Alemtuzumab is effective against severe chronic lymphocytic leukaemia-associated paraneoplastic pemphigus

Alemtuzumab (ALZ) is a monoclonal antibody used in the treatment of a variety of lymphoproliferative diseases, primarily chronic lymphocytic leukaemia (CLL). Paraneoplastic pemphigus (PNP) is a severe mucocutaneous disease, which can occur in association with B-cell malignancies. A correct diagnosis of PNP relies on distinct clinical and histopathological features, and the demonstration, by direct immunofluorescence, of intercellular and basement membrane IgG deposits in the affected tissue. PNP is often refractory to immunosuppressive drugs and frequently has a fatal outcome. We report three cases where sustained remissions of both PNP and CLL were induced by ALZ. In one of these cases, ALZ was able to reinduce a sustained remission of PNP at the reappearance of the disorder years after the primary treatment. In all cases, the PNP diagnosis was confirmed by immunofluorescence. In conclusion, ALZ should be considered as a treatment option in severe CLL-associated PNP. Patients should be carefully selected and receive appropriate infectious prophylaxis before, during and after ALZ treatment, due to the risk of opportunistic infections secondary to combined disease- and drug-induced immunosuppression.

Tumor-associated CD66b+ neutrophil and CD8+ lymphocyte densities as independent prognostic factors for recurrence in localized cervical cancer: Automated digital image analysis and observer-assisted stereological assessments

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Background: The prognostic impact of tumor-associated immune cells in cervical cancer is unclear. Methods: Automated digital image analysis (DIA) software and observer-assisted stereological (OAS) assessments were used to obtain densities of immunostains for CD66b+ neutrophils, CD163+ macrophages, and CD8+lymphocytes in scanned whole slide images of tumor sections from 101 patients with FIGO stage IB and IIA cervical cancer. Primary end-point was recurrence-free survival (RFS). Results: The highest densities of CD66b+ neutrophils and CD163+ macrophages were observed by OAS in the peritumoral compartment (median 53.1 cells/mm2 and 1.3% area fraction, respectively). DIA required far less human resources than OAS assessments. We observed high correlations between DIA and OAS variables of corresponding parameters; spearman ρ was 0.79 for CD8+ lymphocytes , 0.85 for CD66b+ neutrophils, and 0.92 for CD163+ macrophages (all p <0.0001). Hazard rates for DIA assessments in the global tumor area were comparable with the prognostically strongest OAS assessments in the peritumoral compartment. In multivariate analysis, high density of CD66b+ neutrophils (HR 2.6; 95% CI 1.2–5.7; p = 0.02), low density of CD8+ lymphocytes (HR 2.3; 95% CI 1.1–4.9; p = 0.03), and presence of lymph node metastases (HR 2.6; 95% CI 1.2–5.5; p = 0.02) were independent predictors of poor RFS, whereas FIGO stage and CD163+macrophage density were not. The CD66b/CD8 immunostain index obtained by DIA had excellent discriminatory power for each quartile with 5-year RFS of 92%, 80%, 65%, and 48% for quartile I (<0.019), II (0.02-0.05), III (0.06-0.24), and IV (>0.25), respectively (p = 0.001). Conclusions: High tumor-associated CD66b+ neutrophil and low CD8+ lymphocyte densities are independent prognostic factors for short recurrence-free survival in cervical cancer assessed by DIA and OAS. Combined CD66b+ neutrophil/CD8+ lymphocyte immunostain index obtained by DIA is a strong and cost-efficient prognostic variable with potential for routine application.

Proliferation indices of phosphohistone H3 and Ki67: strong prognostic markers in a consecutive cohort with stage I/II melanoma

Cellular proliferation is correlated with the progression of melanoma. Accordingly, the proliferation index of H&E-stained thin melanomas was recently included in the staging system of the American Joint Committee on Cancer. Yet, the immunohistochemical markers of proliferation phosphohistone H3 and Ki67 may improve such indices. To accurately quantify these markers, they should be combined with a melanocytic marker, for example, MART1 in an immunohistochemical double stain; also enabling automated quantification by image analysis. The aim of the study was to compare the prognostic impact of phosphohistone H3/MART1, Ki67/MART1, and H&E stains in primary cutaneous melanoma, and to determine the difference between indices established in hot spots and the global tumor areas. The study included 153 consecutive stage I/II melanoma-patients. The follow-up time was 8-14 years for event-free melanoma. Recurrent disease occurred in 43 patients; 37 died of melanoma. Both events occurred in only three thin melanomas. Their paraffin-embedded tissue was stained for phosphohistone H3/MART1, Ki67/MART1, and with H&E. And proliferation indices were established in 1-mm(2) hot spots and in the global tumor areas. In multivariate Cox analyses, only hot spot indices of phosphohistone H3/MART1 and Ki67/MART1 were independent prognostic markers. Phosphohistone H3/MART1 tended to be better than Ki67/MART1 with adjusted hazard ratios of 3.66 (95% CI, 1.40-9.55; P=0.008) for progression-free survival and 3.42 (95% CI, 1.29-9.04; P=0.013) for melanoma-specific death. In all stains, prognostic performance was substantially improved by using hot spots instead of the global tumor areas. In conclusion, phosphohistone H3/MART1 and Ki67/MART1 were superior to H&E stains, and hot spots superior to the global tumor areas. Given the potential for automated analysis, these double stains seem to be robust alternatives to conventional mitotic detection by H&E in stage I/II melanomas in general. This was particularly true for thick melanomas whereas no specific analyses for thin melanomas only could be performed.

Evaluation of BRAF mutation testing methodologies in formalin-fixed, paraffin-embedded cutaneous melanomas

Patients diagnosed with BRAF V600E mutated cutaneous melanoma show response to treatment with the BRAF inhibitor Vemurafenib. Different methods for BRAF mutation detection exist; however, only the Cobas 4800 BRAF V600 Mutation Test has been approved by the US Food and Drug Administration for patient selection. The results from this test depend on the percentage of tumor cells in the samples, which clinically may be estimated with substantial variation. We have evaluated five different methods: the Cobas test, Sanger sequencing, pyrosequencing, TaqMan-based allele-specific PCR, and Competitive Amplification of Differentially Melting Amplicons (CADMA), for detection of BRAF c.1799T>A (V600E) mutations in 28 formalin-fixed paraffin-embedded (FFPE) cutaneous melanoma samples. We show that the frequency of the BRAF V600E mutation is influenced by the analytical sensitivity of the applied method. However, a 100% consensus was observed among all five methods when the tumor tissue fraction was more than 10% of all tissue or more than 50% of cell-dense tissue. When using Sanger sequencing, pyrosequencing, or the Cobas test, it may be advisable to perform macrodissection before mutation testing if the tumor cell fraction is low. CADMA and TaqMan may not require macrodissections for a reliable test. Therefore, the use of more sensitive methods may have a future in testing for BRAF mutations in clinical settings.

PET hypoxia imaging with FAZA: reproducibility at baseline and during fractionated radiotherapy in tumour-bearing mice

PURPOSE

Tumour hypoxia is linked to treatment resistance. Positron emission tomography (PET) using hypoxia tracers such as fluoroazomycin arabinoside (FAZA) may allow identification of patients with hypoxic tumours and the monitoring of the efficacy of hypoxia-targeting treatment. Since hypoxia PET is characterized by poor image contrast, and tumour hypoxia undergoes spontaneous changes and is affected by therapy, it remains unclear to what extent PET scans are reproducible. Tumour-bearing mice are valuable in the validation of hypoxia PET, but identification of a reliable reference tissue value (blood sample or image-derived muscle value) for repeated scans may be difficult due to the small size of the animal or absence of anatomical information (pure PET). Here tumour hypoxia was monitored over time using repeated PET scans in individual tumour-bearing mice before and during fractionated radiotherapy.

METHODS

Mice bearing human SiHa cervix tumour xenografts underwent a PET scan 3 h following injection of FAZA on two consecutive days before initiation of treatment (baseline) and again following irradiation with four and ten fractions of 2.5 Gy. On the last scan day, mice were given an intraperitoneal injection of pimonidazole (hypoxia marker), tumours were collected and the intratumoral distribution of FAZA (autoradiography) and hypoxia (pimonidazole immunohistology) were determined in cryosections.

RESULTS

Tissue section analysis revealed that the intratumoral distribution of FAZA was strongly correlated with the regional density of hypoxic (pimonidazole-positive) cells, even when necrosis was present, suggesting that FAZA PET provides a reliable measure of tumour hypoxia at the time of the scan. PET-based quantification of tumour tracer uptake relative to injected dose showed excellent reproducibility at baseline, whereas normalization using an image-derived nonhypoxic reference tissue (muscle) proved highly unreliable since a valid and reliable reference value could not be determined. The intratumoral distribution of tracer was stable at baseline as shown by a voxel-by-voxel comparison of the two scans (R = 0.82, range 0.72-0.90). During treatment, overall tracer retention changed in individual mice, but there was no evidence of general reoxygenation.

CONCLUSION

Hypoxia PET scans are quantitatively correct and highly reproducible in tumour-bearing mice. Preclinical hypoxia PET is therefore a valuable and reliable tool for the development of strategies that target or modify hypoxia.

Automated Quantification of MART1-Verified Ki67 Indices by Digital Image Analysis in Melanocytic Lesions

Context.—The proliferation marker Ki67 is an important diagnostic and prognostic aid in surgical pathology. However, manual quantification in a counting frame to accurately establish the proliferation rate (Ki67 index) is cumbersome and time-consuming. Instead, digital image analysis of Ki67/MART1 double stains may provide fast and novel index computations for entire tumor sections.

Objectives.—To design and compare image analysis protocols that compute Ki67 indices of Ki67/MART1 double stains, to compare automated indices with previously published manual indices, and to compare the total number of proliferating cells (mimicking a Ki67 single stain) with the number of MART1-verified proliferating cells.

Design.—Whole slide images were captured from 48 melanomas and 77 nevi stained with an immunohistochemical cocktail against Ki67 and MART1. Ki67 indices were determined by digital image analysis and different equations based on number or area.

Results.—The differences between mean indices of melanomas and nevi were significant (P &lt; .001) in all index computations. Number-based image analysis of lesions with more than 250 melanocytic cells misclassified 1 of 42 melanomas and 4 of 53 nevi, numbers comparable with manual counting. Automated indices were significantly higher than manual indices, as were indices of mimicked Ki67 single stains compared with MART1-verified Ki67 indices (P &lt; .001).

Conclusions.—Ki67 indices established by digital image analysis of Ki67/MART1 double stains demonstrated excellent abilities to discriminate melanomas from nevi with diagnostic performances equal to manually performed indices. Testing different definitions of the automated MART1-verified Ki67 index, no single definition stood out; thus, a variety of definitions may be used.

Tumor-promoting macrophages induce the expression of the macrophage-specific receptor CD163 in malignant cells

Tumor-associated macrophages (TAMs) represent a distinct malignancy-promoting phenotype suggested to play a key role in tumor formation and metastasis. We aimed to investigate the expression of the monocyte/macrophage-restricted receptor CD163 in bladder tumor biopsies and assess the potential mechanism inducing the CD163 expression in tumor cells. A high CD163 mRNA expression (n = 87) was significantly associated with a poor 13-year overall survival (log-rank test, χ(2) = 8.931; p = 0.0028). Moreover, CD163 mRNA expression was significantly increased in muscle invasive (T2-T4), p = 0.017, and aggressive (grade III/IV) cancers (p = 0.015). The expression strongly correlated with local expression of IL-6 (r = 0.72; p <0.0001) and IL-10 (r = 0.75; p <0.0001), mediators known to induce CD163 expression in vitro. CD163 immunostaining (n = 46) confirmed the association between dense TAM infiltration and histologically advanced disease. In 39% of the biopsies, CD163 immunoreactivity was also observed in tumor cells, and CD163-expressing metastatic cells were identified in lymph node biopsies (n = 8). Bladder cancer cell lines did not express CD163; however, when cocultured with macrophages the bladder cancer cell expression of CD163 was significantly induced in an IL-6/IL-10 independent manner. In conclusion, we show a strong association between CD163 mRNA expression in bladder cancer biopsies and poor patient outcome. CD163 expression was not confined to the infiltrating TAMs, but was also expressed by a significant portion of the malignant cells in both tumors and lymph nodes. CD163 expressing tumor cells may constitute a subpopulation of tumor cells with a phenotypic shift associated with epithelial-to-mesenchymal transition (EMT) and increased metastatic activity induced by TAMs.

Dermatofibrosarcoma protuberans diagnosed by a single biopsy

This brief report is about a 9 year old girl presenting with a 2.5 cm circular blue to violet discoloration on the anterolateral upper left thigh. The first biopsy taken revealed the diagnosis dermatofibrosarcoma protuberans. The patient underwent surgery at a specialized sarcoma center with post operative histology showing free wide resection margin. Preoperative chest x-ray showed no sign of metastasis. This brief report emphasizes the significance of the use of biopsy when cutaneous elements look suspicious and diagnosis is unclear.

Digital image analysis: a review of reproducibility, stability and basic requirements for optimal results

Digital image analysis (DIA) is increasingly implemented in histopathological research to facilitate truly quantitative measurements, decrease inter-observer variation and reduce hands-on time. Originally, efforts were made to enable DIA to reproduce manually obtained results on histological slides optimized for light microscopy and the human eye. With improved technical methods and the acknowledgement that computerized readings are different from analysis by human eye, recognition has been achieved that to really empower DIA, histological slides must be optimized for the digital 'eye', with reproducible results correlating with clinical findings. In this review, we focus on the basic expectations and requirements for DIA to gain wider use in histopathological research and diagnostics. With a reference to studies that specifically compare DIA with conventional methods, this review discusses reproducibility, application of stereology-based quantitative measurements, time consumption, optimization of histological slides, regions of interest selection and recent developments in staining and imaging techniques.

Intratumoral neutrophils and plasmacytoid dendritic cells indicate poor prognosis and are associated with pSTAT3 expression in AJCC stage I/II melanoma

BACKGROUND

Tumor cell and host immune cell interaction plays a key role in carcinogenesis. Signal transducer and activator of transcription 3 (STAT3) is constitutively activated in cancer and believed to be an important mediator of tumor-induced immunosuppression. This paper aims to describe the prognostic impact of neutrophil and dendritic cell infiltration in primary melanoma and the association of this infiltration with activated STAT3 (pSTAT3) in primary melanoma cells.

METHODS

Formalin-fixed, paraffin-embedded primary melanomas from 186 stage-I/II melanoma patients surgically resected from 1997 to 2000. Infiltrating neutrophils (CD66b), dendritic cells (CD123+ and DC-LAMP+), T-lymphocytes (CD8) and pSTAT3 melanoma cell expression were studied by immunohistochemistry and evaluated as present or absent. DC-LAMP+ cell infiltration was evaluated as absent/few versus dense. Study endpoints: relapse-free survival, melanoma-specific, and overall survival.

RESULTS

The median observation time was 12.2 years (range, 10.4-14.2 years). Fifty-one deaths were observed of which 38 (20%) were melanoma-specific. In a multivariate Cox proportional hazards model including ulceration and melanoma thickness, neutrophil and CD123+ dendritic cell infiltration were independently associated with poor prognosis (CD66b: hazard ratio [HR] = 3.13; 95% confidence interval [CI], 1.43-6.83; P = .004; CD123: HR = 2.45; 95% CI, 1.22-4.92; P = .012). The association between melanoma cell pSTAT3 expression and immune infiltration (neutrophils and CD123+ cells) was strong. pSTAT3 expression, CD8 and DC-LAMP infiltration were not independently associated with poor prognosis.

CONCLUSIONS

Neutrophil infiltration and CD123+ dendritic cell infiltration in primary melanoma are independently associated with poor prognosis. Melanoma cell expression of pSTAT3 is strongly associated with the surrounding immune infiltrate.

Inhibition of tumor lactate oxidation: consequences for the tumor microenvironment

BACKGROUND AND PURPOSE

Tumor cells are recognized as being highly glycolytic. However, recently it was suggested that lactate produced in hypoxic tumor areas may be taken up by the monocarboxylate transporter MCT1 and oxidized in well-oxygenated tumor parts. Furthermore, it was shown that inhibition of lactate oxidation using the MCT1 inhibitor α-cyano-hydroxycinnamate (CHC) can radio-sensitize tumors possibly by forcing a switch from lactate oxidization to glycolysis in oxygenated cells, which in turn improves tumor oxygenation and indirectly kills radio-resistant hypoxic tumor cells from glucose starvation.

MATERIAL AND METHODS

To provide direct evidence for the existence of a targetable energetic symbiosis, mice bearing SiHa or FaDu(dd) tumors were treated with CHC for different time periods. One hour prior to sacrifice, mice were administered with the glucose analog fluorodeoxyglucose (FDG) and the hypoxia-marker pimonidazole. Tumor cryosections were analyzed for regional glucose retention (FDG autoradiograms), hypoxia (pimonidazole retention) and glucose and lactate levels (bioluminescence imaging).

RESULTS

Treatment did not influence metabolite concentrations, necrosis or extent of hypoxia, but pixel-by-pixel analysis comparing FDG retention and hypoxia (a measure of the apparent in vivo Pasteur effect) showed that CHC treatment caused a transient reduction in the Pasteur effect in FaDu(dd) 1.5 h following CHC administration whereas a reduction was only observed in SiHa following repeated treatments.

CONCLUSIONS

In summary, our data show that CHC is able to influence the intratumoral distribution of glucose use between hypoxic and non-hypoxic tumor areas. That is in accordance with a functional tumor lactate-shuttle, but the absence of any detectable changes in hypoxic extent and tissue metabolites was unexpected and warrants further investigation.

Abstract 539: The expression of monocyte/macrophage-restricted scavenger receptor CD163 by malignant cells may be a consequence of cell fusion with tumor-associated macrophages: A novel target for cancer therapy

Solid tumors contain large a number of infiltrating macrophages, which are believed to play a key role in progression and metastasis. Recent research has indicated that malignant cells at times express molecular pathways normally only observed in myeloid cells such as macrophages, hence suggesting that macrophages may fuse with tumor cells. In the present work, we aimed to investigate tumor cell expression of the monocyte/macrophage-restricted scavenger receptor CD163. Initially, the tumor expression of CD163 was examined using a bladder cancer tissue microarray (TMA) containing 425 cores of tumor tissue from 425 patients and 43 paired metastatic lymph nodes. Tumor cells showed a characteristic pleomorphic and atypical morphology with large nuclei, and they were easily distinguished from macrophages. Immunohistochemical staining revealed that CD163-expressing tumor cells could be detected in 98% of the tumor cores, and CD163-expressing metastatic cells could be identified in 77% of the cores of lymph node biopsies. Quantitative real-time polymerase chain reaction and flow cytometric analysis showed that bladder cancer cell lines did not express CD163; however, when co-cultured with macrophages a significant induction of CD163 expression was observed. Utilizing the xCELLigence Real-Time Cell Analyzer System we showed that macrophage-tumor hybrid cells exhibited a significantly increased migratory capacity compared to non-hybrid tumor cells. Tracing the Y chromosome in co-cultures of male macrophages and female T24 cells, we found T24 cell nuclei to be fused with the macrophages. A Cre-inducible mouse model of melanoma expressing a fluorescent reporter system (GFP) was used to characterize hybrid cell formation of macrophages with GFP positive tumors cells in vivo. Flow cytometric analysis demonstrated that &gt;90% of the murine GFP positive tumor cells co-expressed CD163.

In conclusion, we show that the expression of the monocyte/macrophage scavenger receptor CD163 was not confined to tumor-associated macrophages. In fact, a significant portion of the tumor cells also expressed CD163, possibly as a result of heterotypic cell fusion between tumor cells and macrophages. Our findings identify CD163 as a possible target for novel cancer therapy.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 539. doi:10.1158/1538-7445.AM2011-539

Assessing hypoxia in animal tumor models based on pharmocokinetic analysis of dynamic FAZA PET

Positron emission tomography (PET) allows non-invasive detection and mapping of tumor hypoxia. However, slow tracer kinetics and low resolution, results in limited tumor-to-normal tissue contrast and the risk of missing areas where hypoxic cells are intermixed with necrosis. The shape of tumor time activity curves (TACs), as deduced from dynamic scans, may allow further separation of tumors/tumor sub-volumes that are inseparable based on static scans. This study was designed to define the added value of dynamic scans.

MATERIAL AND METHODS

Three squamous cell carcinoma tumor models were grown in mice. Mice were injected with the (18)F-labeled PET hypoxia-tracer fluoroazomycin arabinoside (FAZA) and the immunologically-detectable hypoxia-marker pimonidazole, and PET scanned dynamically for three to six hours. Subsequently, microregional tracer retention (autoradiography) and the distribution of pimonidazole-retaining cells (immunohistology) and necrosis were analyzed in tumor tissue sections. Dynamic PET data were analysed based on a two-compartment model with irreversible tracer binding generating estimates of the putative hypoxia surrogate markers k(3) (tracer trapping rate constant) and K(i) (influx rate constant from plasma into irreversible bound tracer).

RESULTS/DISCUSSION

High tumor-to-reference tissue ratios and a strong linear correlation (R∼0.7 to 0.95) between density of hypoxic cells and FAZA concentration was observed three hours after tracer administration, suggesting that late time PET images provides an accurate measure of hypoxia against which kinetic model estimates can be validated. Tumor TACs varied widely (ranging from distinctly wash-out to accumulative type) among tumor types although pimonidazole-stainings revealed extensive hypoxia in all models. Kinetic analysis of tumor sub-volumes showed that k(3) correlated poorly with late time FAZA retention regionally in two of the three tumor models. The influx rate constant K(i) displayed far less variability and correlated strongly with late time FAZA retention (hypoxia) in two of three tumor models, whereas a non-consistent relationship was observed in the last tumor model. Our study demonstrates the potential usefulness of dynamic PET, but also that a simple two-compartment model may be inappropriate in some tumor models.

Mutations in TP53 tumor suppressor gene in wood dust-related sinonasal cancer

The causal role of work-related exposure to wood dust in the development of sinonasal cancer has long been established by numerous epidemiologic studies. To study molecular changes in these tumors, we analyzed TP53 gene mutations in 358 sinonasal cancer cases with or without occupational exposure to wood dust, using capillary electrophoresis single-strand conformation polymorphism analysis and direct sequencing. A significant association between wood-dust exposure and adenocarcinoma histology was observed [adjusted odds ratio (OR) 12.6, 95% confidence interval (CI), 5.0-31.6]. TP53 mutations occurred in all histologies, with an overall frequency of 77%. TP53 mutation positive status was most common in adenocarcinoma (OR 2.0, 95% CI, 1.1-3.7; compared with squamous cell carcinoma), and mutation positivity showed an overall, nonsignificant association with wood-dust exposure (OR 1.6, 95% CI, 0.8-3.1). Risk of TP53 mutation was significantly increased in association with duration (> or =24 years, OR 5.1, 95% CI, 1.5-17.1), average level (>2 mg/m(3); OR 3.6, 95% CI, 1.2-10.8) and cumulative level (> or =30 mg/m(3) x years; OR 3.5, 95% CI, 1.2-10.7) of wood-dust exposure; adjustment for formaldehyde affected the ORs only slightly. Smoking did not influence the occurrence of TP53 mutation; however, it was associated with multiple mutations (p = 0.03). As far as we are aware, this is the first study to demonstrate a high prevalence of TP53 mutation-positive cases in a large collection of sinonasal cancers with data on occupational exposure. Our results indicate that mutational mechanisms, in particular TP53 mutations, are associated with work-related exposure to wood dust in sinonasal cancer.