Despite the similarities in the incidence and nature of EGFR-mutated lung adenocarcinoma and breast cancer bone metastases, current guidelines (e.g., ESMO, National Comprehensive Cancer Network [NCCN], and National Institute for Health and Care Excellence [NICE], ASCO) provide different recommendations for screening of bone metastases for different primary tumors [18,64,65,66,67]. This evidence concerns the gene EGFR and breast cancer.