NR4A1 and invasive ductal breast carcinoma: The FROST trial (NCT01992250) was a prospective, phase 2 multicenter study evaluating the outcome of cryoablation in the management of stage I, hormone receptor-positive, human epidermal growth factor receptor 2 (HER2)-negative, node-negative invasive ductal carcinoma.<h4>Methods</h4>Women 50 years old or older with unifocal, ultrasound-visible tumors were stratified by age: stratum 1 (age ≥70 years, endocrine therapy only) and stratum 2 (age 50-69 years, endocrine therapy + radiotherapy + optional sentinel node biopsy).