Pleuropulmonary blastoma (PPB) and other DICER1-associated high-grade malignancies are morphologically, genetically and epigenetically related - A comparative study of 4 PPBs and 6 sarcomas.

DICER1-related tumors occur hereditary or sporadically, with high-grade malignancies sharing clinicopathological and (epi)genetic features. We compared 4 pleuropulmonary blastomas (PPBs) and 6 sarcomas by mutation analysis, whole transcriptome sequencing and methylation profiling. 9/10 patients were female. PPB patients were 0-4 years. 3/4 were alive; 2 without disease. One patient died of metastatic disease (median follow-up, 16 months). Sarcoma patients were 16-56 years. Locations included: uterine cervix/corpus (3/1), soft tissue back/shoulder (1) and paravertebral (1). 5/6 patients were alive; 2 developed metastases: intracranial (1) and lung and kidney (1) (median follow-up, 17 months). The deceased patient previously had a PPB and a Sertoli-Leydig cell tumor. Histologically, tumors showed atypical primitive-looking cells with incomplete rhabdomyoblastic differentiation and cartilage (n = 5). Immunohistochemistry demonstrated desmin- (n = 9/10), myogenin- (n = 6/10) and keratin positivity (n = 1/1). Eight cases harbored biallelic DICER1 mutations with confirmed germline mutations in 4 cases. Two cases showed a monoallelic mutation. By RNA expression- and methylation profiling, distinct clustering of our cases was seen demonstrating a close relationship on (epi)genetic level and similarities to embryonal rhabdomyosarcoma. In conclusion, this study shows overlapping morphological, immunohistochemical and (epi)genetic features of PPBs and DICER1-associated high-grade sarcomas, arguing that these neoplasms form a spectrum with a broad clinicopathological range.

Local recurrence after surgery for primary extra-abdominal desmoid-type fibromatosis.

BACKGROUND: Desmoid-type fibromatosis is a locally aggressive soft tissue tumour with a biological behaviour that varies between relatively indolent and progressive growth. Although there is a trend towards conservative treatment, surgery remains the standard treatment for extra-abdominal desmoid tumours. METHODS: Databases of three hospitals were searched to identify patients who had been treated for desmoid-type fibromatosis between November 1989 and May 2011. The risk of local recurrence was evaluated and predictive factors were assessed in patients who underwent surgical resection as initial treatment for a primary tumour. RESULTS: A total of 132 patients had surgical treatment for a primary tumour. A complete resection (R0) was achieved in 87 patients (65.9 per cent). In addition to surgery, 54 patients received radiotherapy. During a median follow-up of 38 months, 18 local recurrences were detected. The estimated 5-year cumulative risk of local recurrence was 17.6 per cent. Univariable Cox regression analysis demonstrated that the risk of local recurrence increased for extremity lesions compared with desmoids on the trunk (odds ratio 6.69, 95 per cent confidence interval 1.42 to 31.54). No significant influence of age, resection margins or adjuvant radiotherapy on the risk for local recurrence was observed. CONCLUSION: Following surgical treatment of a primary extra-abdominal desmoid tumour, the 5-year risk of local recurrence is modest and not influenced by microscopically clear resection margins or adjuvant radiotherapy.

A possible role for Epstein-Barr virus in the pathogenesis of pleural effusion.

A high percentage of pleural effusions remain unexplained despite an intensive diagnostic workup. Epstein-Barr virus (EBV) infections occur worldwide and affect the majority of the population. The present study investigated the prevalence and clinical relevance of EBV in pleural effusions. A prospective study was performed in which 60 consecutive patients with pleural effusion were enrolled. Real-time quantitative EBV-PCR was performed on pleural fluid and serum. Pleural fluid was further evaluated using standard biochemical, cytological and microbiological procedures. Demographic data, medical history and medication were recorded. A total of 24 (40%), from 60 pleural fluids tested, were positive in the EBV-PCR. Median EBV-DNA levels for positive samples was 454 genome equivalents (geq).mL-1 (range 36-163,446 geq.mL-1). A total of 20 (59%) out of 34 unexplained pleural effusions were EBV-PCR positive. Serological analysis of all patients with a positive PCR revealed a previous infection. Patients with a positive EBV-PCR on pleural fluid were more likely to have a positive EBV-PCR on serum than patients with a negative PCR on pleural fluid. Epstein-Barr virus reactivation in pleural fluid is a frequent event and the absence of an alternative diagnosis to explain the nature of the effusion in the majority of cases suggests an aetiological role for Epstein-Barr virus in the development of pleural effusion.

Enhanced antitumour efficacy by combining conventional chemotherapy with angiostatin or endostatin in a liver metastasis model.

BACKGROUND: Tumour-induced microvascular networks have become attractive targets in cancer therapy. Strategies that target both tumour cells and vasculature have not been investigated in models of early metastatic colorectal disease. The efficacy of a combination of conventional chemotherapy with a potent angiogenesis inhibitor (endostatin or angiostatin) in a murine model of early colorectal liver metastasis was studied. METHODS: Sixty-six mice were subjected to intrasplenic injection of C26 tumour cells to induce colorectal liver metastases. Control animals received phosphate-buffered saline (n = 8) or citrate buffer (n = 8). Treatment included conventional chemotherapy (n = 9), endostatin (n = 8), high-dose (n = 5) or low-dose (one-tenth of optimal dose; n = 10) angiostatin, as well as the combination of either of these drugs with chemotherapy (n > 5). Clinical appearance was scored daily using a semiquantitative scale. Liver weight, macroscopic and histological tumour involvement (hepatic replacement area; HRA) were measured upon death at day 12. RESULTS: Treated mice displayed significantly better clinical scores than controls, except for those animals treated with low-dose angiostatin with or without chemotherapy. Treatment with conventional chemotherapy resulted in a decrease in HRA from 42.3 to 29.1 per cent (P < 0.001). The addition of angiostatin or endostatin to conventional chemotherapy improved antitumoral efficacy, in a multiplicative manner, resulting in a HRA of approximately 3.5 per cent (P < 0.001). CONCLUSION: The addition of angiostatin or endostatin to conventional chemotherapy enhanced antitumoral efficacy in a murine model of early colorectal liver metastasis.

Aromatase and COX-2 expression in human breast cancers.

We have investigated aromatase and the inducible cyclooxygenase COX-2 expression using immunocytochemistry in tumors of a series of patients with advanced breast cancer treated with aromatase inhibitors. Aromatase was expressed in 58/102 breast cancers. This is similar to the percentage previously reported for aromatase activity. Interestingly, aromatase was expressed in a variety of cell types, including tumor, stromal, adipose, and endothelial cells. Since prostaglandin E2 is known to regulate aromatase gene expression and is the product of COX-2, an enzyme frequently overexpressed in tumors, immunocytochemistry was performed on the tissue sections using a polyclonal antibody to COX-2. Aromatase was strongly correlated (P<0.001) with COX-2 expression. These results suggest that PGE2 produced by COX-2 in the tumor may be important in stimulating estrogen synthesis in the tumor and surrounding tissue. No correlation was observed between aromatase or COX-2 expression and the response of the patients to aromatase inhibitor treatment. However, only 13 patients responded. Nine of these patients were aromatase positive. Although similar to responses in other studies, this low response rate to second line treatment suggests that tumors of most patients were no longer sensitive to the effects of estrogen. Recent clinical studies suggest that greater responses occur when aromatase inhibitors are used as first line treatment. In the intratumoral aromatase mouse model, expression of aromatase in tumors is highly correlated with increased tumor growth. First line treatment with letrozole was effective in all animals treated and was more effective than tamoxifen in suppressing tumor growth. Letrozole was also effective in tumors failing to respond to tamoxifen, consistent with clinical findings. In addition, the duration of response was significantly longer with the aromatase inhibitor than with tamoxifen, suggesting that aromatase inhibitors may offer better control of tumor growth than this antiestrogen.

An Epstein-Barr virus-associated pulmonary lymphoproliferative disorder as complication of immunosuppression.

Inherited or acquired immunodeficiencies as well as autoimmune diseases treated with cytotoxic drugs are associated with an increased incidence of lymphoma. Non-Hodgkin's lymphomas that occur in the context of drug-induced immunosuppression, acquired or congenital immunodeficiency, are frequently associated with Epstein-Barr virus infection. This report describes the occurrence of an Epstein-Barr virus associated pulmonary B cell lymphoma in a patient with longstanding rheumatoid arthritis treated with methotrexate.

Hepatocyte growth factor/scatter factor promotes adhesion of lymphoma cells to extracellular matrix molecules via alpha 4 beta 1 and alpha 5 beta 1 integrins.

Hepatocyte growth factor (HGF)/scatter factor (SF) is the ligand for a tyrosine kinase cell surface receptor encoded by the MET protooncogene (c-MET). HGF/SF can induce proliferation and motility in epithelial cells and promotes invasion of carcinoma cells and NIH3T3 fibroblasts transfected with both HGF/SF and c-MET genes. Our results show that HGF/ SF and c-MET also play a role in adhesion and invasion of human lymphoma cells. c-MET mRNA is expressed in hemopoietic cells, such as hemopoietic progenitor cells (CD34+ cells) in bone marrow (BM) and mobilized peripheral blood, immature B cells in cord blood and BM, and germinal center B-centroblasts. In normal peripheral blood B cells, which are c-MET-, c-MET expression was induced by PMA, ConA, HGF/ SF, and Epstein-Barr virus (EBV) infection. Using immunohistochemistry, we detected c-MET on the cell surface of large activated centroblasts in lymph nodes from patients with B-non-Hodgkin's lymphoma and Hodgkin's disease. In the latter group, c-MET expression correlated well with the presence of EBV. Because HGF/SF and c-MET promote metastasis of carcinoma cells, we studied the effects of c-MET stimulation by HGF/SF of B-lymphoma cells on properties relevant for metastasis, ie, adhesion, migration, and invasion. HGF/SF stimulated adhesion of the c-MET+ B-cell lines to the extracellular matrix molecules fibronectin (FN) and collagen (CN) in a dose dependent manner. However, adhesion to laminin was not affected by HGF/SF. Adhesion to FN was mediated by beta 1-integrins alpha 4 beta 1 (VLA4) and alpha 5 beta 1 (VLA5) since blocking antibodies against beta 1- (CD29), alpha 4-(CD49d), or alpha 5- (CD49e) integrin subunits, completely reversed the effect of HGF/SF. Furthermore, HGF/SF induced adhesion was abrogated by addition of genistein, which blocks protein tyrosine kinases, including c-MET. Addition of HGF/SF resulted in a sixfold increase in migration of c-MET B-lymphoma cells through Matrigel, compared to medium alone. In rat fibroblast cultures, HGF/SF doubled the number of c-MET+ B-lymphoma cells that invaded the fibroblast monolayer. In these adhesion, migration and invasion assays HGF/SF had no effect on c-MET- cell lines. In conclusion, c-MET is expressed or can be induced on immature, activated, and certain malignant B cells. HGF/SF increased adhesion of c-MET+ B-lymphoma cells to FN and CN, mediated via beta 1-integrins alpha 4 beta 1 and alpha 5 beta 1, and furthermore promoted migration and invasion.

Histopathology and growth rate of interval breast carcinoma. Characterization of different subgroups.

BACKGROUND: Interval breast cancers are defined as carcinomas occurring within 2 years after a negative screening Distinction has to made between cancers existent at the time of screening but missed for some reason, and fast-growing incident cancers. This is important because the natural history and the implications for the treatment of the patient might differ. METHODS: Radiologic and histopathologic characteristics were assembled for 104 interval cancers diagnosed within the DOM project, the Utrecht program for the early detection of breast cancer. At a mammographic review for 27 cases, signs of malignant or benign tumor were found (missed cases). For 77 cases no radiologic signs were present on review. Twenty of these cases had a mitotic rate of > 3 and a high tumor growth rate (mean doubling time: 51 days). This combination seemed implausible, therefore, it was thought hypothesized that these tumors were most likely present, although radiologically invisible (masked), at the time of screening. The remaining cases (n = 57) were classified as true interval cancers and further divided into 14 fast-growing cases (mitotic rate > or = 3/high-power field [HPF]) and 43 cases with an intermediate growth rate (mitotic rate < 3/HPF). RESULTS: Factors associated with the masking of tumors were the histologic tumor type, absence of microscopic calcifications, and presence of dense breast tissue. Fast-growing tumors were characterized by a young patient age, absence of microscopic calcifications, and a high percentage of regional lymph node positive tumors. The 5-year survival probability was 100% for missed cases, 70% for masked cases, 80% for cases with an intermediate growth rate, and 54% for fast-growing cases. CONCLUSIONS: It is possible to separate interval breast cancers in true interval cases and cases (most likely) existent at the time of screening. Part of this last group is invisible by mammography (masked).