Drug-induced inhibition of phosphorylation of STAT5 overrides drug resistance in neoplastic mast cells

Systemic mastocytosis (SM) is a mast cell (MC) neoplasm with complex pathology and a variable clinical course. In aggressive SM (ASM) and MC leukemia (MCL) responses to conventional drugs are poor and the prognosis is dismal. R763 is a multi-kinase inhibitor that blocks the activity of Aurora-kinase-A/B, ABL1, AKT and FLT3. We examined the effects of R763 on proliferation and survival of neoplastic MC. R763 produced dose-dependent inhibition of proliferation in the human MC lines HMC-1.1 (IC₅₀ 5-50 nM), HMC-1.2 (IC₅₀ 1-10 nM), ROSA^{KIT WT} (IC₅₀ 1-10 nM), ROSA^{KIT D816V} (IC₅₀ 50-500 nM) and MCPV-1.1 (IC₅₀ 100-1000 nM). Moreover, R763 induced growth inhibition in primary neoplastic MC in patients with ASM and MCL. Growth-inhibitory effects of R763 were accompanied by signs of apoptosis and a G2/M cell cycle arrest. R763 also inhibited phosphorylation of KIT, BTK, AKT and STAT5 in neoplastic MC. The most sensitive target appeared to be STAT5. In fact, tyrosine phosphorylation of STAT5 was inhibited by R763 at 10 nM. At this low concentration, R763 produced synergistic growth-inhibitory effects on neoplastic MC when combined with midostaurin or dasatinib. Together, R763 is a novel promising multi-kinase inhibitor that blocks STAT5 activation and thereby overrides drug-resistance in neoplastic MC.

Midostaurin: a magic bullet that blocks mast cell expansion and activation

Clinically relevant features in patients with systemic mastocytosis (SM) include the cosmetic burden of lesional skin, mediator-related symptoms, and organ damage resulting from mast cell (MC) infiltration in advanced forms of SM. Regardless of the SM variant, expansion of neoplastic MC in the skin and other organs is triggered by mutant forms of KIT, the most prevalent being D816V. Activation of MC with subsequent release of chemical mediators is often caused by IgE-dependent mechanisms in these patients. Midostaurin, also known as PKC412, blocks the kinase activity of wild-type KIT and KIT D816V, counteracts KIT-dependent growth of neoplastic MC, and inhibits IgE-dependent mediator secretion. Based on this activity-profile, the drug has been used for treatment of patients with advanced SM. Indeed, encouraging results have been obtained with the drug in a recent multi-center phase II trial in patients with advanced SM, with an overall response rate of 60% and a substantial decrease in the burden of neoplastic MC in various organs. Moreover, midostaurin improved the overall survival and relapse-free survival in patients with advanced SM compared with historical controls. In addition, midostaurin was found to improve mediator-related symptoms and quality of life, suggesting that the drug may also be useful in patients with indolent SM suffering from mediator-related symptoms resistant to conventional therapies or those with MC activation syndromes. Ongoing and future studies will determine the actual value of midostaurin-induced MC depletion and MC deactivation in these additional indications.

Proposed diagnostic criteria and classification of basophilic leukemias and related disorders

Basophils form a distinct cell lineage within the hematopoietic cell family. In various myeloid neoplasms, including chronic myeloid leukemia, basophilia is frequently seen. Acute and chronic basophilic leukemias, albeit rare, have also been described. However, no generally accepted criteria and classification of basophilic leukemias have been presented to date. To address this unmet need, a series of Working Conferences and other meetings were organized between March 2015 and March 2016. The current article provides a summary of consensus statements from these meetings, together with proposed criteria to delineate acute basophilic leukemia (ABL) from chronic basophilic leukemia (CBL) and primary forms of the disease where no preceding myeloid malignancy is detected, from the more common 'secondary' variants. Moreover, the term hyperbasophilia (HB) is proposed for cases with a persistent peripheral basophil count ⩾1000 per μl of blood. This condition, HB, is highly indicative of the presence of an underlying myeloid neoplasm. Therefore, HB is an important checkpoint in the diagnostic algorithm and requires a detailed hematologic investigation. In these patients, an underlying myeloid malignancy is often found and is then labeled with the appendix -baso, whereas primary cases of ABL or CBL are very rare. The criteria and classification proposed in this article should facilitate the diagnosis and management of patients with unexplained basophilia and basophil neoplasms in routine practice, and in clinical studies.

The West German Study Group Breast Cancer Intrinsic Subtype study: a prospective multicenter decision impact study utilizing the Prosigna assay for adjuvant treatment decision-making in estrogen-receptor-positive, HER2-negative early-stage breast cancer

PURPOSE

The West German Study Group (WSG) Breast Cancer Intrinsic Subtype (BCIST) study was designed to assess the influence of Prosigna gene signature assay results on physicians' adjuvant treatment recommendations by determining the extent of change in pre-test treatment recommendations following assay results. Secondary objectives were to assess the influence of Prosigna results on physicians' confidence in their therapeutic recommendations and on patients' decisional conflict status, anxiety levels, and functional status.

METHODS

This prospective, observational, decision impact study enrolled consecutive postmenopausal patients with estrogen-receptor (ER)-positive, HER2-negative, lymph-node-negative early-stage breast cancer in 11 centers in Germany. Physicians based their pre-test adjuvant treatment recommendations on standard clinico-pathological parameters. Tumor specimens were assayed using the Prosigna test in a WSG central pathology laboratory following manufacturer's guidelines. An independent pathology laboratory performed subsequent Prosigna assays on tumor sections to assess assay result concordance with the central laboratory. Physicians completed treatment confidence questionnaires prior to and after receiving Prosigna test results. Patients completed standardized questionnaires on decisional conflict, anxiety, and health status both before and after Prosigna testing.

RESULTS

The present study population consisted predominantly of low-to-intermediate risk patients (N = 198). Prosigna had 29.3% discordance in intrinsic subtyping with local immunohistochemistry test results. After Prosigna test results, a change in the adjuvant therapy recommendation occurred in 36 (18.2%) patients; 22 (11.1%) patients switched from no chemotherapy to chemotherapy. After Prosigna test results, physicians expressed increased confidence in their prognostic assessment in 87.9% of patients, and increased confidence in their treatment recommendation in 89.4%. Patients reported improved anxiety and emotional/functional well-being after receiving Prosigna test results.

CONCLUSIONS

Use of the Prosigna assay led to a change in 18.2% of adjuvant treatment decisions. Prosigna testing was associated with increased patient and physician confidence in treatment decisions, and with decreased patient anxiety and improved well-being. Any comparison of the therapeutic decision-making impacts of different genomic assays must account for potential confounding factors.

Abstract P1-06-02: A force-sensitive organoid assay to quantify regenerative potential of single primary human mammary cells

We have developed an organoid regeneration assay to quantify the ability of freshly isolated, single human mammary epithelial cells to generate complex branched ductal structures with basal and luminal features.

For this purpose, cells are cultured in adherent or floating collagen gels, corresponding to a rigid or compliant matrix. In both conditions, single luminal progenitors form spheres, whereas basal cells generate branched ductal structures. In compliant but not rigid collagen gels, branching ducts in multicellular structures generated by basal cells develop a lumen and alveoli at their tips. Importantly, branched structures generated by single basal cells express basal and luminal markers at correct positions, thereby demonstrating bi-potential. Functionally, basal cells in branched structures display cellular contractility, which we reveal to be required for alveologenesis. In conclusion, branched structures generated by single basal cells in compliant collagen gels resemble terminal ductal-lobular units (TDLU), the functional units of the mammary gland.

To prospectively isolate basal cells with regenerative potential, we added the membrane metallo-endopeptidase CD10 as a cell surface marker to existing sorting protocols, thereby enriching for TDLU-formation and enabling rigorous quantification of regenerative potential by extreme limiting dilution assay (ELDA). Moreover, the use of CD10 as a cell surface marker reveals the presence of stromal cells with endothelial qualities within the CD49fhi/EpCAM– population, previously labeled basal. In summary, we describe a defined in vitro assay system to quantify primary human mammary epithelial cells with regenerative potential and systematically investigate their interaction with the physical environment at distinct steps of morphogenesis.

Citation Format: Scheel CH, Linnemann JR, Miura H, Meixner LK, Irmler M, Kloos UJ, Hirschi B, Bartsch HS, Sass S, Beckers J, Theis FJ, Gabka C, Sotlar K. A force-sensitive organoid assay to quantify regenerative potential of single primary human mammary cells. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P1-06-02.

Abstract P1-13-01: Comparison of 12 weeks neoadjuvant Nab-paclitaxel combined with carboplatinum vs. gemcitabine in triple- negative breast cancer: WSG-ADAPT TN randomized phase II trial

Background: Pathological complete response (pCR) is associated with improved prognosis in TNBC, but optimal chemotherapy remains unclear. Use of weekly nab- paclitaxel (Nab-Pac) vs. conventional paclitaxel and also addition of carboplatinum(Carbo) to anthracycline-taxane(A/T) containing chemotherapy results in significantly higher pCR rates in TNBC with unclear impact on survival and increased toxicity.

The ADAPT study seeks to compare Carbo vs. gemcitabine(Gem) added to nab- paclitaxel as a short 12-week A-free regimen. It also assesses efficacy in early responders vs. non-responders by 3-week proliferation and/or imaging response.

Methods: ADAPT TN compares 12-week neoadjuvant regimens: Carbo vs. Gem combined with Nab-Pac and aims to identify early-response markers for pCR (yPN0 and ypT0/is). TNBC patients (centrally confirmed ER/PR <1%, HER2 neg.), cT1c- cT4c, cN0/+ were randomized to arm A (Nab-Pac 125/Gem 1000 d1,8 q3w) vs. B (Nab-Pac 125/Carbo AUC2 d1,8 q3w). Randomization was stratified by center and nodal status. The trial is powered for pCR comparison by therapy arm and by presence vs. absence of early response markers. Pre-planned interim analysis aimed to identify a dynamic biomarker, e.g. drop of 3-week Ki-67, and to validate trial assumptions.

Results: 336 patients were enrolled from 47 centers between 06/13-02/15 (n=182 ArmA: Nab-Pac/Gem and n=154 ArmB: Nab-Pac/Carbo). 90% and 95% completed therapy according to protocol respectively (n.s.). Median age was 50y. At baseline: A/B: 73% and 74%% had G3 tumors, median Ki-67 of 70% and 75%; 62.6% and 62.9%% had cT2-4c tumors, pN0 status prior to chemotherapy was confirmed in 50.5% and 50%, respectively.

pCR (ypT0/is/ypN0) was A: 28.7% and B: 45.9% (p<0.001). Total pCR (ypT0/ypN0) was A: 25.8% and B: 45.2% respectively (p <0.001).

Nab/Gem arm was associated with significantly higher frequency of dose reductions (20.6% vs. 11.9% (p=0.03), treatment related SAE's (13% vs. 5%, p=0.02), grade 3-4 infections (6.1% vs. 1.3%, p=0.04) and ALAT elevations (11.7 vs. 3.3%, p=0.01) compared to the Nab-Carbo arm.

Within the planned interim analysis (n=130: A/B: 69/61), baseline Ki-67 (Nab- Pac/Carbo arm), age>50 years, and low cellularity (<500 tumor cells and/or Ki-67≤10% in the 3-week biopsy) (Nab-Pac/Gem arm) were positively associated with pCR by logistic regression analysis (separately by therapy arm). In all patients, therapy arm itself was significant for pCR.

Validation of responder definitions for the whole study will be presented at the meeting.

Conclusions:

This is the first large randomized study comparing two short 12-week anthracycline- free regimens in unselected TNBC. Our results suggest superior efficacy and excellent toxicity of Nab-Pac/Carbo vs. Gem. Longer A/T-Carbo containing regimens render quite comparable pCR rates, thus overtreatment by 4xEC in unselected TNBC may be present in some patients. Early response criteria seem to differ according to regimen; their assessment may be impaired by substantial tumor necrosis already after the first therapy cycle.

Citation Format: Gluz O, Nitz U, Liedtke C, Christgen M, Sotlar K, Grischke EM, Forstbauer H, Braun M, Warm M, Hackmann J, Uleer C, Aktas B, Schumacher C, Bangemann N, Lindner C, Kuemmel S, Clemens M, Potenberg J, Staib P, Kohls A, Pelz E, Kates RE, Wuerstlein R, Kreipe HH, Harbeck N. Comparison of 12 weeks neoadjuvant Nab-paclitaxel combined with carboplatinum vs. gemcitabine in triple- negative breast cancer: WSG-ADAPT TN randomized phase II trial. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P1-13-01.

Additional mutations in SRSF2, ASXL1 and/or RUNX1 identify a high-risk group of patients with KIT D816V(+) advanced systemic mastocytosis

Most patients with KIT D816V(+) advanced systemic mastocytosis (SM) are characterized by somatic mutations in additional genes. We sought to clarify the prognostic impact of such mutations. Genotype and clinical characteristics of 70 multi-mutated KIT D816V(+) advanced SM patients were included in univariate and multivariate analyses. The most frequently identified mutated genes were TET2 (n=33 of 70 patients), SRSF2 (n=30), ASXL1 (n=20), RUNX1 (n=16) and JAK2 (n=11). In univariate analysis, overall survival (OS) was adversely influenced by mutations in SRSF2 (P<0.0001), ASXL1 (P=0.002) and RUNX1 (P=0.03), but was not influenced by mutations in TET2 or JAK2. In multivariate analysis, SRSF2 and ASXL1 remained the most predictive adverse indicators concerning OS. Furthermore, we found that inferior OS and adverse clinical characteristics were significantly influenced by the number of mutated genes in the SRSF2/ASXL1/RUNX1 (S/A/R) panel (P<0.0001). In conclusion, the presence and number of mutated genes within the S/A/R panel are adversely associated with advanced disease and poor survival in KIT D816V(+) SM. On the basis of these findings, inclusion of molecular markers should be considered in upcoming prognostic scoring systems for patients with SM.

Molecular profiling of myeloid progenitor cells in multi-mutated advanced systemic mastocytosis identifies KIT D816V as a distinct and late event

To explore the molecular profile and its prognostic implication in systemic mastocytosis (SM), we analyzed the mutation status of granulocyte-macrophage colony-forming progenitor cells (CFU-GM) in patients with KIT D816V(+) indolent SM (ISM, n=4), smoldering SM (SSM, n=2), aggressive SM (ASM, n=1), SM with associated clonal hematologic non-mast cell lineage disorder (SM-AHNMD, n=5) and ASM-AHNMD (n=7). All patients with (A)SM-AHNMD (n=12) carried 1-4 (median 3) additional mutations in 11 genes tested, most frequently TET2, SRSF2, ASXL1, CBL and EZH2. In multi-mutated (A)SM-AHNMD, KIT D816V(+) single-cell-derived CFU-GM colonies were identified in 8/12 patients (median 60%, range 0-95). Additional mutations were identified in CFU-GM colonies in all patients, and logical hierarchy analysis indicated that mutations in TET2, SRSF2 and ASXL1 preceded KIT D816V. In ISM/SSM, no additional mutations were detected and CFU-GM colonies were exclusively KIT D816V(-). These data indicate that (a) (A)SM-AHNMD is a multi-mutated neoplasm, (b) mutations in TET2, SRSF2 or ASXL1 precede KIT D816V in ASM-AHNMD,

Proposed diagnostic algorithm for patients with suspected mastocytosis: a proposal of the European Competence Network on Mastocytosis

Mastocytosis is an emerging differential diagnosis in patients with more or less specific mediator-related symptoms. In some of these patients, typical skin lesions are found and the diagnosis of mastocytosis can be established. In other cases, however, skin lesions are absent, which represents a diagnostic challenge. In the light of this unmet need, we developed a diagnostic algorithm for patients with suspected mastocytosis. In adult patients with typical lesions of mastocytosis in the skin, a bone marrow (BM) biopsy should be considered, regardless of the basal serum tryptase concentration. In adults without skin lesions who suffer from mediator-related or other typical symptoms, the basal tryptase level is an important parameter. In those with a slightly increased tryptase level, additional investigations, including a sensitive KIT mutation analysis of blood leucocytes or measurement of urinary histamine metabolites, may be helpful. In adult patients in whom (i) KIT D816V is detected and/or (ii) the basal serum tryptase level is clearly increased (>25-30 ng/ml) and/or (iii) other clinical or laboratory features suggest the presence of 'occult' mastocytosis or another haematologic neoplasm, a BM investigation is recommended. In the absence of KIT D816V and other signs or symptoms of mastocytosis or another haematopoietic disease, no BM investigation is required, but the clinical course and tryptase levels are monitored in the follow-up. In paediatric patients, a BM investigation is usually not required, even if the tryptase level is increased. Although validation is required, it can be expected that the algorithm proposed herein will facilitate the management of patients with suspected mastocytosis and help avoid unnecessary referrals and investigations.

Refined diagnostic criteria and classification of mast cell leukemia (MCL) and myelomastocytic leukemia (MML): a consensus proposal

Mast cell leukemia (MCL), the leukemic manifestation of systemic mastocytosis (SM), is characterized by leukemic expansion of immature mast cells (MCs) in the bone marrow (BM) and other internal organs; and a poor prognosis. In a subset of patients, circulating MCs are detectable. A major differential diagnosis to MCL is myelomastocytic leukemia (MML). Although criteria for both MCL and MML have been published, several questions remain concerning terminologies and subvariants. To discuss open issues, the EU/US-consensus group and the European Competence Network on Mastocytosis (ECNM) launched a series of meetings and workshops in 2011-2013. Resulting discussions and outcomes are provided in this article. The group recommends that MML be recognized as a distinct condition defined by mastocytic differentiation in advanced myeloid neoplasms without evidence of SM. The group also proposes that MCL be divided into acute MCL and chronic MCL, based on the presence or absence of C-Findings. In addition, a primary (de novo) form of MCL should be separated from secondary MCL that typically develops in the presence of a known antecedent MC neoplasm, usually aggressive SM (ASM) or MC sarcoma. For MCL, an imminent prephase is also proposed. This prephase represents ASM with rapid progression and 5%-19% MCs in BM smears, which is generally accepted to be of prognostic significance. We recommend that this condition be termed ASM in transformation to MCL (ASM-t). The refined classification of MCL fits within and extends the current WHO classification; and should improve prognostication and patient selection in practice as well as in clinical trials.

Prognostic impact of blast cell counts in dysplastic bone marrow disorders (MDS and CMML I) with concomitant fibrosis

In a retrospective study, 43 patients with dysplastic neoplasms of the bone marrow (myelodysplastic syndromes and myelodysplastic/myeloproliferative-overlap neoplasms) associated with marked (grades 2-3) fibrosis were examined. Histopathologic and morphologic findings as well as cytogenetic and molecular results were correlated with clinical endpoints. Multilineage dysplasia (34 of 43 patients, 79 %) and hypercellular bone marrow (64 %) were found in most patients. In ten of 35 patients, poor risk karyotypes according to the International Prognostic Scoring System (IPSS) were recorded. The JAK2 V617F mutation was detected in four of 30 patients (13 %), and the KIT D816V mutation was found in two of 30 patients (6 %). Patients were mainly treated with palliative drugs and best supportive care. After an observation time of 1-41 (median 21) months, ten of 43 patients (23 %) had developed a secondary acute leukemia. The median survival of all 43 patients was 21.4 months (range 1.8-88.2 months). Of all prognostic parameters examined, the blast cell count at diagnosis was found to be a most reliable and most predictive marker concerning survival and leukemia progression. This confirms previous studies in dysplastic bone marrow neoplasms without fibrosis.

[Mastocytosis and eosinophilic leukemia: diagnostics and classification]

Mastocytosis and myeloid eosinophilic neoplasms are rare diseases of the bone marrow and are often a diagnostic challenge for hematopathologists. In mastocytosis, compact mast cell infiltrates represent the main diagnostic criterion and for myeloid eosinophilic neoplasms, eosinophilic granulocytes dominate the histological picture. Both disease groups include phenotypically and prognostically very different entities which are each defined by WHO criteria. For systemic mastocytosis (SM), a differentiation between indolent and aggressive or even leukemic forms is of prognostic importance. In indolent variants of SM, a local and/or systemic, usually reactive increase in eosinophilic granulocytes (SM-eo) is often observed. In contrast, an increase in neoplastic eosinophils is often observed in advanced SM, predominantly in diseases designated SM with associated non-mastocytic hematological neoplasms (SM-AHNMD), e.g. in SM with chronic eosinophilic leukemia (SM-CEL). Apart from mastocytoses, immunophenotypically aberrant tissue mast cells are only observed in certain rare forms of myeloid neoplasms with eosinophilia, in particular in myeloproliferative neoplasms (MPN-eo) with cytogenic anomalies in the platelet-derived growth factor receptor (PDGFR). The World Health Organization (WHO) classification of eosinophilic leukemias, however, fulfils the morphological and clinical requirements in a limited way only and needs an update.

Evaluation of mast cell activation syndromes: impact of pathology and immunohistology

Mast cell activation syndromes (MCAS) are clinically defined disease states with a largely unknown morphological background. Since mastocytosis may be associated with MCAS, it is crucial in every patient to document or exclude mastocytosis by appropriate histological, molecular, and serological investigations of tissues/organs that are commonly involved in mastocytosis like skin, mucosa of the gastrointestinal tract and bone marrow. Accordingly, histopathological investigation including immunohistological stains is crucial to reach the final diagnosis in such patients and to classify MCAS into primary MCAS, which can present with or without evidence of overt mastocytosis, or secondary MCAS, where an underlying disease with or without tissue inflammation is detected. Cases without evidence of mastocytosis, monoclonal mast cells, or any underlying disease should be termed idiopathic MCAS. When the activating point mutant KIT D816V is detectable but criteria for diagnosis of mastocytosis are not completely met, a so-called (mono)clonal MCAS as a subvariant of primary MCAS should be diagnosed.

[HPV-associated squamous cell carcinogenesis]

About 7-8% of all human cancers are thought to be related to infections with high-risk (HR) human papilloma virus (HPV). Besides cervical cancer, especially squamous cell carcinomas of the anogenital and oropharyngeal regions are associated with HR-HPV. Transmission of HPV is due to sexual activity. Harald zur Hausen was awarded in 2008 with the Nobel price in medicine for the establishment of a causal link between certain HPV infections and cervical cancer. Meanwhile potent prophylactic vaccines are available to prevent infections with HPV-16 and HPV-18, the two most frequently observed HR HPV types worldwide. On molecular grounds a persistent HPV infection is the central risk factor for the development of HPV-associated neoplasias. Continued expression of the viral E6 and E7 oncogenes disrupts cell cycle control mechanisms in infected cells, thereby gaining limitless proliferative capacity and resistance against apoptotic signals. However acquisition of mutations and genomic instability might cause malignant transformation in these cells.

[Human papillomavirus infection. Pathology and molecular pathology]

Cervical cancer is the second most frequent female malignoma worldwide and accounts for about 500,000 cases every year. The peak incidence lies between 35 and 55 years of age. Persistent infections with a group of 15 so-called high-risk human papillomaviruses (HR-HPV) are the cause of cervical carcinogenesis of squamous cell carcinomas and for most of the adenocarcinomas. The transforming potential of HR-HPVs is based on the interaction of viral oncogene products E6 and E7 with the cellular tumor suppressor proteins p53 and pRB. The resulting loss of cell cycle control sets the basis for additional, as yet only incompletely discovered, genetic and epigenetic changes, finally leading to invasive growth. Preneoplastic changes, cervical intraepithelial neoplasias, can be identified morphologically, thus allowing for therapeutic interventions. Since November 2007, the Ständige Impfkommission, the German standing committee on immunizations, has recommended the prophylactic use of vaccines against the two most frequent HR-HPV genotypes, HPV-16 and HPV-18, in women age 12-17 years before first sexual intercourse. In addition to cervical cancer, HPV infections are responsible for the development of genital warts (condyloma) and a number of vaginal, vulvar, and anal intraepithelial neoplasias. HPV infections are usually transmitted sexually.

Microsatellite instability and HPV genotype in Polish women with cervical cancer

INTRODUCTION

Human papillomaviruses (HPVs) are associated with anogenital cancer. Little is known about the prevalence of microsatellite instability (MSI) in cervical cancer. The aim of this study was to investigate the incidence of microsatellite instability in cervical cancer and to see whether there is a relation between MSI, HPV and clinicopathological characteristics in the study population.

RESULTS

Using three assays (pU1M/2R, GP5+/6+ and E6-nested multiplex PCR) HPV was detected in 110 out of 113 patients with histologically confirmed cervical cancer. The presence of MSI was investigated in 95 of the 113 cases using seven microsatellite loci. In total, 12 out of the 95 patients (12.6%) showed MSI. None of clinicopathological parameters showed a significant difference between microsatellite stable and MSI cases.

CONCLUSION

In this population of Polish cervical cancer patients, 12.6% showed microsatellite instability. There was no correlation between MSI positivity and clinicopathological parameters and/or survival.

Management of late recurrence of a low-grade endometrial stromal sarcoma (LGESS): treatment with letrozole

Low grade endometrial stromal sarcoma (LGESS) is a rare disease. LGESS usually expresses steroidal receptors and is regarded to be hormone-sensitive. Due to the rarity of the tumor, only few case series have been published so far. Here, we report the case of a 36-year-old woman who underwent an abdominal hysterectomy with bilateral salpingo-oophorectomy and adjuvant radiotherapy for a G1 LGESS in 1991. Twelve years later she presented to us with pelvic and peritoneal masses. The patient was treated with letrozole achieving a partial response which is lasting 39 months. Treatment is ongoing. Aromatase inhibitors represent an interesting treatment option for LGESS.

Interdisziplinäre Untersuchungen zur Verbesserung der Behandlungsqualität des Prostatakarzinoms

BACKGROUND

After sufficient oncological treatment of prostate cancer the life quality becomes most important. A multi disciplinary research network aims to optimize the diagnostics and the resulting treatment of prostate cancer.

METHODS

Main characteristics of the interdisciplinary cooperation are the interlocked individual projects. A major research field is investigation of the whole mounted prostate sections to study the peripheral nerves and the comparison of histological tumor locations with the MRI. Using serial sections of prostate specimens, three-dimensional computer-animated models are created illustrating the tumors histological and immunohistochemical distributions. For nodal staging, a new methodology is investigated to demonstrate single tumor cells in lymphatic tissue lysates. A retrospective evaluation of life quality including the functional outcome is performed by using questionnaire surveys.

RESULTS

Anatomical studies gave new insights into the exact localizations of peripheral nerves which may lead to an improvement of the surgical approach in nerve-sparing radical prostatectomy. For the preoperative planning the MRI imaging might need a different interpretation in relation to the topographic location. Studies using molecular markers and their relation and distribution patterns gave new insights regarding interpretation of histological biopsy results concerning the tumor extension. Numerical quantification of tumor cells in each lymph node demonstrated micro metastases in histological negative nodes contributing to the nodal staging. A close connection of the nerve-sparing technique was demonstrated with quality of life aspects and functional results.

CONCLUSION

An interdisciplinary approach is mandatory for translational prostate cancer research. As a result, individualized diagnostic and therapeutic approaches improve oncological results and at the same time provide the best quality of life in these patients.

Increased Translocator Protein (TSPO) mRNA Levels in Colon but Not in Rectum Carcinoma

BACKGROUND

The peripheral-type benzodiazepine receptor or translocator protein (TSPO) is an 18-kDa protein involved in cell proliferation and apoptosis. TSPO was shown to be overexpressed in malignant tumors and cancer cell lines, correlating with enhanced malignant behavior. The present study analyzed the role of TSPO in patients with colorectal carcinomas.

METHODS

Tumor tissues and corresponding normal mucosa from 55 patients who underwent resection for colorectal carcinomas were analyzed for TSPO expression in correlation to GAPDH expression(glyceraldehyde-3-phosphate dehydrogenase) using a multiplex RT-PCR assay.

RESULTS

TSPO was overexpressed in 67% of the tumors in comparison to corresponding normal mucosa, and positivity as well as expression levels in colon carcinomas were significantly higher than in the rectum carcinomas. In contrast, TSPO expression was not different in intermediate versus high-grade tumors or in lymph node-positive versus -negative patients.

CONCLUSION

The differences in TSPO expression between colon and rectum carcinoma may imply that these tumors are of different biological behavior.

Standards and standardization in mastocytosis: consensus statements on diagnostics, treatment recommendations and response criteria

Although a classification for mastocytosis and diagnostic criteria are available, there remains a need to define standards for the application of diagnostic tests, clinical evaluations, and treatment responses. To address these demands, leading experts discussed current issues and standards in mastocytosis in a Working Conference. The present article provides the resulting outcome with consensus statements, which focus on the appropriate application of clinical and laboratory tests, patient selection for interventional therapy, and the selection of appropriate drugs. In addition, treatment response criteria for the various clinical conditions, disease-specific symptoms, and specific pathologies are provided. Resulting recommendations and algorithms should greatly facilitate the management of patients with mastocytosis in clinical practice, selection of patients for therapies, and the conduct of clinical trials.

[Therapeutically relevant mutations in the receptor tyrosine kinase KIT in mastocytosis]

Mastocytosis is characterized by an abnormal proliferation and accumulation of mast cells (MC) in one or more organ systems. The current WHO classification discriminates cutaneous mastocytosis (CM) and various forms of systemic mastocytosis (SM). While CM usually follows a bening and often self-limiting course, SM is a persistent disease in which a somatic KIT mutation at codon 816 (i.e. D816V) is detectable in MC in at least 80% of cases. Symptoms in mastocytosis result from MC-derived mediators and, less frequently, from destructive tissue infiltration by MC. The clinical course of SM is usually indolent, but sometimes it may be highly aggressive and rapidly devastating. KIT is a transmembrane class III receptor tyrosine kinase which is required for MC growth, differentiation, and functional activation. Mutations in codon 816 of the KIT gene result in ligand-independent (constitutive) activation of KIT signaling and, thus, may play a central role in the pathogenesis of SM. Since there are no curative options, therapy for the aggressive forms of SM is based on cytoreductive agents, e.g. interferon-alpha (IFN-alpha) and cladribine. The expression of KIT in neoplastic MC has led to the development of targeted therapies using tyrosine kinase inhibitors (TKI) like STI571 (Imatinib, Gleevec). Unfortunately, the KIT mutation D816V is associated with relative resistance against STI571. However, TKIs with activity against KIT D816V-positive cells have recently been developed, and some of them (dasatinib, nilotinib/AMN107, PKC412) are already tested in phase I/II trials. In addition, non-TK KIT signaling inhibitors (e.g. geldanamycin, rapamycin) or monoclonal antibodies directed against neoplastic MC may evolve as future therapeutic options.

Expression of the target receptor CD33 in CD34+/CD38-/CD123+ AML stem cells

BACKGROUND

CD33 (Siglec-3) is becoming increasingly important as a target of antibody-mediated therapy in acute myeloid leukaemia (AML). In normal myelopoiesis, expression of CD33 is restricted to advanced stages of differentiation, whereas primitive stem cells do not express CD33. In the present study, we asked whether leukaemic stem cells in patients with AML express CD33.

MATERIALS AND METHODS

A multicolour-staining technique was applied in 11 patients with AML, and leukaemic progenitors defined as CD34(+)/CD38(-)/CD123(+) cells. AML stem cells were purified by cell sorting and were examined for expression of CD33 mRNA by reverse transcriptase-polymerase chain reaction (RT-PCR).

RESULTS

In all patients in whom the majority of myeloblasts expressed CD33 (n = 8), AML progenitors reacted with the CD33 antibody P67.6. Repopulation experiments utilizing irradiated NOD/SCID mice confirmed that AML stem cells in these patients reside within the CD33(+) subpopulation of the leukaemic clone. Moreover, highly purified AML stem cells (> 98% purity) from patients with CD33(+) AML were found to express CD33 mRNA in RT-PCR analyses. CD33 was neither detectable on CD34(+)/CD38(-) cells in normal bone marrow nor on leukaemic stem cells in patients with CD33-negative AML.

CONCLUSIONS

Leukaemic stem cells in patients with CD33(+) AML express CD33. This observation is in favour of novel treatment concepts employing CD33-targeting antibodies in AML.

Simplified detection of microsatellite instability in colorectal cancer without the need for corresponding germline DNA analysis

A panel of five quasimonomorphic mononucleotide repeats that dispenses with the need to analyse corresponding germline DNA was proposed by Suraweera et al for the detection of high-frequency microsatellite instability (MSI) in colorectal cancer. Using this panel, a simplified and a more sensitive (compared with the original) algorithm (p<0.05) was developed to define the instability of each repeat by assessing the morphological shape of its plot and not its absolute length. 103 cases of colorectal tumours were investigated and the results compared with those obtained by the analysis of five consensus microsatellites (Bethesda reference panel). By the proposed method, a higher specificity, but no loss of sensitivity, was found. Thus, the use of the five mononucleotide repeats in combination with the modified assessment technique simplifies the assessment of MSI, while retaining the sensitivity of the Bethesda panel for the detection of high-frequency MSI.

"Occult" mastocytosis with activating c-kit point mutation evolving into systemic mastocytosis associated with plasma cell myeloma and secondary amyloidosis

A case of a 70-year-old man presenting with exsudative enteropathy due to light-chain-associated amyloidosis is reported. The diagnosis of systemic mastocytosis associated with IgG/lambda plasma cell myeloma and secondary generalised amyloidosis was carried out by morphological evaluation of bone marrow biopsy. The c-kit point mutation D816Y was detected by molecular analysis. Two years before, a cystadenolymphoma of the left parotid gland had been removed. A moderate increase of loosely scattered spindle-shaped mast cells, a subpopulation of them expressing CD25, an antigen that is not expressed by normal or reactive mast cells, was shown by retrospective analysis carried out on an intraparotideal lymph node. The c-kit mutation D816Y was shown by the molecular analysis of the lymph node. In summary, the notion that systemic mastocytosis may very rarely be associated with B cell neoplasms and that neoplastic mast cell infiltrates may be obscured because of only a minimal increase of atypical mast cells, which are outnumbered by other non-neoplastic cells in the same tissue, is supported by this case. This finding was preliminarily termed "occult" mastocytosis.

The tryptase positive compact round cell infiltrate of the bone marrow (TROCI-BM): a novel histopathological finding requiring the application of lineage specific markers

AIMS

Compact tryptase-positive round cell infiltrates of the bone marrow (TROCI-BM) are very rare histopathological findings and may pose challenging problems with regard to the cell type involved (either mast cells or basophilic granulocytes) and the exact diagnosis.

METHODS

A selected panel of immunohistochemical markers against mast cell and basophil related antigens, including CD25, CD34, CD117/Kit, and the 2D7 antigen (which is found only in basophilic granulocytes) on a total of 410 routinely processed bone marrow biopsy specimens (including 88 cases of systemic mastocytosis (SM), 20 cases of chronic myeloid leukaemia (CML), 92 cases of myeloid neoplasms other than CML, and 210 controls with normal/reactive bone marrows).

RESULTS

In total, 17 cases with TROCI-BM could be identified: 11 SM (including two cases of well-differentiated SM and two mast cell leukaemias; MCL), 2 myelomastocytic leukaemia (MML), 2 CML with excess of basophils (secondary basophilic leukaemia (CMLba)), and 2 tryptase positive acute myeloid leukaemia (AML). Regarding the cell types involved, TROCI-BM cells were found to express CD117/Kit in all cases of SM and MCL. In MML and tryptase postitive AML, TROCI-BM cells were found to coexpress CD34 and Kit. The basophil specific antigen 2D7 was only detected in CD34/Kit negative TROCI-BM cells in two patients with CMLba. The activating point mutation D816V was detected in 8/11 patients with SM but not in any of the other haematological malignancies.

CONCLUSIONS

In summary, a total of six rare myeloid neoplasms may present with a novel immunohistochemical phenomenon tentatively termed TROCI-BM.

An unusual case of systemic mastocytosis associated with chronic lymphocytic leukaemia (SM-CLL)

AIMS

Whereas focal accumulations of reactive lymphocytes around mast cell (MC) infiltrates are often seen in indolent systemic mastocytosis (ISM) involving the bone marrow, an association of systemic mastocytosis (SM) with malignant lymphoma/lymphatic leukaemia is very rare. This report contributes to the differential diagnosis of ISM by demonstrating that such lymphocytic aggregates may be neoplastic.

METHODS

Biopsy specimens (bone marrow and gastrointestinal mucosa) of a 69 year old woman with mild blood lymphocytosis and a history of urticaria pigmentosa-like skin lesions that had disappeared a few years earlier, were investigated immunohistochemically using antibodies against CD3, CD5, CD20, CD23, CD25, CD34, CD117, chymase, and tryptase. Rearrangements of the IgH and TCRy genes were studied by seminested PCR. Mutation analysis of c-kit was performed by melting point analysis of nested PCR using amplified DNA from pooled microdissected single cells (MC and B cells) of both sites.

RESULTS

The histomorphological features of the bone marrow corresponded to that of ISM with multifocal accumulations of MC surrounded by clusters of lymphocytes of mature appearance. However, these lymphocytes revealed an aberrant immunophenotype with coexpression of CD5, CD20, and CD23, thus enabling the final diagnosis of SM with an associated clonal haematological non-MC lineage disease, in particular SM with associated B cell chronic lymphocytic leukaemia (SM-CLL). Monoclonality for both ISM and B-CLL could be confirmed by demonstrating the typical activating c-kit point mutation D816V in bone marrow MC, and a monoclonal IgH rearrangement in bone marrow B cells.

CONCLUSIONS

Usually, focal accumulations of lymphocytes around MC infiltrates in the bone marrow of patients with SM are reactive in nature (lymphocytosis). However, a low grade malignant lymphoma should also be included in the differential diagnosis. We describe here the first case, to our knowledge, with synchronous diagnosis of SM and associated B-CLL. This diagnosis could only be established by application of appropriate immunohistochemical and molecular techniques, as the bone marrow histology on first investigation resembled that of typical ISM.

Her-2/neu expression in breast cancer--A comparison of different diagnostic methods

BACKGROUND

Determination of Her-2/neu overexpression in breast cancer has previously been shown to be of prognostic significance. In this study, Her-2/neu expression in breast cancer was characterised by real-time PCR (RLT-PCR) based LightCycler-HER-2/neu DNA Quantification with immunohistochemistry (IHC) and fluorescence in situ hybridisation (FISH).

MATERIAL AND METHODS

Fifteen specimens of invasive breast cancer - whole tissue sections as well as microdissected tumour cells - were subjected to RLT-PCR. Additionally, IHC and FISH were performed.

RESULTS

Her-2/neu overexpression was detected by FISH and by real-time PCR in the same tumours. In contrast, IHC revealed discordant results.

CONCLUSION

Determination of Her-2/neu amplification by real-time PCR is a sensitive and specific method with some advantages over FISH. This method is simple and reliable and has the potential of categorizing those tumours with borderline Her-2/neu overexpression as determined by IHC.

[Detection of high-risk human papillomavirus (HPV) E6 and E7 oncogene transcripts increases the specificity of the detection of a cervical intraepithelial neoplasia (CIN)]

AIMS

The oncogenic potential of the high-risk human papillomavirus (HR-HPV) genotypes depends on the expression of the viral oncogenes E6 and E7. Thus, the detection of these transcripts could serve as a factor in the evaluation of a woman's risk of development of cervical intraepithelial neoplasia (CIN).

METHODS

A nested RT-PCR assay for the detection of E6/E7 oncogene transcripts of all known HR-HPV genotypes was established. Cervical scrapes of 779 HR-HPV-DNA-positive women exhibiting all grades of CIN were examined.

RESULTS

Spliced E6/E7 oncogene transcripts of all the HR-HPVs were detected in numerous samples. In 459 cases with agreement between the cytologic and histologic findings, the prevalence increased with lesion severity: CIN 0, 18%; CIN I, 58%; CIN II, 77%; CIN III, 84%. While sensitivity and negative predictive value of HR-HPV DNA-positivity for the detection of a CIN lesion were significantly (p < 0.0001) higher than those of E6/E7 mRNA positivity (90.3% vs. 65.5% and 93% vs. 83.1%), the opposite was true for the specificity and positive predictive value (72.8 % vs. 95.2%) and 65.1% vs. 88.5%, p < 0.0001). Preliminary follow-up data in 120 initially HPV-16 DNA-positive women revealed the development, persistence or progression of a CIN lesion in 33% (8/24) of HR-HPV DNA-positive and E6/E7 mRNA-negative women, compared to 93% (66/71, p < 0.0001) in women in whom transcriptional activity of the E6/E7 oncogenes was detectable.

CONCLUSIONS

Besides the identification of HPV DNA, the detection of HR-HPV E6/E7 oncogene transcripts may serve as a valuable tool in increasing the specificity of HPV testing.

[Immunohistochemical and molecular characterization of systemic mastocytoses]

The WHO has published an updated classification of mastocytosis and the criteria for the diagnosis of systemic mastocytosis (SM). These include one major criterion, compact mast cell (MC) infiltrates in extracutaneous tissues, and four minor criteria, i.e. cytomorphologic atypia with spindling of MC (>25 %), detection of the activating somatic c-kit mutation D816 V in MC, aberrant expression of CD2 and/or CD25 on MC, and an elevated serum tryptase level (>20 ng/ml). Systemic mastocytosis is diagnosed when the major plus one minor, or three minor criteria are fulfilled. In the present study, we have established methods for the detection of CD25 and the c-kit mutation D816V in paraffin-embedded bone marrow trephine biopsy specimen of 57 patients with various subtypes of mastocytoses and 239 controls. While MCs in almost all patients with SM (55/57) expressed CD25, only 2/239 of the control samples contained CD25-positive MCs. With newly designed molecular pathological methods, c-kit codon 816 mutations were detected by "peptide nucleic acid" (PNA)-mediated PCR-clamping and/or analysis of microdissected MC in 52/57 cases with SM. All cases with detectable c-kit mutations also contained CD25-positive MC. The c-kit mutation D816 V was also detected in microdissected cells of associated hematologic neoplasias in 6/15 cases. With the methods established for the investigation of paraffine-embedded tissues, the pathologist plays a central role in the diagnosis of SM.

Influence of tumor biological factors on tumor cell dissemination in primary breast cancer

BACKGROUND

The presence of disseminated tumor cells in the bone marrow (BM) of breast cancer patients is associated with poor prognosis and may therefore be related to aggressive breast cancer as indicated by tumor biological and clinicopathological factors. The aim of this study was to identify those features of the primary tumor related to the presence of disseminated tumor cells in the BM.

PATIENTS AND METHODS

Clinical data from 508 primary breast cancer patients were analyzed. Tumor biological features of the primary tumor including HER2, p53, Ki-67, bcl-2 and hormone receptor status, as well as clinicopathological factors including histology, menopausal status, lymph node status, tumor size and grade, were studied for their association with BM involvement by univariate and multivariate analysis.

RESULTS

Two-hundred and two out of 508 (40%) primary breast cancer patients had disseminated tumor cells in the BM. p53 expression, hormone receptor status, HER2 and Ki-67 were significantly related to BM involvement. The multivariate analysis revealed that p53 expression (OR: 1.9, 95% CI: 1.2 - 3.0) followed by progesterone receptor status (OR: 1.5, 95% CI: 1.0 - 2.2) were the only independent determinants for BM involvement.

CONCLUSION

The presence of disseminated tumor cells in the BM was not influenced by tumor load as reflected by tumor size and lymph node involvement, whereas tumor biological factors were independently correlated to BM involvement. The results substantiate the important role of tumor biological factors of the primary tumor for tumor cell dissemination.

Detection and typing of human papillomavirus by e6 nested multiplex PCR

A nested multiplex PCR (NMPCR) assay that combines degenerate E6/E7 consensus primers and type-specific primers was evaluated for the detection and typing of human papillomavirus (HPV) genotypes 6/11, 16, 18, 31, 33, 35, 39, 42, 43, 44, 45, 51, 52, 56, 58, 59, 66, and 68 using HPV DNA-containing plasmids and cervical scrapes (n = 1,525). The performance of the NMPCR assay relative to that of conventional PCR with MY09-MY11 and GP5+-GP6+ primers, and nested PCR with these two primer sets (MY/GP) was evaluated in 495 cervical scrapes with corresponding histologic and cytologic findings. HPV prevalence rates determined with the NMPCR assay were 34.7% (102 of 294) in the absence of cervical intraepithelial neoplasia (CIN 0), 94.2% (113 of 120) in the presence of mild or moderate dysplasia (CIN I/II), and 97.8% (44 of 45) in the presence of severe dysplasia (CIN III). The combination of all four HPV detection methods applied in the study was taken as "gold standard": in all three morphological subgroups the NMPCR assay had significantly (P < 0.0001) higher sensitivities than the MY09-MY11 and GP5+-GP6+ assays and sensitivities comparable or equal to those of the MY/GP assay. All 18 HPV genotypes investigated were detected among the clinical samples. The ratio of high- to low-risk HPV genotypes increased from 4:1 (80 of 103) in CIN 0 to 19:1 (149 of 157) in CIN I to III. Multiple infections were detected in 47.9% (124 of 259) of the patients. In conclusion, the novel NMPCR method is a sensitive and useful tool for HPV DNA detection, especially when exact HPV genotyping and the identification of multiple HPV infections are required.