Hippo signaling instructs ectopic but not normal organ growth.

The Hippo signaling pathway is widely considered a master regulator of organ growth because of the prominent overgrowth phenotypes caused by experimental manipulation of its activity. Contrary to this model, we show here that removing Hippo transcriptional output did not impair the ability of the mouse liver and Drosophila eyes to grow to their normal size. Moreover, the transcriptional activity of the Hippo pathway effectors Yap/Taz/Yki did not correlate with cell proliferation, and hyperactivation of these effectors induced gene expression programs that did not recapitulate normal development. Concordantly, a functional screen in Drosophila identified several Hippo pathway target genes that were required for ectopic overgrowth but not normal growth. Thus, Hippo signaling does not instruct normal growth, and the Hippo-induced overgrowth phenotypes are caused by the activation of abnormal genetic programs.

[Barbarism: education without history of medicine]. / Barbarij: opleiding zonder medische geschiedenis.

Rudolf Virchow regarded medical education that did not include the history of medicine as barbarism. Despite this view, current education on medical history in medical faculties in the Netherlands is minimal in terms of the number of teaching staff and the hours spent on the subject. Important arguments for teaching medical history to medical students are academic development, a better understanding of the historic fundamentals of research, clinical practice and the medical profession and, more recently, a better understanding of the historical and social context of medicine. Modern education on the history of medicine provides a perfect opportunity for critical reflection on the complexity of modern-day medicine. On the basis of these arguments, history of medicine belongs within the framework for Undergraduate Medical Education as an independent domain with appropriate assessment.

[The court physician, the clergyman, a learned society and smallpox]. / De hofarts, de dominee, een geleerd genootschap en de pokken.

Variolation was introduced in England in the first half of the 18th century. The positive effects of this new method for preventing smallpox were already known in the Netherlands around 1720, one of whom was the Dutch physician Boerhaave. In spite of this, it took another 30 years before variolation was used in the Netherlands. Despite receiving positive advice and information from his learned English friends Sloane and Sherard, Boerhaave did not apply nor advise the use of variolation. There were various arguments for this restrained approach. In 1754 Thomas Schwencke found that conditions were favourable for the introduction of variolation in The Hague. There was support from the House of Orange-Nassau (the current royal family in the Netherlands) and from a learned society; a highly motivated clergyman acted as ambassador for the new technique and the court physician Schwencke was willing to take the lead. A similar combination had previously been effective in England, though the ambassador there was not a clergyman but an influential noble lady.

The prognostic value of the soluble urokinase-type plasminogen activator receptor (s-uPAR) in plasma of breast cancer patients with and without metastatic disease.

Elevated levels of soluble uPAR (s-uPAR) and other fibrinolytic parameters functionally related to the urokinase-type plasminogen activator system might indicate the presence of cancer cells. In 25 breast cancer patients with metastases s-uPAR was significantly increased compared with 25 patients without metastases and with 25 healthy controls: 420 pg mL-1 vs. 145 pg mL-1 (P = 0.005) and 190 pg mL-1 (P = 0.003). Plasmin-alpha2-antiplasmin (PAP) complexes and d-dimers were significantly increased in breast cancer patients with metastases compared with patients without metastases and with healthy controls. The levels of plasminogen activator inhibitor (PAI)-1 activity, uPA antigen and factor (F)XIIa did not significantly differ between the patient groups and healthy controls. PAP complexes (529 microg L-1 vs. 420 microg L-1; P = 0.03), d-dimers (278.5 ng mL-1 vs. 79.0 ng mL-1; P = 0.005) and FXIIa (1.64 ng mL-1 vs. 1.19 ng mL-1; P = 0.01) were significantly higher in patients with metastases not surviving compared with patients with metastases surviving the 3-year follow-up period. Plasma s-uPAR levels in the patients with metastases did not discriminate between patients surviving and patients not surviving after 3-year follow-up. No significant differences in s-uPAR or any of the other parameters were found in the five patients developing metastases during follow-up. A single value of s-uPAR is of limited value in the follow-up of breast cancer patients with and without metastatic disease and does not predict survival or future metastases.

The unknown biology of the unknown primary tumour: a literature review.

The unknown primary tumour (UPT) is an intriguing clinical phenomenon found in approximately 5% of all newly diagnosed patients with cancer. It is unclear whether UPT forms a distinct biological entity with specific genetic and phenotypic characteristics, or whether it is merely a clinical presentation of metastases in patients in whom the primary tumour cannot be detected and does not result in any visible clinical signs. Understanding the basic biology of UPT may shed light on this issue and, moreover, may have a direct impact on clinical care. A review of the literature revealed only a limited number of publications describing the genetic and phenotypic features of UPT, most of which focus only on the potential of these markers to predict prognosis. The question as to whether the biology of UPT is different from tumours of known primaries therefore remains unanswered. Further insight into the molecular mechanisms underlying the oncogenesis of UPT, e.g. by applying newly available DNA and gene profiling microarray techniques, will be necessary to understand its specific biology and to develop more effective treatments.

Flow cytometric quantification of tumour endothelial cells; an objective alternative for microvessel density assessment.

Assessment of microvessel density by immunohistochemical staining is subject to a considerable inter-observer variation, and this has led to variability in correlation between microvessel density and clinical outcome in different studies. In order to improve the method of microvessel density measurement in tumour biopsies, we have developed a rapid, objective and quantitative method using flow cytometry on frozen tissues. Frozen tissue sections of archival tumour material were enzymatically digested. The single-cell suspension was stained for CD31 and CD34 for flow cytometry. The number of endothelial cells was quantified using light scatter- and fluorescence-characteristics. Tumour endothelial cells were detectable in a single cell suspension, and the percentage of endothelial cells detected in 32 colon carcinomas correlated highly (r=0.84, P<0.001) with the immunohistochemical assessment of microvessel density. Flow cytometric endothelial cells quantification was found to be more sensitive especially at lower levels of immunohistochemical microvessel density measurement. The current method was found to be applicable for various tumour types and has the major advantage that it provides a retrospective and quantitative approach to the angiogenic potential of tumours.

Epidemiology of unknown primary tumours; incidence and population-based survival of 1285 patients in Southeast Netherlands, 1984-1992.

Patients with an unknown primary tumour (UPT) represent 5-10% of all new cancer patients. Data on survival and prognostic factors of UPTs are based on selected patient series from specialised institutions. Population-based data on incidence, histology and determinants of survival for patients with UPT are not available. All patients diagnosed with UPT between 1984 and 1992 and entered in the population-based Eindhoven Cancer Registry for Southeast Netherlands were included. Follow-up of vital status is complete up to 1999. 1285 patients were registered. In 1024 patients, the diagnosis was confirmed histopathologically: 479 (47%) had adenocarcinoma, 453 (44%) poorly differentiated carcinoma (PDC) or adenocarcinoma (PDA), 76 (7%) squamous cell carcinoma and 16 patients (2%) had an undifferentiated malignant neoplasm. In 26% of these patients with UPT, the tumour was already widely disseminated at presentation. The majority of patients (67%) received only supportive treatment. The median survival was 11 weeks and only 15% were still alive 1 year after diagnosis. Favourable subgroups comprised young patients and patients with metastases localised in lymph nodes. In 261 cases, the diagnosis was made clinically. These patients were evaluated separately. They were older than the biopsy-confirmed patients, received less cancer therapy and their prognosis was even worse (median survival of 7 weeks). In a comparison with data from a tertiary referral centre in the United States of America (USA), our patients were older, received less therapy and had a poorer prognosis. Demographics of our favourable subgroup resembled the patients from the American study. The differences were most likely caused by the differences in the patient populations. In conclusion, we have demonstrated in a population-based study that the prognosis for patients with UPT is more unfavourable than suggested in most clinical studies.

Renal function and renal disease in the elderly: Part II.

In all industrialized countries, life expectancy has risen in the past 100 years. The incidence of elderly patients reaching end-stage renal disease (ESRD) and requiring renal replacement therapy has also increased. During the past few decades, the pattern of ESRD has changed significantly with the emerging predominance of elderly patients. The causes of this phenomenon are manifold and include an increasing number of chronic diseases typical of the 'third age', such as type 2 diabetes mellitus and vascular disease. In many species, a consequence of aging includes deterioration of renal function, partly due to structural alterations, and partly as the result of a diminishing blood flow. In humans, the aging kidney is characterized by modifications resulting from organic and functional disturbances. In particular, type 2 diabetes mellitus has emerged as an important condition, the microvascular and macrovascular complications of which are a common cause of morbidity and mortality in older patients. In Part II of this review, the specific aspects of renal replacement therapy in the elderly will be discussed.

Renal function and renal disease in the elderly: Part I.

In all industrialized countries, life expectancy has risen in the past 100 years. The incidence of elderly patients reaching end-stage renal disease (ESRD) and requiring renal replacement therapy has also increased. During the past few decades, the pattern of ESRD has changed significantly with the emerging predominance of elderly patients. The causes of this phenomenon are manifold and include an increasing number of chronic diseases typical of the 'third age', such as type 2 diabetes mellitus and vascular disease. In many species, a consequence of aging includes deterioration of renal function, partly due to structural alterations, and partly as the result of a diminishing blood flow. In humans, the aging kidney is characterized by modifications resulting from organic and functional disturbances. In particular, type 2 diabetes mellitus has emerged as an important condition, the microvascular and macrovascular complications of which are a common cause of morbidity and mortality in older patients. In part I of this review, the morphological and functional changes of the aging kidney will be reviewed, as well as the pathological conditions leading to the loss of renal function in the elderly.

Anginex, a designed peptide that inhibits angiogenesis.

Novel beta-sheet-forming peptide 33-mers, betapep peptides, have been designed by using a combination approach employing basic folding principles and incorporating short sequences from the beta-sheet domains of anti-angiogenic proteins. One of these designed peptides (betapep-25), named anginex, was observed to be potently anti-angiogenic. Anginex specifically inhibits vascular endothelial cell proliferation and induces apoptosis in these cells, as shown by flow-cytometric detection of sub-diploid cells, TUNEL (terminal deoxyribonucleotidyl transferase-mediated dUTP-nick-end labelling) analysis and cell morphology. Anginex also inhibits endothelial cell adhesion to and migration on different extracellular matrix components. Inhibition of angiogenesis in vitro is demonstrated in the sprout-formation assay and in vivo in the chick embryo chorio-allantoic membrane angiogenesis assay. Comparison of active and inactive betapep sequences allows structure-function relationships to be deduced. Five hydrophobic residues and two lysines appear to be crucial to activity. This is the first report of a designed peptide having a well-defined biological function as a novel cytokine, which may be an effective anti-angiogenic agent for therapeutic use against various pathological disorders, such as neoplasia, rheumatoid arthritis, diabetic retinopathy and restenosis.

Detection, treatment and outcome of axillary recurrence after axillary clearance for invasive breast cancer.

BACKGROUND: The aim was to gain insight into the diagnosis, treatment and prognosis of axillary recurrence after axillary clearance for invasive breast cancer in a large patient series. METHODS: Between 1984 and 1994, 4669 patients with invasive breast cancer underwent axillary clearance in eight community hospitals in the south-eastern part of the Netherlands. Using follow-up data in a population-based cancer registry, 59 patients with axillary recurrence were identified. RESULTS: The median interval between treatment of the primary tumour and the diagnosis of axillary recurrence was 2.6 (range 0.3-10.7) years. In 51 patients (86 per cent), axillary recurrence was found by palpation during routine follow-up. Surgery was part of the treatment of recurrence for 41 of 59 patients. Regional control (complete eradication of axillary recurrence) was achieved in 34 patients (58 per cent). The 5-year actuarial survival rate was 39 (95 per cent confidence interval 25-53) per cent. Patients with negative axillary lymph nodes at the time of diagnosis of the primary tumour and complete eradication of axillary recurrence had the best prognosis. CONCLUSION: Patients with axillary recurrence had a poor prognosis, except when complete eradication was achieved and axillary lymph nodes were negative at the time of diagnosis of the primary tumour.

Unknown primary tumours.

Unknown primary tumours (UPTs) are defined by the absence of a primary tumour in biopsy proved metastatic cancer. These tumours have a specific biology with clinical characteristics of rapid progression and random atypical metastases. Cytogenetic abnormalities have been demonstrated, particularly deletion of chromosome 1p. Diagnostic evaluation that includes pathology review, physical examination, chest radiography, computed tomography of the abdomen, and mammography is directed at the identification of treatable subsets. Based on clinicopathological criteria, therapy responsive subsets of patients with UPTs can be defined. These subsets have a better prognosis than the average median survival time of four months in patients with UPTs.

Thrombosis in cancer patients.

VTE is a common complication in cancer patients and may even be the first sign of malignancy. Cancer induces activation of the blood coagulation in most cancer patients. Tissue factor and cancer procoagulant are expressed on tumour cells, leading to activation of clotting factors VII and X. Cytokines released from tumour cells activate coagulant activity on monocytes, thrombocytes, and endothelial cells. This process of activated clotting enhances clinical VTE. Low-molecular weight heparins are effective and safe for the prevention and treatment of VTE in cancer patients. Activated coagulation supports tumour growth and angiogenesis. This concept may offer interesting new strategies for the treatment of cancer [28].

Cancer in the very elderly Dutch population.

BACKGROUND: Cancer incidence and mortality rates rarely are studied in people age > 85 years. Usually, patients ages 65 years, 75 years, and 85 years of age are combined into 1 group because of small numbers. The number of people age > or = 85 years in the Netherlands increased from 99,000 in 1976 to 203,000 in 1995 (an increase of 105%). The growth of the total population in this period was only 13%. This study addressed cancer incidence and mortality rates among the very elderly in the Netherlands. METHODS: Cancer mortality data (1976-1995) and population data were obtained from Statistics Netherlands, whereas cancer incidence data (1989-1995) were provided by the Netherlands Cancer Registry. Cancer incidence and mortality rates were calculated and trends in cancer mortality were studied. RESULTS: Total cancer incidence rates were highest in the age group 85-94 years, in men and women (3466/100,000 person-years and 1604/100,000 person-years, respectively). Prostate carcinoma was the most frequent cancer in men ages 85-94 years, followed by colorectal carcinoma. In women ages 85-94 years, colorectal carcinoma was most frequent, closely followed by breast carcinoma. In the 95+ years age group squamous cell skin carcinoma was the most frequent cancer in both men and women, followed by prostate carcinoma in men and breast carcinoma in women. Cancer mortality rates increased with increasing age to nearly 3700/100,000 person-years in men age 95+ years and 2500/100,000 person-years in women age 95+ years. In men, lung carcinoma was the most frequent cancer-related cause of death in patients age < or = 85 years, whereas in older men this applied to prostate carcinoma. In women, breast carcinoma was the most frequent cancer-related cause of death in all age groups > 55 years. Cancer as a cause of death became less prominent with increasing age. Over the period 1991-1995, 42% of deaths in men ages 55-64 years were attributed to cancer versus 52% of deaths in women (total population); these proportions in the 95+ years age group were 11% and 7%, respectively. CONCLUSIONS: Peak incidence rates of major cancers were found in the very elderly population in the Netherlands. Different trends in age specific mortality rates of individual cancer sites were found, with stable rates in the middle age groups and increasing rates in the oldest age groups. This may reflect a real increase caused for instance by changes in mortality from other diseases and/or an artifactual increase caused by increased cancer detection rates in the (very) elderly.

Increased D-dimer levels correlate with binding of activated protein C, but not tissue factor expression, on peripheral blood monocytes in cancer patients.

Monocyte tissue factor expression is supposed to play an important role in the hypercoagulability of blood in cancer patients. The relation between coagulation parameters and the expression of monocyte membrane proteins involved in hemostasis or monocyte activation was studied in 21 patients with a disseminated malignancy and 21 age- and sex-matched healthy controls. In the cancer patient group no increase of monocyte tissue factor expression was found (8. 4% vs. 7.8%; P = 0.83), but a significant increase of monocyte-bound activated protein C (APC) (28.8% vs. 13.4%; P = 0.009) and monocyte CD16 expression (34.5% vs. 27.0%; P = 0.007) was observed. There was also a significant increase of D-dimers (2.0 vs. 0.2 microg/ml; P = 0.001), a decrease of antithrombin (83.5% vs. 102.0%; P = 0.004), but no increase of TAT complexes (1.7 vs. 1.5 microg/l; P = 0.38) or factor VII(a) (68.5% vs. 75.0%; P = 0.52). The increase of D-dimers was significantly correlated with the monocyte APC (R = 0.60; P = 0. 005), but not with monocyte tissue factor levels (R = -0.22; P = 0. 35) or TAT complexes (R = 0.12; P = 0.60). These results reflect a local rather than systemic thrombin and fibrin formation. It is suggested that the APC formed locally enters the circulation and binds to peripheral blood monocytes. APC bound on monocytes is known to inhibit monocyte cytokine production and might therefore be involved in regulatory responses of monocytes in cancer patients.

[Breast cancer in patients, 70 years or older]. / Borstkanker bij patiënten van 70 jaar en ouder.

Over 30% of breast cancers are diagnosed after age 70. The incidence of breast cancer in the elderly has increased since 1960. Risk factors for breast cancer are a medical history without pregnancy, a first pregnancy after age 30 and the use of hormonal replacement therapy. The biology of breast cancer at advanced age indicates a relative slow, less aggressive and hormone dependent tumour growth. In spite of these favourable characteristics, the prognosis is not better than at middle age. Over 20% of older patients die from co-existing other diseases within 5 years after the diagnosis of breast cancer. This comorbidity, mostly cardiovascular or pulmonary, affects the possibilities and the outcome of treatment. Treatment of the primary tumour is performed according to the same guidelines as in younger patients. Indication exists for hormonal adjuvant treatment with tamoxifen in patients with oestrogen receptor positive tumours. Hormonal treatment is the treatment of choice in metastatic disease. Chemotherapy is given in patients with oestrogen receptor negative tumours and in patients with progressive hepatic or pulmonary metastases.