Lymph node density as a surrogate marker for positive lymph nodes

We read with interest the paper by Polterauer et al (2010) in which they evaluated the prognostic value of lymph node density (LND) in patients with lymph node-positive cervical cancer. LND is defined as the ratio of the number of metastatic lymph nodes to the total number of lymph nodes removed. They showed that LND>10% is associated with an impaired disease-free and overall survival. Lymph node involvement and lymph vascular space involvement have always been noted to be a poor prognostic factor in cancer of the cervix ( Pecorelli, 2006 ), and thus this confirms the fact that the higher the number of lymph nodes involved, the worse the prognosis of the patient becomes. The benefit of using LND could be that it also incorporates the extent of surgical staging. Indeed, it is probably true that when you perform a complete lymph node dissection instead of a sampling you have more chance of finding all involved lymph nodes. However, there is more to it than positive lymph nodes and surgical skills.