Pathological and molecular characteristics distinguishing contralateral metastatic from new primary breast cancer

摘要

Background: Breast cancer patients have a cumulative lifetime risk of 2%–15% of developing a contralateral metastatic or ex novo primary cancer. From prognostic and therapeutic viewpoints, it is important to differentiate metastatic from second primary. To distinguish these entities, we investigated whether the pattern of X chromosome inactivation could determine whether the two tumors derived from different progenitor cells.