Study to measure how well aspirin is able to reduce the number of platelets in the blood of patients with reactive thrombocytosis caused by pseudomyxoma peritonei (a rare form of cancer that affects the lining of the abdomen and pelvis)

ISRCTN ISRCTN41194672
DOI https://doi.org/10.1186/ISRCTN41194672
IRAS number 318927
Secondary identifying numbers IRAS 318927, CPMS 54712
Submission date
16/01/2023
Registration date
02/02/2023
Last edited
10/03/2025
Recruitment status
Stopped
Overall study status
Stopped
Condition category
Cancer
Prospectively registered
Protocol
Statistical analysis plan
Results
Individual participant data
Record updated in last year

Plain English summary of protocol

Background and study aims
Pseudomyxoma peritonei (PMP) is a rare form of cancer that affects the lining of the abdomen and pelvis. In some cases, people with PMP may develop reactive thrombocytosis, which can be caused by the cancer itself or as a response to treatment. This can increase the risk of blood clots and other complications.
Patients who have surgery for pseudomyxoma peritonei can sometimes have high platelet counts after the operation. Platelets are a type of blood cell in the body that is involved in the blood clotting process. High platelet counts can sometimes cause abnormal blood clots to form so they are prescribed aspirin which blocks platelets. Previous research has shown that in some patients aspirin does not block platelets and therefore is ineffective. This phenomenon is known as aspirin resistance. In this study we want to identify those patients who are aspirin resistant.

Who can participate?
Patients undergoing surgery for pseudomyoma peritonei and who develop high platelet counts after surgery are eligible to take part in the study.

What does the study involve?
The study involves taking blood samples before patients are administered aspirin and at different time points after they take aspirin.

What are the possible benefits and risks of participating?
It is beneficial to know if patients are aspirin resistant as it means the drug is not effectively working. The risks are minimal and only involve slight discomfort during venepuncture.

Where is the study run from?
Hampshire Hospitals NHS Foundation Trust (UK)

When is the study starting and how long is it expected to run for?
July 2021 to June 2025

Who is funding the study?
1. Pelican Cancer Foundation (UK)
2. Peritoneal Malignancy Institute (UK)

Who is the main contact?
Dr Sophia Stanford, sophia.stanford@hhft.nhs.uk

Contact information

Dr Sophia Stanford
Principal Investigator

Peritoneal Malignancy Unit
The Ark Centre
Dinwoodie Drive
Basingstoke
RG24 9NN
United Kingdom

ORCiD logoORCID ID 0000-0002-7855-1991
Phone +44 1256319811
Email sophia.stanford@hhft.nhs.uk

Study information

Study designProspective observational study
Primary study designObservational
Secondary study designCohort study
Study setting(s)Hospital
Study typeDiagnostic
Participant information sheet Not available in web format, please use the contact details to request a participant information sheet.
Scientific titleA prospective observational study to measure platelet inhibition by aspirin administered for reactive thrombocytosis in Pseudomyxoma Peritonei patients
Study objectivesThe main stay treatment for Pseudomyxoma Peritonei (PMP) is complete cytoreductive surgery (CRS) with Hyperthermic Intraperitoneal Chemotherapy (HIPEC). Following surgery a proportion of these patients develop reactive thrombocytosis and are administered prophylactic dose of aspirin (75mg) for 6 weeks. Previous studies have shown that patients with reactive thrombocytosis are at risk of abnormal thrombosis. Although these patients are administered aspirin because they are at risk of thrombosis we do not know how effectively platelets are being inhibited by aspirin. The phenomenon of aspirin resistance or aspirin treatment failure has been previously described and we currently do not know what proportion of our patients are aspirin resistant i.e. if the aspirin prescribed is effectively inhibiting patients.

This study will measure aspirin inhibition using VerifyNow a point of care test.
Ethics approval(s)Approved 28/11/2022, North of Scotland Research Ethics committee (Summerfield house, 2 Eday Road, Aberdeen, AB15 6RE, UK; +44(0)1224 558458; gram.nosres@nhs.scot), ref: 22/NS/0156
Health condition(s) or problem(s) studiedPseudomyxoma peritonei
InterventionAn observational study using blood samples to measure aspirin resistance in post-operative PMP patients who have reactive thrombocytosis and are prescribed aspirin.
Blood samples will be taken at baseline before administration of aspirin, 4 hours after (day 0), day 1, day 3, Day 5 and day 14 or day of discharge whichever comes first for VerifyNow measurements. In addition, a blood sample will be taken simultaneously at the same time points for full blood count analysis which will provide information on platelet count. At day 60 patients will be contacted via a telephone call to determine if they have had a thrombotic event.
Intervention typeDrug
Pharmaceutical study type(s)
PhaseNot Applicable
Drug / device / biological / vaccine name(s)Aspirin
Primary outcome measureAspirin resistance measured at baseline, 4 hours post aspirin administration, day 1, day 3, day 5 and day 14 or day of discharge, which ever comes first using the VerifyNowTM.
Secondary outcome measuresDetermine if there are any thromboembolic events at 60 days post-operatively via completion of a questionnaire.
Overall study start date21/07/2021
Completion date30/06/2025
Reason abandoned (if study stopped)Objectives no longer viable

Eligibility

Participant type(s)Patient
Age groupAdult
Lower age limit18 Years
SexBoth
Target number of participants156
Total final enrolment30
Key inclusion criteria1. Patients >18 years of age
2. Diagnosis of Pseudomyxoma Peritonei
3. Patients undergoing CRS and HIPEC
4. Post-operative platelet count of >1000 x 10^9/L
Key exclusion criteria1. Patients <18 years of age
2. Having CRS and HIPEC for other conditions apart from Pseudomyxoma Peritonei
3. Allergic to aspirin
4. On other antiplatelet or drugs that affect platelet function e.g. NSAIDs
5. Ischaemic vascular events, percutaneous coronary intervention, or coronary artery bypass within the last 12 months
Date of first enrolment16/01/2023
Date of final enrolment31/12/2024

Locations

Countries of recruitment

  • England
  • United Kingdom

Study participating centre

Hampshire Hospitals NHS Foundation Trust
Basingstoke and North Hampshire Hos
Aldermaston Road
Basingstoke
RG24 9NA
United Kingdom

Sponsor information

Hampshire Hospitals NHS Foundation Trust
Hospital/treatment centre

Aldermaston road
Basingstoke
RG24 9NA
England
United Kingdom

Phone +44 1962825883
Email natasha.chigbo@hhft.nhs.uk
Website https://www.hampshirehospitals.nhs.uk
ROR logo "ROR" https://ror.org/04shzs249

Funders

Funder type

Charity

Pelican Cancer Foundation
Private sector organisation / Trusts, charities, foundations (both public and private)
Location
United Kingdom
Peritoneal Malignancy Institute

No information available

Results and Publications

Intention to publish date31/01/2025
Individual participant data (IPD) Intention to shareNo
IPD sharing plan summaryNot expected to be made available
Publication and dissemination planPlanned publication in a high-impact peer-reviewed journal
IPD sharing planThe datasets generated and/or analysed during the current study are not expected to be made available due to patient confidentiality.

Study outputs

Output type Details Date created Date added Peer reviewed? Patient-facing?
HRA research summary 28/06/2023 No No

Editorial Notes

10/03/2025: The study was stopped as there were several protocol deviations that affected the aims of the study. These deviations included discontinuation of aspirin prior to 6 weeks as required by standard care. In some patients, aspirin was discontinued prior to discharge for clinical reasons which affected the study significantly and we were not able to collect study-specific data. The protocol required blood samples to be taken at baseline before administration of aspirin, 4 hours post aspirin, day 1, day 3 and day 5. There were however several missing time points because the patients were discharged or the aspirin was stopped. Of the 30 that were recruited the researchers only have 7 evaluable patients which is not enough to get meaningful results. Furthermore, the VerifyNow machine was unreliable and did not work at some time points and it was not ethical to approach the patient again for additional blood samples. The company was contacted for advice and recalibrated the instrument but it did not make a difference. No patients were affected by the study or clinical decisions outside of the study.
01/03/2023: Internal review.
31/01/2023: Trial's existence confirmed by North of Scotland Research Ethics committee.