Metronomic doxifluridine chemotherapy combined with the anti-angiogenic agent TNP-470 inhibits the growth of human uterine carcinosarcoma xenografts.

Uterine carcinosarcoma is a highly aggressive gynecological neoplasm that responds poorly to conventional chemotherapy and radiotherapy. Metronomic chemotherapy is accepted as a new approach for cancer treatment, and its underlying mechanism seems to involve the suppression of angiogenesis. However, the efficacy of metronomic and anti-angiogenic therapies against uterine carcinosarcoma is unknown. The anti-angiogenic effect of doxifluridine was assessed in vitro using human umbilical vein endothelial cells (HUVEC) co-cultured with FU-MMT-1 human uterine carcinosarcoma cells. The antitumor and anti-angiogenic effects of metronomic doxifluridine (delivered via oral gavage) in combination with TNP-470 were evaluated in vivo. Tumor vascularity was assessed by contrast-enhanced color Doppler ultrasound, laser Doppler and microvessel density staining. Doxifluridine suppressed tube formation of HUVEC and vascular endothelial growth factor production by FU-MMT-1 cells. Metronomic doxifluridine alone significantly suppressed tumor growth compared with the untreated (control) group, while metronomic doxifluridine in combination with TNP-470 significantly inhibited tumor growth compared with each treatment alone. A significant reduction of intratumoral vascularity was observed in FU-MMT-1 xenografts following treatment with metronomic doxifluridine in combination with TNP-470, as compared with each treatment alone. Intestinal bleeding was only observed when the maximum tolerated dose of doxifluridine was administered in combination with TNP-470. Metronomic doxifluridine chemotherapy in combination with TNP-470 might be effective for uterine carcinosarcoma without marked toxicity, possibly acting via its potent anti-angiogenic effects. Clinical studies are needed to evaluate the safety and efficacy of this treatment in humans.

Two cases of breast carcinoma with osteoclastic giant cells: are the osteoclastic giant cells pro-tumoural differentiation of macrophages?

Breast carcinoma with osteoclastic giant cells (OGCs) is characterized by multinucleated OGCs, and usually displays inflammatory hypervascular stroma. OGCs may derive from tumor-associated macrophages, but their nature remains controversial. We report two cases, in which OGCs appear in common microenvironment despite different tumoural histology. A 44-year-old woman (Case 1) had OGCs accompanying invasive ductal carcinoma, and an 83-year-old woman (Case 2) with carcinosarcoma. Immunohistochemically, in both cases, tumoural and non-tumoural cells strongly expressed VEGF and MMP12, which promote macrophage migration and angiogenesis. The Chalkley count on CD-31-stained sections revealed elevated angiogenesis in both cases. The OGCs expressed bone-osteoclast markers (MMP9, TRAP, cathepsin K) and a histiocyte marker (CD68), but not an MHC class II antigen, HLA-DR. The results indicate a pathogenesis: regardless of tumoural histology, OGCs derive from macrophages, likely in response to hypervascular microenvironments with secretion of common cytokines. The OGCs have acquired bone-osteoclast-like characteristics, but lost antigen presentation abilities as an anti-cancer defense. Appearance of OGCs may not be anti-tumoural immunological reactions, but rather pro-tumoural differentiation of macrophage responding to hypervascular microenvironments induced by breast cancer.

Angiogenesis and expression of angiogenic agents in uterine and ovarian carcinosarcomas.

Carcinosarcomas of the female genital tract are a heterogeneous group of aggressive malignant neoplasms characterized by poor prognosis that contain elements expressing both carcinomatous and sarcomatous characteristics. In this study specimens from 25 patients were treated with labeled antibodies to vascular endothelium (FVIII), and to vascular endothelial growth factor (VEGF) for analysis of angiogenesis, and to vascular endothelial growth factor receptor 3 (VEGFR-3) for analysis of lymphangiogenesis, in 11,099 vessels. Automated quantitative image analysis was used and the results were compared with clinical data. Microvessel density increased from a median value of 18.32 vessels/mm(2) in non-neoplastic stroma to 131.25 vessels/mm(2) in neoplasms. In areas around tumor islets expressing predominantly epithelial carcinomatous characteristics, microvessel density was increased three-fold compared with the islets themselves. Vessels were arranged in a garland-type pattern, or in bursts, and they exhibited directional angiogenesis. Clinical indicators of poor survival were high tumor stage (p=0.002) and age above 65 (p=0.0769). A high number of small vessels (16-300 mum(2) in cross-sectional area) predicted poor survival (p=0.0149), and more so in tumors exhibiting predominantly sarcomatous characteristics (p=0.0087). Tumor tissue area above the median exhibiting VEGF expression was also a sign of poor survival (p=0.0267), as was an area of positive staining for VEGFR-3 exceeding the median (p=0.00487). In this study, active angiogenesis (increased number of vessels, variable in shape and exhibiting decreased antibody staining intensity) was a distinct feature of carcinosarcomas, its extent and distribution depending upon neoplasm morphology. Increased vessel numbers and increased VEGF and VEGFR-3 expression indicated poor survival.

The endothelin B (ETB) receptor agonist IRL 1620 is highly vasoconstrictive in two syngeneic rat tumour lines: potential for selective tumour blood flow modification.

The vascular effects of the endothelin B (ET(B)) receptor agonist IRL 1620 were investigated in the rat P22 carcinosarcoma and a range of normal tissues in BDIX rats. Tissue blood flow rate was calculated from measurements of tissue uptake of radiolabelled iodoantipyrine. A comparison of vascular effects in the P22 tumour and the HSN sarcoma growing in CBH/CBi rats was made using laser Doppler flowmetry, showing similar effects of IRL 1620, with red cell flux rapidly decreasing by 50-60% and then returning to control levels within approximately 30 min. This corresponded to similar levels but different spatial organisation of ET(B) binding sites in the two tumours, as measured by autoradiography. The decrease in tumour blood flow and an increase in vascular resistance suggest that the vascular component of ET(B) receptors in the P22 tumour is localised on contractile elements rather than on endothelial cells. ET(A) receptors were also identified. Vasoconstriction occurred uniformly throughout the P22 tumour mass, consistent with a measured homogeneous distribution of ET(B) receptors. IRL 1620 caused vasoconstriction in normal skeletal muscle, kidney and small intestine of the BDIX rat as well as in tumour, but did not affect blood flow in other tissues. These effects could be useful for limiting toxicity of certain chemotherapeutic agents. Fully functional ET(B) receptors are clearly expressed on tumour vasculature and IRL 1620 shows promise for short-term modification of tumour blood flow. Expression levels of ET(B) receptors on the tumour vasculature could be useful for predicting which tumours are likely to respond to IRL 1620.

The combination of Jun N-terminal kinase inhibitor and TNP-470 blocks carcinosarcoma-induced endothelial cell tube formation in a synergistic manner.

We assessed the usefulness of Jun N-terminal kinase inhibitor (JNK-I) as an anti-angiogenic agent against a human uterine carcinosarcoma cell line (FU-MMT-1). JNK-I blocked FU-MMT-1-induced human arterial endothelial cell (HAEC) tube formation in an in vitro co-culture model. Cell proliferation of FU-MMT-1 or HAEC was inhibited by JNK-I. In addition, JNK-I blocked matrix metalloproteinase production but not vascular endothelial growth factor (VEGF) secretion in HAECs. Although low concentrations of JNK-I or TNP-470, an anti-cancer agent, did not separately block FU-MMT-1-induced tube formation, such tube formation was blocked by the combination of low concentrations of JNK-I and TNP-470 because TNP-470 blocked VEGF production, suggesting that JNK-I and TNP-470 had a synergistic effect and might be effective in patients with carcinosarcoma.

Localization of the VEGF and angiopoietin genes in uterine carcinosarcoma.

OBJECTIVE: Carcinosarcoma of the uterus is a highly aggressive tumor. However, the angiogenesis in this tumor remains unclear. This is the first study to examine the characteristics of angiogenesis in this tumor at the molecular level while also comparing the findings with those of high-grade endometrial carcinoma. METHODS: The expression of vascular endothelial growth factors (VEGF) and angiopoietins (Ang) genes were examined in 35 primary uterine carcinosarcomas as well as in 12 high-grade endometrial carcinomas by in situ hybridization. RESULTS: A strong expression of VEGF-A mRNA was significantly seen in carcinosarcomas compared to high-grade endometrial carcinomas. Interestingly, in uterine carcinosarcoma, VEGF-A mRNA was more strongly expressed in the carcinoma cells than in the sarcoma cells. In addition, a decrease in the VEGF-A mRNA expression was found in the transitional areas between carcinomatous and sarcomatous elements in most carcinosarcomas evaluated. Moreover, the Ang-2 mRNA expression was significantly seen in the vasculature adjacent to the periphery of the carcinoma cells in most carcinosarcomas, in comparison to that of endometrial carcinomas. CONCLUSIONS: A high angiogenic activity in uterine carcinosarcoma was shown, in comparison to that of endometrial carcinoma. Tumor angiogenesis in uterine carcinosarcoma might be chiefly influenced by VEGF-A in the carcinoma cells, in cooperation with Ang-2 in the surrounding microvessels, however, this is not fully usually the case in sarcoma cells.

Effect of angiogenesis inhibitor TNP-470 on the growth, blood flow, and microvessel density in xenografts of human uterine carcinosarcoma in nude mice.

OBJECTIVES: Carcinosarcoma is the most aggressive neoplasm of among the known uterine malignancies. Most tumors show lymph-vascular space invasion and are clinically resistant to any chemotherapeutic drug currently used as well as any radiotherapy. This is the first study to investigate a novel therapeutic approach using an angiogenesis inhibitor TNP-470, a synthetic analogue of fumagillin, for human uterine carcinosarcoma in vivo. METHODS: The growth-inhibitory and anti-angiogenic effects of TNP-470 were examined after inoculating a human uterine carcinosarcoma cell line, FU-MMT-1, in nude mice. Intratumoral blood flow was evaluated weekly by color Doppler ultrasound (CDU) after the xenografts measurably developed during the period of treatment. The microvessel density (MVD) in TNP-470-treated xenografts was also immunohistochemically examined. RESULTS: TNP-470 significantly reduced the volume as well as the weight of the xenografts when this therapy was started 3 weeks (Day 21) after the inoculation of FU-MMT-1, in comparison to the controls. Neither weight loss nor ataxia was observed in any mice of this therapy. A main feeding artery for the xenograft was detected by CDU in all mice treated in this study. However, no significant difference in either the vessel density visualized by CDU or MVD between the TNP-470-treated xenografts and controls was observed. CONCLUSION: These results suggest that TNP-470 may inhibit the growth of human uterine carcinosarcoma in vivo. We speculate that TNP-470 may be a useful agent for adjuvant therapy in patients with advanced or recurrent uterine carcinosarcomas. However, a further evaluation in molecular level of the anti-angiogenic effect of TNP-470 against this tumor in vivo is thus called for.

Effects of tin-protoporphyrin IX on blood flow in a rat tumor model.

Carbon monoxide (CO), one of the products of heme oxygenase (HO) catalyzed heme degradation, is a vasodilator. The aim of the present study was to clarify the role of HO in blood flow maintenance in tumors. Male BD9 rats bearing subcutaneous transplants of the P22 carcinosarcoma tumor were treated intraperitoneally (i.p.) with either tin-protoporphyrin IX (SnPP; 45 micromol/kg), a selective inhibitor of HO or copper-protoporphyrin IX (CuPP; 45 micromol/kg), used as a negative control. The extent of HO activity inhibition was measured using a spectrophotometric assay of bilirubin production and blood flow rates to the tumor and a range of normal tissues were assessed using the uptake of the radiolabelled tracer, iodo-antipyrine ((125)I-IAP). The animals were cannulated under fentanyl citrate/fluanisone (Hypnorm)/midazolam anesthesia. In the P22 tumor, SnPP, but not CuPP, caused a complete inhibition of HO activity 15 min post-treatment. Administration of SnPP 15 min before blood flow measurements reduced tumor blood flow by 17%, with no effects in any of the normal tissues studied. However, CuPP induced a greater reduction in tumor blood flow than SnPP (45% decrease). Furthermore, CuPP caused a reduction in blood flow to the skin and small intestine but a significant increase to skeletal muscle. The current findings conclusively establish only a minor role played by the HO/CO system in the maintenance of blood flow in this tumor system, despite relatively high levels of HO-1 protein and HO activity. The results also highlight the potential usefulness of CuPP as a tumor blood flow modifier.

The vascular response of tumor and normal tissues in the rat to the vascular targeting agent, combretastatin A-4-phosphate, at clinically relevant doses.

The antivascular actions of disodium combretastatin A-4 3-O-phosphate (CA-4-P) were investigated in the rat P22 carcinosarcoma after single doses of 10 or 30 mg x kg(-1). Pharmacokinetic data showed that 10 mg x kg(-1) in the rat gave a plasma exposure similar to that achieved in the clinic. Blood flow rate to the tumor and normal tissues was measured using the uptake of radiolabelled iodoantipyrine (IAP). Quantitative autoradiography was used to determine changes in spatial distribution of tumor blood flow. Both doses caused an increase in mean arterial blood pressure (MABP) and a reduction in heart rate 1 h after treatment. Blood flow rate to the tumor decreased to below 15% of control for both doses at 1 h, whereas the normal tissues were much less affected. A further reduction (to 2% of control at 6 h) was found for 30 mg x kg(-1). Recovery was essentially complete by 24 h for both doses. Vascular resistance increased 80-fold in tumor at 6 h after 30 mg x kg(-1), compared with a maximum 5-fold increase in normal tissues. Analysis of the spatial distribution of tumor blood flow illustrated an overall reduction in all areas of the tumor at 1 h after 10 mg x kg(-1), with a tendency for blood flow in the peripheral regions of the tumor to recover more quickly than in central regions. Tumor blood flow reduction was related to vascular damage including vessel distension, coagulation and haemorrhage, and tumor cell damage culminating in necrosis. No pathology was evident in any of the normal tissues following treatment. The data provide an insight into the mechanisms underlying tissue blood flow changes occurring after clinically relevant doses of CA-4-P. It is currently being used to aid interpretation of pharmacodynamic data obtained from phase I/II clinical trials of CA-4-P and is relevant for future drug development in this area.

Evaluation of the anti-vascular effects of combretastatin in rodent tumours by dynamic contrast enhanced MRI.

The anti-vascular effects of the tubulin binding agent, disodium combretastatin A-4 3-O-phosphate (CA-4-P), have been investigated in the rat P22 carcinosarcoma by measurements of radiolabelled iodoantipyrine uptake and dynamic contrast-enhanced MRI. The iodoantipyrine estimates of absolute tumour blood flow showed a reduction from 0.35 to 0.04 ml g(-1) min(-1) 6 h after 10 mg kg(-1) CA-4-P and to <0.01 ml g(-1) min(-1) after 100 mg kg(-1). Tumour blood flow recovered to control values 24 h after 10 mg kg(-1) CA-4-P, but there was no recovery by 24 h after the higher dose. Dynamic contrast-enhanced MR images were obtained at 4.7 T, following injection of 0.1 mmol kg(-1) Gd-DTPA and analysed assuming a model arterial input function. A parameter, K(trans), which is related to blood flow rate and permeability of the tumour vasculature to Gd-DTPA, was calculated from the uptake data. K(trans) showed a reduction from 0.34 to 0.11 min(-1) 6 h after 10 mg kg(-1) CA-4-P and to 0.07 min(-1) after 100 mg kg(-1). Although the magnitude of changes in K(trans) was smaller than that in tumour blood flow, the time course and dose-dependency patterns were very similar. The apparent extravascular extracellular volume fraction, nu(e), showed a four-fold reduction 6 h after 100 mg kg(-1) CA-4-P, possibly associated with vascular shutdown within large regions of the tumour. These results suggest that K(trans) values for Gd-DTPA uptake into tumours could be a useful non-invasive indicator of blood flow changes induced by anti-vascular agents such as combretastatin.

Mechanisms associated with tumor vascular shut-down induced by combretastatin A-4 phosphate: intravital microscopy and measurement of vascular permeability.

The tumor vascular effects of the tubulin destabilizing agent disodium combretastatinA-4 3-O-phosphate (CA-4-P) were investigated in the rat P22 tumor growing in a dorsal skin flap window chamber implanted into BD9 rats. CA-4-P is in clinical trial as a tumor vascular targeting agent. In animal tumors, it can cause the shut-down of blood flow, leading to extensive tumor cell necrosis. However, the mechanisms leading to vascular shut-down are still unknown. Tumor vascular effects were visualized and monitored on-line before and after the administration of two doses of CA-4-P (30 and 100 mg/kg) using intravital microscopy. The combined effect of CA-4-P and systemic nitric oxide synthase (NOS) inhibition using N(omega)-nitro-L-arginine (L-NNA) was also assessed, because this combination has been shown previously to have a potentiating effect. The early effect of CA-4-P on tumor vascular permeability to albumin was determined to assess whether this could be involved in the mechanism of action of the drug. Tumor blood flow reduction was extremely rapid after CA-4-P treatment, with red cell velocity decreasing throughout the observation period and dropping to <5% of the starting value by 1 h. NOS inhibition alone caused a 50% decrease in red cell velocity, and the combined treatment of CA-4-P and NOS inhibition was approximately additive. The mechanism of blood flow reduction was very different for NOS inhibition and CA-4-P. That of NOS inhibition could be explained by a decrease in vessel diameter, which was most profound on the arteriolar side of the tumor circulation. In contrast, the effects of CA-4-P resembled an acute inflammatory reaction resulting in a visible loss of a large proportion of the smallest blood vessels. There was some return of visible vasculature at 1 h after treatment, but the blood in these vessels was static or nearly so, and many of the vessels were distended. The hematocrit within larger draining tumor venules tended to increase at early times after CA-4-P, suggesting fluid loss from the blood. The stacking of red cells to form rouleaux was also a common feature, coincident with slowing of blood flow; and these two factors would lead to an increase in viscous resistance to blood flow. Tumor vascular permeability to albumin was increased to approximately 160% of control values at 1 and 10 min after treatment. This could lead to an early decrease in tumor blood flow via an imbalance between intravascular and tissue pressures and/or an increase in blood viscosity as a result of increased hematocrit. These results suggest a mechanism of action of CA-4-P in vivo. Combination of CA-4-P with a NOS inhibitor has an additive effect, which it may be possible to exploit therapeutically.

Markers of apoptosis and angiogenesis indicate that carcinomatous components play an important role in the malignant behavior of uterine carcinosarcoma.

Carcinosarcoma of the uterine body is a relatively uncommon neoplasm that contains carcinoma components (CCs) and sarcoma components (SCs). Which component is responsible for the aggressive biologic behavior of this tumor has been a matter of discussion. Recently, many studies have indicated that angiogenesis and apoptosis play an important role in the biologic behavior of tumors. The aim of this study was to clarify, through the exploration of angiogenesis and apoptosis, which compartment is more important for the biologic behavior of carcinosarcoma. Paraffin sections from 10 uterine carcinosarcomas were stained by using anti-CD34 monoclonal antibodies for quantifying tumor vascularization. DNA nick was labeled immunostained by using an Apop Tag in situ apoptosis detection kit for exploring apoptosis. In addition, immunohistochemical staining for Ki-67 labeling index (LI) was conducted for evaluating cell proliferation. Although there was no significant difference in Ki-67 LI between SCs and CCs (P =.06), the microvessel density (MVD) in CCs was significantly higher than in SCs (P =.003), and the apoptotic index (AI) was significantly higher in SCs than in CCs (P =.002). Accordingly, CCs may play an important role in aggressive biologic behavior in carcinosarcoma. HUM PATHOL 31:1448-1454.

Angiogenesis in carcinosarcomas of the uterus: differences in the microvessel density and expression of vascular endothelial growth factor between the epithelial and mesenchymal elements.

Carcinosarcoma of the uterus is a highly aggressive neoplasm. However, the angiogenesis of this neoplasm is still unknown. This is the first study to examine the differences in angiogenesis between the epithelial and mesenchymal elements of this biphasic neoplasm. Surgical specimens from 21 primary uterine carcinosarcomas were histopathologically evaluated, and then immunohistochemically analyzed for tumor angiogenesis, using an anti-vascular endothelial growth factor (VEGF) antibody. The microvessel density (MVD) was also measured in each element of these neoplasms, using anti-CD34 monoclonal antibody. The MVD in the epithelial element was found to be higher than that of the mesenchymal element in 20 of 21 (95.2%) primary tumors. The epithelial elements showed a higher MVD (mean, 81.6 +/- 41.1) than the mesenchymal elements (mean, 36.7 +/- 23.8) in these primary tumors (P < .0001). Moreover, the epithelial elements showed a higher VEGF expression (mean, 0.78 +/- 0.23) than the mesenchymal elements (mean, 0.37 +/- 0.20) (P < .0001). The tumors with lymph-vascular invasion showed a higher VEGF expression (n = 17; mean, 0.85 +/- 0.17) than the tumors without lymph-vascular invasion (n = 4, mean, 0.47 +/- 0.12) (P < .01). Microscopically, neither lymph-vascular space invasion nor metastatic tumors consisted of sarcoma alone in this series. In addition, a decrease in the VEGF expression was found in the transitional areas between carcinomatous and sarcomatous elements in all 10 homologous and 4 heterologous tumors evaluated. These results suggest that the tumor angiogenesis in the epithelial element may be more active than that of the mesenchymal element and also substantiated the high metastatic potential of the epithelial element in uterine carcinosarcoma. Based on these findings, carcinoma cells thus may play a key role in the angiogenesis of this biphasic neoplasm.

Increased expression of ornithine decarboxylase messenger RNA in human esophageal carcinoma.

Ornithine decarboxylase (ODC) is a key enzyme in the biosynthesis of polyamines, which are essential for cell proliferation. The purpose of this study was to evaluate ODC expression in human esophageal cancer at the mRNA level. Sixty-four pairs of primary esophageal cancers and normal esophageal epithelia were examined by reverse transcription-PCR for ODC mRNA expression. The ODC mRNA levels were higher in primary esophageal carcinoma than in adjacent normal esophageal epithelium in 58 (90.6%) of 64 cases. The tumor:normal (T:N) ratio of ODC mRNA expression in esophageal specimens has a significant correlation with tumor-node-metastasis staging (P = 0.043), lymph node metastasis (P = 0.039), vascular vessel invasion (P = 0.035), and histology (P = 0.034) of the tumor. In well- and moderately differentiated squamous cell carcinoma, the patients with a higher T:N ratio showed a significantly poorer prognosis (P = 0.027), and multivariate analysis also confirmed that the T:N ratio has a significant correlation with poor prognosis (P = 0.043). The steady-state of ODC mRNA overexpression in esophageal carcinoma implies that the ODC gene may play an important role in tumorgenesis in squamous epithelium. Furthermore, ODC mRNA expression may be used as a prognostic marker, especially for well- and moderately differentiated squamous cell carcinoma.

True malignant mixed tumor (carcinosarcoma) of tonsillar minor salivary gland origin: diagnostic imaging and endovascular therapeutic embolization.

We report a case of carcinosarcoma of the minor salivary glands of the left palatine tonsil, an especially rare location. Imaging characteristics assessed at CT, MR imaging, and angiography are presented. In addition, we describe our experience with preoperative therapeutic endovascular embolization of this hypervascular tumor.

Reduced capacity of tumour blood vessels to produce endothelium-derived relaxing factor: significance for blood flow modification.

The effect of nitric oxide-dependent vasodilators on vascular resistance of tumours and normal tissue was determined with the aim of modifying tumour blood flow for therapeutic benefit. Isolated preparations of the rat P22 tumour and normal rat hindlimb were perfused ex vivo. The effects on tissue vascular resistance of administration of sodium nitroprusside (SNP) and the diazeniumdiolate (or NONO-ate) NOC-7, vasodilators which act via direct release of nitric oxide (NO), were compared with the effects of acetylcholine (ACh), a vasodilator which acts primarily via receptor stimulation of endothelial cells to release NO in the form of endothelium-derived relaxing factor (EDRF). SNP and NOC-7 effectively dilated tumour blood vessels after preconstriction with phenylephrine (PE) or potassium chloride (KCl) as indicated by a decrease in vascular resistance. SNP also effectively dilated normal rat hindlimb vessels after PE/KCl constriction. Vasodilatation in the tumour preparations was accompanied by a significant rise in nitrite levels measured in the tumour effluent. ACh induced a significant vasodilation in the normal hindlimb but an anomalous vasoconstriction in the tumour. This result suggests that tumours, unlike normal tissues are incapable of releasing NO (EDRF) in response to ACh. Capacity for EDRF production may represent a difference between tumour and normal tissue blood vessels, which could be exploited for selective pharmacological manipulation of tumour blood flow.

A comparative study of tumour blood flow modification in two rat tumour systems using endothelin-1 and angiotensin II: influence of tumour size on angiotensin II response.

Tumour blood flow modification following i.v. administration of angiotensin II (AT II, 0.19 nmol kg-1 min-1) or endothelin-1 (ET-1, 1 nmol kg-1) was compared in the P22 carcinosarcoma-bearing BD9 rat and the HSN fibrosarcoma-bearing CBH/CBi rat using the tissue uptake of radiolabelled iodoantipyrine. Results were compared with a range of normal tissues. HSN tumour blood flow was unmodified by either peptide, whereas P22 tumour blood flow was unmodified by ET-1 but was reduced to 80% of the control flow by AT II. Both peptides reduced absolute blood flow in the skin overlying the tumour, in contralateral skin, skeletal muscle, kidney and small intestine, whereas blood flow to the brain and heart was significantly increased by ET-1 and unmodified by AT II. Both peptides significantly increased vascular resistance (mean arterial blood pressure / tissue blood flow) in all normal tissues and both tumours, thus demonstrating the existence of vascular receptors for these 2 vasomodifiers, and the capacity of the vessels to respond to receptor activation. Dependency of response on tumour size was examined in the P22 tumour. In contrast to that in small P22 tumours (1.22 +/- 0.06 g), blood flow to large P22 tumours (7.18 +/- 0.25 g) was unmodified by AT II. Vascular resistance was equally increased in both tumour groups, thus illustrating little difference in the vascular response to AT II in the size range examined. Results show that the 2 rat tumours responded directly to ET-1 and AT II, but do not indicate any advantage of ET-1 over AT II in tumour blood flow modification. However, the existence of tumour vascular endothelin receptors suggests that the advent of less toxic and more controllable receptor ligands may make endothelin receptors of value in the modification of tumour blood flow.

Intratumoral blood flow analysis in endometrial cancer: does it differ among individual tumor characteristics?

To evaluate whether intratumoral blood flow analysis in endometrial cancer provides individual tumor characteristics, 36 patients with endometrial cancer (5 in stage IA, 14 in stage IB, 5 in stage IC, 4 in stage II, and 8 in stage III) underwent transvaginal color and pulsed Doppler ultrasound before surgery. Histologically, there were 18 patients with well-differentiated adenocarcinoma, 8 with moderate differentiated adenocarcinoma, 4 with poorly differentiated adenocarcinoma, 4 with adenoacanthoma, and 2 with carcinosarcoma. Intratumoral blood flow was recorded, and peak systolic velocity (PSV) and resistance index (RI) were calculated. Endometrial thickness (ET) was also measured. There were no significant differences among PSV and RI values for each stage. There were also no significant differences among PSV and RI values for each histological diagnosis. ET in stages IA, IB, and II was significantly thinner than that in stage III (P < 0.05). Moreover, ET in stage IA was significantly thinner than that in stage IC (P < 0.05). There were significant differences in ET for some histological diagnoses. These results suggest that intratumoral blood flow analysis in endometrial cancer could not predict the tumor staging and histological diagnosis. However, in view of the small number of patients, these observations must be considered preliminary.