Epidermal growth factor receptor exon 20 mutation in lung cancer: types, incidence, clinical features and impact on treatment

Figures & data

Table 1 Demographic and clinical profiles of the three patient cohorts

Variables	EGFR TKI-sensitizing activating mutations (n=227)	Exon 20 (n=20)	EGFR and ALK mutation negative (n=333)
Median age, years	56 (IQR 50–63)	59 (IQR 47.8–65)	56 (IQR 49–62)
Gender distribution, n (%)	Male: 141 (62.1)	Male: 12 (60.0)	Male: 222 (66.7)
	Female: 86 (37.9)	Female: 8 (40.0)	Female: 111 (33.3)
Nonsmokers, n (%)	168 (74.0)	13 (65.5)	168 (52.0)
PS, n (%)	0–1: 110 (48.5)	0–1: 12 (60.0)	0–1: 260 (78.5)
	2 or >2: 117 (51.5)	2 or >2: 8 (40.0)	2 or >2: 73 (21.9)
Extrathoracic metastasis, n (%)	105 (46.3)	11 (55.0)	106 (31.8)
Brain metastasis, n (%)	29 (12.8)	06 (30.0)	10 (3.0)
Bone metastasis, n (%)	59 (26.0)	05 (25.0)	84 (25.2)
Liver metastasis, n (%)	39 (17.2)	02 (10.0)	29 (08.7)
Multiple organ metastases, n (%)	19 (8.3)	02 (10.0)	17 (5.1)

Abbreviations: EGFR, epidermal growth factor receptor; TKI, tyrosine kinase inhibitor; ALK, anaplastic lymphoma kinase; IQR, interquartile range; PS, performance status.

Table 2 Distribution and median OS of exon 20-mutated patients

Type of exon 20 mutation	Point mutation/insertion sequence	Proportion of patients (n=20), n (%)	Median OS in months
S768 I c. 2303 G>T	EILDEAYVMASVDNPHVCR	7 (35)	6.0 (0–16.3)
H773_V774insH 2319–2320 (CAC)	EILDEAYVMASVDGNPHVCR	4 (20)	12.0 (0.2–23.98)
V769_D770insASV (2307–2308) GCCAGCGTG	EILDEAYVMASVASVDNPHVC	5 (25)	2.0 (1.1–2.9)
T790M c. 2369 C>T	EILDEAYVMASVDNPHVCRLLGICLTSTVQLITQ	4 (20)	5.0 (1.2–8.8)

Abbreviation: OS, overall survival.

Figure 1 Graph of survival in different types of exon 20-mutated patients.

Abbreviations: OS, overall survival; EGFR, epidermal growth factor receptor.

Figure 2 Graph of OS in all three cohorts.

Abbreviation: OS, overall survival.

Table 3 Multivariate analysis results for OS

Variable	HR	95% CI of HR	P-value
Presence of EGFR TKI-sensitizing activating mutations compared to rest	0.74	0.58–0.94	0.013
Presence of exon 20 mutations compared to rest	2.10	1.20–3.65	0.009
Presence of extrathoracic disease	1.34	1.01–1.77	0.042
Presence of multiple organ metastases	0.99	0.59–1.68	0.990
Presence of brain metastasis	1.41	0.85–2.33	0.178
Presence of liver metastasis	1.33	0.87–2.04	0.192
Presence of poor PS (PS ≥2)	1.17	0.93–1.46	0.182

Note: Bold values are statistically significant.

Abbreviations: OS, overall survival; CI, confidence interval; HR, hazard ratio; EGFR, epidermal growth factor receptor; TKI, tyrosine kinase inhibitor; PS, performance status.