Impact of Radiotherapy Pattern on the Prognosis of Stage IV Lung Adenocarcinomas Harboring EGFR Mutations

Figures & data

Table 1 Characteristics of 205 NSCLC Patients

Characteristics	Patients
	N = 205 (%)
Age, years
> 60	68 (33.2)
≤ 60	137 (66.8)
Sex
Female	140 (68.3)
Male	65 (31.7)
Smoking Status
Never	161 (78.5)
Former/current	44 (21.5)
EGFR Mutation
Exon 18	4 (2.0)
Exon 19	92 (44.9)
Exon 20	1 (0.5)
Exon 21	107 (52.2)
Exon 18 and 20	1 (0.5)
Systemic Therapy
Platinum treatment	158 (77.1)
First-line EGFR TKIs therapy	130 (63.4)
Second-line EGFR TKIs therapy	75 (36.6)
Location of Metastasis
Brain	138 (67.3)
Bone	161 (78.5)
Abdomen	13 (6.3)
Soft tissue	1 (0.5)
The Site of Radiotherapy
Thoracic	101 (49.3)
Brain	113 (55.1)
Bone	96 (46.8)
Adrenal	8 (3.9)
Liver	4 (2.0)
Spleen	1 (0.5)
Soft tissue	1 (0.5)
Number of Radiotherapy
1	111 (54.1)
2	71 (34.6)
3	20 (9.8)
4	3 (1.5)

Note: Data are presented as n (%) or median (interquartile range).

Abbreviations: EGFR, epidermal growth factor receptor; TKIs, tyrosine kinase inhibitors.

Table 2 Characteristics of Patients in the Two Groups and with the X² Test for Categorical Variables

Characteristics	Single-Site Radiotherapy	Multiple-Site Radiotherapy	P
Age(y)	57 (50–64)	52 (47.75–59.25)	0.002
>60	47 (42.3)	21 (22.3)
≤60	64 (57.7)	73 (77.7)
Sex			0.808
Female	75 (67.6)	65 (69.1)
Male	36 (32.4)	29 (30.9)
Smoking Status			0.458
Never	85 (76.6)	76 (80.9)
Former/current	26 (23.4)	18 (19.1)
EGFR Mutation			0.264
Exon 18	1 (0.9)	3 (3.2)
Exon 19	55 (49.5)	37 (39.4)
Exon 20	0 (0.0)	1 (1.1)
Exon 21	55 (49.5)	52 (55.3)
Exon 18 and 20	0 (0.0)	1 (1.1)
Systemic Therapy
Platinum treatment	80 (72.1)	78 (83.0)	0.064
First-line EGFR TKIs therapy	74 (66.7)	56 (59.6)	0.294
Second-line EGFR TKIs therapy	37 (33.3)	38 (40.4)	0.294
Location of Metastasis
Brain	68 (61.3)	70 (74.5)	0.045
Bone	84 (75.7)	77 (81.9)	0.278
Abdomen	2 (1.8)	11 (11.7)
Soft tissue	1 (0.9)	0 (0.0)
The Site of Radiotherapy
Thoracic	20 (18.0)	81 (86.2)	<0.001
Brain	48 (43.2)	65 (69.1)	<0.001
Bone	42 (37.8)	54 (57.4)	0.005
Adrenal	2 (1.8)	6 (6.4)
Liver	0 (0.0)	4 (4.3)
Spleen	0 (0.0)	1 (1.0)
Soft tissue	1 (0.9)	0 (0.0)
Number of Radiotherapy
1	111 (100.0)	0 (0.0)
2	0 (0.0)	71 (75.5)
3	0 (0.0)	20 (21.3)
4	0 (0.0)	3 (3.2)

Note: Data are presented as n (%) or median (interquartile range).

Abbreviations: EGFR, epidermal growth factor receptor; TKI, tyrosine kinase inhibitor.

Figure 1 Overall survival (OS) of the entire cohort (A) and of patients stratified according to EGFR mutation status (B) and the lines of EGFR TKIs (C).

Figure 2 Overall survival (OS) of patients treated with multiple-site radiotherapy (MSR) or single-site radiotherapy (SSR).

Figure 3 Effect of thoracic radiotherapy on overall survival (OS) in the entire cohort (A), in the single-site radiotherapy group (B), and in the multiple-site radiotherapy group (C).

Figure 4 Effect of brain radiotherapy on overall survival (OS) in patients with brain metastasis (A). Effect of bone radiotherapy on overall survival (OS) in patients with bone metastasis (B).

Table 3 Univariable and Multivariable Analyses of Covariable Associated with OS

Variable	Univariable Analysis			Multivariable Analysis
	HR	95% CI	P	HR	95% CI	P
Age(y)
<60 v ≤60	0.926	0.656 to 1.307	0.662
Sex
Female v male	0.945	0.670 to 1.333	0.746
Smoking Status
Never v current/former	0.866	0.589 to 1.275	0.466
EGFR Mutation
Exon 19 v Exon 21	0.740	0.531 to 1.031	0.075
Systemic Therapy
Platinum treatment
Yes v no	0.749	0.500 to 1.120	0.159
First-line EGFR TKIs therapy
Yes v no	1.132	0.808 to 1.587	0.468
Location of Metastasis
Brain Metastasis
Yes v no	1.266	0.890 to 1.801	0.189
Bone Metastasis
Yes v no	1.300	0.855 to 1.975	0.220
The Site of Radiotherapy
Thoracic Radiotherapy
Yes v no	0.544	0.388 to 0.763	<0.001	0.514	0.323 to 0.818	0.005
Brain Radiotherapy
Yes v no	1.105	0.796 to 1.534	0.550
Bone Radiotherapy
Yes v no	1.273	0.919 to 1.762	0.146
Number of Radiotherapy sites
2–4 v 1	0.696	0.499 to 0.970	0.032	1.087	0.688 to 1.719	0.721

Abbreviations: EGFR, epidermal growth factor receptor; TKIs, tyrosine kinase inhibitors.