Importantly, a pooled analysis from the SAFIR02-BREAST and SAFIR-PI3K trials showed a significant PFS benefit (60% reduction in the risk of progression and death, P < .001) only in the presence of ESCAT Tier I-II alterations.39,40 These results highlight the importance of avoiding an excess of off-label prescription of target drugs, especially if only preclinical evidence of activity exists or only activity/efficacy in other cancer types has been proved. Here, PIK3CA is linked to cancer.