Table 4. Trends of RAS mutations prevalence of classical PTCs from individual institutions.
| Country | City (State) | Institution (Reference) |
Prevalence of RAS rearrangements in classical PTCs | ||||
|---|---|---|---|---|---|---|---|
| Period 1 | Period 2 | Period 3 | Period 4 | P | |||
| US | San Francisco (CA) | UCSF [13] | 1991-1995 3/74 (4.1 %) DS |
1996-2000 3/103 (2.9%) DS |
2001-2005 0/51 (0%) DS |
NS | |
| US | Pittsburgh (PA) | Univ. of Pittsburgh [14] | 1974-1985 0/52 (0.0%) FMCA |
1990-1992 0/21 (0.0%) FMCA |
2000 0.24 (0.0%) FMCA |
2009 1/65 (1.5%) FMCA |
NS |
Abbreviations: DS, direct sequencing; FMCA, fluorescent melting curve analysis