Prognostic value of preoperative mean corpuscular volume in esophageal squamous cell carcinoma

Table 1 Clinicopathological parameters and preoperative mean corpuscular volume n (%)

Characteristics	Case numbers	Preoperative MCV		P valuePearson’sχ2test
		Low	High
Age, yr (mean ± SE)	58.2 ± 9.2
≤ 65	231	184 (79.7)	47 (20.3)
> 65	67	55 (82.1)	12 (17.9)	0.660
Gender
Male	230	176 (76.5)	54 (23.5)
Female	68	63 (92.6)	5 (7.4)	0.003
BMI, kg/m2 (mean ± SE)	22.3 ± 3.2
≤ 20	65	46 (70.8)	19 (29.2)
> 20 and ≤ 25	180	144 (80.0)	36 (20.0)
> 25	53	49 (92.5)	4 (7.5)	0.017
Smoking index	440.1 ± 483.1
≤ 400	171	141 (82.5)	30 (17.5)
> 400	127	98 (77.2)	29 (22.8)	0.257
Preoperative RBC, × 1012/L (mean ± SE)	4.5 ± 0.6
≤ 4.01	56	31 (55.4)	25 (44.6)
> 4.0	242	208 (86.0)	34 (14.0)	< 0.001
Preoperative albumin, g/L (mean ± SE)	42.9 ± 4.6
≤ 432	149	115 (77.2)	34 (22.8)
> 43	149	124 (83.2)	25 (16.8)	0.191
pT status, UICC7th (mean ± SE)
T1	33	31 (93.9)	2 (6.1)
T2	52	44 (84.6)	8 (15.4)
T3	213	164 (77.0)	49 (23.0)	0.051
N0	138	116 (84.1)	22 (15.9)
N1	89	67 (75.3)	22 (24.7)
N2	51	42 (82.4)	9 (17.6)
N3	20	14 (70.0)	6 (30.0)	0.250
Histologic grade
G1	94	71 (75.5)	23 (24.5)
G2	156	127 (81.4)	29 (18.6)
G3	48	41 (85.4)	7 (14.6)	0.324
pTNM stage (UICC7th)
Stage I	37	32 (86.5)	5 (13.5)
Stage II	120	100 (83.3)	20 (16.7)
Stage III	141	107 (75.9)	34 (24.1)	0.191
Tumor location
Upper	48	37 (77.1)	11 (22.9)
Middle	150	125 (83.3)	25 (16.7)
Lower	100	77 (77.0)	23 (23.0)	0.393

¹Normal limit of red blood cell count;

²Mean value of preoperative hemoglobin. MCV: Mean corpuscular volume; Low: Low preoperative MCV (≤ 95.6 fl); High: High preoperative MCV (> 95.6 fl); BMI: Body mass index; RBC: Red blood cell; UICC: Union for International Cancer Control.

Table 2 Univariate and multivariate Cox regression analysis for overall survival

Factors	Univariate analysis		Multivariate analysis
	HR (95%CI)	P value1	HR (95%CI)	P value1
Age, yr	1.007 (0.985-1.029)	0.527
Gender (male vs female)	0.744 (0.464-1.196)	0.222
Smoking index ( ≤ 400 vs > 400)	1.391 (0.940-2.060)	0.099	1.302 (0.874-1.940)	0.194
BMI, kg/m2 ( ≤ 20 vs > 20; ≤ 25 vs > 25)	0.878 (0.638-1.207)	0.422
Preoperative MCV, fl ( ≤ 95.6 vs > 95.6)	2.495 (1.644-3.787)	< 0.001	2.108 (1.372-3.241)	0.001
Preoperative RBC, × 1012/L ( ≤ 4 vs > 4)	0.685 (0.433-1.082)	0.105	0.835 (0.507-1.350)	0.462
Preoperative albumin, g/L	0.954 (0.919-0.990)	0.012	0.938 (0.900-0.977)	0.002
pT status (pT1 vs pT2 and pT3)	1.641 (1.147-2.348)	0.007	1.589 (1.084-2.327)	0.018
pN status (pN0 vs pN1, pN2 and pN3)	1.954 (1.603-2.382)	< 0.001	1.957 (1.602-2.392)	< 0.001
Histologic grade (G1 vs G2 and G3)	0.961 (0.714-1.293)	0.791
Tumor location (upper thoracic vs middle thoracic and lower thoracic)	0.798 (0.605-1.051)	0.109	0.692 (0.522-0.916)	0.01

¹Cox proportional hazards model. HR: Hazard ratio; BMI: Body mass index; MCV: Mean corpuscular volume; RBC: Red blood cell.

Table 3 Comparison of prognosis in specified cohort stratified by preoperative mean corpuscular volume

Variable	Case numbers	Overall survival (mo)(mean ± SE)	P valueLog-Rank test
All cohort			< 0.001
Low	239	33.7 ± 24.7
High	59	25.8 ± 24.2
pT status
T1-T2			0.075
Low	75	39.1 ± 27.1
High	10	27.6 ± 22.7
T3			< 0.001
Low	164	31.2 ± 23.2
High	49	25.4 ± 24.7
pN status
N0			0.464
Low	116	40.0 ± 26.0
High	22	35.5 ± 28.7
N1-N3			< 0.001
Low	123	27.9 ± 22.0
High	37	20.0 ± 19.2
Histologic grade
G1			0.211
Low	71	32.9 ± 27.6
High	23	27.4 ± 24.3
G2-G3			< 0.001
Low	168	34.1 ± 23.4
High	36	24.8 ± 24.4
pTNM stage
Stage I			0.581
Low	32	37.9 ± 27.1
High	5	37.6 ± 32.6
Stage II			0.061
Low	100	39.6 ± 25.4
High	20	31.1 ± 27.7
Stage III			0.001
Low	107	27.0 ± 21.6
High	34	20.9 ± 19.8

Low: Low preoperative mean corpuscular volume (≤ 95.6 fl); High: High preoperative mean corpuscular volume (> 95.6 fl).