NP Screen™
The Problem: : Over 70% of patients with NPC are already in advanced stage of cancer when they first present to the physician for examination.
Early NPC can be treated effectively with radiation with a high cure rate and long term survival is excellent. Late stage NPC require complex radiation and chemotherapy, with higher treatment related complications and reduced survival.
Some of the reasons for frequent late stage NPC detection include:
- Lack of signs and symptoms in early NPC due to the obscure location of the cancer
- Difficult to examine with routine and standard medical office equipment
- Detection of NPC requires skilful subjective and visual examination of the Nasopharynx, using the endoscope. Small or early cancer can be missedSometimes NPC is hidden underneath the mucosal surface and not visible by endoscopy
Our Solution: Paradigm Shift from Effective Treatment to Early Detection
Early and accurate detection of NPC improves five year survival rates from 30-40% to over 90%.
NP Screen™ provides an accurate, simple, non-invasive way to detect NPC accurately.
In combination with endoscopy, NP Screen™ significantly enhances the chance of detecting NPC, even in cases when endoscopy is uncertain or falsely negative.
The technology behind NP Screen™
Using a specially designed brush, a small amount of tissue samples containing the NP cells (also containing the cancer cells) are brushed from the nasopharynx area (this process is done through the mouth painlessly). The sample is stored in special fluid in room temperature to preserve the DNA and then send to a special genetic laboratory for testing.
An innovative laboratory method known as Polymerase Chain Reaction (PCR) is used to detect a minute amount of the Epstein Barr Virus DNA (a small piece of genetic material from the virus) present in the cells collected. The EBV DNA is a very strong and definite marker of NPC. The presence of EBV DNA in large quantity indicate the risk of NPC in over 99% of the cases.
On the other hand, if the sample has low or non-detectable levels of the EBV DNA, the chance of NPC is negligible.
Accurate, Simple, Non-invasive
The test has been shown to be highly sensitive and specific in detecting NPC with high Positive and Negative Predictive Values (accuracy in confirming NPC). Even in cases where endoscopy can not visualize the cancer (either due to small invisible early cancer; submucosal growth, or human error), NP Screen™ would still detect high levels of EBV DNA indicating the presence of NPC.
|
NP Screen™ |
|
|
Sensitivty |
Specificity |
|
98.0% |
99.1% |
| Positive Predictive Value (PPV)* |
Negative Predictive Value (NPV) |
| 84.48% |
99.9% |
*Based on clinical trials
Risks of NPC for Different Combinations of Endoscopy and NP Screen Results
|
Endoscopy (Degree of Suspicion) |
N | Pre-test Risk
of NPC (prevalence) |
Positive
NP Screen Result |
Equivocal
NP Screen Result |
Negative
NP Screen Result |
||||||
| Risk of NPC | 95% CI | Risk of NPC | 95% CI | Risk of NPC |
95% CI |
||||||
|
High Suspicion |
49 | 79.6%
(39/49) |
100%
(33/33) |
(91.5%; 100%) | 83.3%
(5/6) |
(48.3%; 98.4%) | 10%
(1/10) |
(0.7%; 37.8%) |
|||
|
Intermediate to High Suspicion |
54 | 16.7%
(9/54) |
90.0%
(9/10) |
(62.1%; 99.4%) | 0.0%
(0/4) |
(0.0%; 45.5%) | 0.0%
(0/40) |
(0.0%; 7.7%) |
|||
|
Low Suspicion |
363 | 1.7%
(6/363) |
66.7%
(6/9) |
(39.4%; 88.0%) | 0.0%
(0/12) |
(0.0%; 18.9%) | 0.0%
(0/342) |
(0.0%; 1.0%) |
|||
|
None |
672 | 0.15%
(1/672) |
16.7%
(1/6) |
(1.6%; 33.6%) | 0.0%
(0/26) |
(0.0%; 4.0%) | 0.0%
(0/640) |
(0.0%; 0.2%) |
|||
|
Combined |
1,138 | 4.8%
(55/1,138) |
84.5%
(49/58) |
(71.7%; 91.7%) | 10.4%
(5/48) |
(3.6%; 21.1%) | 0.10% (1/1,032) |
(0.01%;0.91%) |
|||
Risks of 0.0% in the table are based on the endoscopy results at the baseline and at 3-month follow-up visits. These risks can be small positive risks.
Likelihood Ratios (LR) for Different Combinations of Endoscopy and NP Screen Results
|
Endoscopy (Degree of Suspicion) |
N | Positive
NP Screen Result |
Equivocal
NP Screen Result |
Negative
NP Screen Result |
||||||
| LR | 95% CI | LR | 95% CI | LR |
95% CI |
|||||
|
High Suspicion |
49 | +Inf | (2.42; +Inf) | 1.13 | (0.21; 14.11) | 0.029 | (0.002; 0.156) | |||
| Intermediate to High Suspicion | 54 | 45.0 | (8.18; 877.80) | 0.00 | (0.00; 4.17) | 0.00 |
(0.00; 0.42) |
|||
|
Low Suspicion |
363 | 119.0 | (38.6; 435.9) | 0.00 | (0.00; 13.90) | 0.00 | (0.00; 0.63) | |||
|
None |
672 | 134.2 | (10.6; 340.1) | 0.00 | (0.00; 28.0) | 0.00 |
(0.00; 0.98) |
|||
| Combined | 1,138 | 105.2 | (54.03; 214.10) | 2.25 | (0.71; 5.16) | 0.019 |
(0.001; 0.181) |
|||
NP Screen™ has an high accuracy rate of 99%, and compares favorably to other major screening tests, including Mammograms (85-90%) and PAP Smears (71-81%).
Recommended Frequency of Testing
The test is recommended to be done when there is signs and symptoms of NPC.
Individuals from high risk endemic regions should be tested regularly, preferably yearly (in conjunction with routine assessment by their physician with detailed endoscopy examination).
Individuals with a strong family history (such as siblings and parents diagnosed with NPC) should consider regular examination with endoscopy and testing using NP Screen™.