Lymphovascular Invasion Is Not An Independent Risk Factor For Breast Cancer Recurrence

Prior studies have suggested that lymphovascular invasion by tumor cells was associated with poorer outcome. It has not been clear, however, whether lymphovascular invasion was sufficient reason to upstage a patient from a low-risk category to a high-risk category in the absence of other high-risk disease features.

In the current study, Bent Ejlertsen, M.D., Ph.D., of the Copenhagen University Hospital in Denmark, and colleagues examined the association between lymphovascular invasion and patient outcomes in more than 15,000 women diagnosed with breast cancer between 1996 and 2002 and included in the Danish Breast Cancer Cooperative Group registry.

Lymphovascular invasion was associated with a greater than two-fold increased risk of disease recurrence and nearly a 2.5-fold increased risk of death in women who were classified by other methods as having high risk of disease. It was not associated with a difference in outcomes for patients classified by other methods as having low-risk disease.

"Based on a cohort of more than 15,000 breast cancer patients, our results do not support that lymphovascular invasion has suf¬ficient independent prognostic influence to move patients from a low-risk group to a high-risk group," the authors conclude.

In an accompanying editorial, Nancy E. Davidson, M.D., of the University of Pittsburgh Medical School, and colleagues note that the newly reported data are in conflict with previous reports supporting the association between lymphovascular invasion and poorer patient outcomes. "…[T]he study gave the unexpected and somewhat disappointing result that lymphovascular invasion was associated with adverse outcome in patients who are at high risk for recurrence by other recognized prognostic factors, but not in those who are low risk by the same criteria," the editorialists write. "It is therefore apparently not useful as a means to subdivide the low risk group, the group in which many clinicians and patients would like assistance."

This research was published in the Journal of the National Cancer Institute May 12, 2009.