However, there were no significant differences in gene amplification frequencies between pure DCIS and invasive carcinoma within the individual subtypes, although FGFR1 amplification frequencies were higher (although not significantly so) in the invasive carcinomas than in the pure DCIS in all subtypes except the triple-negative, nonbasal subtype. Here, FGFR1 is linked to ductal breast carcinoma in situ.