Primary tumor regression patterns in esophageal squamous cell cancer treated with definitive chemoradiotherapy and implications for surveillance schemes

Figures & data

Table 1 Clinical characteristics of patients

			Tumor regression (n=82)
Characteristics	n	%	Correlation Coefficient	p-value
Gender			0.1197	0.284
Male	69	84.1
Female	13	15.9
Median age (y, range)	59 (39–76)		−0.1179	0.291
ECOG scoring			0.1307	0.242
0	16	19.5
1	66	80.5
Tumor location			−0.2183	0.049
Cervical	9	11.0
Upper	31	37.8
Middle	38	40.3
Lower	4	4.9
Clinical T stage			0.0571	0.393
T2	11	13.4
T3	38	46.3
T4	33	40.3
Clinical N stage			0.3932	0.001
N0	24	29.3
N1	58	70.7
Clinical M stage			0.1646	0.140
M0	63	76.8
M1	19	23.2
Clinical stage			0.2600	0.018
II	21	25.6
III	15	18.3
IVA	27	32.9
IVB	19	23.2
Maxim tumor length (cm)	5.5(2.5–14)		−0.0984	0.385
Maxim tumor width (cm)	1.6(0.5–5.1)		−0.0745	0.512
Dose (Gy, range)
GTV	61.5 (50–66)		0.0672	0.539
CTV	50 (45–54)		−0.1269	0.256

Abbreviations: CTV, clinical target volume; ECOG, Eastern Cooperative Oncology Group; GTV, gross tumor volume.  

Figure 1 Study flowchart. *Later-CR and later-IR patients were applied for time to FTR analysis.Abbreviations: CR, complete response; CRT, chemoradiotherapy; DFFS, distant failure-free survival; ESCC, esophageal squamous cell carcinoma; FTR, full tumor regression; IR, incomplete response; LFFS, locoregional failure-free survival; OS, overall survival; PD, progression of disease; SD, stable disease.

Table 2 Survival and failure patterns in various subgroup patients

		OS (%)				LFFS (%)				DFFS (%)				Failure patterns (n, %)
Subgroups	Total	1-y	2-y	3-y	p-value	1-y	2-y	3-y	p-value	1-y	2-y	3-y	p-value	LF	DF	LDF	p-value	MTF median (range)	p-value
Early-CR	21	100	95.2	85.7	<0.001^a	100	100	100	<0.001^a	100	95.2	90.2	0.012 ^a	1 (4.8)	3 (14.3)	1 (4.8)	0.439^a	23.5 (11–43)	0.152^a
Later-CR	14	71.4	50	16.7	0.828 ^b	70.7	48.5	48.5	0.816 ^b	62.9	52.4	34.9	0.266^b	6 (42.9)	6 (42.9)	1 (7.1)	0.442^b	11 (3–48)	0.179^b
Early-IR	15	73.3	20	20		51.9	44.4	14.8		80	61	61		10 (66.7)	5 (33.3)	0 (0)		11 (5–12)
Later-IR	9	77.8	33.3	11.1		77.8	43.2	21.6		87.5	72.9	72.9		4 (44.4)	1 (11.1)	1 (11.1)		11 (5–12)
SD	16	81.3	25	6.3	0.003 ^c	50	40	40	0.219 ^c	87.5	75	75	0.170 ^c	8 (50.0)	2 (12.5)	1 (6.3)	0.857^c	11 (7–20)
PD	7	28.6	0	0		42.9	0	0		71.4	35.7	0		4 (57.1)	2 (28.6)	1 (14.3)

Notes: ^ap-value of early-CR vs non-early-CR. ^bp-value among non-early-CR. ^cp-value of non-early-CR vs PD.

Abbreviations: CR, complete response; IR, incomplete response; SD; stable disease; PD, progression of disease; OS, overall survival; LFFS, locoregional failure-free survival; DFFS, distant failure-free survival; LF, locoregional failure; DF, distant failure; LDF, locoregional and distant failure; MTF, median time to failure.

Figure 2 Survival in different subgroups.

Abbreviations: CR, complete response; IR, incomplete response; SD, stable disease; PD, progression of disease; OS, overall survival; LFFS, locoregional failure-free survival; DFFS, distant failure-free survival.