Top Line: All lymphovascular invasion (LVI) is not created equal.
The Study: Most of us are familiar with the concept of focal LVI, but is any LVI not technically focal by definition thereby extensive? A group at MSKCC set out to describe an intermediate “usual” degree of LVI. This path analysis! retrospectively evaluated 8837 specimens, of which roughly one-third (n=3253) had some degree of LVI present. These 37% of cases were then further stratified into harboring focal (n=461), usual (n=2315), or extensive (n=477) LVI. As you can see, “usual” was aptly named. Focal was defined as a single lymphovascular tumor emboli near tumor, while extensive was defined here as multifocal LVI in two or more sections or in at least one section that did not also have invasive tumor present (suggesting it was further away from the primary tumor and therefore more insidious) or large volume LVI that completely occluded a vessel. When compared to tumors with usual LVI, those with extensive LVI occurred in younger women (median age 57), larger tumors (median 2.5 cm) and higher grade (94% were grade 3). Despite all this, it proved an independent predictor of locoregional recurrence on multivariable analysis: relative to usual LVI, risk was lower for no LVI (HR 0.69), the same for focal LVI, and higher for extensive LVI (HR 1.62).
TBL: More important than a binary description of focal versus multifocal LVI is an understanding of whether breast tumor LVI is truly extensive, as this is the feature that portends greater risk of locoregional recurrence than does run-of-the-mill focal or multifocal LVI present on a single tumor section. | Koleoso, Int J Radiat Oncol Biol Phys 2024
The Study: Most of us are familiar with the concept of focal LVI, but is any LVI not technically focal by definition thereby extensive? A group at MSKCC set out to describe an intermediate “usual” degree of LVI. This path analysis! retrospectively evaluated 8837 specimens, of which roughly one-third (n=3253) had some degree of LVI present. These 37% of cases were then further stratified into harboring focal (n=461), usual (n=2315), or extensive (n=477) LVI. As you can see, “usual” was aptly named. Focal was defined as a single lymphovascular tumor emboli near tumor, while extensive was defined here as multifocal LVI in two or more sections or in at least one section that did not also have invasive tumor present (suggesting it was further away from the primary tumor and therefore more insidious) or large volume LVI that completely occluded a vessel. When compared to tumors with usual LVI, those with extensive LVI occurred in younger women (median age 57), larger tumors (median 2.5 cm) and higher grade (94% were grade 3). Despite all this, it proved an independent predictor of locoregional recurrence on multivariable analysis: relative to usual LVI, risk was lower for no LVI (HR 0.69), the same for focal LVI, and higher for extensive LVI (HR 1.62).
TBL: More important than a binary description of focal versus multifocal LVI is an understanding of whether breast tumor LVI is truly extensive, as this is the feature that portends greater risk of locoregional recurrence than does run-of-the-mill focal or multifocal LVI present on a single tumor section. | Koleoso, Int J Radiat Oncol Biol Phys 2024