The proportion of germline BRCA2 mutation carriers among patients with metastatic PC was available from 10 articles, for a total of 3963 patients, and was equal to 4.51% (95% CI: 2.93–6.42), with significant heterogeneity (I2 = 81.54%; p < 0.0001) (Figure 3c). Here, BRCA2 is linked to pachyonychia congenita.