Fig. 6

Schematic illustration of the prognostic value of LGR5 in ER⁻ vs. ER⁺ BC. Both LGR5^low and LGR5^high DCIS tumors can progress into BC, however only LGR5^high DCIS tumors progress into invasive tumors (possibly high-grade LGR5^high ER⁻) with related BC death. ER⁺ BC expressing high levels of LGR5 have a lower risk of recurrence, are smaller in size and of lower grade whereas ER⁺ BC expressing low levels of LGR5 have a higher risk of recurrence, are larger in size and of higher grade. It could be that as ER⁺ tumors progress, they become larger in size, of higher grade and lose their LGR5 expression. In stark contrast, high grade ER⁻ BC tumors with higher LGR5 expression stratifies a significantly greater recurrence rate as compared to tumors with lower LGR5 levels