Clinical characterization of ERBB2 exon 20 insertions and heterogeneity of outcomes responding to afatinib in Chinese lung cancer patients

Figures & data

Table 1 Summary of baseline clinical characteristics of patients with ERBB2 20ins

Patient characteristics	ERBB2 20ins	Afatinib treatment
Total	171	19
Gender
Female	106 (62%)	12 (63%)
Male	65 (38%)	7 (37%)
Age (years)
Median	56	57
Range	23–86	41–86
Histological types
Adenocarcinoma	136	18
Adenosquamous carcinoma	1	0
SCC	1	1
Unknown	33	0

Abbreviations: 20ins, exon 20 insertions; SCC, squamous cell carcinoma.

Figure 1 Structure and distribution of ERBB2 20ins.

Notes: (A) Schematic diagram demonstrates the amino acids change of 20ins subtypes in ERBB2 kinase domain. The black arrows indicate the insertion position and trapezoid shape presents the position of deletion combined with insertion. (B) The pie chart presents the proportion of each 20ins subtype in the 171 cohort.
Abbreviations: 20ins, exon 20 insertions; delins, deletion and insertion; dup, duplicate; ins, insertion.

Figure 2 The Integrative Genomics Viewer screenshots displayed the reads of rare and novel 20ins subtypes identified by NGS.

Abbreviations: 20ins, exon 20 insertions; ins, insertion; NGS, next-generation sequencing.

Figure 3 Correlation of 20ins subtypes and PFS.

Notes: (A, B) Association of distinct 20ins subtypes and PFS/OS. (C, D) Glycine at ERBB2 778 site was correlated with longer trend of PFS/OS.
Abbreviations: 20ins, exon 20 insertions; delins, deletion and insertion; dup, duplicate; OS, overall survival; PFS, progression-free survival.

Figure 4 PFS information for each ERBB2 20ins patient treated with afatinib.

Notes: Each line represents a patient. The length of each line indicates the period of PFS. Each color presents each 20ins subtype. Solid circle means the time when patient achieved PR and solid triangle indicates the time of SD achievement. P008–P019 are patient ID numbers.
Abbreviations: 20ins, exon 20 insertions; delins, deletion and insertion; dup, duplicate; PD, progressive disease; PFS, progression-free survival; PR, partial response; SD, stable disease.

Figure 5 A lung SCC patient was identified as harboring ERBB2 20ins and responded to afatinib.

Notes: (A) Hematoxylin–eosin staining revealed the histological appearance of SCC. The green arrow and a green circle indicate typical histological appearance of SCC. (B) Responses of an ERBB2 20ins patient with lung SCC to afatinib. Computed tomography scans of the chest were obtained at baseline and after 3 months treatment of afatinib. The red arrows indicate tumor lesion.
Abbreviations: 20ins, exon 20 insertions; SCC, squamous cell carcinoma.