Patient Characteristics
In this 85 NPC cohort, there were 55 (64.7%) male patients and 30 (35.3%) female patients. The median age was 56 years (range, 19- 86 years). Out of the 85 NPC patients, 35 (41.2%) had WHO type I disease, 36 (42.4%) had WHO type II disease and 14 (16.5%) had WHO type III disease. Fifty- seven (67.1%) were insured while 28 (32.9%) had no insurance. More than half of the patients 60 (70.6%) had a history of smoking and the use of alcohol was fifty-fifty in this group. The stage distribution in this cohort was Stage I (5.9%), Stage II (9.4%), Stage III (16.5%), Stage IV (52.9%) and Unknown Stage (15.3%). Fifty-one (60%) were treated with concurrent chemoRT, 20 (23.5%) with induction chemo followed by the chemoRT and 14 (16.5%) NPC patients were hospice (Table- 1).
Table-1. Demographic & Treatment description of the Nasopharyngeal Study Population by Histology -WHO classification
|
Variable
|
WHO Type I
|
WHO Type II
|
WHO Type III
|
All patients
|
p-value
|
|
n= 35 (41.2%)
|
n= 36 (42.4%)
|
n= 14 (16.5%)
|
n = 85 (100%)
|
|
GENDER/SEX
|
|
|
|
|
|
Male
|
24 (68.6%)
|
20 (55.6%)
|
11 (78.6%)
|
55 (64.7%)
|
|
Female
|
11 (31.4%)
|
16 (44.4%)
|
3 (21.4%)
|
30 (35.3%)
|
0.256
|
AGE
|
|
|
|
|
|
< 35 years
|
1 (2.9%)
|
5 (13.9%)
|
3 (21.4%)
|
9 (10.6%)
|
|
35 - 60 years
|
22 (62.9%)
|
16 (44.4%)
|
6 (42.9%)
|
44 (51.8%)
|
|
> 60 years
|
12 (34.3%)
|
15 (41.7%)
|
5 (35.7%)
|
32 (37.6%)
|
0.232
|
ETHNICITY
|
|
|
|
|
|
African American
|
16 (45.7%)
|
22 (61.1%)
|
9 (64.3%)
|
47 (55.3%)
|
|
Caucasian
|
17 (48.6%)
|
12 (33.3%)
|
4 (28.6%
|
33 (38.8%)
|
|
Other Ethnicity
|
2 (5.7%)
|
2 (5.6%)
|
1 (7.1%)
|
5 (5.9%)
|
0.633
|
INSURANCE
|
|
|
|
|
|
Medicaid
|
9 (25.7%)
|
11 (30.6%)
|
3 (21.4%)
|
23 (27.1%)
|
|
Medicare
|
8 (22.9%)
|
7 (19.4%)
|
4 (28.6%)
|
19 (22.4%)
|
|
Private
|
5 (14.3%)
|
8 (22.2%)
|
2 (14.3%)
|
15 (17.6%)
|
|
Self-pay
|
13 (37.1%)
|
10 (27.8%)
|
5 (35.7%)
|
28 (32.9%)
|
0.921
|
DISTANCE
|
|
|
|
|
|
< 30 miles
|
12 (34.3%)
|
7 (19.4%)
|
5 (35.7%)
|
24 (28.2%)
|
|
30 - 75 miles
|
6 (17.1%)
|
8 (22.2%)
|
1 (7.1%)
|
15 (17.6%)
|
|
> 75 miles
|
17 (48.6%)
|
21 (58.3%)
|
8 (57.1%)
|
46 (54.1%)
|
0.499
|
SMOKING
|
|
|
|
|
|
Smoker
|
29 (82.9%)
|
22 (61.1%)
|
9 (64.3%)
|
60 (70.6%)
|
|
Non-Smoker
|
6 (17.1%)
|
14 (38.9%)
|
5 (35.7%)
|
25 (29.4%)
|
0.113
|
ALCOHOL
|
|
|
|
|
|
Drinker
|
22 (62.9%)
|
14 (38.9%)
|
7 (50.0%)
|
43 (50.6%)
|
|
Non-Drinker
|
13 (37.1%)
|
22 (61.1%)
|
7 (50.0%)
|
42 (49.4%)
|
0.130
|
TUMOR STAGE
|
|
|
|
|
|
Stage I
|
2 (5.7%)
|
1 (2.8%)
|
2 (14.3%)
|
5 (5.9%)
|
|
Stage II
|
3 (8.6%)
|
5 (13.9%)
|
0 (0.0%)
|
8 (9.4%)
|
|
Stage III
|
6 (17.1%)
|
8 (22.2%)
|
0 (0.0%)
|
14 (16.5%)
|
|
Stage IV
|
21 (60.0%)
|
19 (52.8%)
|
5 (35.7%)
|
45 (52.9%)
|
|
Unknown Stage
|
3 (8.6%)
|
3 (8.3%)
|
7 (50.0%)
|
13 (15.3%)
|
0.005
|
TREATMENT
|
|
|
|
|
|
Concurrent chemoRT
|
21 (60.0%)
|
24 (66.7%)
|
6 (42.9%)
|
51 (60.0%)
|
|
Induction chemo + chemoRT
|
9 (25.7%)
|
8 (22.2%)
|
3 (21.4%)
|
20 (23.5%)
|
|
Hospice
|
5 (14.3%)
|
4 (11.1%)
|
5 (35.7%)
|
14 (16.5%)
|
0.292
|
n= number, WHO= World Health Organization, chemoRT= chemo radiation therapy, Induction chemo= Induction chemotherapy.
QoL data
The average QALYs gained and average DALYs saved for different variables stratified by the histology of the NPC in the study population (Table 2). The average LE for this 85- patient NPC cohort was 34.51 years, average DALYs saved with treatment was 20.06 years and average QALYs gained with treatment was 11.77 years.
The DALYs saved with concurrent chemoRT was 12.2 years vs 5 years with induction chemo followed by concurrent chemoRT. The QALYs gained with concurrent chemoRT was 6.9 years vs. 3.1 years with induction chemo followed by concurrent chemoRT.
Survival Outcomes
The median follow up for this study population was 24 months. The 5-year OS of WHO Type I was 34.8%, Type II 58% and Type III 77.1% (p= 0.042). The median survival of WHO type I was 34 months, Type II 194 months and Type III 123 months (shown in Fig. 1).
The OS curve for different tumor stages are represented (shown in Fig. 1). For all histologies the 5-year OS for Stage I was 80.0%, Stage II 57.1%, Stage III 52.6%, Stage IV 44.5% and Stage Unknown 64.5% ( p= 0.321) .
Univariate Analyses
In the univariate analyses, the variables of gender, age, ethnicity, insurance, distance traveled to the treatment facility, alcohol history, and the treatment modality was significantly associated with the OS (Table 3).
The OS curves for the treatment modalities used are represented (shown in Fig. 2). Five-year OS of NCPs treated by concurrent chemoRT for WHO Type I 54.7%, WHO Type II 60.1%, WHO Type III 83.3 % (p= 0.029). Five-year OS of NCPs treated by induction chemo followed by concurrent chemoRT for WHO Type I 14.8 %, WHO Type II 58.3% and WHO Type III 50.0% (p = 0.029).
Table-2. QALYs & DALYs of the Nasopharyngeal Study Population
|
Variable
|
Ave QALYs Gained
|
Ave DALYs Saved
|
GENDER/SEX
|
|
|
Male
|
11.63
|
20.19
|
Female
|
10.06
|
18.53
|
AGE
|
|
|
< 35 years
|
17.01
|
26.01
|
35 - 60 years
|
12.35
|
21.37
|
> 60 years
|
7.67
|
15.38
|
ETHNICITY
|
|
|
African American
|
11.53
|
20.09
|
Caucasian
|
11.51
|
19.62
|
Other Ethnicity
|
4.06
|
15
|
INSURANCE
|
|
|
Medicaid
|
13.55
|
22.75
|
Medicare
|
8.67
|
15.77
|
Private
|
8.33
|
16.63
|
Self-pay
|
12.17
|
21.22
|
DISTANCE
|
|
|
< 30 miles
|
11.49
|
20.73
|
30 - 75 miles
|
13.1
|
20.35
|
> 75 miles
|
10.21
|
18.78
|
SMOKING
|
|
|
Smoker
|
10.86
|
19.43
|
Non-Smoker
|
11.62
|
20.04
|
ALCOHOL
|
|
|
Drinker
|
11.03
|
19.84
|
Non-Drinker
|
11.13
|
19.36
|
TUMOR STAGE
|
|
|
Stage I
|
7.71
|
15.67
|
Stage II
|
8.07
|
17.28
|
Stage III
|
11.2
|
18.52
|
Stage IV
|
12.4
|
21.27
|
Unknown Stage
|
9.49
|
17.95
|
TREATMENT
|
|
|
Concurrent chemoRT
|
10.93
|
19.9
|
Induction chemo + chemoRT
|
12.61
|
20.22
|
Hospice
|
9.75
|
17.66
|
Ave= average, QALY= quality-adjusted life year, DALY= disability-adjusted life year, chemoRT= chemo radiation therapy, Induction chemo = induction chemotherapy.
Table -3. Univariate analysis by tumor histology
|
Variable
|
p Value
|
GENDER/SEX
|
0.013
|
AGE
|
0.013
|
ETHNICITY
|
0.042
|
INSURANCE
|
0.026
|
DISTANCE
|
0.041
|
SMOKING
|
0.960
|
ALCOHOL
|
0.010
|
TUMOR STAGE
|
0.321
|
TREATMENT
|
0.029
|
Table -4. Multivariate Cox regression analysis
|
Variable
|
HR (95%CI)
|
p value
|
GENDER/SEX
|
0.52 (0.24 - 1.15)
|
0.111
|
AGE
|
0.84 (0.48 - 1.47)
|
0.557
|
ETHNICITY
|
0.87 (0.50 - 1.53)
|
0.879
|
INSURANCE
|
1.13 (0.85 - 1.49)
|
0.389
|
DISTANCE
|
0.87 (0.58 – 1.29)
|
0.496
|
ALCOHOL
|
1.40 (0.71 – 2.78)
|
0.324
|
TREATMENT
|
0.88 (0.48 – 1.59)
|
0.682
|
HISTOLOGY
|
0.61 (0.39 – 0.94)
|
0.027
|
95 %= 95 percentage, CI= confidence interval
Multivariate Analyses
The variables which were significantly associated with survival outcomes were included in the Cox proportional hazards regression model (Table 4). In the multivariate analyses, only tumor histology was significantly associated with OS, with HR of 0.61 (95% CI 0.39-0.94), p= 0.027.