Introduction
Material and methods
Patients
Characteristics | No. of patients (%) |
---|---|
Gender | |
Male | 197 (96.6) |
Female | 7 (3.4) |
Age, years | |
Mean | 60.75 |
SD | 9.64 |
Differentiation | |
Well/moderate | 187 (91.7) |
Poor/undifferentiation | 17 (8.30) |
Tumor invasion | |
T1 | 61 (29.9) |
T2 | 70 (34.3) |
T3 | 57 (27.9) |
T4 | 16 (7.8) |
TNM stage | |
I | 56 (27.5) |
II | 35 (17.2) |
III | 74 (36.3) |
IV | 39 (19.1) |
Lymph node metastasis (LNM) | |
Yes | 66 (32.4) |
No | 138 (67.6) |
Smoking history | |
Yes | 141 (69.1) |
No | 63 (30.9) |
Pack-years | |
≤30 | 149 (73.0) |
>30 | 55 (27.0) |
Survival status | |
Dead | 113 (55.4) |
Alive | 91 (44.60) |
DNA preparation
mtDNA copy number analysis
Genes | Forward primer sequence | Probe sequence | Reverse primer sequence | Amplification |
---|---|---|---|---|
(5′ → 3′) | (5′ → 3′) | (5′ → 3′) | Efficiency (%) | |
MT-ND1
| CCCCTAAAACCCGCCACATC | 6FAM-ACCCTCTACATCACCGCCCCGACC-TAMRA | GTAGAAGAGCGATGGTGAGAGC | 94.6 |
β-actin | TCACCCACACTGTGCCCATCTACGA | 6FAM-ATGCCCTCCCCCATGCCATCC-TAMRA | TCGGTGAGGATCTTCATGAGGTA | 95.2 |
Statistical analysis
Results
Relative mtDNA copy number in laryngeal cancer
Association of variable mtDNA copy number with clinicopathological characteristics of laryngeal cancer patients
Characteristics | Copy number <4.02 | Copy number >5.42 | ||
---|---|---|---|---|
OR* (95% CI) |
P
| OR* (95% CI) |
P
| |
Male vs. Female | 2.73 (0.37-20.28) | 0.33 | 1.89 (0.30-11.86) | 0.50 |
Age | 1.00 (0.96-1.05) | 0.92 | 1.01 (0.97-1.05) | 0.78 |
Differentiation1 | 1.02 (0.25-4.10) | 0.98 | 0.64 (0.17-3.01) | 0.64 |
Tumor invasion2 | 1.43 (0.92-2.25) | 0.11 | 0.94 (0.60-1.46) | 0.77 |
TNM stage3 | 1.53 (1.04-2.25) | 0.03 | 1.04 (0.71-1.51) | 0.84 |
LNM4 | 2.31 (0.90-5.95) | 0.08 | 1.50 (0.58-3.89) | 0.41 |
Smoking history5 | 0.46 (0.16-1.34) | 0.16 | 0.29 (0.10-0.84) | 0.02 |
Survival status6 | 0.81 (0.36-1.84) | 0.61 | 0.79 (0.35-1.77) | 0.56 |
Characteristics | Copy number <4.02 | Copy number >5.42 | ||
---|---|---|---|---|
OR*(95% CI) |
P
| OR*(95% CI) |
P
| |
Age | 1.00 (0.94-1.06) | 0.93 | 1.03 (0.98-1.09) | 0.29 |
Tumor invasion1 | 1.25 (0.39-4.04) | 0.71 | 0.48 (0.15-1.52) | 0.21 |
Smoking history2 | 0.25 (0.05-1.31) | 0.10 | 0.17 (0.04-0.85) | 0.03 |
Survival status3 | 1.09 (0.34-3.54) | 0.88 | 0.54 (0.17-1.69) | 0.29 |
Characteristics | Copy number <4.02 | Copy number >5.42 | ||
---|---|---|---|---|
OR*(95% CI) |
P
| OR*(95% CI) |
P
| |
Male vs. Female | 8.83 (0.74-105.58) | 0.09 | 3.58 (0.46-28.17) | 0.23 |
Age | 0.99 (0.93-1.06) | 0.76 | 0.97 (0.91-1.04) | 0.37 |
Differentiation1 | 0.37 (0.08-1.81) | 0.22 | 0.36 (0.07-1.84) | 0.22 |
Tumor invasion2 | 1.05 (0.48-2.33) | 0.90 | 0.78 (0.35-1.74) | 0.54 |
LNM3 | 1.57 (0.48-5.12) | 0.45 | 1.37 (0.41-4.56) | 0.61 |
Smoking history4 | 0.78 (0.19-3.21) | 0.73 | 0.49 (0.12-2.04) | 0.33 |
Survival status5 | 0.64 (0.20-2.08) | 0.45 | 1.05 (0.32-3.47) | 0.94 |
Characteristics | Copy number <4.02 | Copy number >5.42 | ||
---|---|---|---|---|
OR*(95% CI) |
P
| OR*(95% CI) |
P
| |
Gender | 3.48 (0.46-26.59) | 0.23 | 2.45 (0.37-16.42) | 0.36 |
Age, years | 1.00 (0.96-1.04) | 0.96 | 1.00 (0.96-1.05) | 0.87 |
Smoking history1 | 0.39 (0.13-1.17) | 0.09 | 0.27 (0.09-0.80) | 0.02 |
TNM stage2 | 1.62 (1.09-2.41) | 0.02 | 1.12 (0.76-1.65) | 0.57 |
Impact of variable mtDNA content on poor survival of laryngeal cancer patients
Univariate analysis | Multivariate analysis | |||
---|---|---|---|---|
Variable | Hazard Ratio (95% CI) |
P
| Hazard Ratio (95% CI) |
P
|
Copy number | ||||
4.02 ~ 5.42 | 1.00 (reference) | 1.00 (reference) | ||
<4.02 | 1.00 (0.54–1.83) | 0.99 | 1.78 (0.93–3.42) | 0.09 |
>5.42 | 0.84 (0.53–1.34) | 0.46 | 1.40 (0.84–2.35) | 0.20 |
Lymph node metastasis | ||||
No | 1.00 (reference) | 1.00 (reference) | ||
Yes | 2.70 (1.71–4.25) | <0.001 | 2.43 (1.46–4.05) | 0.001 |
Tumor invasion | ||||
T1 | 1.00 (reference) | 1.00 (reference) | ||
T2 | 1.98 (1.15–3.43) | 0.015 | 1.71 (0.95–3.06) | 0.07 |
T3 | 2.32 (1.29–4.18) | 0.005 | 2.24 (1.22–4.14) | 0.01 |
T4 | 5.46 (2.28–13.11) | <0.001 | 5.42 (2.08–14.13) | 0.001 |
Differentiation | ||||
Well/moderate | 1.00 (reference) | 1.00 (reference) | ||
Poor/undifferentiation | 2.78 (1.10–7.07) | 0.03 | 2.33 (0.88–6.15) | 0.09 |