KLF6-SV1 is a new prognostic biomarker in postoperative patients with non-small cell lung cancer

Figures & data

Table 1 Correlation between KLF6-SV1 expression and clinicopathological features of the patients with non-small cell lung cancer (real-time PCR and Western blot)

Clinical characteristics	KLF6-SV1 (real-time PCR)			KLF6-SV1 (Western blot)
	mRNA assay	t, t′	P-valuea	Protein assay	t, t′	P-valuea
Gender		1.076	0.285		1.203	0.233
Male	2.2175±1.3532			0.5513±0.3434
Female	2.5636±1.5031			0.6479±0.3709
Age, years		0.937	0.351		0.700	0.486
<60	2.2233±1.3416			0.5681±0.3406
≥60	2.5265±1.5026			0.6249±0.3744
Smoking		1.587	0.117		1.740	0.086
No	2.1850±1.4794			0.5433±0.3754
Yes	2.7032±1.3129			0.6852±0.3166
Histological type		2.156	0.034		2.206	0.046
SCC	2.0700±1.2686			0.5238±0.3388
ADC	2.7497±1.5327			0.6843±0.3650
Differentiation			>0.05a			>0.05b
Well	1.9333±1.3248			0.5000±0.3643
Moderately	2.3236±1.4337			0.5838±0.3542
Poorly	2.9000±1.4243			0.7135±0.3580
pT			>0.05c		>0.05d
pT1	2.006±1.7428			0.4793±0.4351
pT2	2.3473±1.3526			0.5975±0.3397
pT3	3.1500±1.2204			0.7750±0.2993
pN		5.136	0.001		5.204	0.001
−	1.1419±1.2236			0.3539±0.2938
+	2.9204±1.2528			0.7355±0.3186
pTNM			<0.05e			<0.05f
pI	1.1074±1.0289			0.2784±0.2381
pII	2.5674±1.3180			0.6414±0.3324
pIII	3.3671±1.0835			0.8500±0.2795
5-year survival rate		9.054	0.001		9.372	0.001
Live	1.1513±0.9052			0.2841±0.2212
Death	3.2306±1.0623			0.8134±0.2621

Notes:

a P-value: t-test (homoscedasticity) or t′-test (homoscedasticity uneven).

b Well: moderately, P-value=0.394; well: poorly, P-value=0.075 and moderately: poorly, P-value=0.156.

c Well: moderately, P-value=0.467; well: poorly, P-value=0.128 and moderately: poorly, P-value=0.198.

d pT1: pT2, P-value=0.430; pT1: pT3, P-value=0.088 and pT2: pT3, P-value=0.085.

e pT1: pT2, P-value=0.277; pT1: pT3, P-value=0.077 and pT2: pT3, P-value=0.127.

f pI: pII, P-value=0.001; pI: pIII, P-value=0.001 and pII: pIII, P-value=0.030.

g pI: pII, P-value=0.001; pI: pIII, P-value=0.001 and pII: pIII, P-value=0.026. pT, tumor size; pN, lymph node metastasis and pTNM, tumor stage.

Abbreviations: ADC, adenocarcinoma; SCC, squamous cell carcinoma; KLF6, Kruppel-like factor 6.

Table 3 KLF6-SV1 expression in NSCLC specimens and paracancerous normal lung tissue (controls)

Group	KLF6-SV1 (real-time PCR)			KLF6-SV1 (Western blot)			KLF6-SV1 (immunohistochemistry)
	mRNA assay	t, t′	P-Valuea	Protein assay	t, t′	P-Valuea	Low	High	P-Valueb
		3.970	0.001		3.978	0.001			0.001c
Cancer specimens	2.3884±1.4306			0.5990±0.3583			34	45
Controls	0.5790±0.3002			0.1450±0.0722			10	0

Notes:

a P-value: t or t′-test.

b P-value: chi-squared test.

c Fisher’s exact probability test.

Abbreviations: NSCLC, non-small cell lung cancer; KLF6, Kruppel-like factor 6.

Figure 1 Western blot of tissue sections demonstrating KLF6-SV1.

Notes: (1) The corresponding normal lung tissue specimen in one patent with pT2N0M0 (contrast). (2–8) Cancer specimen.

Abbreviation: KLF6, Kruppel-like factor 6.

Table 2 Correlation between KLF6-SV1 expression and clinicopathological features of the patients with non-small cell lung cancer (immunohistochemistry)

Clinical features	Patients (N=79)	KLF6-SV1 expression		P-valuea
		Low (n=34)	High (n=45)
Gender				0.721
Male	40	18	22
Female	39	16	23
Age, years				0.496
<60	36	14	22
≥60	43	20	23
Smoking				0.120
No	48	24	24
Yes	31	10	21
Histological type				0.025
SCC	42	23	19
ADC	37	11	26
Differentiation				>0.05b
Well	12	8	4
Moderately	50	22	28
Poorly	17	4	13
pT				>0.05b
pT1	14	9	5
pT2	55	22	33
pT3	10	3	7
pN				0.019
−	28	17	11
+	51	17	34
pTNM				<0.05b
pI	19	13	6
pII	43	17	26
pIIIa	17	4	13

Notes:

a P-value: chi-squared test.

b Fisher’s exact probability test. pT, tumor size; pN, lymph node metastasis and pTNM, tumor stage.

Abbreviations: ADC, adenocarcinoma; SCC, squamous cell carcinoma; KLF6, Kruppel-like factor 6.

Table 4 Univariate analysis with respect to 5-year survival of the patients with non-small cell lung cancer (immunohistochemistry)

Clinical features	Patients (N=79)	5-year survival (%)		P-valuea
		No of patients	Rate (%)
		32	40.5
Gender				0.674
Male	40	16	40.0
Female	39	16	40.1
Age, years				0.762
<60	36	14	38.9
≥60	43	18	41.9
Smoking				0.199
No	48	22	45.8
Yes	31	10	32.3
Histological type				0.923
SCC	42	16	38.1
ADC	37	16	43.2
Differentiation				0.028
Well	12	6	50.0
Moderately	60	23	46.0
Poorly	17	3	17.6
pT				0.077
pT1	14	9	64.3
pT2	55	22	40.0
pT3	10	1	10.0
pN				0.001
−	28	22	78.6
+	51	10	19.6
pTNM				0.001
pI	19	18	94.7
pII	43	13	30.2
pIIIa	17	1	5.9
Chemotherapy				0.094
No	18	11	61.1
Yes	61	21	34.4
Radiotherapy				0.394
No	48	22	45.8
Yes	31	10	32.3
EGFR-TKI therapy				0.118
No	51	24	47.1
Yes	28	8	28.6
KLF6-SV1 expression				0.001
Low	34	21	61.8
High	45	11	24.4

Notes:

a P-Value: log-rank test. pT, tumor size; pN, lymph node metastasis; and pTNM, tumor stage.

Abbreviations: ADC, adenocarcinoma; EGFR-TKI, growth factor receptor-tyrosine kinase inhibitor; SCC, squamous cell carcinoma; KLF6, Kruppel-like factor 6.

Table 5 Results of Cox regression multivariate 5-year survival analysis of the patients with non-small cell lung cancer (immunohistochemistry)

Clinical features	B	SE	Wald	P	HR	95.0% CI for HR
Gender	0.541	0.359	2.274	0.132	1.718	0.850–3.471
Age	−0.411	0.353	1.354	0.245	0.663	0.332–1.325
Smoking	−0.595	0.394	2.279	0.131	0.552	0.255–1.194
Histological type	−0.650	0.398	2.674	0.102	0.522	0.239–1.138
Differentiation	0.892	0.310	8.266	0.004	2.439	1.328–4.480
pT	0.523	0.340	2.368	0.124	1,688	0.867–3.288
pN	1.792	0.601	8.903	0.003	6.002	1.850–19.477
pTNM	0.548	0.368	2.222	0.136	1.730	0.841–3.558
Chemotherapy	−0.542	0.499	1.180	0.277	0.582	0.219–1.546
Radiotherapy	0.088	0.324	0.074	0.786	1.092	0.579–2.061
EGFR-TKI therapy	0.312	0.387	0.648	0.421	1.366	0.640–2.915
KLF6-SV1 expression	0.783	0.363	4.654	0.031	2.187	1.074–4.453

Notes: B, regression coefficient; Wald, Wald value; pT, tumor size; pN, lymph node metastasis and pTNM, tumor stage.

Abbreviations: EGFR-TKI, growth factor receptor-tyrosine kinase inhibitor; SE, standard error; KLF6, Kruppel-like factor 6..

Figure 2 Immunohistochemical staining of lung cancer tissue sections demonstrating KLF6-SV1 (original magnification ×400).

Notes: (A) Lung squamous cell carcinoma specimen with high expression of KLF6-SV1. (B) Lung squamous cell carcinoma specimen with low expression of KLF6-SV1. (C) The corresponding normal lung tissue specimen with no KLF6-SV1 expression (contrast). (D) Lung adenocarcinoma specimen with high expression of KLF6-SV1. (E) Lung adenocarcinoma specimen with low expression of KLF6-SV1. (F) The corresponding normal lung tissue specimen with no KLF6-SV1 expression (contrast).

Abbreviation: KLF6, Kruppel-like factor 6.

Figure 3 A Kaplan–Meier analysis of the cumulative survival rate after operation in patients with high and low expression of KLF6-SV1, respectively.

Abbreviation: KLF6, Kruppel-like factor 6.