1. Characteristics of SCC of OMF
The age of patients with SCC varied from 19 to 87 years (mean age was 58.89±10.91 years) with a peak age of 45-74 years. Oral cavity was the most commonly affected primary region, followed by lip and oral pharynx. Males were involved predominantly with a ratio of 1.44:1 to females (Shown in Table-1).
Table 1: Characteristics of SCC of OMF
Site,Sex Age(y)
|
LP OC MS OP SG
M F M F M F M F M F
|
sZn
(μmol/L)
|
≦25
|
3
|
4.30±7.45
|
26-44
|
3 29 27 2 1
|
13.03±2.44
|
45-59
|
15 9 107 76 1 7 2
|
12.63±2.64
|
60-74
|
27 18 118 100 23 7 2
|
12.45±2.23
|
75-89
|
5 2 18 7 1
|
13.14±2.64
|
sZn (μmol/L)
|
13.07±2.53 12.51±2.52 6.5 12.65±2.51 10.78±0.60
|
|
(Abbreviations: SCC-squamous cell carcinoma; OMF-oral and maxillofacial region; LP-lip; OC-oral cavity; MS-maxillary sinus; OP-oral pharynx; SG-salivary gland; M-male; F-female; sZn-serum Zinc.)
2. Serum Zinc status in malignant and control groups
In the male subgroup, significantly reduced concentration of sZn with SCC was observed of 12.50±2.53 μmol/L to 14.53±2.35 μmol/L of its controls (P=0.000). 71 patients of SCCs involved in sZnd with a prevalence of 19.72 %; while, in its control group, 21 patients were affected by sZnd, therefore, the incidence was 5.8 %. The difference in the incidence of sZnd between the two groups was found to be statistically significant using Chi-square test (P=0.000) . In the female subgroup, the results were identical with males. Significant decrease in the concentration of sZn and increase in the prevalence of sZnd in patients with SCC were gained compared to its controls (P=0.000) (Shown in Table-2). While there was no difference in the prevalence of sZnd and concentration of sZn between males and females.
Tolly caculated, the concentration of serum Zinc in SCC group was 12.57±2.53 μmol/L much decreased than controls of 14.65±2.25 μmol/L, and the difference was statistically significant (P=0.000). 109 patients suffered from sZnd in SCC, and thus the prevalence of sZnd in research group was 17.87 %; while, in the control group, 29 patients were affected by sZnd, therefore, the prevalence of sZnd in controls was 4.75 %. The difference in the incidence of sZnd in malignant cases versus controls was found to be statistically significant using Chi-square test (P=0.000). Relative risk of developing SCC of OMF in persons with sZnd was 4.36 (95% confidence interval 2.85-6.68) compared to those with normal serum Zinc (Shown in Table-2).
Table 2: Prevalence of sZnd and concentration of sZn in SCC and control groups
|
|
Prevalece of sZnd (case)
|
Concentration of sZn (μmol/L)
|
|
Reference interval of sZn (μmol/L)
|
Control
|
SCC
|
Control
|
SCC
|
Male
|
10.8⁓19.4
|
21/360
|
71/360*
|
14.53±2.35
|
12.50±2.53*
|
Female
|
10.7⁓17.5
|
8/250
|
38/250*
|
14.81±2.09
|
12.67±2.53*
|
Sum
|
|
29/610
|
109/610*
|
14.65±2.25
|
12.57±2.53*
|
(Abbreviations: sZnd-serum Zinc deficiency; sZn-serum Zinc level; SCC-squamous cell carcinoma; *p﹤0.01.)
3. Serum Zinc status in different T-stages of SCC
According to WHO T-stage standard, patients with SCC were divided into four groups: T1、T2、T3 and T4. Concentration of sZn decreased with the development of T-stage, and the difference was statistically significant (p=0.000), while no significant difference was observed within T1 vs T2 and T3 vs T4 groups (Shown in Table-3).
Prevalence of sZnd significantly increased with the progession of T-stages using Chi-square test (p=0.007, Shown in Table-3).
Table 3: Prevalence of sZnd and concentration of serum Zinc level in T1-T4 stage of SCC
Group
|
Early stage
|
Late stage
|
T1 T2
|
T3 T4
|
Prevalence of sZnd (case)
|
23/174 35/234
|
23/101*@ 28/101*@
|
Concentration of sZn (μmol/L)
|
13.10±2.34 12.77±2.55
|
12.14±2.11*& 11.63±2.86*@
|
(Abbreviations: sZnd-serum Zinc deficiency; sZn-serum Zinc level; SCC-squamous cell carcinoma; * p﹤0.01、#p﹤0.05 versus T1; @ p﹤0.01、&p﹤0.05 versus T2.)
4. Serum Zinc status in lymph node metastasis of SCC
112 patients were involved in lymph node metastasis with an incidence of 18.4%. Two groups were gained on the basis of lymph node metastasis (N1) or not (N0) in patients with SCC.
The concentration of serum Zinc in group with lymph node metastasis is 11.70±2.72 μmol/L, while 12.77±2.44 μmol/L in group without metastasis. Reduction in serum Zinc level correlated with the metastasis of lymph node metastasis, and the difference was statistically significant (p=0.000, Shown in Table-4).
Table 4: Prevalence of sZnd and concentration of sZn in SCC with lymph node metastasis or free
|
Prevalence of sZnd (case)
|
Concentration of sZn (μmol/L)
|
|
N0
|
N1
|
N0
|
N1
|
T1
|
21/150
|
2/24
|
13.13±2.42
|
12.88±1.77
|
T2
|
27/193
|
8/41
|
12.88±2.58
|
12.23±2.35
|
T3
|
22/98
|
1/3
|
12.17±2.14
|
11.47±1.17
|
T4
|
8/57
|
20/44
|
12.43±2.33
|
10.60±3.16
|
Sum
|
78/498
|
31/112*
|
12.77±2.44
|
11.70±2.72*
|
( Abbreviations: sZnd-serum Zinc deficiency; sZn-serum Zinc level; SCC-squamous cell carcinoma; N0-non lymph node metastasis group; N1-lymph node metastasis group; * p﹤0.01. )
Significant increased prevalence of sZnd correlated to cervical lymph node metastasis using Chi-square test (p=0.003, Shown in Table-4). Relative risk of having metastasis in SCC patients suffering from sZnd is 2.06 (95% confidence interval 1.28-3.33) versus those with normal serum Zinc.