Chronic Post Operative PainNCT06418295
Cytokine Alterations and Chronic Post-Surgical Pain
An observational study of Chronic Post Operative Pain, run by London Health Sciences Centre Research Institute OR Lawson Research Institute of St. Joseph's.
Trial summary
Chronic Post-Surgical Pain (CPSP) is a condition that involves experiencing pain and/or discomfort that lasts for more than 3 months following surgery without any explainable cause of this pain such chronic infection or pain caused from a condition preceding surgery. Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Chronic Post Operative Pain
- What is being tested?
- Unilateral thoracotomy
- How many people
- 0 participants
- Where
- No sites listed yet
- Study dates
- 1 Jan 2026to 31 Dec 2028
- Phase
- Observational
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Study population: Adult patients scheduled to undergo thoracotomy for malignancy at Victoria Hospital, London Health Science Centre.
Who may be able to join
- 18 years of age or older
- Undergoing unilateral thoracotomy for the first time on that side
- Willing to provide informed consent for study participation.
- Patient with malignancy that needs thoracotomy for surgical resection.
Who cannot join
- Chronic pain prior to surgery
- Pre-existing fibromyalgia
- Long-term opioid use
- Diabetes mellitus
- Inflammatory bowel disease
- Pre-existing neurological disease
Show all 13Show fewer
- Pre-existing nerve injury
- Evidence of dementia, delirium or cognitive disorder that may interfere with study participation
- Malignancy other than lung cancer
- Autoimmune disorder (e.g. rheumatoid arthritis and psoriatic arthritis)
- Pregnancy
- Inability to communicate in the English language (required for completion of questionnaires and provision of pain scores).
- Patents on antiepileptic medications
About this study
Official title: Cytokine Alterations Associated With Persistent Post-surgical Pain and Their Regulation Through Epigenetic Changes - A Pilot Study
Chronic Post-Surgical Pain (CPSP) is a condition that involves experiencing pain and/or discomfort that lasts for more than 3 months following surgery without any explainable cause of this pain such chronic infection or pain caused from a condition preceding surgery. This condition negatively impacts health related quality of life and is associated with significant financial burden both for the patient and health care system. Patients undergoing common surgeries such as amputation, breast surgery, hernia repair, coronary artery bypass, and caesarean section can be prone to developing CPSP. CPSP may be caused by the release and expression of different cellular molecules called cytokines and chemokines that can cause a pain response when they are present in the body at certain levels. After surgical incision, tissue cells have been shown to release cytokines and chemokines, thus increasing the concentration of these molecules in the patient's blood. It is not entirely known what mechanisms cause the increased expression of chemokines and cytokines. One method that may play a role in in this expression is epigenetics which is the alteration of gene expression without permanently altering the structure of DNA. Unlike mutations, epigenetic changes are dynamic, possibly reversible, and are influenced by environmental and behavioral changes such as diet, exercise, disease, stress, toxin exposure etc. Epigenetic changes occur all throughout our life and have been associated with several disease processes such as cancer, diabetic complications, and chronic pain. At the molecular level, certain events take place that can regulate (increase or decrease) the expression of cytokines and chemokines, most notably DNA methylation of their promotor (which involves adding molecules to DNA that does not change its structure but changes it's activity). The investigators are conducting this study to determine if the alteration of specific cytokines are associated with the occurrence of CPSP and whether these cytokines are regulated by DNA methylation at their promoter. This study will take place at London Health Sciences Centre and will recruit up to 60 patients who will be undergoing a thoracotomy procedure (surgery of the chest area).
Read the detailed description
Chronic Post-Surgical Pain (CPSP), defined by the International Association for the Study of Pain, is a clinical discomfort that lasts more than 3 months post-surgery without other causes of pain such as chronic infection or pain from a chronic condition preceding the surgery. This condition negatively impacts health related quality of life and is associated with significant financial burden both for the patient and health care system. Patients undergoing a multitude of procedures, from amputation to hernia repair, are prone to develop CPSP with variable incidences.
CPSP may be a result of peripheral and central sensitization triggered by the release of cytokines and chemokines following surgery due to possible alterations in genetic expression. At the cellular level, after surgical incision, tissue cells from local areas have been implicated to drive synthesis of such cytokines/chemokines leading to alterations of their serum levels, including nerve growth factors (NGF) and interleukins (IL-1β). Specific regulatory mechanisms leading to augmented synthesis of these cytokines in the context of CPSP remain elusive. Several regulatory mechanisms may influence production of each cytokine. One method is via epigenetic mechanisms, which are defined as the alteration of gene expression without any structural genomic alterations that may regulate cytokine production at the transcriptional and post transcriptional levels. Among these listed epigenetic mechanisms, DNA methylation has been well studied and plays a key role in translation4. In general, hypomethylation of the promoter region leads to increased gene expression and vice versa. In this study the investigators wish to investigate how these mechanisms could be implicated in the expression of cytokines and chemokines in CPSP.
Patients undergoing unilateral thoracotomy will be included in this study. Their surgery and follow up care will proceed according to standard of care guidelines. Thoracic epidural analgesia, or patient controlled analgesia (PCA) pumps will be offered to each study participant as per standard of care. Patients' pain will be assessed preoperatively and postoperatively on day 1 and 3 months. Blood samples will also be taken during these times points and analyzed to determined the concentrations of the following cytokines, chemokines and growth factors:epidermal growth factor, eotaxin, fibroblast growth factor basic, G-CSF, GM-CSF, human growth factor, IFN-α, IFN-γ, IL-1ra, IL-1β, IL-2, IL-2r, IL-4, IL-5, IL-6, IL-7, IL-8, IL-10, IL-12 (p40/p70), IL-13, IL-15, IL-17, IP-10, MCP-1, MIG, MIP-1α, MIP-1β, RANTES, TNF-α, and VEGF. The occurrence of DNA methylation at the promotor region of these targets will be assessed via polymerase chain reaction (PCR) analysis. Results of these postoperative analyses will be compared to pre-operative molecular concentrations and pain scores to determine the association between epigenetic modifications (if any) and the development of CPSP and whether these modifications are driven by DNA promotor methylation.
- Conditions
- Chronic Post Operative Pain
- Being tested
- Unilateral thoracotomy
- Keywords
- chronic pain, epigentics
- Medical subject headings
- Pain, Postoperative, Chronic Pain
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Unilateral thoracotomyOther
Unilateral thoracotomy to proceed as per standard of care guidelines. Thoracic epidural analgesia, or patient controlled analgesia (PCA) pumps will be offered to each study participant as per standard of care. Pre- and post-operative (post-operative day 1 and 3 months) pain scores and blood samples will be collected. Blood samples will be analyzed to determine the concentration of cytokines, chemokines, and growth factors that are potentially associated with CPSP (epidermal growth factor, eotaxin, fibroblast growth factor basic, G-CSF, GM-CSF, human growth factor, IFN-α, IFN-γ, IL-1ra, IL-1β, IL-2, IL-2r, IL-4, IL-5, IL-6, IL-7, IL-8, IL-10, IL-12 (p40/p70), IL-13, IL-15, IL-17, IP-10, MCP-1, MIG, MIP-1α, MIP-1β, RANTES, TNF-α, and VEGF). DNA promotor methylation for these targets will also be investigated.
| Study group | Role | What they receive |
|---|---|---|
| Unilateral thoracotomy | Unilateral thoracotomy to proceed according to standard of care guidelines. Receives: Other: Unilateral thoracotomy |
What is being measured
The primary outcome is the main question the study is designed to answer.
Identification of temporal alterations of cytokines in patients with CPSP.
Cellular assays will be performed on blood samples obtained pre-and postoperatively to determined the level of expression of certain chemokines, cytokines, and growth factors that have been shown to be potentially related to CPSP. Pre and postoperative results will be compared to determine the association that each may have on the development of CPSP.
Measured: 3 months
Identification of specific DNA promoter methylation regulating production of specific cytokines
Cellular assays will be performed on blood samples obtained pre-and postoperatively to determine if DNA promotor methylation is associated with changes in expression of the cytokines being investigated. Pre and postoperative results will be compared to determine the impact that this potential epigenetic change (DNA promotor methylation) may have on the development of CPSP.
Measured: 3 months
Generate initial data to determine the sample size needed to adequately power a larger trial
As this is a pilot study, data will be analyzed to determine the sample size needed to power a larger, randomized controlled trial.
Measured: 3 months
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted17 May 2024
- Study start1 Jan 2026 (estimated)
- Primary completion1 Dec 2028 (estimated)
- Study completion31 Dec 2028 (estimated)
Why it stopped: Was unable to achieve funding for this study
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (6)Papers the sponsor has linked to this study.
- Other trials for Chronic Post Operative PainStudies of the same condition, open and under way.
- More trials run by London Health Sciences Centre Research Institute OR Lawson Research Institute of St. Joseph'sThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Observational
- Observational model
- Cohort
- Time perspective
- Prospective
- Enrolment
- 0 participants (actual)
Sponsor and investigators
- Lead sponsor
- London Health Sciences Centre Research Institute OR Lawson Research Institute of St. Joseph's
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Abhijit Biswas, London Health Sciences Centre Research Institute OR Lawson Research Institute of St. Joseph's
- Investigators
- Abhijit Biswas, Principal investigator, Western University
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06418295
- Sponsor's protocol ID
- CPSP Epigenetics
- Status last verified
- Sep 2026
- First submitted
- 13 May 2024
- Last updated
- 22 Sep 2026
- Results posted
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Publications
Macrae WA, Davies HTO, Crombie IK, Linton S, Croft P, Von Korff M, LeResche L. Chronic postsurgical pain, Epidemiology of Pain, 1999, Seattle International Association for the Study of Pain (pg. 125-42)
Macrae WA. Chronic post-surgical pain: 10 years on. Br J Anaesth. 2008 Jul;101(1):77-86. doi: 10.1093/bja/aen099. Epub 2008 Apr 22.
PubMed 18434337Richebe P, Capdevila X, Rivat C. Persistent Postsurgical Pain: Pathophysiology and Preventative Pharmacologic Considerations. Anesthesiology. 2018 Sep;129(3):590-607. doi: 10.1097/ALN.0000000000002238.
PubMed 29738328Aroke EN, Joseph PV, Roy A, Overstreet DS, Tollefsbol TO, Vance DE, Goodin BR. Could epigenetics help explain racial disparities in chronic pain? J Pain Res. 2019 Feb 18;12:701-710. doi: 10.2147/JPR.S191848. eCollection 2019.
PubMed 30863142Descalzi G, Ikegami D, Ushijima T, Nestler EJ, Zachariou V, Narita M. Epigenetic mechanisms of chronic pain. Trends Neurosci. 2015 Apr;38(4):237-46. doi: 10.1016/j.tins.2015.02.001. Epub 2015 Mar 9.
PubMed 25765319Zigmond AS, Snaith RP. The hospital anxiety and depression scale. Acta Psychiatr Scand. 1983 Jun;67(6):361-70. doi: 10.1111/j.1600-0447.1983.tb09716.x.
PubMed 6880820
Study at a glance
From the registry record, last updated by the sponsor on 22 Sep 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Cytokine Alterations Associated With Persistent Post-surgical Pain and Their Regulation Through Epigenetic Changes - A Pilot Study
- ClinicalTrials.gov ID
- NCT06418295
- Acronym / sponsor ID
- CPSP Epigenetics
- Conditions
- Chronic Post Operative Pain
- Keywords
- chronic pain, epigentics
- Study type
- Observational
- Recruitment status
- WithdrawnReason stopped: Was unable to achieve funding for this study
- Enrolment
- 0 participants (actual)
- Lead sponsor
- London Health Sciences Centre Research Institute OR Lawson Research Institute of St. Joseph'sUniversity, hospital or other
- Study start
- 1 Jan 2026 (estimated)
- Primary completion
- 1 Dec 2028 (estimated)
- Study completion
- 31 Dec 2028 (estimated)
- First posted
- 17 May 2024 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
Chronic Post-Surgical Pain (CPSP) is a condition that involves experiencing pain and/or discomfort that lasts for more than 3 months following surgery without any explainable cause of this pain such chronic infection or pain caused from a condition preceding surgery. This condition negatively impacts health related quality of life and is associated with significant financial burden both for the patient and health care system. Patients undergoing common surgeries such as amputation, breast surgery, hernia repair, coronary artery bypass, and caesarean section can be prone to developing CPSP. CPSP may be caused by the release and expression of different cellular molecules called cytokines and chemokines that can cause a pain response when they are present in the body at certain levels. After surgical incision, tissue cells have been shown to release cytokines and chemokines, thus increasing the concentration of these molecules in the patient's blood. It is not entirely known what mechanisms cause the increased expression of chemokines and cytokines. One method that may play a role in in this expression is epigenetics which is the alteration of gene expression without permanently altering the structure of DNA. Unlike mutations, epigenetic changes are dynamic, possibly reversible, and are influenced by environmental and behavioral changes such as diet, exercise, disease, stress, toxin exposure etc. Epigenetic changes occur all throughout our life and have been associated with several disease processes such as cancer, diabetic complications, and chronic pain. At the molecular level, certain events take place that can regulate (increase or decrease) the expression of cytokines and chemokines, most notably DNA methylation of their promotor (which involves adding molecules to DNA that does not change its structure but changes it's activity). The investigators are conducting this study to determine if the alteration of specific cytokines are associated with the occurrence of CPSP and whether these cytokines are regulated by DNA methylation at their promoter. This study will take place at London Health Sciences Centre and will recruit up to 60 patients who will be undergoing a thoracotomy procedure (surgery of the chest area).
Detailed description
Chronic Post-Surgical Pain (CPSP), defined by the International Association for the Study of Pain, is a clinical discomfort that lasts more than 3 months post-surgery without other causes of pain such as chronic infection or pain from a chronic condition preceding the surgery. This condition negatively impacts health related quality of life and is associated with significant financial burden both for the patient and health care system. Patients undergoing a multitude of procedures, from amputation to hernia repair, are prone to develop CPSP with variable incidences.
CPSP may be a result of peripheral and central sensitization triggered by the release of cytokines and chemokines following surgery due to possible alterations in genetic expression. At the cellular level, after surgical incision, tissue cells from local areas have been implicated to drive synthesis of such cytokines/chemokines leading to alterations of their serum levels, including nerve growth factors (NGF) and interleukins (IL-1β). Specific regulatory mechanisms leading to augmented synthesis of these cytokines in the context of CPSP remain elusive. Several regulatory mechanisms may influence production of each cytokine. One method is via epigenetic mechanisms, which are defined as the alteration of gene expression without any structural genomic alterations that may regulate cytokine production at the transcriptional and post transcriptional levels. Among these listed epigenetic mechanisms, DNA methylation has been well studied and plays a key role in translation4. In general, hypomethylation of the promoter region leads to increased gene expression and vice versa. In this study the investigators wish to investigate how these mechanisms could be implicated in the expression of cytokines and chemokines in CPSP.
Patients undergoing unilateral thoracotomy will be included in this study. Their surgery and follow up care will proceed according to standard of care guidelines. Thoracic epidural analgesia, or patient controlled analgesia (PCA) pumps will be offered to each study participant as per standard of care. Patients' pain will be assessed preoperatively and postoperatively on day 1 and 3 months. Blood samples will also be taken during these times points and analyzed to determined the concentrations of the following cytokines, chemokines and growth factors:epidermal growth factor, eotaxin, fibroblast growth factor basic, G-CSF, GM-CSF, human growth factor, IFN-α, IFN-γ, IL-1ra, IL-1β, IL-2, IL-2r, IL-4, IL-5, IL-6, IL-7, IL-8, IL-10, IL-12 (p40/p70), IL-13, IL-15, IL-17, IP-10, MCP-1, MIG, MIP-1α, MIP-1β, RANTES, TNF-α, and VEGF. The occurrence of DNA methylation at the promotor region of these targets will be assessed via polymerase chain reaction (PCR) analysis. Results of these postoperative analyses will be compared to pre-operative molecular concentrations and pain scores to determine the association between epigenetic modifications (if any) and the development of CPSP and whether these modifications are driven by DNA promotor methylation.
Study design
- Observational model
- Cohort
- Time perspective
- Prospective
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| Unilateral thoracotomy | – | Other: Unilateral thoracotomyUnilateral thoracotomy to proceed according to standard of care guidelines. |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
- Study population
- Adult patients scheduled to undergo thoracotomy for malignancy at Victoria Hospital, London Health Science Centre.
Key inclusion criteria (4 listed)
- 18 years of age or older
- Undergoing unilateral thoracotomy for the first time on that side
- Willing to provide informed consent for study participation.
- Patient with malignancy that needs thoracotomy for surgical resection.
Key exclusion criteria (13 listed)
- Chronic pain prior to surgery
- Pre-existing fibromyalgia
- Long-term opioid use
- Diabetes mellitus
- Inflammatory bowel disease
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Unilateral thoracotomyUnilateral thoracotomy to proceed as per standard of care guidelines. Thoracic epidural analgesia, or patient controlled analgesia (PCA) pumps will be offered to each study participant as per standard of care. Pre- and post-operative (post-operative day 1 and 3 months) pain scores and blood samples will be collected. Blood samples will be analyzed to determine the concentration of cytokines, chemokines, and growth factors that are potentially associated with CPSP (epidermal growth factor, eotaxin, fibroblast growth factor basic, G-CSF, GM-CSF, human growth factor, IFN-α, IFN-γ, IL-1ra, IL-1β, IL-2, IL-2r, IL-4, IL-5, IL-6, IL-7, IL-8, IL-10, IL-12 (p40/p70), IL-13, IL-15, IL-17, IP-10, MCP-1, MIG, MIP-1α, MIP-1β, RANTES, TNF-α, and VEGF). DNA promotor methylation for these targets will also be investigated. | Other | Unilateral thoracotomy |
Primary outcome
Identification of temporal alterations of cytokines in patients with CPSP.
Time frame: 3 months
Cellular assays will be performed on blood samples obtained pre-and postoperatively to determined the level of expression of certain chemokines, cytokines, and growth factors that have been shown to be potentially related to CPSP. Pre and postoperative results will be compared to determine the association that each may have on the development of CPSP.
Identification of specific DNA promoter methylation regulating production of specific cytokines
Time frame: 3 months
Cellular assays will be performed on blood samples obtained pre-and postoperatively to determine if DNA promotor methylation is associated with changes in expression of the cytokines being investigated. Pre and postoperative results will be compared to determine the impact that this potential epigenetic change (DNA promotor methylation) may have on the development of CPSP.
Generate initial data to determine the sample size needed to adequately power a larger trial
Time frame: 3 months
As this is a pilot study, data will be analyzed to determine the sample size needed to power a larger, randomized controlled trial.
Results and safety
The study was withdrawn before enrolling participants, so there are no results.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 22 Sep 2026.
- BackgroundMacrae WA, Davies HTO, Crombie IK, Linton S, Croft P, Von Korff M, LeResche L. Chronic postsurgical pain, Epidemiology of Pain, 1999, Seattle International Association for the Study of Pain (pg. 125-42)
- Background: PubMed 18434337Macrae WA. Chronic post-surgical pain: 10 years on. Br J Anaesth. 2008 Jul;101(1):77-86. doi: 10.1093/bja/aen099. Epub 2008 Apr 22.
- Background: PubMed 29738328Richebe P, Capdevila X, Rivat C. Persistent Postsurgical Pain: Pathophysiology and Preventative Pharmacologic Considerations. Anesthesiology. 2018 Sep;129(3):590-607. doi: 10.1097/ALN.0000000000002238.
- Background: PubMed 30863142Aroke EN, Joseph PV, Roy A, Overstreet DS, Tollefsbol TO, Vance DE, Goodin BR. Could epigenetics help explain racial disparities in chronic pain? J Pain Res. 2019 Feb 18;12:701-710. doi: 10.2147/JPR.S191848. eCollection 2019.
- Background: PubMed 25765319Descalzi G, Ikegami D, Ushijima T, Nestler EJ, Zachariou V, Narita M. Epigenetic mechanisms of chronic pain. Trends Neurosci. 2015 Apr;38(4):237-46. doi: 10.1016/j.tins.2015.02.001. Epub 2015 Mar 9.
- Background: PubMed 6880820Zigmond AS, Snaith RP. The hospital anxiety and depression scale. Acta Psychiatr Scand. 1983 Jun;67(6):361-70. doi: 10.1111/j.1600-0447.1983.tb09716.x.
- Individual participant dataSharing planned: No
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Abhijit Biswas principal investigator
Western University
Questions about this trial
What is this clinical trial studying?
An observational study of Chronic Post Operative Pain, run by London Health Sciences Centre Research Institute OR Lawson Research Institute of St. Joseph's.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 4 inclusion and 13 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: withdrawn, as of the sponsor's last update on 22 Sep 2026. Status can change between updates, so confirm with the study contact before making plans.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study was withdrawn before enrolling participants, so there are no results.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Identification of temporal alterations of cytokines in patients with CPSP. (time frame: 3 months). The study lists 3 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT06418295, which also lists 6 linked publications.
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 22 Sep 2026.