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

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