Clinical Trial Details
— Status: Completed
Administrative data
| NCT number |
NCT03379610 |
| Other study ID # |
NP swabs |
| Secondary ID |
|
| Status |
Completed |
| Phase |
|
| First received |
|
| Last updated |
|
| Start date |
January 2006 |
| Est. completion date |
December 2018 |
Study information
| Verified date |
April 2021 |
| Source |
The University of Hong Kong |
| Contact |
n/a |
| Is FDA regulated |
No |
| Health authority |
|
| Study type |
Observational
|
Clinical Trial Summary
To evaluate the sensitivity and specificity of the combination of EBV and methylation marker
genes in body fluids of both plasma and nasopharyngeal brush together for screening of early
salvageable local residual and recurrent NPC that are missed by conventional clinical
follow-up protocol.
Description:
1. Background: Treatment failure can occur at distant sites which have no effective cure yet.
Early local residual or recurrent NPC are salvageable with over 50% 5-year survival rate. It
is however difficult for clinical detection of early residual or recurrent NPC after
radiotherapy by nasoendoscopy in the heavily irradiated nasopharynx with severe
nasopharyngitis and inflammatory swelling and crusting changes. Radiologic imaging and
nasopharyngeal biopsy have their role, but they are invasive, expensive and cannot be
repeated often as routine follow-up screening method. Unfortunately, 50% local recurrences
are in advanced rT3-4 stage and 28% local recurrences are not salvageable. Therefore,
detection of the early stage residual/recurrent NPC that are missed by our conventional
clinical follow-up is important for successful salvage treatment. Non-invasive, inexpensive
and repeatable sampling of blood and nasopharyngeal brush/swab for molecular detection of NPC
is our research focus for future improvement of treatment result of local failure.
There are two potential molecular markers of detection of minimal residual/recurrent NPC.
1. EBV DNA is a molecular marker for NPC. We have reported that only 61% patients with
local recurrence undergoing nasopharyngectomy had positive plasma EBV DNA. The
sensitivity was lower in local recurrence compared with same stage in pretreatment NPC,
86% T1 versus 38% rT1. EBV DNA in nasopharyngeal brush has been reported to be 96%
sensitive and 96% specific for NPC before treatment. EBV DNA in nasopharyngeal swab was
reported to disappear after radiotherapy and re-appear with mucosal local recurrence
with 100 % sensitivity and 98% specificity in a small case study of 11 patients with
local recurrences, the results demonstrate its potential detection of local recurrences
that are missed by our conventional follow-up. It however needs further prospective
longitudinal study for verification.
2. Methylation of the CG rich promoter region of many tumor suppressor genes have been
found to be a common genetic abnormality in NPC, but not in normal nasopharynx. We have
shown that methylated promoter DNA are detectable in peripheral blood and nasopharyngeal
swab of NPC patients, but rarely in normal controls. By using combination of 3
methylated genes in plasma, we have found 38% sensitive for detection of local
recurrence.
2. Study objective To evaluate the sensitivity and specificity of the combination of EBV and
methylation marker genes in body fluids of both plasma and nasopharyngeal brush together for
screening of early salvageable local residual and recurrent NPC that are missed by
conventional clinical follow-up protocol.
3. Hypothesis tested:
1. Patients in remission without residual or recurrent tumor after treatment should have
persistently negative or very low background level of markers in both nasopharyngeal
brush and plasma on follow-up.
2. Patients with residual or recurrent local or nodal tumors have either persistently high
level of markers beyond 8th week or initial disappearance/reduction to very low
background level followed by reappearance/increasing level of markers again on
follow-up. The temporal change in quantity of markers is important to reflect the tumor
load of residual and recurrent NPC before clinical presentation. We hypothesize that
these pattern will be observed in those patients with residual/recurrent NPC at their
early salvageable stages before clinical presentation.
4. Methodology of study:
1. Before treatment
1. Nasopharyngeal brush of tumor is collected under endoscopic guidance.
2. NPC biopsy specimen is then collected for histologic section and also freshly
frozen in liquid nitrogen and stored in -80C freezer for subsequent study.
3. 20ml EDTA blood is also collected for study.
4. The EBV DNA and methylation markers will be screened in the tumor, nasopharyngeal
brush and blood by using methylation specific quantitative PCR method. The
laboratory protocols have been reported from our previous publications on EBV DNA
and methylation studies.
2. Post-treatment reassessment of residual NPC
1. Based on our published results on the study of time of remission of residual NPC
after treatment, we have our routine follow-up protocol to perform endoscopic
assessment and random biopsy of the nasopharynx at post-treatment 8th week for
evaluation of residual NPC.
2. At the time of endoscopy at 8th week, nasopharyngeal brush and 20 ml of blood will
be collected for study of biomarkers. The EBV and specific methylation markers of
the patient selected from patient's tumor biopsy findings will be used for each
individual patient to screen residual NPC.
3. Of those patients who have positive biopsy at 8th week, repeat biopsy will be done
at 10th week. If the biopsy is still positive at 10th week, salvage treatment of
either re-irradiation or nasopharyngectomy as appropriate will be arranged. If the
repeat biopsy at 10th week becomes negative, the patient will be reassessed in 4
weeks.
4. Of those patients with negative findings of both biomarkers and biopsy at 8th week,
the patient will be followed-up according to schedule monthly.
5. Of those patients who have positive biomarkers but negative biopsy at 8th week,
further nasopharyngeal biopsies will be performed at 10th week to maker sure there
is no missing of local residual NPC from the previous biopsy at 8th week.
Radiologic imaging will also be performed at this time. The nasopharyngeal brush
and blood tests will also be repeated to keep track of the temporal change with
time. Patients who have positive biopsy at 10th week will be given appropriate
salvage treatment of radiotherapy or surgery, and these patients are benefited by
the molecular screening. Patients who have persistently negative biopsy at 10th
week will be followed up according to schedule, and if they have no recurrence at
follow-up, these patients have false positive molecular surveillance.
3. Subsequent follow-up for detection of recurrent NPC
1. A patient who has negative post-treatment nasopharyngeal biopsy at 8th/10th week
will be followed up every month in first year, every 2 months in second year and
every 3 months in third - fifth year for total 5 years. It is expected that 11% of
them in fact will subsequently develop local recurrence. It is our routine protocol
to perform nasoendoscopy to examine the nasopharynx during each follow-up. If there
is no suspicious lesion seen in the nasopharynx, biopsy will not be done and the
patient will be rescheduled for follow-up.
2. Nasopharyngeal biopsy will be taken if suspicious lesion is seen during follow-up
endoscopy. If the biopsy is proven to be recurrence, the patient will be managed
accordingly. If the biopsy is negative, the patient will be rescheduled for regular
follow-up.
3. Nasopharyngeal brush and 20 ml of blood will be collected at follow-up every 2
months for 1st and 2nd year and every 3 months in 3rd to 5th year for study.
The EBV and specific methylation markers of the patient selected from patient's
tumor biopsy findings will be reassessed for each individual patient to screen
local recurrence.
4. If a patient has negative nasoendoscopic finding and negative molecular biomarker
findings in both plasma and nasopharyngeal brush, the patient will be regularly
followed up as scheduled.
5. If a patient has negative nasoendoscopic finding, but a positive molecular marker
result is found in at least one of the body fluids or marker, the patient will be
thoroughly reassessed for recurrence that are missed during routine clinical
follow-up. The patient will have PET/CT/MRI imaging and random multiple
nasopharyngeal biopsies to assess for possible local recurrence. Since a positive
plasma finding may be due to nodal or distant metastasis, other sites of recurrence
or new cancer will be investigated as judged necessary clinically. If the
nasopharyngeal biopsy is positive or other site of recurrence is found, the patient
will be managed by salvage treatment accordingly as appropriate. These patients are
benefited by the molecular surveillance with true positive result. If the search
for recurrence are all negative, the patient will be rescheduled for regular
follow-up, and if the patient is proven no recurrence on further follow-up, the
molecular surveillance is considered false positive.
4. End point of follow-up Post-treatment 5 years follow-up status will be our end point of
study for each patient.
5. Number of patients recruited and recruitment criteria:
There are 130-150 new NPC patients annually in Queen Mary Hospital. We plan to recruit 350
patients for the longitudinal study starting from January 2006. The patients recruited should
be medically fit for curative radiotherapy without distant metastasis before treatment. A
total of 350 patients are expected to be recruited in 2008. Of these 350 patients, we expect
to see about 35 patients who are found to have no residual local tumor with imaging and
biopsy assessment at 8th week after radiotherapy with conventional follow-up, but
subsequently develop isolated local recurrence within 5 years of follow-up. We would be able
to know how many of these local recurrence will be benefited by early detection with
molecular surveillance, their stage of recurrence and treatment outcome. Of these 350
patients, we expect to have about 20 patients with nodal recurrence.
