Table 1. Average performance score according to the number of years that a laboratory participated to the EQA scheme.
| EQA participation |
Average performance score | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| EGFR | ALK FISH | ALK IHC | ROS1 FISH | ROS1 IHC | ||||||
| N= | % | N= | % | N= | % | N= | % | N= | % | |
| 1st | 222 | 78.8 | 184 | 90.0 | 125 | 91.0 | 90 | 86.3 | 41 | 92.1 |
| 2nd | 99 | 90.0 | 113 | 90.9 | 74 | 94.9 | 34 | 94.9 | 21 | 86.7 (97.1*) |
| 3rd | 48 | 91.0 | 60 | 93.7 | 51 | 96.7 | NA | NA | NA | NA |
| 4th | NA | NA | 24 | 95.4 | 18 | 100.0 | NA | NA | NA | NA |
The scheme period included in the analysis, ranges from 2012 to 2015. The number represents the number of laboratories who participated to only one, two, three, or four years of EQA for that specific marker or subscheme. *Average score with the exclusion of a challenging positive ROS1 IHC case in 2015. Abbreviations: ALK, anaplastic lymphoma kinase; EGFR, epidermal growth factor receptor; EQA, external quality assessment; FISH, fluorescence in situ hybridization; IHC, immunohistochemistry; ROS1, proto-oncogene 1 tyrosine-protein kinase; N, number of laboratories; NA, not applicable because no EQA scheme was organized in this year.