Clinical outcomes of luminal-like breast cancers with estrogen receptors loss at metastatic relapse

A new case control study published on European Journal of Cancer with first author Stefania Morganti, winner of the first edition of the international fellowship named after Gianni Bonadonna supported by the Gianni Bonadonna Foundation and AIRC Foundation, shows that luminal-like breast cancers with estrogen receptors loss at metastatic relapse have intermediate features and clinical outcomes compared with metastatic luminal-like and ab initio triple negative tumors.
Morganti and researchers from European Institute of Oncology in Milan compared clinicopathological characteristics and clinical outcomes between a cohort of 51 patients with primary ER+/HER2- and paired triple-negative metastasis and two control cohorts of paired early-metastatic ER+/HER2- and triple- negative breast cancers. ER loss at metastatic relapse occurs in up to 20% of luminal-like primary breast tumors and these new results demonstrated that these tumors have lower ER expression and intermediate features and outcomes compared with metastatic luminal-like and ab initio triple-negative tumors. High tumor infiltrating lymphocytes were associated with worse outcomes in patients with ER loss. «After ER loss, tumors are treated as ab initio triple negative breast cancers; however, few studies described the clinicopathologic features and outcomes of these tumors. We observed intermediate clinicopathological features and outcomes compared with tumors without receptor conversion at metastatic relapse. Validation of our findings on larger cohorts is warranted, and correlative analyses addressing the biology underpinning ER loss are of utmost importance as they could allow to fine-tune treatments in the early setting, thus avoiding some relapses», Carmen Criscitiello senior author concludes.