Long-term outcomes and prognostic factors for patients with esophageal cancer following radiotherapy

Table 1 Radiographic tumor characteristics

Characteristic	mean ± SD	Range
Length of lesion in barium esophagogram (cm)	5.8 ± 2.3	1.6-12.8
Largest diameter (cm)	3.4 ± 1.0	1.5-6.0
X dimension (cm)	3.2 ± 1.0	1.2-5.9
Y dimension (cm)	2.5 ± 0.6	1.2-4.4
Esophageal wall thickness (cm)	1.5 ± 0.6	0.5-4.2
Length of lesion in CT (cm)	6.6 ± 2.2	2.4-16.0
GTV-E (cm3)	31.8 ± 20.7	3.4-114.3
GTV-LN (cm3)	4.3 ± 10.6	0-78.8
GTV-T (cm3)	36.1 ± 23.8	3.4-124.0

GTV-E: Gross tumor volume of primary lesion; GTV-LN: Volume of positive lymph nodes; GTV-T: Total gross tumor volume.

Table 2 Univariate analysis for survival of patients

Feature		Cases	Median survival (mo)	5-yr OS	χ2value	P value
Gender	Male	120	19.2	24.2%	0.896	0.344
	Female	33	24.3	34.6%
Age (yr)	≤ 60	77	22.1	29.5%	1.159	0.282
	> 60	76	20	23.2%
Lesion location	Neck, upper thorax	73	23.4	38.8%	6.497	0.011
	Middle, lower thorax	80	18.5	13.5%
LCAH	No	137	19.2	26.7%	0.257	0.612
	Yes	16	30.4	25%
RT dose (Gy)	≤ 64	86	19.4	23.8%	0.429	0.512
	> 64	67	22.4	29.7%
Chemotherapy	No	99	18.4	26.5%	0.438	0.508
	Yes	54	23.4	25.5%
The length of lesion in barium esophagogram (cm)	≤ 3	12	-	80.8%	13.627	0.003
	> 3, ≤ 5	57	22.4	23.8%
	> 5, ≤ 7	52	16.8	20.9%
	> 7	32	17.8	21.7%
Largest diameter (cm)	≤ 2	11	-	72.7%	12.729	0.002
	> 2, ≤ 3	43	23.4	33.7%
	> 3	99	17.3	17.3%
Y diameter (cm)	≤ 2	29	-	60.3%	11.574	0.001
	> 2	124	18.4	18.3%
X diameter (cm)	≤ 2	16	-	62.5%	15.319	0.006
	> 2, ≤ 3	49	22.1	31.7%
	> 3, ≤ 4	59	18.1	23%
	> 4	29	17.8	0%
Thickness of esophageal wall (cm)	≤ 1	32	34.8	46.2%	8.224	0.016
	> 1, ≤ 2	104	18.4	22.0%
	> 2	17	17.2	12.8%
Length of lesion (cm)	< 4	10	-	57.1%	7.462	0.024
	≥ 4, ≤ 9	126	20	26%
	> 9	17	13.9	9.2%
GTV-E (cm3)	< 18	40	37.8	42.9%	9.934	0.007
	≥ 18, ≤ 48	82	18.4	24.6%
	> 48	31	14.5	8.6%
Invasion to adjacent structure	No	65	24.3	38.1%	7.289	0.007
	Yes	88	17.7	17.8%
Invasion to trachea	No	96	22.5	27.5%	0.865	0.352
	Yes	57	17.8	24.5%
Invasion to bronchus	No	131	22.1	29.9%	3.992	0.046
	Yes	22	15.8	5.6%
Invasion to aorta	No	128	22.1	29%	1.469	0.226
	Yes	25	17.8	13.9%
Invasion to pericardia	No	145	20	27.9%	1.559	0.212
	Yes	8	16.9	0%
SLNM1	Yes	25	15.9	21.1%	1.317	0.251
	No	107	22.4	23.6%
Number of positive lymph nodes2	0	55	30.4	38.4%	9.709	0.008
	1-2	85	18.4	21.2%
	> 2	13	13.8	7.7%
GTV-LN (cm3)	0	55	30.4	38.4%	9.229	0.010
	0-3	59	19.2	22.8%
	> 3	39	15.9	14%
GTV-T (cm3)	< 20	41	39.8	41.5%	12.891	0.002
	20-40	64	18.1	28.6%
	> 40	48	15.4	9.2%

¹SLNM: Supraclavicular lymph node metastasis, only the thoracic cases were included;

²N0: No positive lymph node was observed. N+: Peri-esophageal lymph node with longest diameter of ≥ 5 mm, mediastinal lymph nodes or supraclavicular lymph nodes with shortest diameter of ≥ 10 mm. LCAH: Late course accelerated hyperfractionated radiotherapy; OS: Overall survival; GTV-E: Gross tumor volume of primary lesion; GTV-LN: Volume of positive lymph nodes; GTV-T: Total gross tumor volume.