KRAS and rectal cancer: The risk factors supporting lung metastases diagnosis are age of onset > 70 years, multiple nodules in both lungs, metachronous intrapulmonary nodules, pleural thickening or effusion, rectal cancer (particularly middle or lower rectal cancer), locally advanced CRC (particularly extramural vascular invasion), higher N stages, lymphovascular invasion at the primary lesion, elevated preoperative CEA levels, KRAS mutations in the primary lesion, and presence of liver metastases or other extrapulmonary metastases [3, 4, 12–20].