Methods for detecting Nasopharyngeal Cancer
Currently there are several methods available for detection of NPC. The most common would be fiberoptic endoscopy of the nasopharynx, performed by ENT physicians. Other methods include CT, MRI and serology. More recently, blood test detecting EBV DNA has been used for disease monitoring of recurrence after treatment.
Despite the availability of multiple test methods, majority of patients (60-70%) with NPC are still diagnosed in the late and advanced stages. About 60-70% of patients are diagnosed for the first time with a neck lump, when cancer has already metastasized in the lymph nodes.
NP Screen™
NP Screen™ is a highly sensitive and specific test for detection of EBV DNA obtained from a nasopharynx swab samples. The test can detect a minute quantity of cells containing the viral DNA, and when used in conjunction with endoscopy, it significant increases the chance of detecting small/early stage or even submucosal NPC. Clinical study also confirmed that even in NPCcases where endoscopy were negative, the NP Screen™ still correctly identify the cancer with positive result.
|
NP Screen™ |
|
| Sensitivty |
Specificity |
|
98.0% |
99.1% |
| Positive Predictive Value (PPV)* |
Negative Predictive Value (NPV) |
| 84.48% |
99.9% |
*Based on clinical trials
Comparing endoscopy and NP Screen™
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) |
|||
Benefits of regular screening
• Better survival rates – In most cases, the earlier the cancer is detected, the better your chance of survival
• Better quality of life – Early detection may also mean less aggressive or invasive treatment or life altering side-effects and less time spent recovering