3.1. Study population
The features and demographics of chronic periodontitis (CP) and head and neck cancer (HNC) patients are shown in (Table 1). In this research population, there were n=26 nasopharyngeal tumors (n=20 nonkeratinizing and n=6 keratinizing carcinomas), (n=6 oropharyngeal squamous cell carcinoma, SCC), (n=8 Laryngeal cancer), (n=6 tongue cancer), and (n=4 primary malignancies of unclear origin). Many patients had a history of smoking, and the mean patient age was 45.8 years (min-max: 28-72 years); 40 (80%) were men. The range of the total radiation dosage was 5700–7000 cGy, with a mean of 6350 cGy. Twenty-eight of the patients (or 56%) had a concomitant systemic therapy (2-3 doses) of cisplatin or cetuximab in addition to radiotherapy. In this research cohort, chronic periodontitis patients without HNCs included: Patients’ average ages ranged from 28 to 65 years, with 40 (80%) of them being male. More than half of them had a history of smoking, with 31 (62%) and 5 (10) of them having used alcohol. A control group was used periodontally healthy as a controlled study, the mean age was 40.12 years (min-max: 29-60 years).
Table 1. Demographic and medical characteristics of cases and control
Variables
|
CP+HNC-post RT
|
CP without HNC
|
Control
(Healthy)
|
Age, years Mean±SD;
(min-max)
|
41.34±8.41; (28-62)
|
40.06±6.41;
(28-60)
|
40.12±6.40;
(29-60)
|
Gender, n (%)
Male:
Female:
|
40 (80)
10 (20)
|
40 (80)
10 (20)
|
40 (80)
10 (20)
|
Body Mass Index (Weight/height2), Mean±SD
|
26.01±5.74
|
27.91± 4.61
|
25.45±4.91
|
Stage of Tumor, n (%)
|
1-2
|
9(18)
|
N/A
|
N/A
|
3-4
|
41(82)
|
Smoking, n (%)
Yes
No
|
36 (72)
14 (28)
|
31 (62)
19 (38)
|
0 (0.0)
50 (100)
|
Drinking, n (%)
Yes
No
|
13 (26)
37 (74)
|
5 (10)
45 (90)
|
0 (0.0)
50 (100)
|
Type of treatment, n (%)
|
RT
|
22(44)
|
N/A
|
N/A
|
CT+RT
|
28(56)
|
RT, n (%)
|
22(44)
|
N/A
|
N/A
|
CT-RT, n (%)
|
28 (56)
|
N/A
|
N/A
|
Note: HNC-post RT: Head and Neck Cancer post-radiotherapy, CP: Chronic Periodontitis, SD: Standard Deviation, RT: Radiotherapy, CT+RT: Chemoradiotherapy, N/A: Not Applicable.
3.2. Clinical Periodontal Parameters, Oral pH, and Hyposalivation
The results noticed, as compared to the healthy group between CP+HNC post-RT and CP without HNC had larger Clinical Attachment Level (CAL), Probing Pocket Depth (PPD), and greater Plaque Index (PI), and Gingival Bleeding Index (GBI) with a significant statistical difference of (P= 0.001). Moreover, Oral pH changed in groups (CP+HNC post-RT, CP without HNC, and control), the mean levels of Oral pH were (6.0), (7.77), and (7.12), respectively (P= 0.001). Furthermore, the mean levels of hyposalivation were 0.155 ml/min, 0.30 ml/min, and 0.35 ml/min, respectively. Comparing the chronic periodontitis with HNC post-RT and chronic periodontitis without HNC groups to the healthy group, the groups with chronic periodontitis had substantially decreased hyposalivation levels (P= 0.001), as shown in (Table 2).
Table 2. Clinical features of head and neck cancer post-RT on periodontal health
Variables
|
CP+ HNC post-RT
|
CP without HNC
|
Healthy
(Control)
|
P
|
CAL
(mm)
|
Mean ± SD
|
7.02 ± 0.43
|
6.34 ± 0.78
|
-
|
0.001
|
(min-max)
|
(6.5-7.5)
|
(5.25-7.50)
|
-
|
PPD
(mm)
|
Mean ± SD
|
7.1 ± 0.46
|
6.12 ± 0.61
|
3.05 ± 0.15
|
0.001
|
(min-max)
|
(6.00-7.50)
|
(4.50-7.25)
|
(3.00-3.50)
|
PI
(mm)
|
Mean ± SD
|
2.52 ± 0.61
|
1.94 ± 1.03
|
0.3 ± 0.46
|
0.001
|
(min-max)
|
(1.00-3.00)
|
(0.00-3.00)
|
(0.00-1.00)
|
GBI
(%)
|
Mean ± SD
|
90.38 ± 0.58
|
63.12± 0.60
|
4.25 ± 0.39
|
0.001
|
(min-max)
|
(89.37-91.65)
|
(60.99-63.88)
|
(3.50-4.90)
|
Oral saliva pH
|
Mean ± SD
|
6.0±0.67
|
7.77±0.28
|
7.12±0.16
|
0.001
|
(min-max)
|
(4.66-7.11)
|
(7.00-8.10)
|
(6.90-7.50)
|
Hyposalivation
(ml/min)
|
Mean ± SD
|
0.15±0.04
|
0.30±0.04
|
0.35±0.05
|
0.001
|
(min-max)
|
(0.11-0.23)
|
(0.25-0.41)
|
(0.28-0.54)
|
Note: CAL: Clinical attachment loss, PPD: periodontal pocket depth, PI: plaque index, GBI: gingival bleeding index
3.3. Stage and grade of periodontitis
In the CP+HNC post-RT patients, stage II periodontitis affected a total of nine (18%) patients, stage III periodontitis affected nineteen (38%) patients, and stage IV periodontitis affected twenty-two (44%) patients. In CP without HNC group stage I periodontitis affected fifteen (30%) patients, stage II periodontitis affected a total of twenty-four (48%) patients, stage III periodontitis affected nine (18%) patients, and stage IV periodontitis affected two (4%) individuals. Grade A and B periodontitis affected 0(0.0), and grade C affected a total of 50 (100%) in CP+HNC post-RT group. Furthermore, grade A periodontitis affected nineteen (38%), grade B affected thirty-one (62%) and grade C affected 0(0.0) in CP without HNC group. At P = 0.001, The value of the variance of stage and grade of periodontitis was significant statistically as can be seen from (Table 3 and Figure 1).
Table 3 Stage and grade of periodontitis in clinical cases.
*P
|
CP without HNC
|
CP+HNC post-RT
|
Variables
|
0.001
|
15 (30)
|
0 (0.0)
|
Stage I
|
Stage of periodontitis, n (%)
|
24 (48)
|
9 (18)
|
Stage II
|
9 (18)
|
19 (38)
|
Stage III
|
2 (4)
|
22 (44)
|
Stage IV
|
0.001
|
19 (38)
|
0 (0.0)
|
Grade A
|
Grade of periodontitis, n (%)
|
31 (62)
|
0 (0.0)
|
Grade B
|
0 (0.0)
|
50 (100)
|
Grade C
|
*: Significant <0.05, Mann-Whitney test or Wilcoxon W test
3. 3. Clinical activity and serum suPAR levels are closely related.
Estimation of serum suPAR was increased in patients with CP+HNC post-RT (506.7 [305.0-991.12] pg/mL, P <0.001) compared to CP without HNC (423.08 [205.0-735.00] pg/ mL, P <0.001), and healthy controls (255.9 [65.00-368.33] pg/mL, P <0.001 (Fig. 2).
3. 4. Receiver Operating Curve Characteristic (ROC)
Receiver Operating Curve Characteristic (ROC) analyses shown in (Table 4 and Figure 3) suggested that a higher ability to identify active patients with CP+HNC post-RT might be achieved by serum suPAR (AUC = 0.976) than CP without HNC (AUC = 0.872). In patients with CP+ HNC post-RT, suPAR level was increased (371.665 pg/ml), which could identify clinical abatement with a sensitivity= 86% and specificity= 100%, P= 0.001. In patients with CP without HNC suPAR level was decreased (371.225 pg/ml), which could identify clinical abatement with a sensitivity= 62%, and specificity= 100%, P= 0.001).
Table 4. Receiver Operating Curve Characteristic (ROC) analyses of serum suPAR to identify clinical abatement.
P
|
Specificity
%
|
Sensitivity
%
|
Cut-off value (pg/ml)
|
AUC
|
Groups
|
Variables
|
0.001
|
100
|
86
|
371.665
|
0.976
|
CP+HNC post-RT
|
suPAR (pg/ml)
|
0.001
|
100
|
62
|
371.225
|
0.872
|
CP without HNC
|
3. 5. Serum suPAR levels are significantly correlated with Periodontitis Indices, Oral pH, and Hyposalivation
Pearson's correlation coefficient was observed, and the clinical periodontal measurements scores: Plaque Index (PI), Gingival Bleeding Index (GBI), Probing Pocket Depth (PPD), and Clinical Attachment Level (CAL) revealed a statistical significance with serum suPAR levels. In addition, hyposalivation and oral pH showed a statistically significant correlation with serum suPAR levels, as shown in (Fig. 4 A, B, C, D, E, F).