of the p53 protein. 9% (1/11) of non-invasive rumours and 21% (5/24) of invasive tumours revealed nuclear accumulation in more than 50% of the tumour cells. PCR analysis of D17S30 showed loss of heterozygosity (LOH) in invasive tumours (3/24; 12%). Two invasive tumours harboured point mutations in exon 6 and exon 7, respectively (8%). Our results indicate that p53 protein overexpression correlates with tumour progression, p53 gene mutations and LOH detected by PCR.

Prognostic relevance of Bcl-2 overexpression in surgically treated prostate cancer is not caused by increased copy number or translocation of the gene

BACKGROUND

Overexpression of anti-apoptotic Bcl-2 plays a role in prostate cancer progression, particularly in transformation to androgen-independent disease. Androgen-independent prostate cancers have been shown to harbor Bcl-2 gene copy number gains frequently suggesting that this genetic alteration might play a role in Bcl-2 overexpression. The relation of Bcl-2 overexpression and copy number gains or translocation of the BCL-2 gene in prostate cancer under hormone-naïve conditions is unknown.

METHODS

Prostate cancers of 3,261 hormone-naïve patients undergoing radical prostatectomy were arrayed in a TMA with one tissue core (diameter 0.6 mm) per tumor. Bcl-2 immunohistochemistry, analyzed for Bcl-2 expression level (negative, low, and high), was correlated with clinical, histopathological and molecular (Ki67, p53) tumor features, and biochemical failure. Cancers with high-level Bcl-2 expression were evaluated for genetic aberrations by fluorescence in situ hybridization (FISH).

RESULTS

Bcl-2 expression was significantly up-regulated in tumors with aggressive phenotype as indicated by high Gleason score (P < 0.0001), advanced stage (P < 0.0001), and high proliferation index (P = 0.0114). The different Bcl-2 expression levels translated into significantly different survival curves showing better outcome for patients with lower Bcl-2 levels. The prognostic information obtained from the anti-apoptotic Bcl-2 was independent from the proliferation index (Ki67) of the cancer. FISH analysis detected no copy number gains or translocation of the Bcl-2 gene.

CONCLUSION

Bcl-2 overexpression in prostate cancers under hormone-naïve conditions is not associated with increased copy numbers of the gene. This suggests that these frequently detected genetic alterations in androgen-independent tumors occur late in prostate cancer progression.

Expression of insulin-like growth factor II mRNA-binding protein 3 in squamous cell carcinomas of the head and neck

BACKGROUND

Insulin-like growth factor II mRNA-binding protein 3 (IMP3) was found overexpressed in various cancer types suggesting its possible role in carcinogenesis. Analysis of IMP3 expression in head and neck squamous cell carcinomas (HNSCC) is rare so that we evaluated it using tissue microarray method.

METHOD

Immunohistochemical analysis of IMP3 was performed on samples from over 400 patients. The expression was measured semiquantitative, subsequently divided into four categories (negative, weak, medium, or strong) and correlated with several available clinicopathologic parameters.

RESULTS

For HNSCC, positive IMP3 expression was observed in patients with all tumor stages (pT1-4) and nodal stages (pN0-3), showing also significant statistical correlation (P=0.023 and P=0.0013, respectively). No further correlations were found. Separate analysis according to tumor localization (oral cavity, oropharyngeal, and laryngeal) showed a significant correlation of positive IMP3 expression and overall survival (P=0.038) only in patients with tumors of the oral cavity. Multivariate analysis showed IMP3 as an independent predictive marker for oral squamous cell carcinomas (OSCC).

CONCLUSION

Insulin-like growth factor II mRNA-binding protein 3 (IMP3) expression might be used as an independent prognostic factor in the subgroup of OSCC.

P3-05-05: Cyclin D1 Gene Amplification Is Rarely Heterogeneous in Breast Cancer

Background: Amplification of Cyclin D1 (CCND1) occurs in about 10–20% of breast cancers and has been suggested to predict resistance to anti-hormonal therapy. As the diagnostic accuracy of predictive biomarkers can be substantially limited by regional expression differences within tumors, heterogeneity of CCND1 amplification was assessed in this study. To assess heterogeneity, a novel tissue microarray based analysis platform was developed.

Material and Methods: To comprehensively asses the three-dimensional molecular composition of breast cancers, a “heterogeneity TMA” was constructed containing 8 different tissue cylinders from as many different cancer containing tumor blocks as possible (at least 4) from 147 primary breast cancers. Additional tissue samples were taken from 1–4 corresponding nodal metastases from 35 of these patients. Dual labeling fluorescence in situ hybridization (FISH) with probes for CCND1 and centromere 11 was applied.

Results: The analysis revealed amplification in 29 of 133 (21.8%) patients with interpretable FISH data. CCND1 amplification was more frequently seen in ductal (22 of 87; 25.29%) than in lobular type (5 of 32; 15.63%) (p=0.251). CCND1 amplification was also associated with high tumor grade with amplification rates of 1 of 18 (5.56%) in grade 1, 15 of 72 (20.83%) in grade 2 and 12 of 40 (30%) in grade 3 carcinoma (p=0.075). CCND1 amplification was more frequently seen in ER positive cases (27 of 110; 24.55%) than in ER negative cases (1 of 17; 5.88%) (p=0.052). No association could be found between CCND1 amplification and tumor stage (p=0.445) and CCND1 amplification and PR status (p=0.752). Heterogeneous amplification status was detected in 9 of 29 (31.0%) amplified tumors, i.e. in 6.8% of all informative cases. Heterogeneity was successfully validated on large sections in all 4 heterogeneous cases with high level amplification. In the remaining 5 “heterogeneous cases” discordant results were due to variable interpretation of borderline amplification results with CCND1/centromer 11 ratios between 1.7 and 2.3. There were no discrepancies seen between primary tumors and matched lymph node metastases.

Discussion: The high degree of homogeneity seen for CCND1 amplification suggests that this alteration represents an early event in tumor development/progression in a subset of breast cancers. CCND1 status determined in a small biopsy will be highly representative of the entire tumor and will thus be appropriate for predicting treatment outcome.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P3-05-05.

Chromosomal deletions, tumor phenotype, and prognosis in prostate cancer

37

Background: Chromosomal deletions are frequent in prostate cancer (PCa) but target genes and potential clinical significance are often unknown. This project aimed at the identification of frequent and new deletions in PCa and to study their association with tumor phenotype and PSA recurrence.

Methods: Array CGH was performed on 77 advanced PCa. Deletions of interest were subsequently analyzed on a tissue microarray containing more than 2000 PCa with clinical follow-up data using fluorescence in situ hybridization (FISH). The FISH probes used included a break-apart probe for TMPRSS2-ERG and dual-labeling probes for centromere 10/PTEN and centromere 3/3p14.

Results: The most frequent circumscribed deletions found by array CGH were 3p14 (including FOXP1) in 18%, 5q31 in 16%, 5q21 in 14%, 6q13 in 21%, 6q21 in 19%, 6q26 in 14%, 8p11 in 17%, 10q23 (including PTEN) in 18%, 12p13 in 14%, 13q14 in 14%, 16q24 in 22% and 21q (representing TMPRSS2-ERG fusion) in 18%. TMPRSS2-ERG fusions, PTEN and FOXP1 deletions were selected for FISH analysis. A TMPRSS2-ERG fusion was observed in 394 of 947 interpretable cases (41.6%). TMPRSS2-ERG fusion was unrelated to tumor stage, Gleason grade, and PSA recurrence. PTEN deletions were observed in 8.9% of 1844 interpretable cases and were associated with advanced tumor stage (p<0.0001), high Gleason grade (p<0.0001), and early biochemical recurrence (p<0.0001). FOXP1 deletions were seen in 5.0% of 619 cases. FOXP1 deletions were not significantly linked to tumor phenotype and outcome. Both PTEN and FOXP1 deletions were strongly linked to TMPRSS2-ERG fusions. TMPRSS2-ERG fusion positive tumors had PTEN deletions in 15.4% and FOXP1 deletions in 10.7%, while TMPRSS2-ERG fusion negative cancers had PTEN deletions in only 5.8% and FOXP1 deletions in only 2.0% of cases (p<0.0001 each).

Conclusions: The TMPRSS2-ERG fusion determines a genetically distinct subgroup of prostate cancers. Our data provide no evidence for a particular clinical behaviour of TMPRSS2-ERG fusion positive cancers in radically operated patients. PTEN and FOXP1 alterations are preferentially found in TMPRSS2-ERG fusion positive cancers. Both genes may potentially be involved in pathway dysregulation in these cancers.

No significant financial relationships to disclose.

Activating BRAF gene mutations are uncommon in hormone refractory prostate cancer in Caucasian patients

Activating mutations in the cytosolic serine/threonine kinase, BRAF, have been reported in a variety of neoplasms. BRAF activation may contribute to tumor growth via activation of the MAP/ERK kinase pathway, and BRAF represents a possible therapeutic target. Activating BRAF mutations were recently reported in approximately 10% of prostate cancer cases in Asian patients. In the present study, 43 hormone refractory prostate cancers were analyzed for BRAF mutations in order to determine whether anti-BRAF therapy is a suitable approach for advanced prostate cancer patients. In all of the studied tumors, BRAF exons 11 and 15 were PCR-amplified and sequenced, including the backward and forward sequences. BRAF mutations were noted only in the positive control tissues, but were not found in any of the 43 analyzed prostate cancers. We conclude that BRAF mutations occur only rarely in prostate cancers in Caucasian patients and are not associated with tumor progression. The application of anti-BRAF therapies may therefore not be beneficial for prostate cancer.

[Tumors of the urinary system. Current and old problems]

Principally there are two different types of bladder cancer. Non-invasive papillary low grade tumors (pTa G1-G2) are genetically stable, recur frequently but show a low risk of progression. On the other hand there are high grade tumors (pT1-4, carcinoma in situ), which are genetically unstable, show biologically aggressive behaviour and progress. The distinction between non-invasive (pTa) and minimal-invasive (pT1) is one of the most challenging areas in bladder pathology. Due to the lack of appropriate auxiliary analysis the diagnosis is based entirely on histopathology. P53 immunohistochemistry can be helpful in the assessment of recurring high grade neoplasia. Targeted therapy in bladder cancer is particularly interesting, since a high number of oncogenes are activated and overexpressed (e.g. HER2 and EGFR).

Gene amplification in ductal carcinoma in situ of the breast

Multiple different biologically and clinically relevant genes are often amplified in invasive breast cancer, including HER2, ESR1, CCND1, and MYC. So far, little is known about their role in tumor progression. To investigate their significance for tumor invasion, we compared pure ductal carcinoma in situ (DCIS) and DCIS associated with invasive cancer with regard to the amplification of these genes. Fluorescence in situ hybridization (FISH) was performed on a tissue microarray containing samples from 130 pure DCIS and 159 DCIS associated with invasive breast cancer. Of the latter patients, we analyzed the intraductal and invasive components separately. In addition, lymph node metastases of 23 patients with invasive carcinoma were included. Amplification rates of pure DCIS and DCIS associated with invasive cancer did not differ significantly (pure DCIS vs. DCIS associated with invasive cancer: HER2 22.7 vs. 24.2%, ESR1 19.0 vs. 24.1%, CCND1 10.0 vs. 14.8%, MYC 11.8 vs. 6.5%; P > 0.05). Furthermore, we observed a high concordance of the amplification status for all genes if in situ and invasive carcinoma of individual patients were compared. This applied also to the corresponding lymph node metastases. Our results indicate no significant differences between the gene amplification status of DCIS and invasive breast cancer concerning HER2, ESR1, CCND1, and MYC. Therefore, our data suggest an early role of all analyzed gene amplifications in breast cancer development but not in the initiation of invasive tumor growth.

[Osteoid osteoma. X-ray-controlled resection and histologic verification using a minimally invasive diamond bone-cutting system]

BACKGROUND

In recent years, osteoid osteomas have been treated more frequently by means of percutaneous procedures. The main disadvantage in patients with suspected osteoid osteoma is the lack of histological verification. Our study presents the results that we obtained using a minimally invasive diamond bone-cutting system allowing histologic verification.

MATERIALS AND METHODS

Six patients (age 10-20 years) with osteoid osteoma in the lower extremities were subjected to resection of the nidus using a minimally invasive water-cooled diamond bone-cutting system. All specimens were histologically processed and diagnosed.

RESULTS

In all patients the nidus was resected successfully, and the diagnosis was histologically confirmed. The mean operating time was 22.8 min. All patients were allowed full weight-bearing immediately, and hospitalization was a maximum of 2 days. All patients were free of pain and relapse-free during the entire 2-year postoperative follow-up.

CONCLUSION

In selected localizations with a clearly visible nidus, the minimally invasive diamond bone-cutting system presented here offers an alternative to the established surgical and percutaneous procedures for treating osteoid osteomas. This procedure combines the advantages of a minimally invasive technique with the option of histological verification of the diagnosis and correct nidus ablation.

Analysis of expression of TGF-β1 receptor (ALK-1) in normal and tumor tissues by tissue microarrays

e22044

Background: TGF-β1 is an important angiogenic factor involved in different aspects of angiogenesis and vessel maintenance. TGF-β1 receptors consist of class I, class II and accessory receptors. Activin-like kinase I (ALK-1) is a class I TGF- β1 receptor which is almost exclusively expressed on endothelial cells. Hereditary hemorrhagic telangiectasia (HHT) is caused by mutations in the ALK-1 gene. Knock-out mice for ALK-1 die during gestation due to vascular malformation. ALK-1 may thus represent an attractive target for anti-angiogenic therapy. A therapeutic monoclonal antibody (PF-03446962) against ALK-1 has been developed which is currently in phase I testing. Here we describe target validation in normal and tumor tissue using tissue micro-arrays (TMAs). Methods: Normal tissue arrays comprised of 609 individual histological samples representing 76 human tissues. Multi-tumor arrays consisted of 3923 individual tumor samples from 87 tumor types. Consecutive sections of tissue arrays were stained for ALK-1 and CD31. CD31 immunohistology (IHC) was performed to ensure presence of vessels within tissue samples. ALK-1 staining was graded 0=absent, 1=weak, 2= moderate and 3=strong by an experienced pathologist blinded to tissue type. Results: ALK-1 staining of vessels in normal tissues was generally weak (mostly grade 1 and rarely grade 2) and was detectable in lymphatic tissues including tonsil, lymph nodes, thymus and spleen, lung, the entire GI tract including parotid, submandibular and sublingual glands as well as pancreas. ALK-1 positive vessels were also found within the female genital tract including placenta, uterus and ovary. In human tumor vessels ALK-1 expression showed high variability between tumor types. The highest ALK-1 expression rate was found in lung cancer (NSCLC 49%, SCLC 83%), neuroendocrine pancreas tumor (71%), colon cancer (50%), chondrosarcoma 50%, angiosarcoma 40% and NHL (44%). Conclusions: TMAs are an excellent tool to verify target expression in normal and tumor tissues. Results may be used to predict side effects of targeted therapy and to direct phase II testing of innovative agents in patients likely to respond.

[Table: see text]

Amplication of the estrogen receptor 1 (ESR1) gene in mastopathy predicts development of breast cancer

Abstract #5037

Background: Mastopathy is a disease with fibrocystic changes (FCC) of the breast tissue commonly seen between the ages 30-50, but rare in postmenopausal women, and therefore suggestive of an association with estrogen stimulation. Whether FCC bears an elevated breast cancer risk is unclear. The role of ESR1 amplification in FCC has not previously been investigated. Material and Methods: Paraffin embedded tissues from 59 women with invasive breast cancer (BrCa) were analyzed. For all women, tissues with FCC taken at least 1.5 years before first diagnosis of BrCa (termed here “FCC old”) were also available. Average latency between FCC and BrCa was 6years (range1.5-17y). Immunohistochemistry (IHC) with antibody against estrogen receptor alpha (ER) and FISH-analyses with a probe for ESR1 (Zytovision, Bremerhafen/Germany) were performed. As a control, tissues from 19 women with FCC without a diagnosis of in situ or invasive breast carcinoma in the observed time frame (12-18y) were taken. Clinical-pathological data, such as histological subtype, tumour stage, tumour diameter, BRE-grade, patient's age and others, were available for statistical analysis. Results: After FISH analyses, 9 of 59 (15%) BrCa were amplified for ESR1. All ESR1-amplified BrCa were strongly positive for ER with IHC (at least 80% of tumour cells labelled). Tumour type or stage and BRE-grade did not correlate with ESR1-status. In all cases of ESR1 amplification in BrCa areas of amplification in FCC adjacent to the tumour were identified. Interestingly, in women with ESR1 amplification in BrCa, an amplification detectable in tissues with FCC prior to the first diagnosis of BrCa (“FCC old”) was noted but was absent in tissues from women with FCC who did not develop BrCa in the observed time frame. Non-neoplastic ESR1 amplified cells within FCC were strongly positive for ER with IHC. In unaltered mammary glands ESR1 amplification was not observed. Discussion: In this pre-selected collective of women with BrCa and history of FCC we found amplification of the ESR1 gene in 15% of BrCa. In these women, ESR1 amplification was also detectable in tissue with FCC taken prior to the first diagnosis of BrCa. This investigation shows that ESR1 amplification is an early event in breast pathology and its occurrence in FCC predicts development of BrCa.

Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 5037.

Oestrogen receptor gene (ESR1) amplification is frequent in endometrial carcinoma and its precursor lesions

Oestrogen receptor alpha (ER) plays a critical, diverse and not fully understood role in endometrial carcinoma. Most endometrial carcinomas express ER and some of these tumours respond favourably to anti-oestrogen therapy. On the other hand, tamoxifen therapy constitutes a major risk factor for endometrial carcinoma development. Amplification of the ESR1 gene encoding ER was recently shown to constitute a mechanism for ER over-expression in breast carcinoma. This study was designed to determine the potential role of ESR1 amplifications in endometrial carcinoma. Tissue microarrays of 368 endometrial carcinomas and large sections of 43 cases of endometrial hyperplasia were analysed for ESR1 gene amplification and ER protein expression by means of fluorescence in situ hybridization (FISH) and immunohistochemistry. FISH revealed ESR1 amplification in 40/176 (23%) cancers, 6/19 (32%) atypical complex hyperplasias, 3/10 (30%) complex hyperplasias without atypia and 2/14 (14%) simple hyperplasias without atypia. Strong ER protein expression was significantly linked to ESR1 amplification in endometrial carcinoma (p = 0.0036). These data indicate that ESR1 amplification might be one mechanism for ER over-expression in endometrial carcinoma, and suggest an early role for ESR1 amplification in the development of a significant fraction of endometrial carcinoma. Given the predictive role of ESR1 amplification for tamoxifen response in breast carcinoma, it will be interesting to investigate the response of ESR1-amplified endometrial cancers to anti-oestrogenic drugs.

[Crystal-induced arthropathies]

Intraarticular crystals (calcium pyrophosphate dihydrate, monosodium urate monohydrate, basic calcium phosphates) can cause acute and chronic inflammation and lead to joint damage. Identification of the crystals by light and polarized microscopy is the key step in diagnosis. Gross macroscopic, contact radiographic and microscopic findings of the most typical lesions of chondrocalcinosis, gout and calcinosis are described with a short review of the pathogenesis.

Alteration of topoisomerase II-alpha gene in human breast cancer and its association with responsiveness to anthracycline- based chemotherapy

524

Background: Topoisomerase II-alpha (TOP2A) gene amplification, and not HER2 amplification, may be the predictive marker for responsiveness to anthracycline chemotherapy. Methods: To address this issue we performed a test set-validation set series of analyses. Amplification of TOP2A and HER2 was evaluated by fluorescence in situ hybridization (FISH) in patients with metastatic breast cancer who participated in a randomized trial (H0648g, n = 469) of anthracycline-based chemotherapy with or without trastuzumab. This group represented the test set. To validate our observations in the H0648g test set we analyzed breast cancers from two other, large, randomized clinical studies of anthracycline-based chemotherapy; one with HER-2 amplification and trastuzumab-based therapy (BCIRG006, n = 3,222) and one without HER-2 amplification and combination-based chemotherapy (BCIRG005, n = 3,298), comparing TOP2A status with clinical outcome. Both of the latter trials were adjuvant trials. Results: In the H0648g test set patients whose breast cancers had TOP2A gene co- amplification and who were treated with doxorubicin, cyclophosphamide (AC) and trastuzumab had a longer progression-free survival compared to those who were treated with AC alone (p = 0.03). Patients treated solely with AC, whose breast cancers had TOP2A gene co-amplification had a statistically significant improvement in duration of survival compared to those without TOP2A gene amplification (p = 0.004). Among all women entered in the HER2-positive BCIRG 006 clinical trial, as well as among women who were treated with anthracycline-containing chemotherapy alone, women whose breast cancers showed TOP2A gene co-amplification had a significantly longer disease-free (p <0.001), recurrence-free (p <0.001) and overall survival (p = 0.01) compared to women whose breast cancers lacked TOP2A amplification. Unexpectedly, the added beneficial effect of trastuzumab was not seen among TOP2A co-amplified breast cancer patients in the larger BCIRG006 trial. Conclusions: In patients treated with chemotherapy alone the findings demonstrate that TOP2A gene co-amplification is a useful predictive marker of responsiveness to anthracycline-containing chemotherapy.

No significant financial relationships to disclose.