Neoplasms

Symptoms and General Pathology

All Conditions

Nervous System Diseases

Rare Diseases

Neoplasm Metastasis

Inflammation

Glioma

Brain Neoplasms

Central Nervous System Neoplasms

Nervous System Neoplasms

Brain Diseases

Central Nervous System Diseases

All patients requirering a surgery for brain or medullar excision

Tumors excised in patients requirering a brain or medullary surgery will be assess to determine their platelet count.

Platelet count in excised tumors

Amélie YACHITZ, MD

Vivien VASSEUR

Pierre Bourdillon, MD

Gregory Torkomian

Pierre BOURDILLON, MD

Platelets are primarily known for their central role in primary hemostasis. However, they are increasingly recognized for their participation in various non-hemostatic processes, such as cancer progression and clinical expression. Experimental and clinical data indicate that the involvement of platelets in the pathophysiology of cancer goes far beyond the realm of cancer-associated thrombosis.

Several experimental studies have shown that platelets can promote the metastatic process by various mechanisms. However, while it has been shown in vitro that direct contact with platelets initiates tumor cells for metastasis, it remains unclear whether such contacts occur in solid tumors. In addition to their ability to promote metastasis, platelets have been shown to stimulate angiogenesis and play a crucial role in lymphangiogenesis.

Considering that blood vessels, lymphatics and immune cells are major components of the tumor ecosystem, our hypothesis is that platelets contribute to the development and / or regulation of the tumor microenvironment. This is because platelets stabilize tumor blood vessels by permanently repairing vascular damage caused by immune cells infiltrating tumors. Targeting platelets destabilizes tumor vessels, causing intra-tumor hemorrhage, which allows intra-tumor accumulation of intravenously administered anti-tumor drugs such as paclitaxel and improves their efficacy.

Studies have also reported the role of platelets in several pathogenic mechanisms of cancer: thrombocytosis is a paraneoplastic syndrome which suggests a poor prognosis in patients with solid tumors; a negative correlation between the platelet count and the response to chemotherapy has been reported in several types of cancer; histological analyzes of esophageal cancer suggested a possible association between the presence of platelets in the tumor stroma and the level of tumor lymphangiogenesis and lymphovascular invasion; finally, a recent study reported the expression of one of the main targets of immunotherapies, PD-L1, on the platelets of patients suffering from different types of solid cancers.

All of these data support our hypothesis that platelets are components and / or regulators of the tumor microenvironment and therefore potential targets for the improvement of anti-tumor therapies. In this context, the objectives of our project are to determine whether platelets are components of the microenvironment of tumors of the central nervous system, and to study the possible correlations between the intratumoral presence of platelets and the evolution of patients with central nervous system tumors

This is a descriptive study that did not include any intervention other than tumor tissue preservation and blood sampling.

Platelets Activation in Brain Neoplasms

Observation of Platelets in Primary and Secondary Tumors of the Central Nervous System and Association With Survival: a Prospective Cohort Study

Fondation Ophtalmologique Adolphe de Rothschild

Blood and Lymph Conditions

Leukemia

Hematologic Diseases

Leukemia, Myeloid

Leukemia, Myeloid, Acute

Neoplasms by Histologic Type

Acute Graft Versus Host Disease

platelet transfusion

Hayden Braine

Kuo-Jang Kao

Jeffrey McCullough

Janice McFarland

Charles Schiffer

Sherrill Schlichter

To determine the best, clinically useful procedure to prevent or minimize platelet alloimmunization as a cause of refractoriness to platelet transfusion in patients undergoing marrow ablative chemotherapy for acute myelogenous leukemia.

BACKGROUND:

Between 1971 and 1980, there was a 598 percent increase in the use of platelet concentrates from 0.41 million to more than 2.86 million annually. In contrast, red cell transfusions in the United States rose concurrently from 6.3 million annually to 9.9 million, an increase of 58 percent. Although red cell transfusions have leveled or even decreased slightly in the past several years, the use of platelets has continued to increase at a rate of at least 5 to 10 percent each year. This dramatic and continued increase in the use of platelet concentrates is largely the result of treating thrombocytopenic cancer patients. In addition, open heart surgery patients and others given massive transfusions also receive substantial platelet support. Nevertheless, it is the chronically transfused thrombocytopenic patient who frequently develops platelet alloimmunization and accounts for a large percentage of the increased demand for platelets. A recent survey in a large transfusion service indicated that 8 percent of the patients had received 35 percent of the random-donor pooled platelet concentrates. Although some alloimmunized patients can be supported by HLA-matched, apheresis-donor platelets, suitably matched donors are not available in sufficient numbers for every patient. Thus, platelet transfusion programs that could prevent, or at least delay platelet alloimmunization would be of substantial benefit.

Limited studies have suggested several approaches that may reduce or prevent platelet alloimmunization: reducing the number of foreign antigens to which a recipient is exposed by providing single donor platelet apheresis products; providing leukocyte-poor blood products; inactivating donor antigen presenting cells (APC's), a type of lymphocyte contained within the transfused platelet products, by ultraviolet (UV) irradiation of platelet concentrates.

The initiative was recommended by the Blood Diseases and Resources Advisory Committee in May 1987 and approved by the National Heart, Lung, and Blood Advisory Council in September 1987. The Requests for Applications were released in June 1988.

DESIGN NARRATIVE:

Randomized, double-blind. There were three treatment arms and one control arm. Patients in the treatment arms received either leukocyte-poor filtered pooled random donor platelets, or ultraviolet irradiated pooled random donor platelets, or leukocyte-poor filtered single donor apheresis platelets. Patients in the control group received routinely pooled, random-donor platelets. Patients remained on their assigned treatments for all transfusions through eight weeks. Assigned transfusions were discontinued only in the event of severe adverse reaction to the platelet transfusions, granulocyte transfusions, bone marrow transplant, withdrawal of informed consent, or death. Pre- and post transfusion counts were obtained for all platelet transfusions. Each patient was followed for one year. Recruitment continued through March 1995. Data analysis ended in July 1997.

The study completion date listed in this record was obtained from the "Completed Date" entered in the Protocol Registration and Results System.

Trial to Reduce Alloimmunization to Platelets (TRAP)

National Heart, Lung, and Blood Institute (NHLBI)

Study title	NCT ID	Conditions	Interventions	Eligibility	Organization
Platelets Activation in Brain Neoplasms	NCT05049148	Glioma Blood Platelets Inflammation Brain Neoplasms	Platelet count ...	18 Years -	Fondation Ophtalmologique Adolphe de Rothschild
Trial to Reduce Alloimmunization to Platelets (TRAP)	NCT00000589	Blood Platelets Hematologic Dis... Immunization Leukemia, Myelo... Blood Transfusi...	platelet transf...	15 Years - 75 Years	National Heart, Lung, and Blood Institute (NHLBI)
Trial to Reduce Alloimmunization to Platelets (TRAP)	NCT00000589	Blood Platelets Hematologic Dis... Immunization Leukemia, Myelo... Blood Transfusi...	platelet transf...	15 Years - 75 Years	National Heart, Lung, and Blood Institute (NHLBI)

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