Platelets Activation in Brain Neoplasms (Platon)

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

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

Study Overview

• Status: Recruiting
• Conditions: Glioma; Inflammation; Brain Neoplasms; Blood Platelets
• Intervention / Treatment: Other: Platelet count in excised tumors

Detailed Description

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

• Study Type: Interventional
• Enrollment (Estimated): 50
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Vivien VASSEUR; Phone Number: +33 (0)148036440; Email: vvasseur@for.paris
• Study Contact Backup: Name: Amélie YACHITZ, MD; Phone Number: +33 (0)148036454; Email: ayavchitz@for.paris

Study Locations

• France
  • Paris, France
    • Recruiting
    • Fondation A de Rothschild
    • Contact: Pierre Bourdillon, MD; Email: pbourdillon@for.paris
    • Contact: Gregory Torkomian; Email: gtorkomian@for.paris

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Patient to undergo excision or biopsy of a brain or medullary tumor
• Patient over 18 years old
• Express consent to participate in the study
• Affiliate member of the Social Security system

Exclusion Criteria:

• Tumor sample volume not allowing the performance of additional analyzes
• Patient benefiting from a legal protection measure
• Pregnant or breastfeeding woman

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Other
• Allocation: N/A
• Interventional Model: Single Group Assignment
• Masking: None (Open Label)

Number of Arms

1

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Other: Patients requirering brain/medullary tumors excision; All patients requirering a surgery for brain or medullar excision	Other: Platelet count in excised tumors; Tumors excised in patients requirering a brain or medullary surgery will be assess to determine their platelet count.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Platelet detection in excised brain/medurally tumors	biopsy: Presence of neo-vessels	1 hour

Collaborators and Investigators

• Sponsor: Fondation Ophtalmologique Adolphe de Rothschild
• Investigators: Principal Investigator: Pierre BOURDILLON, MD, Fondation A. de Rothschild

Study record dates

Study Major Dates

• Study Start (Actual): October 27, 2022
• Primary Completion (Estimated): October 1, 2026
• Study Completion (Estimated): October 1, 2029

Study Registration Dates

• First Submitted: August 18, 2021
• First Submitted That Met QC Criteria: September 10, 2021
• First Posted (Actual): September 17, 2021

Study Record Updates

• Last Update Posted (Actual): January 5, 2026
• Last Update Submitted That Met QC Criteria: December 30, 2025
• Last Verified: December 1, 2025

More Information

Terms related to this study

• Keywords: Platelets activation
• Additional Relevant MeSH Terms: Brain Diseases; Central Nervous System Diseases; Nervous System Diseases; Pathologic Processes; Neoplasms by Site; Neoplasms; Neoplasms by Histologic Type; Neoplasms, Glandular and Epithelial; Neoplasms, Neuroepithelial; Neuroectodermal Tumors; Neoplasms, Germ Cell and Embryonal; Neoplasms, Nerve Tissue; Nervous System Neoplasms; Central Nervous System Neoplasms; Pathological Conditions, Signs and Symptoms; Inflammation; Glioma; Brain Neoplasms; Investigative Techniques; Clinical Laboratory Techniques; Diagnostic Techniques and Procedures; Diagnosis; Cell Count; Cytological Techniques; Hematologic Tests; Cell Physiological Phenomena; Blood Physiological Phenomena; Circulatory and Respiratory Physiological Phenomena; Platelet Function Tests; Blood Cell Count; Platelet Count
• Other Study ID Numbers: PBN_2021_6

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No