Microangiopathic haemolytic anaemia and experimental tumour-cell emboli

Microangiopathic Hemolytic Anemia as a Paraneoplastic Syndrome in a Patient with Metastatic Gastric Cancer

Cancer-associated microangiopathic hemolytic anemia (CA-MAHA) is a rare paraneoplastic syndrome. The most effective approach to treating CA-MAHA is to address the underlying malignancy. Documented cases of CA-MAHA are limited to fewer than 50 patients in the literature. Herein, we present a 51-year-old female patient who developed CA-MAHA as a complication of gastric adenocarcinoma. Despite receiving neoadjuvant and adjuvant chemotherapy for gastric cancer, the patient experienced disease progression with metastatic lesions in the liver, pancreas, and other sites. This report highlights the challenges in diagnosing and distinguishing CA-MAHA from other similar conditions such as disseminated intravascular coagulation (DIC), hemolytic uremic syndrome (HUS), thrombotic thrombocytopenic purpura (TTP), and rheumatological paraneoplastic syndromes. Additionally, it concludes that CA-MAHA is associated with a poor prognosis and limited clinical benefit from treatment, emphasizing the need for early diagnosis and effective management strategies.

A Metastatic Signet Ring Cell Carcinoma Presented as Acquired Thrombotic Thrombocytopenic Purpura: A Case Report

Microangiopathic hemolytic anemia (MAHA) may occur as a paraneoplastic syndrome in some solid tumors, but MAHA accompanied by signet ring cell carcinoma (SRCC) of an unknown origin is very rare. We report a patient who presented with an acute onset of Coombs negative hemolytic anemia and frequent schistocytes in the peripheral blood smear which are typical for MAHA as initial presentation of metastatic SRCC. Our patients fulfilled the criteria of thrombotic thrombocytopenic purpura (TTP) and received the specific treatment for TTP without improvement.

Two Lines of Walker Carcinoma 256: Their Peculiarities and Different Interactions with the Host

Two sublines of Walker 256 carcinoma have been characterized for their ability to metastasize and to induce cachexia. The invasive, metastasizing line A induced terminal anorexia in rats with a mean survival time of 27 ± 1.5 days. The non-invasive line B induced early anorexia and cachexia with a mean survival time of only 15 + 1 days. At death, the line B tumor was still smaller than the line A one, and no metastases were detectable. These two sublines are discussed as a composite model for studying anorexia and cachexia together with invasion and metastasis.

Platelets in cancer metastasis: To help the "villain" to do evil

Cancer progress is accompanied by platelet activation and thrombotic complications. Platelets are a dangerous alliance of cancer cells, and are a close engager in multiple processes of cancer metastasis. Platelet adhesion to cancer cells forms a protective cloak that helps cancer cells to escape immune surveillance and natural killer cell-mediated cytolysis. Platelets facilitate tethering and arrest of disseminated cancer cells in the vasculature, enhance invasive potentials and thus extravasation of cancer cells. Moreover, platelets recruit monocytes and granulocytes to the sites of cancer cell arrest, and collaborate with them to establish a pro-metastatic microenvironment and metastatic niches. Platelets also secret a number of growth factors to stimulate cancer cell proliferation, release various angiogenic regulators to regulate tumor angiogenesis and subsequently promote cancer growth and progress. Albeit platelets are helping the "villain" cancer to do evil, the close engagements of platelets in cancer metastasis and progress can be used as the intervention targets for new anti-cancer therapeutic developments. Platelet-targeted anti-cancer strategy may bring in novel anti-cancer treatments that can synergize the therapeutic effects of chemotherapies and surgical treatments of cancer.

Hemolytic anemia and metastatic carcinoma: case report and literature review

Hemolytic anemia can complicate the development of a variety of solid tumors and hematologic malignancies. Although patients may have an established diagnosis with documented metastases, microangiopathic hemolytic anemia (MAHA) can be a presenting feature of an occult malignancy. Prompt diagnosis is essential because conditions that mimic the symptoms of MAHA, including thrombotic thrombocytopenic purpura, have different prognoses and therapeutic options. Although the exact pathogenesis is not yet delineated, we present herein a case of cancer-associated MAHA and discuss the known pathways that can contribute to the initiation and propagation of hemolytic anemia in patients with cancer. The patient is a 69-year-old woman with breast carcinoma that had metastasized to her rectum, urinary bladder, and brain. She eventually developed progressive decline in her functional status, with intermittent epistaxis and melena. The results of laboratory studies revealed hemolytic anemia and thrombocytopenia; results of a bone-marrow biopsy confirmed the involvement by metastatic carcinoma. The patient received red blood cell and platelet transfusions and was discharged to hospice care after clinical stabilization. She died soon thereafter.

Microangiopathic hemolytic anemia as the first manifestation of metastatic signet ring cell carcinoma of unknown origin: a case report and review of literature

Microangiopathic hemolytic anemia (MAHA) occurs occasionally as a paraneoplastic syndrome in some solid tumors, but MAHA accompanied by signet ring cell carcinoma of an unknown origin is very rare. In this study, we present the case of an 80-yr-old man who was admitted to the hospital because of a 1-month history of lower back pain and dyspnea. He was diagnosed with MAHA on the basis of the laboratory findings that revealed anemia with schistocytes, decreased haptoglobin levels, and a negative direct Coombs' test. Bone marrow examination, which was performed because of the progression of anemia, revealed bone marrow metastases of signet ring cell carcinoma with extensive bone marrow necrosis. However, the primary origin of this signet ring cell carcinoma was not found. When the cause of progressive MAHA is unknown, the possibility of cancer-associated MAHA must be excluded by performing additional tumor workup, including the detection of tumor markers, gastric and colorectal endoscopic examinations, bone marrow examinations, and positron emission tomography-computed tomography or bone scans.

[Hemolytic-uremic syndrome complicating a long-term treatment with gemcitabine. Report of a case and review of the literature]

INTRODUCTION

Gemcitabine is a nucleoside analog used in solid tumors since 1987. The main side effect is myelosuppression. Acute renal failure with thrombotic microangiopathy has also been reported. We report a new case and suggest to screen for this complication.

EXEGESIS

A 71-year-old man with metastatic adenocarcinoma of the pancreas was treated with gemcitabine. He developed episodes of recurred haemolysis followed by haemolytic uremic syndrome. One single haemodialysis session was performed. No other known causes for haemolytic and uremic syndrome were found. Gemcitabine appears to be a new cause of thrombotic microangiopathy. It results from cumulative effects, arises preferentially when there is a renal dysfunction and diagnosis is often delayed. Treatment must be stopped.

CONCLUSION

We suggest that reticulocyte count, haptoglobin level and urinalysis could help the clinician to maintain high vigilance and to have a rapid diagnosis for this rare disorder.

The mechanism of metastasis

The establishment of clinically detectable skeletal metastasis is a multifactorial process. This process can be divided into three general areas of understanding. The first is that of the intrinsic characteristics and properties of the tumor cells, which allow and facilitate their migration from the site of primary neoplasia to the distant host skeleton. Second, there are anatomic considerations of the human body, which influence the distribution of metastatic seeding. Third, there are the considerations of the host organism's biology, including the immune system, the circulatory system, and the affected host skeleton, which hinder and, at times, potentiate the ability of neoplastic cells to establish skeletal lesions.

A Case of Microangiopathic Hemolytic Anemia Associated with Breast Cancer: Improvement with Chemoendocrine Therapy

Microangiopathic hemolytic anemia (MAHA) is a term which describes the association of hemolytic anemia with red cell fragmentation caused by microangiopathy mechanically. This paper reports a 45-year-old woman with bone metastases from breast cancer. She developed MAHA and disseminated intravascular coagulation (DIC). Although the prognosis of MAHA associated with malignant tumor has been very poor, she achieved remission of the syndrome after chemoendocrine therapy.

Hemolytic disorders associated with cancer

Three principal environmental causes of hemolytic anemia in malignancy have been identified: (1) hemolysis mediated by auto-antibodies to red cells; (2) hemolysis due to microangiopathic disorders; and (3) chemotherapy-induced red cell destruction. These three environmental stressors occur rarely in cancer patients, and they form the subject of this review.

Characterization of platelet aggregation induced by human breast carcinoma and its inhibition by snake venom peptides, trigramin and rhodostomin

MCF-7 cells, a metastatic human breast carcinoma line, caused dose-dependent platelet aggregation in heparinized human platelet-rich plasma (PRP). MCF-7 tumor cell-induced platelet aggregation (TCIPA) was almost blocked by apyrase (0.5 U/ml) and completely inhibited by hirudin (5 U/ml). This TCIPA was unaffected by cysteine proteinase inhibition with E-64 (10 microM), but was limited by cell pretreatment with phospholipase A2. MCF-7 cell suspension caused marked, dose-dependent decrease in plasma recalcification times using normal, Factor VIII-deficient, and Factor IX-deficient human plasma. This effect was potentiated in cell lysates but was inhibited in intact cells preincubated with sphingosine. MCF-7 cell suspension did not affect the recalcification time of Factor VII-deficient plasma. Taken together, these data suggest that MCF-7 TCIPA arises from MCF-7 tissue factor activity expression. Trigramim and rhodostomin, RGD-containing snake venom peptides which antagonized the binding of fibrinogen to platelet membrane glycoprotein IIb/IIIa, prevented MCF-7 TCIPA. Likewise, synthetic peptide GRGDS as well as monoclonal antibodies against human tissue factor, platelet membrane glycoprotein IIb/IIIa and Ib prevented MCF-7 TCIPA, which was unaffected by control peptide GRGES. On a molar basis, trigramin (IC50, 0.1 microM) and rhodostomin (IC50, 0.03 microM), were about 5,000 and 18,000 times, respectively, more potent than GRGDS (IC50, 0.54 mM).

Procoagulant activity of the MC28 fibrosarcoma cell line in vitro and in vivo

Experimental evidence suggests that many tumours can activate blood coagulation and that such interaction is part of the pathology of metastatic tumour growth. This study aimed to study the procoagulant activity of the methylcholanthrene-induced (MC28) fibrosarcoma to determine whether coagulation activation by these cells could explain the previously reported effects of oral anticoagulants on lung seeding in this model. MC28 cells shortened the recalcification times of normal and factor VII-deficient plasma and directly activated factor X in a chromogenic assay, but did not aggregate platelets in vitro in either whole blood or platelet-rich plasma. Cellular coagulant activity was calcium-dependent, blocked by DFP and concanavalin A but not inhibited by iodoacetamide, E-64 or antibodies to human tissue factor or factor VII. Injection of viable MC28 cells into hooded Lister rats induced a decrease in platelet count (P < 0.001), plasma factor X (P < 0.001) and fibrinogen (P < 0.05) and a marked increase in plasma haemoglobin (P < 0.001). These effects were either not observed or were considerably less marked in heparinized or warfarinized animals. Injection of MC28 cells treated with concanavalin A in vitro completely abolished the clotting changes observed with untreated cells. In conclusion, MC28 cells possessed a potent factor X-activating serine proteinase procoagulant in vitro, which had some of the characteristics of a tissue factor/factor VIIa complex. In vivo, MC28 cells caused clotting activation and intravascular fibrin generation. Since thrombocytopenia was abolished by heparin and the cells lacked platelet aggregating activity in vitro, thrombocytopenia was probably secondary to intravascular coagulation and thrombin generation. The trigger for intravascular clotting activation appeared to be the cellular procoagulant activity since it was abolished by prior in vitro blockade of the latter with concanavalin A.

Interactions between Platelets and Human Hepatoma Cell Lines: The Influence of Endothelial Cells

The properties of human hepatoma cell lines in relation to their ability to aggregate isolated human platelets were investigated because of the possible relevance to tumour metastasis. Mahlavu, HepG2 and SK55 cells were all able to aggregate platelets irreversibly, but required the presence of small amounts of plasma, which could not be replaced by fibrinogen or other common plasma proteins. They also required the presence of Ca(2+). The plasma factor was non-dialysable and heat-labile. In the case of Mahlavu cells and SK55 cells the aggregatory activity was released from the cells as a non-dialysable material of high molecular weight. HepG2 cells were required intact and did not release materials which induced platelet aggregation. In all cases the aggregation was inhibited by hirudin. However, the requirements for plasma factors suggested that the material was not thrombin itself. The aggregatory property of all the cells was inhibited by prostacyclin and in the case of Mahlavu and HepG2 cells, to a lesser extent by nitric oxide. Addition of very small numbers of bovine aortic endothelial cells (but not human umbilical cord cells) inhibited the aggregation induced by Mahlavu and HepG2 cells, but not SK55 cells. If the endothelial cells were pre-treated with aspirin, this inhibitory property was abolished, indicating that a cyclo-oxygenase product was the principal agent.

Mitomycin C-induced hemolytic uremic syndrome. Six case reports and review of the literature on renal, pulmonary and cardiac side effects of the drug

Six new cases of mitomycin C (MMC)-induced hemolytic uremic syndrome are reported and the literature on renal-, pulmonary- and cardiotoxicity of the drug is reviewed. The number of reports concerning these side effects is still increasing. The incidence of all three side effects will be below 10%, while there appears to be a dose-dependency, with toxicity mainly occurring at cumulative doses of 20-30 mg/m2 or more. Toxicity often develops very sudden and the mortality rate especially of HUS is very high despite supportive care. The pathogenesis of toxicity is still unknown, although for HUS there are indications for a role of circulating immune complexes. The pulmonary toxicity can often be treated by corticosteroids, while the left ventricular cardiac failure can be treated with diuretics. The possible role of oxygen radicals in the development of MMC side effects is mentioned.

Basic mechanisms of metastasis

Metastatic disease is responsible for the majority of deaths caused by cancer. The process of metastasis is an orderly, stepwise process that results in the selection of cells that possess the capability to establish viable metastases. These cells must be locally invasive and be able to survive the physical traumas of dissemination and normal host defenses. Once metastatic cells have been arrested in a capillary bed, they must be able to invade the host organ parenchyma and survive in that milieu. Studies in a number of model systems have documented the phenotypic alterations in cells that have "metastatic potential." These differences may stem from normal tumor cell heterogeneity and surprisingly reflect only minor differences in gene expression. The role of activated oncogenes in metastasis is unclear, but a number of laboratories have documented that transfection with activated Ha-Ras results in increased metastatic potential. An increased understanding of the genetic basis of metastatic potential may suggest new directions for intervening in this deadly process.

A syndrome of microangiopathic hemolytic anemia, renal impairment, and pulmonary edema in chemotherapy-treated patients with adenocarcinoma

Chemotherapy is frequently used to treat adenocarcinoma. Thirty-nine cases are reviewed in which the patients developed a hemolytic-uremic-like syndrome, apparently in response to chemotherapy. About 44% of the patients had gastric adenocarcinoma, and 82% had received mitomycin C. Most patients (75%) developed the syndrome 6 to 12 months after starting chemotherapy, and 60% were in remission. Severe microangiopathic hemolytic anemia, thrombocytopenia, and renal impairment were each noted in about 90% of the cases. Neurologic symptoms were usually absent, but 49% of the patients developed adult respiratory distress syndrome (ARDS). The overall case fatality rate was 72%; those patients with ARDS had a 95% mortality rate, while 50% of those without ARDS survived. The half-life of survival of those who ultimately died was 2 months. Treatment is unsatisfactory, although steroids and plasmapheresis may prolong survival.

Recovery from mitomycin C-induced hemolytic uremic syndrome. A case report

Mitomycin C (MMC) is a cytotoxic agent that may induce a hemolytic uremic syndrome (HUS) with severe renal insufficiency. Of all reported patients with terminal renal failure only two survived with chronic hemodialysis. A patient with advanced gastric cancer in complete remission, who developed MMC-induced HUS, is reported; hemodialysis was necessary because of oliguria. Hemolysis subsided, and after addition of captopril renal function recovered partially. The patient is alive 6 months after discontinuation of hemodialysis. Recently she developed brain metastases. Symptoms of hemolysis did not recur. The pathogenesis and treatment of HUS are discussed.

Tumor interaction with hemostasis: the rationale for the use of platelet inhibitors and anticoagulants in the treatment of cancer

Clinical and experimental observations have firmly established the concept of a two-way interaction between malignancy and the hemostatic system. On the one hand, certain tumors can activate platelets and the coagulation mechanism in vivo, on the other, a convincing case has been made for the involvement of platelets and fibrin in tumor growth and metastasis. A large number of clinical and experimental studies have been conducted in order to test the efficacy of platelet inhibitors and anticoagulants as adjuvants in the treatment of cancer. Antiplatelet drugs gave variable results, depending on the drug and the tumor system tested. Prostaglandin synthetic pathways by both the host and tumor seem to be an important determinant in the response to platelet function inhibitors. Of the various anticoagulants tested, the coumarin derivatives gave somewhat consistent antitumor effect in certain human and experimental cancer. The antitumor effect of oral anticoagulants does not appear to be a primary drug effect and seems related to their role as vitamin K antagonists. It should be emphasized that although the antitumor potential of antithrombotic agents is a subject of keen interest at the present, their use in treating human cancer is still controversial.

A new mechanism for tumor induced platelet aggregation. Comparison with mechanisms shared by other tumor with possible pharmacologic strategy toward prevention of metastases

Because tumor-induced platelet aggregation appears to play a role in the development of certain experimental tumor metastases, we examined the mechanism(s) of tumor-induced platelet aggregation as well as the effect of various anti-platelets agents. Two mechanisms for tumor-induced platelets aggregation have been previously described: (1) a mechanism which requires complement, a stable plasma factor, divalent cation and a sialo-lipo-protein vesicular component of the tumor membrane for platelet aggregation; and (2) a mechanism which operates via the generation of thrombin and requires a phospholipid component of the tumor membrane. We now report a new mechanism of tumor-induced platelet aggregation which is shared by three different tumors: a spontaneously metastatic human melanoma, HM29, a murine melanoma, B16F10, and a carcinogen-induced metastatic murine colon carcinoma, CT26. These tumors do not require cell-surface sialic acid or serum complement as does the first mechanism. They do not require cell-surface phospholipid, as do the tumors representing the other two mechanism. They do not aggregate platelets via the generation of thrombin as do tumors representing the second mechanism. These tumors are unique in that they require a trypsin-sensitive surface protein for activity. The ability of the thrombin-generating tumors to aggregate platelets is uniquely sensitive to two highly specific, synthetic thrombin-competitive inhibitors: DAPA and No. 805. The other two groups of tumors are at least 10 times more sensitive to inhibition of platelet aggregation by elevation of cyclic AMP levels (prostacyclin, 6-keto-PGE1, dibutyryl cyclic AMP) and at least 10 times more sensitive to inhibition of prostaglandin synthesis (indomethacin, ibuprofen). Thus, tumor-induced platelet aggregation is heterogeneous with respect to mechanism of action as well as inhibition by anti-platelet pharmacologic agents. Sensitivity to anti-platelet agents correlates with the mechanism by which tumor cells aggregate platelets.

Microangiopathic haemolytic anaemia associated with recurrent pulmonary emboli and benign pelvic tumours

A 42-year-old woman presented with a huge benign pelvic tumour and recurrent pulmonary emboli associated with severe microangiopathic haemolytic anaemia (MAHA). Following removal of the tumour and anticoagulation, all signs of MAHA disappeared. MAHA may occur when red blood cells pass through abnormal blood vessels in tumours. This patient is unusual in that the tumour was benign, rather than malignant. A further site of microangiopathy was the pulmonary vasculature.

Anticoagulants and experimental metastases-evaluation of antimetastatic effects in different model systems

Intravenous tumor cell injection and spontaneously metastasising transplantable tumors have been used as models for haematogenous tumor spread. To evaluate the validity of these two experimental approaches for the study of blood coagulability and metastases, the effect of anticoagulants on "secondary" tumor growth was investigated in both models and the results were compared. The B16 melanoma and the Lewis lung carcinoma in C57BL mice were employed throughout the study, and anticoagulation was rendered through the use of phenprocoumon, heparin and ancrod. All anticoagulants were capable of reducing lung colonies after i.v. tumor cell injection, whereas only phenprocoumon significantly diminished the formation of spontaneous metastases. A review of the current literature on anticoagulants and tumor dissemination and the observations described lead to the following conclusions: (1) Results from studies with i.v. introduced tumor cells cannot be extrapolated to spontaneously metastasising tumors. (2) Spontaneously metastasising tumors represent the preferable model for the study of antimetastatic effects of anticoagulants. (3) Little evidence exists to support the concept of the pathogenetic role of fibrin formation in the establishment of spontaneous metastases from blood-borne tumor cells. (4) Coumarin derivatives are potent antimetastatic drugs, their mode of action appears to be independent of their anticoagulant activity.

Microangiopathic haemolytic anaemia in cancer patients with bone marrow infiltration

Eight patients suffering from wide-spread malignancies presented with a severe microangiopathic haemolytic anaemia (MHA) without gross evidence for coagulation abnormalities. The common feature in these patients was bone marrow infiltration with malignant cells, suggesting a pathogenic link between bone marrow carcinosis and red cell destruction. Furthermore, it is concluded that MHA is a rare complication of malignancy and a terminal syndrome rather than an early manifestation of the disease.

The influence of platelet aggregation inhibitors on metastasis formation in mice (3LL)

Platelets were suggested to play a specific role in the haematogenous spread of experimental tumours. To test this hypothesis mice were treated with various inhibitors or platelet function (acetyl-salicylic acid, RA 233, bencyclan-, cyproheptadine). The effect of treatment on the development of lung colonies after i.v. tumour cell injection as well as on the formation of spontaneous metastases from the solid Lewis-lung carcinoma was evaluated. A significant increase of lung colonies after pretreatment with the platelet aggregation inhibitors was found. The effect of long term treatment on spontaneous metastasis formation gave equivocal results. The present investigations do not support the importance of the integrity of platelet function as a prerequisite for metastasis formation.